Quantifying aphantasia through drawing: Those without visual imagery show deficits in object but not spatial memory

Episodic memory without autonoetic consciousness

Ever since Tulving's influential 1985 article 'Memory and consciousness', it has become traditional to think of autonoetic consciousness as necessary for episodic memory. This paper questions this claim. Specifically, it argues that the construct of autonoetic consciousness lacks validity and that, even if it was valid, it would still not be necessary for episodic memory. The paper ends with a proposal to go back to a functional/computational characterization of episodic memory in which its characteristic phenomenology is a contingent feature of the retrieval process and, as a result, open to empirical scrutiny. The proposal also dovetails with recent taxonomies of memory that are independent of conscious awareness and suggests strategies to evaluate within- and between-individual variability in the conscious experience of episodic memories in human and non-human agents. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

Non-visual spatial strategies are effective for maintaining precise information in visual working memory

Visual working memory content is commonly thought to be composed of a precise visual representation of stimulus information (e.g., color, shape). Nevertheless, previous research has shown that individuals represent this visual information in different formats, historically dichotomized into "verbal" and "visual" formats. With growing popular knowledge of aphantasia, or the absence of sensory mental imagery, recent studies have demonstrated that individuals with aphantasia perform similarly to individuals with typical imagery on visual working memory tasks. This suggest that the use of non-visual strategies may be sufficient to perform visual working memory tasks, which were previously thought to be strictly visual. To investigate the effects of different strategies on performance in a visual working memory task, we recruited individuals across the visual imagery spectrum and tested their ability to identify relatively small (3°), medium (6°), or large (10°) changes in the degree of orientation of gratings held in working memory. Subsequently, participants indicated the extent to which they used five different strategies: visual, spatial, verbal, semantic, and sensorimotor. Results revealed that individuals with aphantasia and typical imagery performed similarly to each other across all task difficulty levels. Individuals with typical imagery dominantly used visuospatial strategies, but surprisingly, individuals with aphantasia overwhelmingly preferred the use of non-visual spatial and sensorimotor strategies over verbal strategies. These results suggest that non-visual spatial and sensorimotor strategies can be adopted in visual working memory tasks and these strategies are equally effective as visuospatial strategies. This calls for a rethinking of the "visual" versus "verbal" dichotomy, and provides evidence for the use of other non-visual mental representations in working memory tasks.

Aphantasia and autism: An investigation of mental imagery vividness

OBJECTIVE

The present study investigated whether autistic adults report different levels of mental imagery vividness than non-autistic adults, and, moreover, if autism is associated with aphantasia which is defined as a condition of reduced or absent voluntary imagery.

DESIGN AND METHODS

Clinically diagnosed and self-identifying autistic participants were compared with non-autistic participants in their mental imagery vividness (vision, sound, smell, taste, touch, bodily sensation and emotional feeling) and autistic traits using an online survey (N = 121).

RESULTS

The autistic group scored significantly lower than the non-autistic group on imagery vividness (d = -0.44), in addition to having a higher proportion of participants scoring at cut-off for aphantasia. Moreover, a similar difference was observed for the emotional feel (η2 = 0.11).

CONCLUSION

The vividness of visual and emotional mental imagery was on average lower for autistic individuals, with a higher proportion presenting at cut-off to be considered an aphantasic.

Phantasia, aphantasia, and hyperphantasia: Empirical data and conceptual considerations

Within the past decade, the term "phantasia" has been increasingly used to describe the human capacity, faculty, or power of visual mental imagery, with extremes of imagery vividness characterised as "aphantasia" and "hyperphantasia". A substantial volume of empirical research addressing these constructs has now been published, including attempts to find inductive correlates of behaviourally defined aphantasia, for example using research questionnaires and functional magnetic resonance imaging. Mental imagery has long been noted as a source of conceptual confusions but no specific conceptual analysis of the new formulation of phantasia, aphantasia, and hyperphantasia has been undertaken hitherto. We offer some conceptual considerations on phantasia, noting the ongoing confusion of perceptual with mental images, and the ubiquitous use of unvalidated subjective assessment instruments such as the Vividness of Visual Imagery Questionnaire (VVIQ) in diagnosis and assessment, development of which was predicated on these conceptual confusions. We offer some suggestions for a conceptual framework for future empirical studies in this field, circumventing these conceptual confusions.

Visual free recall and recognition in art students and laypeople

Artists and laypeople differ in their ability to create drawings. Previous research has shown that artists have improved memory performance during drawing; however, it is unclear whether they have better visual memory after the drawing is finished. In this paper, we focused on the question of differences in visual memory between art students and the general population in two studies. In Study 1, both groups studied a set of images and later drew them in a surprise visual recall test. In Study 2, the drawings from Study 1 were evaluated by a different set of raters based on their drawing quality and similarity to the original image to link drawing evaluations with memory performance for both groups. We found that both groups showed comparable visual recognition memory performance; however, the artist group showed increased recall memory performance. Moreover, they produced drawings that were both better quality and more similar to the original image. Individually, participants whose drawings were rated as better showed higher recognition accuracy. Results from Study 2 also have practical implications for the usage of drawing as a tool for measuring free recall - the majority of the drawings were recognizable, and raters showed a high level of consistency during their evaluation of the drawings. Taken together, we found that artists have better visual recall memory than laypeople.

Metacognitive Awareness and the Subjective Experience of Remembering in Aphantasia

Individuals with aphantasia, a nonclinical condition typically characterized 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 3-D 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. In addition, 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.

