Metacognitive Awareness and the Subjective Experience of Remembering in Aphantasia 

Michael J. Siena 

Jon S. Simons 

Department of Psychology, University of Cambridge, Cambridge CB2 3EF, United Kingdom 

 

 

 

 

 

 

In press, Journal of Cognitive Neuroscience 

 

 

 

 

 

 

 

 

 

 

Keywords 

Aphantasia, consciousness, episodic memory, mental imagery  

 

Correspondence 

Please address correspondence to Professor Jon S. Simons (jss30@cam.ac.uk).  

 

mailto:jss30@cam.ac.uk


 

 

Abstract 

Individuals with aphantasia, a non-clinical condition typically characterised by mental 

imagery deficits, often report reduced episodic memory. However, findings have hitherto 

rested largely on subjective self-reports, with few studies experimentally investigating both 

objective and subjective aspects of episodic memory in aphantasia. In this study, we tested 

both aspects of remembering in aphantasic individuals using a custom 3D object and spatial 

memory task that manipulated visuospatial perspective, which is considered to be a key factor 

determining the subjective experience of remembering. Objective and subjective measures of 

memory performance were taken for both object and spatial memory features under different 

perspective conditions. Surprisingly, aphantasic participants were found to be unimpaired on 

all objective memory measures, including those for object memory features, despite reporting 

weaker overall mental imagery experience and lower subjective vividness ratings on the 

memory task. These results add to newly emerging evidence that aphantasia is a heterogenous 

condition, where some aphantasic individuals may lack metacognitive awareness of mental 

imagery rather than mental imagery itself. Additionally, we found that both participant 

groups remembered object memory features with greater precision when encoded and 

retrieved in the first person versus third person, suggesting a first-person perspective might 

facilitate subjective memory reliving by enhancing the representational quality of scene 

contents. 

 

 

 

 

 

 

 

 

 



 

Introduction 

In most individuals, mental imagery—the ability to form sensory-like representations 

in the absence of perception (Pearson & Kosslyn, 2015)—pervades subjective conscious 

experience. For example, mental imagery allows us to direct our senses inward and ‘see’ with 

our mind’s eye the contents of a dream or ‘hear’ with our mind’s ear the voice of a loved one. 

More concretely, visual mental imagery is thought to support cognitive faculties such as 

visual working memory and episodic processing (Pearson, 2019), where visual mental 

imagery is typically evoked during the recollection of personal events (i.e., episodic memory) 

or while imagining future or counterfactual ones (Schacter et al., 2012; Schacter & Madore, 

2016). Although mental imagery has long been reported to vary across individuals (Galton, 

1888), the study of mental imagery extremes has only recently received renewed scientific 

interest. Of relevance to this study, a minority of individuals self-report a profound weakness 

in, or a complete inability to voluntarily form, mental imagery. This phenomenon has 

recently been termed ‘aphantasia’ (Zeman et al., 2015). 

Aphantasia is estimated to occur in approximately 2-4% of the general population and 

is usually congenital (Dance et al., 2022; Faw, 2009; Zeman et al., 2015, 2020), although it 

can also be acquired through psychiatric disturbances or brain injury (Bartolomeo, 2008; 

Farah, 1984; Zago et al., 2011; Zeman et al., 2010; see also de Vito & Bartolomeo, 2016). 

While aphantasia is typically identified via subjective self-reports, often using scales such as 

the Vividness of Visual Imagery Questionnaire (VVIQ; Marks, 1973), the condition is 

considered by many to reflect an objective deficit in voluntary mental imagery ability. For 

instance, aphantasics show little imagery-based binocular rivalry priming relative to non-

aphantasic controls (Keogh & Pearson, 2018; see also Pearson, 2014). Additionally, 

aphantasics do not typically show automatic physiological responses associated with mental 

imagery. For example, aphantasics do not show a significant imagery-based pupillary light 

response, which has been shown to index both perceptual luminance and the trial-by-trial 

vividness of visual mental imagery in typical imagers (Kay et al., 2022). Similarly, 

aphantasics show flat-line levels of skin conductance while imagining fear-inducing 

scenarios, unlike non-aphantasic control participants (Wicken et al., 2021). Some aphantasics 

report experiencing involuntary mental imagery during lower states of awareness such as 

dreaming, but also as intrusions during wakefulness (Dawes et al., 2020; Milton et al., 2021; 

Palermo et al., 2022; Zeman et al., 2015, 2020), although such intrusions may be less 

common in aphantasics than in typical imagers (Dawes et al., 2020). 



 

Visual mental imagery is thought to be separable into object and spatial 

subcomponents (Farah et al., 1988; Levine et al., 1985). Object imagery concerns low-level 

perception-like representations of visual object attributes such as size, shape, colour, or 

brightness. By contrast, spatial imagery involves the representation of environments such as 

spatial configurations among or within objects, their locations, and movements. On measures 

distinguishing between these imagery subcomponents, aphantasics typically indicate 

difficulties with object, but not spatial, imagery (Bainbridge et al., 2021; Dawes et al., 2020, 

2022; Koegh & Pearson, 2018). Accordingly, mental imagery has been suggested to 

dissociate along the classic ventral “what” and dorsal “where” processing streams associated 

with visual perception (Levine et al., 1985), with aphantasia reflecting selective dysfunction 

of the “what” stream (Pearson, 2019).   

While aphantasia is typically defined primarily by a deficit in visual (i.e., object) 

imagery, other areas of cognition can also appear to be impaired. For example, many 

aphantasics report difficulty with recognising faces, termed prosopagnosia (Dawes et al., 

2020). Many aphantasics also report reduced memory for personal events (i.e., episodic 

memory) (Dawes et al., 2020, 2022; Milton et al., 2021; Zeman et al., 2020). In the first 

large-scale questionnaire study to explore the cognitive profile of aphantasia, Dawes et al. 

(2020) found that aphantasics report less vivid and phenomenologically rich autobiographical 

memory (ABM) recall and imagined future scenarios than control participants. In a large 

sample online study, Bainbridge et al. (2021) found aphantasics had objective memory 

deficits consistent with their self-reported selective object memory difficulties when tasked 

with drawing photographs from memory. Although such objective task-based evidence for 

selective object memory deficits is currently scarce, mnemonic deficits are perhaps 

unsurprising given the importance of visual mental imagery in episodic processing 

(D’Argembeau & van der Linden, 2006; Greenberg & Knowlton, 2014; Palombo et al., 2018; 

Vannucci et al., 2016; Simons et al., 2022; Zaman & Russell, 2022). Indeed, a recent 

proposal extending the constructive episodic simulation hypothesis (Schacter et al., 2012, 

2020) has argued that aphantasia may reflect a condition of the episodic system rather than 

mental imagery per se (Blomkvist, 2022). However, aphantasics do not always show deficits 

on memory tasks. For example, while Monzel et al. (2022) found evidence for a general 

memory impairment across both visual and verbal short-term and long-term memory tasks, 

others have not observed such deficits (Milton et al., 2021; Pounder et al., 2022). These 

mixed findings raise the question of whether objective memory deficits necessarily 



 

accompany subjective memory complaints made by aphantasics, which may, in some cases, 

reflect deficient metacognitive awareness of mental imagery (Nanay, 2021; see also Pounder 

et al., 2022). Therefore, direct examination of both objective and subjective memory 

measures in the same task and participants is needed. 

Aphantasics are as accurate as controls on mental rotation tasks thought to tap spatial 

imagery (Pounder et al., 2022; Zeman et al., 2010). However, aphantasics do not always 

exhibit the expected linear increase in response times as the angular disparity between 

different presented object orientations increases (Pounder et al., 2022; Zeman et al., 2010; but 

see Zhao et al., 2022), suggesting spatial processing may not be entirely unaffected. Indeed, 

the rotation-related negativity, an electrophysiological correlate of mental spatial 

transformations, has been shown to be absent in a patient with acquired aphantasia (Zhao et 

al., 2022). Moreover, recent evidence suggests a spatial subtype of aphantasia (Palermo et al., 

2022), and visual imagery often involves the adoption of a particular visuospatial perspective 

(Libby & Eibach, 2011). A first-person self-referential (i.e., egocentric) visuospatial 

perspective is thought to play an important role in the subjective experience of remembering, 

enabling one to project oneself into recollected scenes (Simons et al., 2022; Zaman & 

Russell, 2022). Aphantasics have previously been shown to score higher on autism traits that 

indicate difficulties with theory of mind (Dance et al., 2021), which may depend on the 

ability to adopt alternative visuospatial perspectives (Conson et al., 2015; Gauthier et al., 

2018; Kessler & Wang, 2012), as well as report a less distinctive perspective during dreaming 

(Dawes et al., 2020) and ABM recall (Dawes et al., 2022). However, visuospatial perspective 

and its impact on the subjective experience of episodic remembering has yet to be 

experimentally investigated in aphantasics, despite subjective reports indicating reduced 

subjective memory reliving (Dawes et al., 2020, 2022). 

