Aphantasia

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...

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...

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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...

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)...

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...

This scientific commentary refers to 'Explicit and implicit motor simulations are impaired in individuals with aphantasia', by Dupont   et al . (https://doi.org/10.1093/braincomms/fcae072) in Brain Communications .

Individuals with aphantasia report having difficulties or an inability to generate visual images of objects or events. So far, there is no evidence showing that this condition also impacts the motor system and the generation of motor simulations. We probed the neurophysiological marker of aphantasia during explicit and implicit forms of motor simulation, i.e. motor imagery and action observation, respectively. We tested a group of individuals without any reported imagery deficits (phantasics) as well as a group of individuals self-reporting the inability to mentally simulate images or movements (aphantasics)...

Predictive processing theories state that our subjective experience of reality is shaped by a balance of expectations based on previous knowledge about the world (i.e. priors) and confidence in sensory input from the environment. Divergent experiences (e.g. hallucinations and synaesthesia) are likely to occur when there is an imbalance between one's reliance on priors and sensory input. In a novel theoretical model, inspired by both predictive processing and psychological principles, we propose that predictable divergent experiences are associated with natural or environmentally induced prior/sensory imbalances: inappropriately strong or inflexible (i...

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...

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...

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...

Aphantasia is a condition in which people are unable to experience visual imagery. Since visual imagery is thought to be key to language processing, we hypothesized the experience of a story would differ between individuals with aphantasia and controls. Forty-seven individuals with aphantasia were compared to fifty-one matched controls on their experience of reading a short story and their general reading habits. Aphantasics were less likely to be engaged with, interested in, and absorbed in the story, and experienced reduced emotional engagement with and sympathy for the story characters, compared to controls...

Little is known about the perceptual characteristics of mental images nor how they vary across sensory modalities. We conducted an exhaustive survey into how mental images are experienced across modalities, mainly targeting visual and auditory imagery of a single stimulus, the letter "O", to facilitate direct comparisons. We investigated temporal properties of mental images (e.g. onset latency, duration), spatial properties (e.g. apparent location), effort (e.g. ease, spontaneity, control), movement requirements (e...

Cognitive neuroscience research on mental imagery has largely focused on the visual imagery modality in unimodal task contexts. Recent studies have uncovered striking individual differences in visual imagery capacity, with some individuals reporting a subjective absence of conscious visual imagery ability altogether ("aphantasia"). However, naturalistic mental imagery is often multi-sensory, and preliminary findings suggest that many individuals with aphantasia also report a subjective lack of mental imagery in other sensory domains (such as auditory or olfactory imagery)...

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)...

Research into the newly-coined 'condition' of 'aphantasia', an individual difference involving the self-reported absence of voluntary visual imagery, has taken off in recent years, and more and more people are 'self-diagnosing' as aphantasic. Yet, there is no consensus on whether aphantasia should really be described as a 'condition', and there is no battery of psychometric instruments to detect or 'diagnose' aphantasia. Instead, researchers currently rely on the Vividness of Visual Imagery Questionnaire (VVIQ) to 'diagnose' aphantasia...

Action reading is thought to engage motor simulations, such as those involved during the generation of mental motor images. These simulations would yield modulations in activity of motor-related cortical regions and contribute to action language comprehension. To test these ideas, we measured corticospinal excitability during action reading, and reading comprehension ability, in individuals with normal and impaired imagery (i.e., phantasia and aphantasia, respectively). Thirty-four participants (17 phantasic and 17 aphantasic) were asked to read manual action sentences...

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)...

Mental imagery enables people to simulate experiences in their minds without the presence of an external stimulus. The underlying biochemical mechanisms are poorly understood but there is vague evidence that dopamine may play a significant role. A better understanding at the biochemical level could help to unravel the mechanisms of mental imagery and related phenomena such as aphantasia (= lack of voluntary mental imagery), but also opens up possibilities for interventions to enhance or restore mental imagery...