Ocular working memory signals are flexible to behavioral priority and subjective imagery strength

The pupillary light response was long considered a brainstem reflex, outside of cognitive influence. However, newer findings indicate that pupil dilation (and eye movements) can reflect content held "in mind" with working memory (WM). These findings may reshape understanding of ocular and WM mechanisms, but it is unclear whether the signals are artifactual or functional to WM. Here, we ask whether peripheral and oculomotor WM signals are sensitive to the task-relevance or "attentional state" of WM content. During eye-tracking, human participants saw both dark and bright WM stimuli, then were retroactively cued to the item that would most likely be tested. Critically, we manipulated the attentional priority among items by varying the cue reliability across blocks. We confirmed previous findings that remembering darker items is associated with larger pupils (vs. brighter), and that gaze is biased toward cued item locations. Moreover, we discovered that pupil and eye movement responses were influenced differently by WM item relevance. Feature-specific pupillary effects emerged only for highly prioritized WM items but were eliminated when cues were less reliable, and pupil effects also increased with self-reported visual imagery strength. Conversely, gaze position consistently veered toward the cued item location, regardless of cue reliability. However, biased microsaccades occurred at a higher frequency when cues were more reliable, though only during a limited post-cue time window. Therefore, peripheral sensorimotor processing is sensitive to the task-relevance or functional state of internal WM content, but pupillary and eye movement WM signals show distinct profiles. These results highlight a potential role for early visual processing in maintaining multiple WM content dimensions.NEW & NOTEWORTHY Here, we found that working memory (WM)-driven ocular inflections-feature-specific pupillary and saccadic biases-were muted for memory items that were less behaviorally relevant. This work illustrates that functionally informative goal signals may extend as early as the sensorimotor periphery, that pupil size may be under more fine-grained control than originally thought, and that ocular signals carry multiple dimensions of cognitively relevant information.

Taking consciousness for real: Increasing the ecological validity of the study of conscious vs. unconscious processes

The study of consciousness has developed well-controlled, rigorous methods for manipulating and measuring consciousness. Yet, in the process, experimental paradigms grew farther away from everyday conscious and unconscious processes, which raises the concern of ecological validity. In this review, we suggest that the field can benefit from adopting a more ecological approach, akin to other fields of cognitive science. There, this approach challenged some existing hypotheses, yielded stronger effects, and enabled new research questions. We argue that such a move is critical for studying consciousness, where experimental paradigms tend to be artificial and small effect sizes are relatively prevalent. We identify three paths for doing so-changing the stimuli and experimental settings, changing the measures, and changing the research questions themselves-and review works that have already started implementing such approaches. While acknowledging the inherent challenges, we call for increasing ecological validity in consciousness studies.

Cognitive strengths in neurodevelopmental disorders, conditions and differences: A critical review

Neurodevelopmental disorders are traditionally characterised by a range of associated cognitive impairments in, for example, sensory processing, facial recognition, visual imagery, attention, and coordination. In this critical review, we propose a major reframing, highlighting the variety of unique cognitive strengths that people with neurodevelopmental differences can exhibit. These include enhanced visual perception, strong spatial, auditory, and semantic memory, superior empathy and theory of mind, along with higher levels of divergent thinking. Whilst we acknowledge the heterogeneity of cognitive profiles in neurodevelopmental conditions, we present a more encouraging and affirmative perspective of these groups, contrasting with the predominant, deficit-based position prevalent throughout both cognitive and neuropsychological research. In addition, we provide a theoretical basis and rationale for these cognitive strengths, arguing for the critical role of hereditability, behavioural adaptation, neuronal-recycling, and we draw on psychopharmacological and social explanations. We present a table of potential strengths across conditions and invite researchers to systematically investigate these in their future work. This should help reduce the stigma around neurodiversity, instead promoting greater social inclusion and significant societal benefits.

Slower but more accurate mental rotation performance in aphantasia linked to differences in cognitive strategies

Mental rotation tasks are frequently used as standard measures of mental imagery. However, aphantasia research has brought such use into question. Here, we assessed a large group of individuals who lack visual imagery (aphantasia) on two mental rotation tasks: a three-dimensional block-shape, and a human manikin rotation task. In both tasks, those with aphantasia had slower, but more accurate responses than controls. Both groups demonstrated classic linear increases in response time and error-rate as functions of angular disparity. In the three-dimensional block-shape rotation task, a within-group speed-accuracy trade-off was found in controls, whereas faster individuals in the aphantasia group were also more accurate. Control participants generally favoured using object-based mental rotation strategies, whereas those with aphantasia favoured analytic strategies. These results suggest that visual imagery is not crucial for successful performance in classical mental rotation tasks, as alternative strategies can be effectively utilised in the absence of holistic mental representations.

Aphantasia and hyperphantasia: exploring imagery vividness extremes

The vividness of imagery varies between individuals. However, the existence of people in whom conscious, wakeful imagery is markedly reduced, or absent entirely, was neglected by psychology until the recent coinage of 'aphantasia' to describe this phenomenon. 'Hyperphantasia' denotes the converse - imagery whose vividness rivals perceptual experience. Around 1% and 3% of the population experience extreme aphantasia and hyperphantasia, respectively. Aphantasia runs in families, often affects imagery across several sense modalities, and is variably associated with reduced autobiographical memory, face recognition difficulty, and autism. Visual dreaming is often preserved. Subtypes of extreme imagery appear to be likely but are not yet well defined. Initial results suggest that alterations in connectivity between the frontoparietal and visual networks may provide the neural substrate for visual imagery extremes.

Vision matters for shape representation: Evidence from sculpturing and drawing in the blind

Shape is a property that could be perceived by vision and touch, and is classically considered to be supramodal. While there is mounting evidence for the shared cognitive and neural representation space between visual and tactile shape, previous research tended to rely on dissimilarity structures between objects and had not examined the detailed properties of shape representation in the absence of vision. To address this gap, we conducted three explicit object shape knowledge production experiments with congenitally blind and sighted participants, who were asked to produce verbal features, 3D clay models, and 2D drawings of familiar objects with varying levels of tactile exposure, including tools, large nonmanipulable objects, and animals. We found that the absence of visual experience (i.e., in the blind group) led to stronger differences in animals than in tools and large objects, suggesting that direct tactile experience of objects is essential for shape representation when vision is unavailable. For tools with rich tactile/manipulation experiences, the blind produced overall good shapes comparable to the sighted, yet also showed intriguing differences. The blind group had more variations and a systematic bias in the geometric property of tools (making them stubbier than the sighted), indicating that visual experience contributes to aligning internal representations and calibrating overall object configurations, at least for tools. Taken together, the object shape representation reflects the intricate orchestration of vision, touch and language.