The present study tested whether visual and spatial aspects of first-person (egocentric) 

episodic recall is impaired in people with aphantasia. A mixed design was employed in which 

aphantasic and non-aphantasic control participants completed a novel 3D object and spatial 

memory task that manipulated visuospatial perspective. In this task, participants first studied 

the location and colour hue of objects placed within familiar virtual environments, which 

were viewed from either a first-person or third-person perspective. Following a brief delay 

period, participants used continuous measures to precisely reproduce each object’s 

remembered study location and colour hue, and to report the subjective vividness of their 

memory. Furthermore, recall perspective was varied such that it either remained unchanged 



 

or was switched to the alternate perspective to test whether aphantasics are impaired at 

manipulating spatial representations, given the abovementioned inconclusive findings from 

mental rotation tasks (Pounder et al., 2022; Zeman et al., 2010; Zhao et al., 2022). 

Accordingly, these manipulations resulted in the following four spatial memory conditions: 

stay first person (i.e., studied and tested in a first-person perspective), switch first person (i.e., 

studied in third person but tested in first person), stay third person (i.e., studied and tested in a 

third-person perspective), and switch third person (i.e., studied in first person but tested in 

third person). To maximise the number of trials available for mixture modelling, there were 

only two object memory conditions by comparison: study first person and study third person. 

First-person spatial recall was predicted to be generally less accurate than third-person 

spatial recall, given prior findings (Iriye & St Jacques, 2021). Moreover, an asymmetric 

perspective switch cost was predicted (Ly & Hu, 2020), with switch third person trials being 

recalled less accurately than switch first person trials relative to the respective perspective 

stay trials. Despite benefitting spatial memory accuracy (Iriye & St. Jacques, 2021), third-

person recall was predicted be rated as less vivid in general than first-person recall (Nigro & 

Neisser, 1983; Rice & Rubin, 2009; Robinson & Swanson, 1993). Turning specifically to the 

aphantasics, the limited previous literature means that our predictions were more speculative. 

However, the subjective vividness of recall was predicted to be rated lower overall when 

compared against controls, as is commonly reported (Dawes et al., 2020, 2022; Milton et al., 

2021; Zeman et al., 2020).). Based on the importance of a first-person visuospatial 

perspective in subjective episodic memory experience (Simons et al., 2022; Zaman & 

Russell, 2022), first-person (egocentric) spatial memory performance was predicted to be 

lower in aphantasics relative to controls. In contrast, third-person spatial memory was 

predicted to be relatively unimpaired in aphantasics (Bainbridge et al., 2021). Finally, 

aphantasics were predicted to have generally worse object memory performance than controls 

based on the previously observed deficits in object imagery (Dawes et al., 2020) and object 

memory (Bainbridge et al., 2021), albeit with potentially greater deficits in the first-person 

condition.  

Materials & Methods 

Participants 

Participants were assigned to the aphantasic or non-aphantasic control group based on 

their score on the VVIQ, which is a widely used non-clinical self-report measure that assesses 

how vividly participants can visualise different scenarios involving people and scenes. The 



 

VVIQ shows high reliability and construct validity across different versions (Campos & 

Pérez-Fabello, 2009; McKelvie, 1995). As there is currently no consensus on the appropriate 

cut-off score to identify aphantasia, a VVIQ score ≤ 32 was used for the aphantasic sample in 

the present study (see Figure 1 for histogram of VVIQ scores in both imagery groups). While 

more conservative thresholds have been used in some previous studies (e.g., ≤ 25 in 

Bainbridge et al., 2021), a cut-off score of 32 nonetheless corresponds to very weak visual 

mental imagery across all questionnaire items and corresponds to the threshold used in an 

influential questionnaire-based cognitive characterisation of aphantasia (Dawes et al., 2020)

Figure 1. Histogram of VVIQ scores for aphantasic and control groups. The dotted vertical line 

indicates the a priori VVIQ cut-off score of 32 used to define aphantasia in this study. 

Aphantasics. 20 congenitally aphantasic individuals (35% male) with a mean VVIQ 

score of 17.70 (SD = 3.18, range = 16 – 28), mean age of 26.70 (SD = 5.01, range = 18 – 35), 

and an undergraduate median education level were included in the analyses. The self-reported 

imagery experience of the current aphantasics closely aligned with that documented in large 

sample surveys of the condition (Dawes et al., 2020; Zeman et al., 2020). Furthermore, the 

majority of aphantasic participants (n = 13) reported a complete absence of visual mental 

imagery (VVIQ = 16). An additional eight aphantasic participants were tested but excluded 

due to study non-completion, excessive anticipatory responses, or below chance mean 

performance in the object or spatial components of the memory task, averaged across 

conditions. Aphantasic participants were recruited from various online aphantasic 

communities on Reddit and Facebook. 



 

Controls. 27 non-aphantasic individuals (44% male) with a mean VVIQ score of 

51.37 (SD = 11.20, range = 34 – 72), mean age of 27.73 (SD = 5.60, range = 20 – 35), and an 

undergraduate median education level were included in the analyses. No control participants 

had VVIQ scores indicating extreme imagery ability/experience, referred to as 

hyperphantasia (VVIQ ≥ 75; Zeman et al., 2015, 2020). A further 17 control participants 

were tested but excluded from analysis due to early withdrawal from the study, excessive 

anticipatory responses, or below chance mean performance across conditions in either 

component of the memory task. All control participants were recruited from the online testing 

platform Prolific (https://www.prolific.co/).  

All participants reported native-like English proficiency, had normal or corrected-to-

normal colour vision, and confirmed they had no current or historical diagnoses of 

developmental, psychiatric, or neurological conditions. Participants gave informed consent 

prior to testing and were remunerated in a manner approved by the University of Cambridge 

Psychology Research Ethics Committee. Given the limited prior literature on episodic 

memory in aphantasia, it is difficult to estimate a priori the appropriate sample size to ensure 

adequate experimental power. Nevertheless, the samples collected in this study are 

comparable in size to those of many other task-based studies of aphantasia more generally 

(e.g., Keogh et al., 2021; Keogh & Pearson, 2018; Pounder et al., 2022). The proportion of 

participants excluded for below chance performance was similar in both groups (n = 2/8 

excluded aphantasics and n = 4/17 excluded controls). 

Stimuli 

 Stimuli were 80 targets comprising everyday objects and 40 external landmarks 

consisting of natural and artificial environmental features. All target object stimuli were 256 

x 256 pixels whereas the landmark stimuli were 512 pixels high but had varying widths (M = 

526, SD = 244.8, range = 167 – 1134). Both target object and landmark stimuli were 

presented as view plane-aligned 2D sprites to equate the amount of perceptual information 

available across both perspective conditions. The landmark stimuli were obtained from 

various internet sources whereas the target stimuli were a subset of object images used by 

Brady et al. (2013). While the landmark stimuli were naturalistically coloured, target stimuli 

were colour-rotated in 360° CIELAB perceptually uniform colour space (International 

Organization for Standardization, 2019) to randomly vary their hue during the study and test 

phases (see Figure 2 for an example of a colour-rotated target object stimulus). The CIELAB 

colour space is well suited for continuous manipulations of colour as a given distance 

https://www.prolific.co/


 

between two colours in this space approximates their perceptual colour distance. This 

property of the CIELAB colour space has previously been leveraged to investigate the 

fidelity of both working memory retrieval (Bays et al., 2009; Zhang & Luck, 2008; 

Panichello et al., 2019) and long-term memory retrieval (Brady et al., 2013; Korkki et al., 

2020, 2023; Richter et al., 2016). To minimise potential biases in colour memory, only 

objects without specific colour associations were selected for use as target stimuli in this 

study.  

Figure 2. An example target object stimulus, colour-rotated in 60° increments. Note that colour hue 

was allowed to vary continuously during the actual experiment. 