Deep Aphantasia: a visual brain with minimal influence from priors or inhibitory feedback?

The authors are both self-described congenital aphantasics, who feel they have never been able to have volitional imagined visual experiences during their waking lives. In addition, Loren has atypical experiences of a number of visual phenomena that involve an extrapolation or integration of visual information across space. In this perspective, we describe Loren's atypical experiences of a number of visual phenomena, and we suggest these ensue because her visual experiences are not strongly shaped by inhibitory feedback or by prior expectations. We describe Loren as having Deep Aphantasia, and Derek as shallow, as for both a paucity of feedback might prevent the generation of imagined visual experiences, but for Loren this additionally seems to disrupt activity at a sufficiently early locus to cause atypical experiences of actual visual inputs. Our purpose in describing these subjective experiences is to alert others to the possibility of there being sub-classes of congenital aphantasia, one of which-Deep Aphantasia, would be characterized by atypical experiences of actual visual inputs.

No clear evidence of a difference between individuals who self-report an absence of auditory imagery and typical imagers on auditory imagery tasks

Aphantasia is characterised by the inability to create mental images in one's mind. Studies investigating impairments in imagery typically focus on the visual domain. However, it is possible to generate many different forms of imagery including imagined auditory, kinesthetic, tactile, motor, taste and other experiences. Recent studies show that individuals with aphantasia report a lack of imagery in modalities, other than vision, including audition. However, to date, no research has examined whether these reductions in self-reported auditory imagery are associated with decrements in tasks that require auditory imagery. Understanding the extent to which visual and auditory imagery deficits co-occur can help to better characterise the core deficits of aphantasia and provide an alternative perspective on theoretical debates on the extent to which imagery draws on modality-specific or modality-general processes. In the current study, individuals that self-identified as being aphantasic and matched control participants with typical imagery performed two tasks: a musical pitch-based imagery and voice-based categorisation task. The majority of participants with aphantasia self-reported significant deficits in both auditory and visual imagery. However, we did not find a concomitant decrease in performance on tasks which require auditory imagery, either in the full sample or only when considering those participants that reported significant deficits in both domains. These findings are discussed in relation to the mechanisms that might obscure observation of imagery deficits in auditory imagery tasks in people that report reduced auditory imagery.

Aphantasia and involuntary imagery

Aphantasia is a condition that is often characterized as the impaired ability to create voluntary mental images. Aphantasia is assumed to selectively affect voluntary imagery mainly because even though aphantasics report being unable to visualize something at will, many report having visual dreams. We argue that this common characterization of aphantasia is incorrect. Studies on aphantasia are often not clear about whether they are assessing voluntary or involuntary imagery, but some studies show that several forms of involuntary imagery are also affected in aphantasia (including imagery in dreams). We also raise problems for two attempts to show that involuntary images are preserved in aphantasia. In addition, we report the results of a study about afterimages in aphantasia, which suggest that these tend to be less intense in aphantasics than in controls. Involuntary imagery is often treated as a unitary kind that is either present or absent in aphantasia. We suggest that this approach is mistaken and that we should look at different types of involuntary imagery case by case. Doing so reveals no evidence of preserved involuntary imagery in aphantasia. We suggest that a broader characterization of aphantasia, as a deficit in forming mental imagery, whether voluntary or not, is more appropriate. Characterizing aphantasia as a volitional deficit is likely to lead researchers to give incorrect explanations for aphantasia, and to look for the wrong mechanisms underlying it.

No verbal overshadowing in aphantasia: The role of visual imagery for the verbal overshadowing effect

The verbal overshadowing effect refers to the phenomenon that the verbal description of a past complex stimulus impairs its subsequent recognition. Theoretical explanations range from interference between different mental representations to the activation of different processing orientations or a provoked shift in the recognition criterion. In our study, 61 participants with aphantasia (= lack of mental imagery) and 70 controls participated in a verbal overshadowing paradigm. The verbal overshadowing effect did not occur in people with aphantasia, although the effect was replicated in controls. We speculate that this is either due to the lack of visual representations in people with aphantasia that verbal descriptions could interfere with, or to the absence of a shift in processing orientation during verbalisation. To rule out criterion-based explanations, further research is needed to distinguish between discriminability and response bias in people with aphantasia. Finally, data indicated that the verbal overshadowing effect may even be reversed in individuals with aphantasia, partly due to a lower memory performance in the no verbalisation condition. Effects of further variables are discussed, such as mental strategies, memory confidence, and difficulty, quantity and quality of verbalisation.

Revisiting the blind mind: Still no evidence for sensory visual imagery in individuals with aphantasia

The inability to visualise was given the name aphantasia in 2015 by Zeman and colleagues. In 2018 we published research showing that fifteen individuals who self-identified as having aphantasia also demonstrated a lack of sensory visual imagery when undergoing the binocular rivalry imagery paradigm, suggesting more than just a metacognitive difference. Here we update these findings with over fifty participants with aphantasia and show that there is evidence for a lack of sensory imagery in aphantasia. How the binocular rivalry paradigm scores relate to the vividness of visual imagery questionnaire (VVIQ) and how aphantasia can be confirmed is discussed.

Working memory signals in early visual cortex are present in weak and strong imagers

It has been suggested that visual images are memorized across brief periods of time by vividly imagining them as if they were still there. In line with this, the contents of both working memory and visual imagery are known to be encoded already in early visual cortex. If these signals in early visual areas were indeed to reflect a combined imagery and memory code, one would predict them to be weaker for individuals with reduced visual imagery vividness. Here, we systematically investigated this question in two groups of participants. Strong and weak imagers were asked to remember images across brief delay periods. We were able to reliably reconstruct the memorized stimuli from early visual cortex during the delay. Importantly, in contrast to the prediction, the quality of reconstruction was equally accurate for both strong and weak imagers. The decodable information also closely reflected behavioral precision in both groups, suggesting it could contribute to behavioral performance, even in the extreme case of completely aphantasic individuals. Our data thus suggest that working memory signals in early visual cortex can be present even in the (near) absence of phenomenal imagery.