Virtual environment 

Participants studied both object feature types and subsequently had their spatial 

memory tested within a 3D virtual circular environment 50 virtual meters (vm) in diameter 

with a solid light grey floor and bounded by a 4vm high solid dark grey wall. These 

dimensions are comparable to those employed in similar object location memory tasks (e.g., 

Bellmund et al., 2020). Four equally spaced distal landmarks were placed 5vm beyond the 

boundary wall at each cardinal direction. Landmark sets persisted for the duration of each 

testing block, serving as both locational memory aids and stable orientation cues. The sky, 

which was visible only in the first-person perspective, had a naturalistic blue gradient but was 

otherwise featureless. Participants viewed the environment in a standard 16:9 aspect ratio via 

first-person and third-person virtual cameras. The first-person camera had a fixed 60° field of 

view (FOV) and was oriented perpendicular to the ground at a fixed height of 1.5vm to 

approximate an average person’s eye level. In contrast, the third-person camera had a 

variable FOV (10 – 75°) that functioned as a variable zoom and was angled 90° down toward 

the ground at a fixed height of 55vm to give a bird’s eye view of the environment. The virtual 

environment was created using the Unity game engine (v2019.4.19f1; Epic Games, 2019).  

Procedure 

 In a mixed design, aphantasic and control participants completed a novel computer-

based 3D object and spatial memory task and two questionnaires relating to mental imagery 



 

and memory experience. Both the memory task and questionnaires were completed in a 

single online testing session, and their order was counterbalanced across participants. The 

main task, which will first be briefly summarised, consisted of 10 testing blocks with each 

comprising an exploration, study, arithmetic, and test phase. In the exploration phase, 

participants familiarised themselves with the empty circular testing environment from both 

first-person and third-person perspectives. The testing environment changed with every block 

and was differentiated by four unique external landmarks placed in cardinal directions just 

beyond the boundary wall. Next, in the study phase, participants learned the colour and 

location (relative to the distal landmarks) of eight target objects. These target objects were 

presented in a sequence at random locations within the testing environment. Participants then 

solved self-paced simple arithmetic problems for a fixed 30s to prevent working memory 

rehearsal before finally beginning the test phase, during which they had to precisely 

reproduce the studied target object features (see Figure 3 for schematic illustration of the 

task). 



 

Figure 3. Schematic representation of a testing block in the object and spatial memory task. 

Participants initially familiarised themselves with the testing environment during the exploration phase 

(not shown). A) Then, in the study phase, participants learned the colour and location of eight target 

objects. These target objects were presented in a series at random locations in the testing 

environment, which were viewed from either a first-person (left) or third-person (right) perspective. 

After the study phase, participants solved simple self-paced arithmetic problems for 30s (not shown). 

B) Finally, in the test phase, studied target objects were first cued in greyscale (top) before 

participants made subjective memory imagery vividness ratings on (not shown), then reproduced, 

their object (middle) and spatial memory features, the latter of which were tested in the same or 

alternative studied perspective (bottom left or right). Vividness ratings always preceded feature 

reproduction, but object and spatial memory assessment order randomly varied. Note that target 

object size has been increased for clarity in this figure. 



 

Participants began each testing block by first exploring the virtual environment to 

increase immersion and gain familiarity with the distal landmarks, which were randomly 

varied each block. In this exploration phase, participants were initially placed at the centre of 

the testing environment with no target objects present, viewing it from either a first-person or 

third-person perspective (see Figure 1 for example). After 15s elapsed, participants were 

placed once again at the centre of the environment and viewed it for another 15s from the 

alternative perspective. Initially, the first-person camera faced a random direction whereas 

the third-person camera was placed at a height of 55vm with a 75° FOV so that all distal 

landmarks were fully visible. In both perspectives, participants pressed the ‘a’, ‘d’, ‘w’, and 

‘s’ keyboard keys to move left, right, forward, and backward within the virtual environment 

with an acceleration of 0.3vm/second (s) and a maximum speed of 25vm/s. This permitted 

quick traversal of the environment while simultaneously allowing fine positional adjustments 

within the span of a trial. The virtual camera was coupled to the position of participants in 

both perspectives. When in first person, participants could move their computer mouse to 

laterally rotate the camera and their heading at 200 arbitrary units/s. In third person, moving 

the computer mouse adjusted camera FOV at 40 units/s to permit variable zoom of target and 

landmark objects. These values were multiplied by the interval (in s) between the previous 

and current frames to ensure consistent (i.e., framerate independent) timing across devices. 

These movement and camera controls were used in the exploration phase, study phase, and 

spatial memory feature reproduction component of the test phase. 

Next, in the study phase, participants memorised the colour and location (relative to 

the distal landmarks) of eight target objects. Importantly, these distal landmarks aided 

locational memory and served as stable orientation cues when in first person. Target object 

colour hues randomly varied, and their locations were uniformly randomly distributed within 

the virtual environment but were constrained to within a 20vm radius to prevent visual 

occlusion by the boundary wall. The colour and location of each target object was memorised 

sequentially, yielding eight study trials per block. Study trials began with a central black 

fixation cross presented for 500ms against a grey background, followed by a fixed 10s period 

in which participants memorised both target object features. Participants began this period at 

the centre of the environment, which they viewed from either a first-person or third-person 

perspective. The studied perspective randomly varied across trials and in equal proportion. 

The first-person camera initially faced the target whereas the third-person camera was placed 

55vm above the centre of the environment to equate the maximum amount of time available 



 

to study a target location in both perspectives. Participants could then freely study the object 

features using the camera/movement controls for the given perspective condition.  

After memorising the target locations, participants completed the arithmetic phase, 

which served as both a distractor task and attention check. The arithmetic phase lasted for 30s 

and involved solving simple addition and subtraction problems on positive double-digit 

integers. Arithmetic trials were self-paced until the fixed 30s timeout was reached, and each 

began with a 500ms central black fixation cross, followed by a randomly generated problem. 

Participants typed their answer, which was displayed on-screen, using the number keys on 

their keyboard. Mistakes could be deleted by pressing the ‘backspace’ key. Responses were 

submitted by pressing the ‘space’ key. 

In the test phase, participants rated the vividness of, and reproduced, both the colour 

(i.e., object memory) and location (i.e., spatial memory) of the eight target objects studied 

earlier in the testing block. No unstudied objects were tested. This resulted in a total of 80 test 

trials in the main task. These trials were equally split across first person and third person 

perspective conditions in the object memory assessment (i.e., 40 target object colours were 

studied in first-person and 40 in third-person), which were further divided into perspective 

switch and stay conditions in the spatial memory assessment (i.e., 20 target object locations 

were studied and tested in first person, 20 were studied in third person but tested in first 

person, 20 were studied and tested in third person, and 20 were studied in first person but 

tested in third person). Furthermore, these conditions were pseudorandomly allocated to each 

test phase in equal proportions. All test trials began with the presentation of a black central 

fixation cross for 500ms. This was followed by the cueing of a studied object in greyscale for 

1s., then the object and spatial memory feature assessments. Both types of feature assessment 

were separated by a 500ms-long black central fixation cross, and their order was randomised 

across trials. However, the subjective vividness of both memory features was assessed before 

objective feature reproduction. This was done to eliminate the influence of objective memory 

performance on subjective vividness ratings (Richter et al., 2016).  

Object memory. The object memory assessment was adapted from the continuous 

report episodic memory task developed by Richter et al. (2016). First, participants rated the 

subjective vividness with which they could remember a cued target object’s studied colour. 

To increase the likelihood that these task-based vividness ratings would tap the same 

construct of mental imagery as the VVIQ, the same language was used to define the ratings 



 

scale. These ratings could span a continuum ranging from 0 (i.e., “no imagery at all” for 

colour) to 100 (i.e., colour imagery “as vivid as sight”) and were made using a horizontal 

response slider. Participants indicated the level of colour vividness by holding the ‘a’ or ‘d’ 

keyboard keys to move the slider left or right. Both the ratings slider and this scale remained 

on-screen until participants made a response by pressing the ‘space’ key or the 10s deadline 

was reached. Following the vividness rating, participants had up to 15 seconds to reproduce 

the studied colour hue of the cued target object as precisely as they could from memory. The 

target object remained on-screen during this period and was initially presented in a random 

hue that differed from its original. Participants adjusted the colour hue of the target object by 

holding the ‘a’ or ‘d’ keys to move a response slider that encircled the target clockwise or 

counterclockwise. As with the vividness rating, participants submitted their response by 

pressing the ‘space’ key. 

Spatial memory. Participants first rated the subjective vividness with which they could 

remember a cued target object’s studied location within the greater scene. Like the object 

memory assessment, these ratings were made using the same continuous scale, response 

slider, and controls and within the same 10s response deadline. Likewise, participants then 

had up to 15s to precisely reproduce the target object’s studied location from memory. The 

testing environment in which these responses were made was viewed from either the same 

(i.e., perspective stay condition) or alternative (i.e., perspective switch condition) studied 

perspective of the target object. At the start of this period, participants were placed in the 

environment’s centre and faced a random direction when in first person whereas the camera 

was placed at fixed height facing down toward the ground when in third person. Viewpoint 

could be adjusted in both conditions by rotating the first-person camera left/right or zooming 

the third-person camera in/out using the computer mouse/trackpad. Using the 

movement/camera controls, participants moved a black crosshair, placed on the ground ahead 

of the first-person camera or centred under the third-person camera, to precisely indicate a 

given target object’s studied location. Responses were submitted by pressing the ‘space’ key. 

Questionnaires 

 Measures of general mental imagery and memory experience were obtained for each 

participant using the VVIQ and the Survey of Autobiographical Memory (SAM; Palombo et 

al., 2013) self-report questionnaires, respectively. The VVIQ consists of 16 items to which 

participants rate their level of agreement with statements related to person and scene visual 

mental imagery. VVIQ items are rated using a 5-point Likert scale, with ratings of 1 



 

corresponding to “no image at all, you only ‘know’ that you are thinking of the object” while 

ratings of 5 correspond to imagery “perfectly clear and as vivid as normal vision”. VVIQ 

scores range from 16 to 80. The SAM has 26 items and measures agreement level with 

statements related to various memory abilities. Like the VVIQ, SAM items are rated using a 

5-point scale, with a score of 1 corresponding to “strongly disagree” while a score of 5 

corresponds to “strongly agree”. The total SAM score, as well as separate scores for the 

episodic, semantic, spatial, and future subcomponents, were derived from item-specific 

weights for each response using materials provided by the questionnaire’s creators.  

Task measures and analysis 

The main analysis was performed on mean object and spatial memory performance 

and their corresponding imagery vividness ratings. Median response time (RT) was also 

examined for both task components. Raw object memory errors were quantified as the 

absolute angular deviation between a given target object’s studied colour hue and the hue 

reproduced by a participant during the test phase (range = 0-180°). Raw spatial memory 

errors reflected the Euclidean distance between a given target object’s studied location in the 

virtual environment and the location indicated by a participant during the test phase. Trials in 

which no responses were given or a response was given within 500ms were excluded from 

analysis (5% of all trials in control participants and 6% of all trials in aphantasic participants 

in the present study). 

Raw errors on continuous report tasks like the one used here to probe object memory 

are thought to reflect both the overall success and varying precision of episodic memory 

retrieval, properties that have been separated behaviourally (Harlow & Yonelinas, 2016) and 

neurally (Richter et al., 2016) using probabilistic mixture modelling (Bays et al., 2009; Zhang 

& Luck, 2008). Given that a measure of the fidelity or precision of object memory retrieval 

rather than its overall success is more likely to be sensitive to visual imagery-based memory 

deficits than alternative verbal or symbolic strategies, probabilistic mixture models were 

fitted to the raw object memory errors for each task condition and in each participant. These 

mixture models had two components: a von Mises circular normal distribution centred at a 

mean raw error of 0°, with a concentration parameter Kappa (K), and a circular uniform 

distribution representing the probability of random guesses (pU). Retrieval success (pT) was 

calculated as the probability of responses emanating from the von Mises distribution versus 

the uniform distribution (pT = 1 – pU ), whereas retrieval precision (K) was the concentration 

of the von Mises distribution. pT ranged from 0 (i.e., complete retrieval failure) to 1 (i.e., 



 

complete retrieval success), with 0.5 reflecting random guesses. By contrast, K had a 

minimum value of 0, reflecting a perfectly uniform response distribution, with increasing 

values indicating increasing levels of object memory retrieval precision.  

As target object locations studied closer to the virtual environment’s boundary have a 

larger maximum possible spatial memory error than those studied in its centre, a correction is 

needed to account for varying difficulty across different target locations. This was achieved 

by computing the accuracy percentile of a given response relative to all other possible 

responses as a memory score (MS) (Jacobs et al., 2016). Each MS was computed by first 

generating 10,000 possible response locations uniformly distributed throughout the 

environment. Next, the distance between each possible response location and a given target 

location was calculated, yielding trial-specific error distributions. Finally, the proportion of 

possible response errors less than the actual response error was calculated for each target, 

resulting in a MS ranging from 0 to 1. A MS of 1 corresponds to perfect performance, a score 

of 0.5 to chance level performance, and a score 0 to the worst possible performance (i.e., the 

furthest possible location from a true target location).  

All analyses were conducted using R Statistical Software (v4.1.2; R Foundation for 

Statistical Computing, Vienna, Austria). Linear mixed models were run on mean object and 

spatial memory vividness ratings and performance measures using the ‘lme4’ package (Bates 

et al., 2015). All models were fitted via restricted maximum likelihood parameter estimation 

and all models included the between-subjects fixed factor of imagery group (controls, 

aphantasics). However, these models differed in their number of within-subjects fixed factors. 

The object memory model had a single within-subjects fixed factor of study perspective (first 

person, third person), representing the perspective in which a given object feature was studied 

and tested. As visuospatial perspective was additionally manipulated in the spatial memory 

component of the task during the test phase, the corresponding model had two within-subjects 

fixed factors of switch status (stay, switch) and test perspective (first person, third person). 

These fixed factors were represented using effects coding as their interactions were of chief 

concern (Singmann & Kellen, 2019). Under this scheme, fixed factor coefficients indicate the 

deviation of each factor level from the grand mean, represented by the intercept. Finally, all 

models accounted for repeated measures by including a by-subject random intercept (Barr, 

2013; Barr et al., 2013). The general form of the object (1) and spatial (2) memory models are 

provided below in lme4 syntax: 



 

object ~ imageryGroup * studyPerspective + (1 | subject)    (1) 

spatial ~ imageryGroup * switchStatus * testPerspective + (1 | subject)   (2) 

Model assumptions were evaluated by inspecting standard diagnostic residual plots. 

Outliers were detected using the interquartile range method (i.e., values greater than 1.5x the 

interquartile range). The influence of outliers, where present, was checked by re-running 

analyses without the subjects who contributed them. P-values for the fixed effects were 

calculated using Satterthwaite degrees of freedom approximation (Satterthwaite, 1941), 

implemented in the ‘lmerTest’ package (Kuznetsova et al., 2017). Significant interactions 

were followed up on with simple contrasts on the estimated marginal means using the 

“modelbased” package (Makowski et al., 2020). All tests were two-sided and used a 

canonical alpha level of 0.05. Exact p-values are reported to three decimal places (unless p < 

0.001). 

Results 

Demographics and questionnaires 

Demographics. Due to unequal sample sizes, a Welch’s two-sample t-test assuming 

unequal between-group variances was conducted on age and found no significant difference 

between aphantasic and non-aphantasic participants (t(42.94) = 0.66, p = .51). These groups 

did not significantly differ in the proportion of males and females as determined by a Fisher’s 

exact test of independence on the sex count data (p = .55, Fisher’s exact test). A Mann-

Whitney U test was performed on formal education level and similarly found no significant 

between-group difference (W = 304, p = .30). Together, these results indicate aphantasic and 

control groups were matched on all demographic variables (see Table 1 for descriptive 

statistics). 

 

 

 

 

 

 



 

Table 1. Mean (SD in brackets) participant demographic and questionnaire data. 

Variable Controls (n = 27) Aphantasics (n = 20) p-value 

Age 27.73 (5.60) 26.70 (5.01) 0.514a 

Sex 12 male, 15 female 7 male, 13 female 0.551b 

Education  undergraduate undergraduate 0.295c 

VVIQ 51.37 (11.20) 17.70 (3.18) < 0.001a  

SAM  93.83 (12.28) 84.90 (12.71) 0.020a  

   Episodic 99.62 (13.75) 86.69 (13.01) 0.002a 

   Semantic 95.12 (13.70) 97.45 (17.90) 0.630a 

   Spatial 90.70 (18.08) 87.49 (18.56) 0.557a 

   Future 90.81 (10.75) 79.43 (2.33) < 0.001a  

Note. VVIQ = Vividness of Visual Imagery Questionnaire, SAM = Survey of Autobiographical 

Memory. The median education level is reported. 

a Tested using a two-sided Welch’s two-sample t-test. 

b Tested using a two-sided Fisher’s exact test of independence. 

c Tested using a two-sided Mann-Whitney U test. 

Questionnaires. Welch’s two-sample t-tests assuming unequal between-group 

variances were performed on the VVIQ, SAM composite, and SAM component scores (see 

Table 1). On the VVIQ, aphantasic participants reported significantly less vivid visual mental 

imagery than controls (t(31.46) = 14.83, p < 0.001). Aphantasic participants also reported 

significantly worse overall memory ability than controls, as measured by the SAM composite 

score (t(40.29) = 2.42, p = 0.020). Consistent with a selective deficit in episodic cognition, 

however, aphantasics reported significantly lower ability in episodic memory (t(42.27) = 

3.29, p = 0.002) and future event prospection (t(29.25) = 5.33, p < 0.001), but not in semantic 

memory (t(34.34) = -0.49, p = 0.630) or spatial memory (t(40.48) = 0.59, p = 0.557).  