Drawings reveal changes in object memory, but not spatial memory, across time

Time has an immense influence on our memory. Truncated encoding leads to memory for only the 'gist' of an image, and long delays before recall result in generalized memories with few details. Here, we used crowdsourced scoring of hundreds of drawings made from memory after variable encoding (Experiment 1) and retentions of that memory (Experiment 2) to quantify what features of memory content change across time. We found that whereas some features of memory are highly dependent on time, such as the proportion of objects recalled from a scene and false recall for objects not in the original image, spatial memory was highly accurate and relatively independent of time. We also found that we could predict which objects were recalled across time based on the location, meaning, and saliency of the objects. The differential impact of time on object and spatial memory supports a separation of these memory systems.

Mental imagery and visual attentional templates: A dissociation

There is a growing interest in the relationship between mental images and attentional templates as both are considered pictorial representations that involve similar neural mechanisms. Here, we investigated the role of mental imagery in the automatic implementation of attentional templates and their effect on involuntary attention. We developed a novel version of the contingent capture paradigm designed to encourage the generation of a new template on each trial and measure contingent spatial capture by a template-matching visual feature (color). Participants were required to search at four different locations for a specific object indicated at the start of each trial. Immediately prior to the search display, color cues were presented surrounding the potential target locations, one of which matched the target color (e.g., red for strawberry). Across three experiments, our task induced a robust contingent capture effect, reflected by faster responses when the target appeared in the location previously occupied by the target-matching cue. Contrary to our predictions, this effect remained consistent regardless of self-reported individual differences in visual mental imagery (Experiment 1, N = 216) or trial-by-trial variation of voluntary imagery vividness (Experiment 2, N = 121). Moreover, contingent capture was observed even among aphantasic participants, who report no imagery (Experiment 3, N = 91). The magnitude of the effect was not reduced in aphantasics compared to a control sample of non-aphantasics, although the two groups reported substantial differences in their search strategy and exhibited differences in overall speed and accuracy. Our results hence establish a dissociation between the generation and implementation of attentional templates for a visual feature (color) and subjectively experienced imagery.

The role of visual imagery in face recognition and the construction of facial composites. Evidence from Aphantasia

People with aphantasia have a markedly impaired ability to form visual images in the mind's eye. Here, by testing people with and without aphantasia, we examine the relationship between visual imagery and face processing. We show that aphantasics have weaker face recognition than people with visual imagery, using both self-report (Prosopagnosia Index) and behavioural measures (Cambridge Face Memory Test). However, aphantasics nonetheless have a fully intact ability to construct facial composites from memory (i.e., composites produced using EFIT6 by aphantasics and imagers were rated as equally accurate in terms of their resemblance to a target face). Additionally, we show that aphantasics were less able than imagers to see the resemblance between composites and a target face, suggestive of potential issues with face matching (perception). Finally, we show that holistic and featural methods of composite construction using EFIT6 produce equally accurate composites. Our results suggest that face recognition, but not face composite construction, is facilitated by the ability to represent visual properties as 'pictures in the mind'. Our findings have implications for the study of aphantasia, and also for forensic settings, where face composite systems are commonly used to aid criminal investigations.

Real-world implications of aphantasia: episodic recall of eyewitnesses with aphantasia is less complete but no less accurate than typical imagers

Individuals with aphantasia report an inability to voluntarily visually image and reduced episodic memory, yet episodic accounts provided by witnesses and victims are fundamental for criminal justice. Using the mock-witness paradigm, we investigated eyewitness memory of individuals with aphantasia versus typical imagers. Participants viewed a mock crime and 48 hours later were interviewed about the event, randomly allocated to one of three conditions. Two interview conditions included techniques designed to support episodic retrieval mode, namely (i) Mental Reinstatement of Context (MRC) and (ii) Sketch Reinstatement of Context (Sketch-RC). A third Control condition did not include retrieval support. Aphantasic mock-eyewitnesses recalled 30% less correct information and accounts were less complete, but they made no more errors and were as accurate as typical imagers. Interaction effects revealed reduced correct recall and less complete accounts for aphantasic participants in MRC interviews versus Sketch-RC and Control. Aphantaisic participants in the Control outperformed those in both the Sketch-RC and MRC, although Sketch-RC improved completeness by 15% versus MRC. Our pattern of results indicates reduced mental imagery ability might be compensated for by alternative self-initiated cognitive strategies. Findings offer novel insights into episodic recall performance in information gathering interviews when ability to voluntarily visualize is impoverished.

Drawing as a versatile cognitive tool

Drawing is a cognitive tool that makes the invisible contents of mental life visible. Humans use this tool to produce a remarkable variety of pictures, from realistic portraits to schematic diagrams. Despite this variety and the prevalence of drawn images, the psychological mechanisms that enable drawings to be so versatile have yet to be fully explored. In this Review, we synthesize contemporary work in multiple areas of psychology, computer science and neuroscience that examines the cognitive processes involved in drawing production and comprehension. This body of findings suggests that the balance of contributions from perception, memory and social inference during drawing production varies depending on the situation, resulting in some drawings that are more realistic and other drawings that are more abstract. We also consider the use of drawings as a research tool for investigating various aspects of cognition, as well as the role that drawing has in facilitating learning and communication. Taken together, information about how drawings are used in different contexts illuminates the central role of visually grounded abstractions in human thought and behaviour.

Probing the unimaginable: The impact of aphantasia on distinct domains of visual mental imagery and visual perception

Different individuals experience varying degrees of vividness in their visual mental images. The distribution of these variations across different imagery domains, such as object shape, color, written words, faces, and spatial relationships, remains unknown. To address this issue, we conducted a study with 117 healthy participants who reported different levels of imagery vividness. Of these participants, 44 reported experiencing absent or nearly absent visual imagery, a condition known as "aphantasia". These individuals were compared to those with typical (N = 42) or unusually vivid (N = 31) imagery ability. We used an online version of the French-language Battérie Imagination-Perception (eBIP), which consists of tasks tapping each of the above-mentioned domains, both in visual imagery and in visual perception. We recorded the accuracy and response times (RTs) of participants' responses. Aphantasic participants reached similar levels of accuracy on all tasks compared to the other groups (Bayesian repeated measures ANOVA, BF = .02). However, their RTs were slower in both imagery and perceptual tasks (BF = 266), and they had lower confidence in their responses on perceptual tasks (BF = 7.78e5). A Bayesian regression analysis revealed that there was an inverse correlation between subjective vividness and RTs for the entire participant group: higher levels of vividness were associated with faster RTs. The pattern was similar in all the explored domains. The findings suggest that individuals with congenital aphantasia experience a slowing in processing visual information in both imagery and perception, but the precision of their processing remains unaffected. The observed performance pattern lends support to the hypotheses that congenital aphantasia is primarily a deficit of phenomenal consciousness, or that it employs alternative strategies other than visualization to access preserved visual information.

Feedback signals in visual cortex during episodic and schematic memory retrieval and their potential implications for aphantasia

Recent findings indicate that visual feedback derived from episodic memory can be traced down to the earliest stages of visual processing, whereas feedback stemming from schema-related memories only reach intermediate levels in the visual processing hierarchy. In this opinion piece, we examine these differences in light of the 'what' and 'where' streams of visual perception. We build upon this new framework to propose that the memory deficits observed in aphantasics might be better understood as a difference in high-level feedback processing along the 'what' stream, rather than an episodic memory impairment.

Assessing aphantasia prevalence and the relation of self-reported imagery abilities and memory task performance

Aphantasia is the experience of having little to no visual imagery. We assessed the prevalence rate of aphantasia in 5,010 people from the general population of adults in the United States through self-report and responses to two visual imagery scales. The self-reported prevalence rate of aphantasia was 8.9% in this sample. However, not all participants who reported themselves as aphantasic showed low-imagery profiles on the questionnaire scales, and scale prevalence was much lower (1.5%). Self-reported aphantasic individuals reported lower dream frequencies and self-talk and showed poorer memory performance compared to individuals who reported average and high mental imagery. Self-reported aphantasic individuals showed a greater preference for written instruction compared to video instruction for learning a hypothetical new task although there were differences for men and women in this regard. Categorizing aphantasia using a scale measure and relying on self-identification may provide a more consistent picture of who lacks visual imagery.

Diversity of aphantasia revealed by multiple assessments of visual imagery, multisensory imagery, and cognitive style

Aphantasia-a condition wherein individuals have a reduced or absent construction of voluntary visual imagery-is diagnosed using either the Vividness of Visual Imagery Questionnaire (VVIQ) or self-identification. However, a significant discrepancy exists between the proportions of aphantasia in the populations assessed using these two criteria. It is unclear why the reported proportions differ excessively and what percentage of people cannot form visual imagery. We investigated the replicability of the proportion of people with aphantasia using both criteria in the same population of participants. Therefore, we explored the potential causes of the discrepancy and characteristics of putative aphantasia in terms of multisensory imagery, cognitive style, and face recognition ability. First, we conducted an online sampling study (Study 1: N = 2,871) using the VVIQ, self-identification of a reduction in visual imagery, Questionnaire upon Mental Imagery (QMI), and Verbalizer-Visualizer Questionnaire (VVQ). We found that 3.7 and 12.1% fulfilled the VVIQ and self-identification criteria, respectively, roughly replicating the proportions reported in previous studies. The self-identification criterion-but not the VVIQ criterion-contains items related to face recognition; hence, we suspected that face recognition ability was factor contributing to this discrepancy and conducted another online sampling study (Study 2: N = 774). We found a significant correlation between VVIQ and face recognition ability in the control group with self-identification, but not in the group defined by low VVIQ (VVIQ ≤32). As the participants in the control group with self-identification tended to exhibit moderately high VVIQ scores but low face recognition ability, we reason that the discrepancy can be partially explained by the contamination of individual differences in face recognition ability. Additional analyses of Study 1 revealed that the aphantasia group included participants who lacked all types of sensory imagery or only visual imagery in multisensory imagery and exhibited a non-specific cognitive style. This study indicates that the VVIQ alone may be insufficient to diagnose individuals who report an inability to form visual imagery. Furthermore, we highlight the importance of multiple assessments-along with the VVIQ-to better understand the diversity of imagery in aphantasia.

Visuo-spatial imagery in dreams of congenitally and early blind: a systematic review

Background

The presence of visual imagery in dreams of congenitally blind people has long been a matter of substantial controversy. We set to systematically review body of published work on the presence and nature of oneiric visuo-spatial impressions in congenitally and early blind subjects across different areas of research, from experimental psychology, functional neuroimaging, sensory substitution, and sleep research.

Methods

Relevant studies were identified using the following databases: EMBASE, MEDLINE and PsychINFO.

Results

Studies using diverse imaging techniques and sensory substitution devices broadly suggest that the "blind" occipital cortex may be able to integrate non-visual sensory inputs, and thus possibly also generate visuo-spatial impressions. Visual impressions have also been reported by blind subjects who had near-death or out-of-body experiences.

Conclusion

Deciphering the mechanistic nature of these visual impression could open new possibility in utilization of neuroplasticity and its potential role for treatment of neurodisability.

Imagined Timed Up and Go test (iTUG) in people with Parkinson's Disease: test-retest reliability and validity

PURPOSE

To determine the test-retest reliability and validity of the Imagined Timed Up and Go Test (iTUG) as a Motor Imagery measure of temporal accuracy in people with Parkinson's Disease (PD).