Object memory 

Vividness. As predicted for the model on object memory vividness (Figure 4A), there 

was a significant main effect of imagery group (β = 14.07, SE = 3.58, t(45) = 3.93, p < .001), 

where aphantasic participants rated their object memory vividness lower than controls (see 

Table 2 for descriptive statistics). There was no significant main effect of study perspective (β 

= 0.39, SE = 0.36, t(45) = 1.08, p = .29) or a significant imagery group x study perspective 

interaction (β = -0.10, SE = 0.36, t(45) = -0.28, p = .78). No outliers were detected in these 

data. For descriptive statistics of the vividness ratings and performance measures on the 

object memory component of task, see Table 2 below. 



 

 

Figure 4. Mean object memory vividness ratings (A) and retrieval success (B, left) and precision (B, 

right) measures across imagery groups and task perspective conditions. Error bars denote SEM. 

Retrieval success. In the model on object memory retrieval success (see Figure 5B, 

left), there were no significant main effects of imagery group (β < 0.01, SE = 0.02, t(45) = 

0.02, p = .98) or study perspective (β < 0.01, SE < 0.01, t(45) = 0.62, p = .54). Likewise, there 

Table 2. Mean (SD in brackets) object memory vividness and performance measures. 

Condition Controls Aphantasics 

 Vividness pT K RT Vividness pT K RT 

First person 62.89 

(15.30) 

0.81 

(0.13) 

11.09 

(7.70) 

4.72 

(1.13) 

34.95 

(32.94) 

0.83 

(0.15) 

11.25 

(5.14) 

5.00 

(1.37) 

Third person 62.31 

(15.68) 

0.82 

(0.13) 

8.11 

(5.19) 

5.01 

(1.32) 

33.98 

(32.80) 

0.80 

(0.21) 

8.73 

(4.55) 

5.38 

(1.36) 



 

was no significant imagery group x study perspective interaction (β < -0.01, SE < 0.01, t(45) 

= -1.20, p = .23). One outlier participant was detected, but their exclusion did not influence 

the results. 

 Retrieval precision. Contrary to our prediction, the model on object memory precision 

(see Figure 3B, right) revealed no significant main effect of imagery group (β = -0.20, SE = 

0.76, t(45) = -0.26, p = .80). However, there was a significant main effect of study 

perspective (β = 1.38, SE = 0.42, t(45) = 3.24, p = .002), where object memory was generally 

recalled with higher fidelity when studied in a first-person versus a third-person perspective 

(see Table 2). There was no significant imagery group x study perspective interaction (β = 

0.12, SE = 0.42, t(45) = 0.27, p = .79). Excluding outlier participants (n = 5) did not affect the 

results. 

 Raw error. For completeness, raw object memory errors, which were not derived 

from mixture modelling, were also analysed. Mirroring the analyses of pT and K, there was a 

significant main effect of study perspective (β = -1.72, SE = 0.63, t(45) = -2.71, p = .010), but 

no significant main effect of imagery group (β = 1.12, SE = 1.71, t(45) = 0.66, p = .52) or a 

significant imagery group x study perspective interaction (β = 0.645, SE = 0.63, t(45) = 1.02, 

p = 0.31), suggesting the lack of group differences in object memory retrieval success and 

precision were unlikely to be attributable to the modelling approach used to derive those 

measures. One outlier participant was excluded, but the results did not change. 

 Response time. Finally, the model on object memory RTs (see Table 2) showed no 

significant main effect of imagery group (β = -0.16, SE = 0.19, t(45) = -0.88, p = .39), but 

there was a significant main effect of study perspective (β = - 0.16, SE = 0.04, t(45) = -4.19, p 

< .001). The imagery group x study perspective interaction was not significant (β = 0.02, SE 

= 0.04, t(45) = 0.59, p = .56). Two outlier participants were detected, but their removal did 

not change the results. 

Spatial memory 

Vividness. As in the object memory analysis, the model on spatial memory vividness 

(see Figure 4A) revealed a significant main effect of imagery group (β = 12.93, SE = 3.24, 

t(45) = 3.99, p < .001), where aphantasic participants rated their spatial memory vividness 

lower than controls. There were no significant main effects of switch status (β = -0.37, SE = 

0.49, t(135) = -0.76, p = .45) or test perspective (β = 0.06, SE = 0.49, t(135) = 0.13, p = .90). 

There was, however, a significant switch status x test perspective interaction (β = -1.55, SE = 



 

0.49, t(135) = -3.18, p = .002), but no significant imagery group x switch status (β = 0.35, SE 

= 0.49, t(135) = 0.71, p = .48) or imagery group x test perspective (β = -0.04, SE = 0.49, 

t(135) = -0.09, p = .93) interactions. Finally, the imagery group x switch status x test 

perspective interaction was significant (β = -1.28, SE = 0.49, t(135) = -2.63, p = .010). 

Excluding outlier participants (n = 3) did not change the pattern of results. See Table 3 below 

for descriptive statistics of all spatial memory measures. 

Table 3. Mean (SD in brackets) spatial memory vividness and performance measures. 

Condition Controls Aphantasics 

 Vividness MS RT Vividness MS RT 

First person       

Stay 47.86 

(15.63) 

0.75 

(0.09) 

5.31 

(1.51) 

25.44 

(27.18) 

0.77 

(0.11) 

5.03 

(1.60) 

Switch 52.50 

(18.91) 

0.78 

(0.13) 

5.53 

(1.72) 

28.10 

(29.53) 

0.81 

(0.11) 

5.16 

(1.76) 

Third person       

Stay 52.65 

(19.64) 

0.85 

(0.10) 

4.06 

(1.79) 

26.26 

(27.92) 

0.85 

(0.12) 

3.64 

(1.46) 

Switch 47.29 

(16.32) 

0.76 

(0.09) 

4.16 

(1.88) 

26.83 

(27.20) 

0.78 

(0.11) 

3.64 

(1.30) 

 

 

 

 

 

 

 

 



 

 

Figure 5. Mean spatial memory vividness ratings (A) and MS (B) across imager groups and switch 

status and test perspective task conditions. Error bars denote SEM.  

To decompose the significant three-way interaction in the analysis of spatial memory 

vividness, the simple effects of imagery group, conditioned on switch status x test 

perspective, were initially investigated. Relative to the aphantasic participants, control 

participants had significantly higher vividness ratings in both stay first person (β = 30.30, SE 



 

= 6.72, t(46) = 4.50, p < .001) and switch first person (β =34.90, SE = 6.72, t(46) = 5.19, p < 

.001) trials. Likewise, control participants rated their vividness significantly higher than 

aphantasics in both stay third person trials (β = 34.70, SE = 6.72, t(46) = 5.16, p < .001) and 

switch third person trials (β = 28.9, SE = 6.72, t(46) = 45.80, p < .001).  

The simple effects of test perspective, conditioned on imagery group and switch 

status, were then examined. Stay first person vividness ratings were significantly lower than 

stay third person vividness ratings in control participants (β = -5.63, SE = 1.88, t(114) = -

2.99, p = .003) but not aphantasic participants (β = -1.20, SE = 2.71, t(114) = -0.44, p = .66). 

In comparison, switch first person vividness ratings were significantly higher than switch 

third person vividness ratings in control participants (β = 5.71, SE = 1.88, t(114) = 3.03, p = 

.003) but not aphantasic participants (β = -0.26, SE = 2.71, t(114) = -0.10, p = .92). 

Finally, the simple effects of switch status, conditioned on imagery group and test 

perspective. Vividness ratings in stay first person trials were significantly lower than in 

switch first person trials in control participants (β = -5.71, SE = 1.88, t(114) = -3.04, p < 

.003), whereas this difference was not significant in aphantasic participants (β = -11.11, SE = 

2.71, t(114) = -0.410, p = .68). In contrast, stay third person vividness ratings were 

significantly higher than switch third person vividness ratings in control participants (β = 

5.62, SE = 1.88, t(114) = 2.99, p = .003) but not in aphantasic participants (β = -0.17, SE = 

2.71, t(114) = -0.06, p = .95). Considering the results of the simple effects analyses together, 

a crossover interaction is apparent in the control group but not the aphantasic group. More 

specifically, spatial memory vividness is higher in those with typical imagery when object 

locations are studied in third person versus first person, irrespective of the test perspective. 

On the other hand, those with atypical imagery have lower spatial memory vividness in 

general.  