MATERIALS AND METHODS

A descriptive study was conducted following the GRRAS recommendations. Thirty-two people with idiopathic, mild to moderate PD (Hoehn and Yahr I-III), without cognitive impairment (MMSE ≥ 24), were assessed twice (7-15 days apart) with the iTUG. The absolute unadjusted difference in seconds, and the absolute adjusted difference as percentage of estimation error, between real and imagined TUG times, were calculated as outcome measures. Test-retest reliability was assessed using a two-way mixed-effects model of the ICC. Construct validity was tested with the Imagined Box and Blocks Test (iBBT) and convergent validity with clinical characteristics of PD, using the Spearman's rank correlation coefficient.

RESULTS

The ICC for the unadjusted and adjusted measures of the iTUG was ICC = 0.61 and ICC = 0.55, respectively. Correlations between iTUG and iBBT were not statistically significant. The iTUG was partially correlated to clinical characteristics of PD.

CONCLUSIONS

Test-retest reliability of the iTUG was moderate. Construct validity between iTUG and iBBT was poor, so caution should be taken when using them concurrently to assess imagery's temporal accuracy.

What about "space" is important for episodic memory?

Early cognitive neuroscientific research revealed that the hippocampus is crucial for spatial navigation in rodents, and for autobiographical episodic memory in humans. Researchers quickly linked these streams to propose that the human hippocampus supports memory through its role in representing space, and research on the link between spatial cognition and episodic memory in humans has proliferated over the past several decades. Different researchers apply the term "spatial" in a variety of contexts, however, and it remains unclear what aspect of space may be critical to memory. Similarly, "episodic" has been defined and tested in different ways. Naturalistic assessment of spatial memory and episodic memory (i.e., episodic autobiographical memory) is required to unify the scale and biological relevance in comparisons of spatial and mnemonic processing. Limitations regarding the translation of rodent to human research, human ontogeny, and inter-individual variability require greater consideration in the interpretation of this literature. In this review, we outline the aspects of space that are (and are not) commonly linked to episodic memory, and then we discuss these dimensions through the lens of individual differences in naturalistic autobiographical memory. Future studies should carefully consider which aspect(s) of space are being linked to memory within the context of naturalistic human cognition. This article is categorized under: Psychology > Memory.

The relationship between interactive-imagery instructions and association memory

Interactive imagery, one of the most effective strategies for remembering pairs of words, involves asking participants to form mental images during study. We tested the hypothesis that the visual image is, in fact, responsible for its memory benefit. Neither subjectively reported vividness (all experiments) nor objective imagery skill (experiments 1 and 3) could explain the benefit of interactive imagery for cued recall. Aphantasic participants, who self-identified little to no mental imagery, benefited from interactive-imagery instructions as much as controls (experiment 3). Imagery instructions did not improve memory for the constituent order of associations (AB versus BA), even when participants were told how to incorporate order within their images (experiments 1 and 2). Taken together, our results suggest that the visual format of images may not be responsible for the effectiveness of the interactive-imagery instruction and moreover, interactive imagery may not result in qualitatively different associative memories.

Is cognitive control of perception and action via attentional focus moderated by motor imagery?

Motor imagery (MI) has emerged as an individual factor that may modulate the effects of attentional focus on motor skill performance. In this study, we investigated whether global MI, as well as its components (i.e., kinesthetic MI, internal visual MI, and external visual MI) moderate the effect of attentional focus on performance in a group of ninety-two young adult novice air-pistol shooters (age: M = 21.87, SD = 2.54). After completing the movement imagery questionnaire-3 (MIQ-3), participants were asked to complete a pistol shooting experiment in three different attentional focus conditions: (1) No focus instruction condition (control condition with no verbal instruction) (2) an internal focus instruction condition, and (3) an external focus condition. Shot accuracy, performance time, and aiming trace speed (i.e., stability of hold or weapon stability) were measured as the performance variables. Results revealed that shot accuracy was significantly poorer during internal relative to control focus condition. In addition, performance time was significantly higher during external relative to both control and internal condition. However, neither global MI, nor its subscales, moderated the effects of attentional focus on performance. This study supports the importance of attentional focus for perceptual and motor performance, yet global MI and its modalities/perspectives did not moderate pistol shooting performance. This study suggests that perception and action are cognitively controlled by attentional mechanisms, but not motor imagery. Future research with complementary assessment modalities is warranted to extend the present findings.

Hidden Differences in Phenomenal Experience

In addition to the many easily observable differences between people, there are also differences in people's subjective experiences that are harder to observe, and which, as a consequence, remain hidden. For example, people vary widely in how much visual imagery they experience. But those who cannot see in their mind's eye, tend to assume everyone is like them. Those who can, assume everyone else can as well. We argue that a study of such hidden phenomenal differences has much to teach cognitive science. Uncovering and describing this variation (a search for unknown unknowns) may help predict otherwise puzzling differences in human behavior. The very existence of certain differences can also act as a stress test for some cognitive theories. Finally, studying hidden phenomenal differences is the first step toward understanding what kinds of environments may mask or unmask links between phenomenal experience and observable behavior.

Sustained neural representations of personally familiar people and places during cued recall

The recall and visualization of people and places from memory is an everyday occurrence, yet the neural mechanisms underpinning this phenomenon are not well understood. In particular, the temporal characteristics of the internal representations generated by active recall are unclear. Here, we used magnetoencephalography (MEG) and multivariate pattern analysis to measure the evolving neural representation of familiar places and people across the whole brain when human participants engage in active recall. To isolate self-generated imagined representations, we used a retro-cue paradigm in which participants were first presented with two possible labels before being cued to recall either the first or second item. We collected personalized labels for specific locations and people familiar to each participant. Importantly, no visual stimuli were presented during the recall period, and the retro-cue paradigm allowed the dissociation of responses associated with the labels from those corresponding to the self-generated representations. First, we found that following the retro-cue it took on average ∼1000 ms for distinct neural representations of freely recalled people or places to develop. Second, we found distinct representations of personally familiar concepts throughout the 4 s recall period. Finally, we found that these representations were highly stable and generalizable across time. These results suggest that self-generated visualizations and recall of familiar places and people are subserved by a stable neural mechanism that operates relatively slowly when under conscious control.