Memory score. The model on spatial memory score (see Figure 4B) revealed 

significant main effects of switch status (β = 0.01, SE < 0.01, t(135) = -3.13, p = .024) and 

test perspective (β = -0.02, SE < 0.01, t(135) = -3.13, p = .002), but not imagery group (β < -

0.01, SE = 0.01, t(45) = -0.20, p = .85). There was a significant switch status x test 

perspective interaction (β = -0.03, SE < 0.01, t(135) = -6.19, p < .001) but not imagery group 

x switch status (β < 0.01, SE < 0.01, t(135) = 0.28, p = .78) or imagery group x test 

perspective (β < -0.01, SE < 0.01, t(135) = -0.49, p = .62). The imagery group x switch status 



 

x test perspective interaction was not significant (β < 0.01, SE < 0.01, t(135) = -1.18, p = .24). 

Excluding outlier participants (n = 2) did not influence the results. 

The significant switch status x test perspective interaction in the analysis of spatial 

memory score was decomposed by examining the simple effects of test perspective, 

conditioned on switch status, and averaged over imagery group. As predicted, stay first 

person MS was significantly lower than stay third person MS (β = -0.09, SE = 0.01, t(135) = -

6.59, p < .001), suggesting that spatial memory accuracy is generally less accurate when 

studied and tested in first person versus third person. In comparison, however, switch first 

person MS was significantly higher than switch third person MS (β = 0.03, SE = 0.01, t(135) 

= 2.16, p = .032). Together, these results indicate that a third person perspective, whether 

encoded as such or adopted during subsequent retrieval, enhances spatial memory accuracy. 

Response time. Lastly, in the model on spatial memory RTs (see Table 3), the main 

effect of imagery group was not significant (β = 0.26, SE = 0.22, t(45) = 1.21, p = .23) but the             

main effect of test perspective was (β = 0.73, SE = 0.05, t(135) = 13.50, p < .001). There was 

no significant main effect of switch status (β = -0.07, SE = 0.05, t(135) = -1.21, p = .23), nor 

were there significant interactions of switch status x test perspective (β = -0.4, SE = 0.05, 

t(135) = -0.74, p = .46), imagery group x switch status (β = -0.02, SE = 0.05, t(135) = -0.37, p 

= .71), imagery group x test perspective (β = -0.02, SE = 0.05, t(135) = -0.37, p = .71), or 

imagery group x switch status x test perspective (β = -0.02, SE = 0.05, t(135) = -0.38, p = 

.71). Three outlier participants were detected, but their exclusion did not affect the results.  

Effects of total aphantasia on task performance  

The aphantasic sample in the present study had a mean VVIQ score of 17.70, which is 

in line with other studies (e.g., Pounder et al., 2022). However, n = 7 of these aphantasic 

participants had VVIQ scores indicating a limited degree of mental imagery experience 

(range = 16 – 28), which might have reduced potential group differences in the object and 

spatial memory task. To explore this possibility, the main analysis was re-run to include only 

those reporting a complete absence of mental imagery (i.e., total aphantasia) in the aphantasic 

group (n = 13). The overall pattern of results did not change as there were no significant main 

effects or interactions involving imagery group on any of the object or spatial memory 

performance measures (all ps ≥ .19). Furthermore, there were no significant main effects or 

interactions involving imagery group in the re-analysis of object memory RT (all ps ≥ .23), 

although a significant imagery group x test perspective interaction was revealed in the re-



 

analysis of spatial memory RT (β = 0.12, SE = 0.06, t(114) = 2.0, p = .048). This interaction 

was decomposed by examining the simple effects of test perspective, conditioned on imagery 

group, and averaged over switch status. No significant group differences emerged for spatial 

memory RT under the first person (β = 0.75, SE = 0.54, t(41.7) = 1.39, p = .171) and third 

person (β = 0.29, SE = 0.54, t(41.7) = 0.54, p = .594) test conditions. However, it should be 

cautioned that these null results may simply reflect a power issue due to the small size of the 

subgroup reporting total aphantasia. 

Relationship between subjective and objective memory measures 

 As indicated by the apparent inconsistency between task-based subjective vividness 

ratings and objective performance in the aphantasic participants, some or all of those 

individuals might have a deficit in meta-cognitive awareness of mental imagery rather than in 

imagery itself (Pounder et al., 2022). To explore this possibility in the present data, 

correlations were run within groups on the memory task vividness ratings and performance 

measures to see whether their assumed relationship in control participants is reduced or 

absent in aphantasic participants. These analyses were run in R using the ‘psych’ package 

(Revelle, 2023). The number of tests was reduced by averaging across task conditions to 

obtain single measures of object and spatial memory vividness and performance. As the 

pattern of results in the main analysis of the object memory component of the task did not 

depend on the measure used (i.e., raw error, retrieval success, or retrieval precision), object 

memory performance was quantified here with the raw errors to further reduce the number of 

tests. By contrast, spatial memory performance remained characterised by MS. 

First, the correlation between vividness ratings and performance in the memory task 

was examined. Rank-based Kendall correlations, which account for floor effects in the 

aphantasic vividness ratings, were run in both participant groups to ensure they were treated 

equally. In the control participants, the correlation between memory vividness and performance 

was significant and in the expected direction for both object memory (τb = -0.54, p < .001; see 

Figure 6, top left) and spatial memory (τb = 0.28, p = .040; see Figure 5, bottom left). In the 

aphantasic participants, this correlation was not significant for object memory (τb = -0.09, p = 

.58; see Figure 5, top right) or spatial memory (τb = 0.26, p = .11; see Figure 6, bottom right). 

These relationships were then compared between groups. Kendall’s formula was used to 

convert each tau value to a Pearson’s r correlation coefficient (Walker, 2003) before submitting 

their group difference, paired according to task component, to a Fisher z-transformation. 



 

Relative to the aphantasic participants, control participants exhibited a significantly higher 

correlation between vividness ratings and memory performance in the object memory 

component of the task (z = 2.65, p = 0.010), but not in the spatial memory task component (z = 

0.13, p = 0.90). 

 

Figure 6. Plots showing the relationship between mean vividness ratings and performance for object 

(top) and spatial (bottom) memory features in control (left) and aphantasic participants (right). Red-

highlighted datapoints denote the subgroup of aphantasic participants who rated their task-based 

memory vividness at floor. 

As the correlations between overall object and spatial memory vividness ratings and 

performance were significant in the control participants (see Figure 6, left), these relationships 

were further broken down in this group by visuospatial perspective. Given the spread of task-

based vividness ratings in the control participants, standard Pearson correlations were run in 

this exploratory analysis. These relationships were significant for object features studied both 

in first person (r(25) = -0.79, p < .001) and in third person (r(25) = -0.60, p = .001). All but the 

stay first-person condition of the spatial memory component of the task were significant (stay 



 

first person: r(25) = 0.25, p = .20; switch first person: r(25) = 0.64, p < .001; stay third person 

r(25) = 0.57, p = .002; switch third person: r(25) = 0.60, p = .001). 

Finally, two distinct clusters were evident in the aphantasic correlation plots (see Figure 

6, right), with one subgroup (n = 9) rating their memory vividness at floor (vividness < 10) 

despite wide ranging performance and another subgroup (n = 11) rating their memory vividness 

and performance ostensibly more in line with controls. Additionally, it should be noted that 

those who rated their memory vividness for object features at floor did so too for spatial 

features. Accordingly, further exploratory Kendall’s rank correlations were run in the latter 

aphantasic subgroup, which remained non-significant for object memory (τb = -0.09, p = .80), 

but became significant for spatial memory (τb = 0.78, p < .005).  

Discussion 

This study investigated objective and subjective aspects of episodic recall in people 

with aphantasia. To this end, a novel 3D object and spatial memory task manipulating 

visuospatial perspective was employed to assess visual and spatial imagery abilities in self-

identified aphantasics and their influence on subjective and objective measures of episodic 

memory. Aphantasic participants showed no objective deficits in object or spatial memory 

performance in either perspective condition, despite rating the subjective vividness of both 

memory features lower than control participants. Furthermore, aphantasic participants did not 

differ from controls in their ability to manipulate visuospatial representations as indicated by 

the comparable levels of switch versus stay trial performance in both groups. The overall 

pattern of results did not change following an exploratory re-analysis restricting the 

aphantasic group to individuals reporting a complete lack of mental imagery (i.e., total 

aphantasia), although an RT difference emerged in the spatial memory task. Further 

exploratory correlation analysis revealed a significant relationship between objective task 

performance and subjective imagery vividness in the control participants but not in the 

aphantasic participants. Together, these results suggest that some aphantasics might have a 

deficit in conscious awareness of mental imagery rather than in imagery itself. 