A generative adversarial model of intrusive imagery in the human brain

The mechanisms underlying the subjective experiences of mental disorders remain poorly understood. This is partly due to long-standing over-emphasis on behavioral and physiological symptoms and a de-emphasis of the patient's subjective experiences when searching for treatments. Here, we provide a new perspective on the subjective experience of mental disorders based on findings in neuroscience and artificial intelligence (AI). Specifically, we propose the subjective experience that occurs in visual imagination depends on mechanisms similar to generative adversarial networks that have recently been developed in AI. The basic idea is that a generator network fabricates a prediction of the world, and a discriminator network determines whether it is likely real or not. Given that similar adversarial interactions occur in the two major visual pathways of perception in people, we explored whether we could leverage this AI-inspired approach to better understand the intrusive imagery experiences of patients suffering from mental illnesses such as post-traumatic stress disorder (PTSD) and acute stress disorder. In our model, a nonconscious visual pathway generates predictions of the environment that influence the parallel but interacting conscious pathway. We propose that in some patients, an imbalance in these adversarial interactions leads to an overrepresentation of disturbing content relative to current reality, and results in debilitating flashbacks. By situating the subjective experience of intrusive visual imagery in the adversarial interaction of these visual pathways, we propose testable hypotheses on novel mechanisms and clinical applications for controlling and possibly preventing symptoms resulting from intrusive imagery.

Patterns of episodic content and specificity predicting subjective memory vividness

The ability to remember and internally represent events is often accompanied by a subjective sense of "vividness". Vividness measures are frequently used to evaluate the experience of remembering and imagining events, yet little research has considered the objective attributes of event memories that underlie this subjective judgment, and individual differences in this mapping. Here, we tested how the content and specificity of event memories support subjectively vivid recollection. Over three experiments, participants encoded events containing a theme word and three distinct elements - a person, a place, and an object. In a memory test, memory for event elements was assessed at two levels of specificity - semantic gist (names) and perceptual details (lure discrimination). We found a strong correspondence between memory vividness and memory for gist information that did not vary by which elements were contained in memory. There was a smaller, additive benefit of remembering specific perceptual details on vividness, which, in one study, was driven by memory for place details. Moreover, we found individual differences in the relationship between memory vividness and objective memory attributes primarily along the specificity dimension, such that one cluster of participants used perceptual detail to inform memory vividness whereas another cluster was more driven by gist information. Therefore, while gist memory appears to drive vividness on average, there were idiosyncrasies in this pattern across participants. When assessing subjective ratings of memory and imagination, research should consider how these ratings map onto objective memory attributes in the context of their study design and population.

Predictive processing and perception: What does imagining have to do with it?

Predictive processing (PP) accounts of perception are unique not merely in that they postulate a unity between perception and imagination, but in claiming that (i) perception should be conceptualised in terms of imagination and (ii) the two involve an identity of neural implementation. This paper argues against these claims, on both conceptual and empirical grounds. Conceptually, the manner in which PP theorists link perception and imagination belies an impoverished account of imagery as cloistered from the external world in its intentionality, akin to a virtual reality, as well as endogenously generated. Yet this ignores a whole class of imagery whose intentionality is directed on the actual environment-projected mental imagery-and also ignores the fact that imagery may be triggered crossmodally in a bottom-up, stimulus-driven way. Empirically, claiming that imagery and perception share neural circuitry ignores relevant clinical results in this area. These evidence substantial perception/imagery neural dissociations, most notably in the case of aphantasia. Taken together, the arguments here suggest that PP theorists should substantially temper, if not outright abandon, their claim to a perception/imagination unity.

Decreased associative processing and memory confidence in aphantasia

Visual imagery and mental reconstruction of scenes are considered core components of episodic memory retrieval. Individuals with absent visual imagery (aphantasia) score lower on tests of autobiographical memory, suggesting that aphantasia may be associated with differences in episodic and associative processing. In this online study, we tested aphantasic participants and controls on associative recognition and memory confidence for three types of associations encoded incidentally: associations between visual-visual and audio-visual stimulus pairs, associations between an object and its location on the screen, and intraitem associations. Aphantasic participants had a lower rate of high-confidence hits in all associative memory tests compared with controls. Performance on auditory-visual associations was correlated with individual differences in a measure of object imagery in the aphantasic group but not in controls. No overall group difference in memory performance was found, indicating that visual imagery selectively contributes to memory confidence. Analysis of the encoding task revealed that aphantasics made fewer associative links between the stimuli, suggesting a role for visual imagery in associative processing of visual and auditory input. These data enhance our understanding of visual imagery contributions to associative memory and further characterize the cognitive profile of aphantasia.

Aphantasia and psychological disorder: Current connections, defining the imagery deficit and future directions

Aphantasia is a condition characterized by a deficit of mental imagery. Since several psychopathologies are partially maintained by mental imagery, it may be illuminating to consider the condition against the background of psychological disorder. After outlining current findings and hypotheses regarding aphantasia and psychopathology, this paper suggests that some support for defining aphantasia as a lack of voluntary imagery may be found here. The paper then outlines potentially fruitful directions for future research into aphantasia in general and its relation to psychopathology in particular, including rethinking use of the SUIS to measure involuntary imagery, whether aphantasia offers protection against addiction, and whether hyperphantasia is a potential risk factor for maladaptive daydreaming, among others.