Contrary to our necessarily speculative predictions given the limited prior literature, 

there were no objective differences between aphantasic and control participants in spatial or 

object memory performance, regardless of perspective. The overall lack of objective memory 

deficits in the aphantasic participants is unlikely to reflect data insensitivity as the standard 

errors for all estimates were small across analyses. The lack of an objective object memory 



 

deficit in the current aphantasic participants is particularly noteworthy given numerous 

previous subjective self-reports and some objective task-based evidence of selective object 

imagery deficits (Bainbridge et al., 2021; Dawes et al., 2020; Dawes et al., 2022). The lack of 

spatial memory deficits in the current aphantasic participants is consistent with previous 

findings that aphantasics typically self-report unimpaired spatial abilities (Dawes et al., 2020) 

and perform normally when these abilities are examined objectively using mental rotation 

tasks (Bainbridge et al., 2021; Zeman et al., 2015), despite potential measurement biases 

toward allocentric spatial processing. While a spatial subtype of aphantasia has recently been 

suggested (Palermo et al., 2022), the current use of the VVIQ to identify aphantasic 

participants more generally likely favours individuals with poor visual imagery.  

It should be cautioned that there may have been sampling bias in the aphantasic group 

given that those with abnormally weak mental imagery (VVIQ ≤ 32) were explicitly 

recruited. It is not uncommon for the majority of aphantasic participants to report a complete 

absence of mental imagery on the VVIQ (as in the present study), despite allowances for 

some degree of weak mental imagery (e.g., Dawes et al., 2020; Zeman et al., 2015). Yet, 

when recruitment biases are explicitly controlled for, total aphantasia has been indicated to be 

rarer in the general population than “moderate aphantasia” (0.8% versus 3.1%, respectively; 

Dance et al., 2022). Thus, the strength of any potential imagery-related memory deficits in 

the current aphantasic sample should have been overestimated rather than underestimated 

relative to the true aphantasic population, making the lack of objective deficits all the more 

puzzling. However, while clear objective imagery deficits have been previously found in 

small samples of aphantasics (e.g., n = 15; Keogh & Pearson, 2018), whether memory should 

be impaired to a similar extent is unclear given the paucity of objective memory studies 

(Bainbridge et al., 2021; Monzel et al., 2022; Pounder et al., 2022). 

This study is not the first to find little to no objective evidence for memory 

differences in people with aphantasia, despite large sample self-report studies providing 

evidence to the contrary (Dawes et al., 2020; Milton et al., 2021; Zeman et al., 2020). A 

recent study by Pounder et al. (2022) found no accuracy differences between aphantasics and 

control participants on visuospatial working memory and verbal/visual pattern recognition 

memory tasks. Importantly, the visual pattern recognition task stimuli used by Pounder et al. 

were abstract and not easily represented verbally or symbolically, which might otherwise 

support good task performance when visual imagery is weak or absent. However, recognition 

memory task performance may also be supported by the vague sense of prior occurrence or 



 

familiarity rather than detailed recollection (e.g., Addante et al., 2012), which is assumed to 

involve mental imagery in most individuals. Reliance on familiarity is less likely to explain 

the present data given the more complex, challenging, and continuous nature of memory 

assessment, although familiarity may have guided responses to some extent in the objective 

memory tasks due to the visual feedback they provided, thereby reducing potential group 

differences due to generative mental imagery. Indeed, it is noteworthy that Bainbridge et al. 

(2021) found a selective object memory deficit on their drawing task, which provided no such 

visual feedback. However, our measure of object memory retrieval precision derived from 

probabilistic mixture modelling has been shown to be highly sensitive to recollection-based 

memory differences (e.g., Korkki et al., 2020), and it is unlikely that familiarity alone 

supported task performance in the current study given the high level of precision in 

responses, which presumably required access to high fidelity memory representations.  

Pounder et al. (2022) found no performance differences on any of their tasks when 

their analyses were restricted to individuals with total aphantasia, although some differences 

did emerge when RTs were examined (e.g., mental rotation). Based on this finding, Pounder 

et al. suggested that RT measures may be more informative than accuracy measures where 

alternative non-imagery-based task strategies are concerned. No significant RT differences 

were found in the main analysis of the present study, although an exploratory re-analysis 

restricted to the subgroup reporting total aphantasia revealed a significant imagery group by 

test perspective interaction for spatial memory RT. However, this result should be interpreted 

with caution given the small size of the subgroup with total aphantasia (n = 13). Moreover, it 

is unclear why RT differences proposed to reflect alternative strategy use would manifest on 

spatial tasks (see also Pounder et al.) when aphantasia is thought to reflect a primarily object 

imagery deficit. Indeed, the subgroup with total aphantasia did not significantly differ from 

controls on any of the other RT or performance measures including object memory retrieval 

precision, which should be the most sensitive to their characteristic mental imagery deficits. 

While it is difficult to imagine how the aphantasics participants might have completed the 

current memory task without the use of mental imagery, it is nevertheless possible that they 

did so using a strategy that has yet to be identified. Ruling out this possibility is of critical 

importance to future research on the question of unconscious mental imagery in aphantasics. 

To this end, non-invasive brain stimulation targeting imagery-related cortical regions in non-

aphantasic participants might be one way to test whether the current task requires mental 

imagery. However, the present findings nevertheless suggest that some self-identified 



 

aphantasics can perform normally on tasks typically thought to require mental imagery, 

regardless of the degree of their phenomenal imagery deficit.  

The overall lack of significant objective memory deficits in the present aphantasics 

poses a challenge to the recent proposal that aphantasia might represent an episodic system 

condition rather than a mental imagery condition (Blomkvist, 2022). This theory extends the 

constructive episodic simulation hypothesis (Schacter & Addis, 2007, 2020), where episodic 

memory retrieval and imagery generation are held to involve common constructive and 

simulative processes (Hassabis et al., 2007; Hassabis & Maguire, 2007; Pearson, 2019), by 

adding hippocampally-based memory indices that point to the storage locations of individual 

episodic elements, multiple modality-specific episodic retrieval processes, and separate 

episodic and semantic spatial retrieval processes. Under this expanded cognitive architecture, 

Blomkvist distinguishes between aphantasics with voluntary mental imagery deficits and 

aphantasics with mental imagery deficits irrespective of volition. Specifically, Blomkvist 

argues that the former type of aphantasics reflects an impairment in activating the episodic 

system to generate mental imagery in a top-down manner only. By contrast, the latter type of 

aphantasics might be deficient at both top-down and bottom-up imagery generation (i.e., 

reflecting impaired access to the episodic system) or, alternatively, have an impaired episodic 

system on its own. Blomkvist notes that, in the case of more “complete” aphantasia, there is 

currently insufficient evidence to favour one possibility over the other. The present data (see 

also Pounder et al., 2022), particularly those from probabilistic mixture modelling indicating 

that aphantasics may have access to high fidelity visual memory representations, is 

inconsistent with the notion that aphantasia necessarily represents more fundamental episodic 

memory deficits. However, it is difficult to reconcile the present lack of objective task-based 

memory impairments and those found in other studies. For instance, Monzel et al. (2022) and 

Pounder et al. (2022) both employed similar complex visual pattern recognition memory 

tasks, yet only Monzel et al.’s aphantasic participants exhibited memory deficits. Findings are 

mixed even regarding more challenging memory tasks that separate object and spatial aspects 

of retrieval. For instance, Bainbridge et al. (2021) found aphantasics had selective object 

memory deficits in their drawing task whereas aphantasics in the present study exhibited 

normal performance in both categories. Therefore, future work should endeavour to identify 

potential task-related drivers of these divergences such as task difficulty or the manner of 

instruction. 



 

One explanation for the present findings is that some aphantasics might retain a latent 

capacity for mental imagery, which they have no conscious awareness of, that nevertheless 

supports a normal level of task performance (see Jacobs et al., 2018; Nanay, 2021; Pounder et 

al., 2022). This would also be consistent with the view that, rather than reflecting a mental 

imagery-related metacognitive/introspective deficit, aphantasia might represent a 

disconnection syndrome, where sub-personal or representational mental imagery is proposed 

to remain intact but be inaccessible at the personal or experiential level (for discussion, see 

Lorenzatti, 2023). While the notion of unconscious mental imagery runs counter to the view 

that mental imagery is necessarily conscious (Farah, 1984; Kosslyn, 2005), more recent 

thinking has entertained this possibility (Brogaard & Gatzia, 2017; Nanay, 2021). Indeed, 

visual perception, which shows behavioural and neural overlap with visual mental imagery 

(for review see Pearson, 2019), has been suggested to occur without conscious awareness 

(Kiefer et al., 2011), although this notion is also controversial (Peters et al., 2017). For 

example, disrupted primary visual cortex function in blindsight patients (see Leopold, 2012 

for review) or in neurologically healthy individuals with non-invasive brain stimulation 

(Boyer et al., 2005) can abolish the conscious experience of visual perception while 

preserving some ability to respond to visual stimuli.  