Imagery-related eye movements in 3D space depend on individual differences in visual object imagery

During recall of visual information people tend to move their eyes even though there is nothing to see. Previous studies indicated that such eye movements are related to the spatial location of previously seen items on 2D screens, but they also showed that eye movement behavior varies significantly across individuals. The reason for these differences remains unclear. In the present study we used immersive virtual reality to investigate how individual tendencies to process and represent visual information contribute to eye fixation patterns in visual imagery of previously inspected objects in three-dimensional (3D) space. We show that participants also look back to relevant locations when they are free to move in 3D space. Furthermore, we found that looking back to relevant locations depends on individual differences in visual object imagery abilities. We suggest that object visualizers rely less on spatial information because they tend to process and represent the visual information in terms of color and shape rather than in terms of spatial layout. This finding indicates that eye movements during imagery are subject to individual strategies, and the immersive setting in 3D space made individual differences more likely to unfold.

Cortical activity involved in perception and imagery of visual stimuli in a subject with aphantasia. An EEG case report

Aphantasia has been described as the inability to voluntarily evoke mental images using the "mind's eye." We studied a congenital aphantasic subject using neuropsychological testsand 64 channel EEG recordings, in order to studycortical activity involved in perception and imagery evaluating event-related potentials(N170, P200, N250). The subject is in the normal range of the neuropsychological tests performed, except for specific imagery tests. The EEG results show that when he evokes the same mental image, he starts the evoking process from left temporal instead of frontal areas, he does not activate occipital visual nor left anterior parietal areas.

Memories with a blind mind: Remembering the past and imagining the future with aphantasia

Our capacity to re-experience the past and simulate the future is thought to depend heavily on visual imagery, which allows us to construct complex sensory representations in the absence of sensory stimulation. There are large individual differences in visual imagery ability, but their impact on autobiographical memory and future prospection remains poorly understood. Research in this field assumes the normative use of visual imagery as a cognitive tool to simulate the past and future, however some individuals lack the ability to visualise altogether (a condition termed "aphantasia"). Aphantasia represents a rare and naturally occurring knock-out model for examining the role of visual imagery in episodic memory recall. Here, we assessed individuals with aphantasia on an adapted form of the Autobiographical Interview, a behavioural measure of the specificity and richness of episodic details underpinning the memory of events. Aphantasic participants generated significantly fewer episodic details than controls for both past and future events. This effect was most pronounced for novel future events, driven by selective reductions in visual detail retrieval, accompanied by comparatively reduced ratings of the phenomenological richness of simulated events, and paralleled by quantitative linguistic markers of reduced perceptual language use in aphantasic participants compared to those with visual imagery. Our findings represent the first systematic evidence (using combined objective and subjective data streams) that aphantasia is associated with a diminished ability to re-experience the past and simulate the future, indicating that visual imagery is an important cognitive tool for the dynamic retrieval and recombination of episodic details during mental simulation.

Spatial transformation in mental rotation tasks in aphantasia

Aphantasia refers to the inability to summon images to one's own mind's eye, resulting in selective deficits of voluntary object imagery. In the present study, we investigated whether M. X., a case of acquired aphantasia, can still retain some form of spatial transformation processes even though he is unable to subjectively experience voluntary object imagery. M. X. and a group of control participants were asked to complete a letter mental rotation task (MRT), typically used to assess the nature of the spatial transformation, while behavioural and electrophysiological responses were recorded. M. X. was able to complete the MRTs as accurately as controls, showing the pattern of increasing RTs as a function of rotation angle typical of MRTs. However, event-related potential (ERP) results showed systematic differences between M. X. and controls. On canonical letter trials, the rotation-related negativity (RRN), an ERP component considered as the psychophysiological correlate of the spatial transformation of mental rotation (MR), was present in both M. X. and controls and similarly modulated by rotation angle. However, no such modulation was observed for M. X. on mirror-reversed letter trials. These findings suggest that, at least under specific experimental conditions, the inability to create a depictive representation of the stimuli does not prevent the engagement of spatial transformation in aphantasia. However, the ability to apply spatial transformation varies with tasks and might be accounted for by the specific type of mental representation that can be accessed.

Congenital lack and extraordinary ability in object and spatial imagery: An investigation on sub-types of aphantasia and hyperphantasia

Studies that have shown a distinction between object and spatial imagery suggest more than one type of aphantasia and hyperphantasia, yet this has not been systematically investigated in studies on imagery ability extremes. Also, if the involuntary imagery is preserved in aphantasia and how this condition affects other skills is not fully clear. We collected data on spatial and object imagery, retrospective, and prospective memory, face recognition, and sense of direction (SOD), suggesting a distinction between two subtypes of aphantasia/hyperphantasia. Spatial aphantasia is associated with difficulties in visuo-spatial mental imagery and SOD. Instead, in object aphantasia there are difficulties in imaging single items and events - with no mental visualization of objects, out-of-focus, and black-and-white mental images more frequent than expected - in SOD and face recognition. Furthermore, associative involuntary imagery can be spared in aphantasia. The opposite pattern of performance was found in spatial and object hyperphantasia.

A tutorial on capturing mental representations through drawing and crowd-sourced scoring

When we draw, we are depicting a rich mental representation reflecting a memory, percept, schema, imagination, or feeling. In spite of the abundance of data created by drawings, drawings are rarely used as an output measure in the field of psychology, due to concerns about their large variance and their difficulty of quantification. However, recent work leveraging pen-tracking, computer vision, and online crowd-sourcing has revealed new ways to capture and objectively quantify drawings, to answer a wide range of questions across fields of psychology. Here, I present a tutorial on modern methods for drawing experiments, ranging from how to quantify pen-and-paper type studies, up to how to administer a fully closed-loop online experiment. I go through the concrete steps of designing a drawing experiment, recording drawings, and objectively quantifying them through online crowd-sourcing and computer vision methods. Included with this tutorial are code examples at different levels of complexity and tutorials designed to teach basic lessons about web architecture and be useful regardless of skill level. I also discuss key methodological points of consideration, and provide a series of potential jumping points for drawing studies across fields in psychology. I hope this tutorial will arm more researchers with the skills to capture these naturalistic snapshots of a mental image.