More direct evidence for unconscious mental imagery is currently scarce, possibly 

due to assumptions about the nature of mental imagery. However, Kwok et al. (2019) 

recently showed that both the active imagining and successful imagery suppression of visual 

stimuli results in comparable levels of binocular rivalry priming in typical imagers. Critically, 

Kwok et al. showed the perceptual presentation of an irrelevant neutral luminous stimulus 

during active imagery and imagery suppression, which should interfere only with imagery-

based priming in the active imagery condition, also affected priming in the imagery 

suppression condition. Using a similar imagery suppression paradigm, Koenig-Robert & 

Pearson (2020) were further able to decode the content of mental imagery using multivoxel 

pattern analysis visual brain areas despite subjects reporting successful imagery suppression. 

In another study using the same analytical methods, both the contents and vividness of mental 

imagery could be decoded from activity patterns in primary visual cortex up to 11 seconds 

before making conscious mental imagery-based judgements (Koenig-Robert & Pearson, 

2019). Finally, Weber et al. (2023) found that working memory-related visual information is 

represented similarly in the early visual cortex of both strong and weak imagers including in 

a subset of participants classed as aphantasic. 



 

Consistent with the interpretation of unconscious mental imagery, some of the current 

aphantasic participants (n = 4) remarked on the surprising ease with which they completed 

the object and/or spatial memory components of the task, despite not being able to say how 

they did so. Other aphantasic participants (n = 7) could describe the strategies they used, 

which included verbal or symbolic strategies (e.g., verbally encoding the colour of objects or 

assigning object positions to numbers on a clockface), but these strategies did not differ from 

those used by control participants. Moreover, exploratory correlation analyses revealed no 

significant relationship between object memory vividness ratings and performance in the 

aphantasic participants. Further exploratory analysis likewise revealed no such relationship in 

the subset of aphantasics who rated their general memory vividness above floor (vividness >= 

10), although a significant correlation between spatial memory vividness and performance 

did emerge in that subgroup. However, the strongest evidence indicating unconscious mental 

imagery in these aphantasics comes from the high level of precision of their object memory, 

which was comparable to that of the control participants. While alternative strategy use has 

been favoured in previous studies as an explanation for unimpaired performance on tasks 

thought to require mental imagery by aphantasics (Jacobs et al., 2018; Keogh et al., 2021; 

Zeman et al., 2010), none until now have used probabilistic mixture modelling to investigate 

the visual fidelity of their memory representations, which should be particularly sensitive to 

the strength of visual imagery. Alternative probabilistic mixture models to the one used here 

can be applied to continuous report data (e.g., Bays, 2014), but two-component models 

describe this type of data well and have previously been used to separate long-term memory 

retrieval success and precision (Brady et al., 2013; Cooper et al., 2017, 2019; Harlow & 

Yonelinas, 2016; Korkki et al., 2020, 2023; Richter et al., 2016; Stevenson et al., 2018; 

Sutterer & Awh, 2016). Moreover, it should be noted that the current results did not change 

when a model-free measure of object memory performance, raw angular colour deviation, 

was analysed. Thus, the present data is among the first to show high-fidelity visual 

representations may be intact and support episodic memory in some aphantasics, apparently 

without their conscious awareness.  

Many individuals with aphantasia report experiencing involuntary mental imagery, 

either as flashes during wakefulness or during dreaming (Dawes et al., 2020; Milton et al., 

2021; Palermo et al., 2022; Zeman et al., 2015, 2020), making the separation of involuntary 

and unconscious mental imagery a challenge. Moreover, the VVIQ typically used to identify 

aphantasia explicitly requires respondents to intentionally generate mental images and thus 



 

fails to distinguish those who can form involuntary unconscious mental imagery. Tasks 

involving the intentional generation of imagery may obscure this latent capacity in some 

aphantasics. Indeed, aphantasics have been shown to perform normally on imagery-based 

visual working memory tasks when instructed to “retrieve” rather than “imagine” object 

features (Jacobs et al., 2018), similar to how the current participants were instructed to 

remember object and spatial features. At surface, this view is harder to reconcile with 

frequent reports made by aphantasics of presumably imagery-related deficits in ABM, the 

contents of which are often spontaneously recalled (Berntsen, 2021). These differences might 

reflect the way ABM is probed, which sometimes involves the intentional recall of specific 

events (e.g., Dawes et al., 2020, 2022). However, aphantasics also report deficits on the SAM 

questionnaire, which assesses ABM more generally, and indicate less frequent involuntary 

memory intrusions than typical imagers (Dawes et al., 2020). Finally, it should be cautioned 

that individuals may generally be less willing or confident to report conscious imagery that is 

weak or dim because it is near the threshold for consciousness (Deroy, 2020). While the 

debate over the precise nature of aphantasia is far from resolved, the condition may be best 

characterised by differences in imagery phenomenology rather than capability. However, 

future studies of aphantasia should endeavour to include an objective measure of mental 

imagery (e.g., Kay et al., 2022; Keogh & Pearson, 2018; Wicken et al., 2021).  

Finally, concerning episodic memory more generally, the greater precision of first-

person versus third-person object memory retrieval in both imagery groups is intriguing. This 

difference was not significant when raw object memory errors or overall retrieval success 

were analysed separately, suggesting a first-person perspective might specifically enhance the 

fidelity of episodic memory retrieval. While the overall level of vividness for spatial memory 

features was lower than that for object memory features, and further exploratory correlation 

analysis revealed both first-person and third-person object memory recall performance to be 

significantly related to vividness ratings in the control participants with normal imagery 

awareness, this relationship was comparatively stronger for object features studied in first 

person. By contrast, the same relationship for spatial memory features was significant for all 

trial types, except for those studied and tested in a first-person perspective (i.e., stay first 

person trials). This pattern of correlations for the spatial memory component of the task may 

be due to stay first person trials reflecting egocentric spatial representations in their purest 

form, which may lead to worse spatial memory performance and less vivid spatial recall in 

comparison to allocentric representations. When considered together, these results suggest 



 

that episodic memory reliving may be promoted more by the greater quality representations 

of scene contents formed when experienced in first person, rather than by a first-person 

(egocentric) perspective on its own. This interpretation is broadly consistent with that of 

Aydin (2018), who suggested object imagery to be recruited in ABM tasks requiring self-

reflective processing, whereas spatial imagery might support direct retrieval of episodic 

details. However, further work is needed to disentangle the relative contributions of object 

versus spatial imagery as well as retrieval perspective to subjective episodic memory re-

experiencing.  

To conclude, this study is among the first to investigate episodic memory in 

aphantasics using objective and subjective measures. A novel 3D object and spatial memory 

task that manipulated visuospatial perspective was employed, but no evidence for impairment 

in either aspect of memory was found. This adds to recently emerging evidence for one 

possible subtype of aphantasia (among potentially many) in which mental imagery may be 

intact and support accurate task performance without conscious awareness (see also Pounder 

et al., 2022). However, further research is required to distinguish metacognitive/introspective 

and disconnection accounts of aphantasia, which differ in the proposed mechanisms by which 

phenomenal imagery may be lost (Lorenzatti, 2023). More work is also needed to address the 

possibly heterogenous nature of the condition, although the study of individuals with atypical 

imagery experience and/or ability offers the promise of gaining further important insights into 

the factors necessary for subjective episodic memory re-experiencing (Simons et al., 2022; 

Zaman & Russell, 2022). Finally, further work should endeavour to systematically rule out 

the potential confound of alternative strategy use by aphantasics on putatively imagery-based 

tasks. 

 

 

 

 

 

 

 



 

Data Availability 

Anonymized data will be made openly available on acceptance.  

 

Author Contributions 

Michael Siena: Conceptualization; Methodology; Software; Formal analysis; Investigation; 

Data curation; Writing – Original draft, Visualization, Project administration. Jon Simons: 

Conceptualization; Supervision; Writing – Review & editing; Funding acquisition. 

 

Acknowledgements 

We are grateful to the funders of this work as well as the research subjects who took part in it. 

We would also like to thank the reviewers of this manuscript for their helpful comments and 

suggestions. For the purpose of open access, the author has applied a Creative Commons 

Attribution (CC BY) licence to any Author Accepted Manuscript version arising from this 

submission. 

 

Funding Information 

This research was carried out within the University of Cambridge Behavioural and Clinical 

Neuroscience Institute, funded by a joint award from the Medical Research Council and the 

Wellcome Trust. 

 

 

 

 

 

 

 



 

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