The pupillary light response is an important automatic physiological response which optimizes light reaching the retina. Recent work has shown that the pupil also adjusts in response to illusory brightness and a range of cognitive functions, however, it remains unclear what exactly drives these endogenous changes. Here, we show that the imagery pupillary light response correlates with objective measures of sensory imagery strength. Further, the trial-by-trial phenomenological vividness of visual imagery is tracked by the imagery pupillary light response. We also demonstrated that a group of individuals without visual imagery (aphantasia) do not show any significant evidence of an imagery pupillary light response, however they do show perceptual pupil light responses and pupil dilation with larger cognitive load. Our results provide evidence that the pupillary light response indexes the sensory strength of visual imagery. This work also provides the first physiological validation of aphantasia.

Recently, the term ‘aphantasia’ has become current in scientific and public discourse to denote the absence of mental imagery. However, new terms for aphantasia or its subgroups have recently been proposed, e.g. ‘dysikonesia’ or ‘anauralia’, which complicates the literature, research communication and understanding for the general public. Before further terms emerge, we advocate the consistent use of the term ‘aphantasia’ as it can be used flexibly and precisely, and is already widely known in the scientific community and among the general public.

It is not yet known whether individuals with aphantasia show deficits in cognitive and neuropsychological tasks thought to relate to aspects of visual imagery. Twenty individuals with congenital aphantasia (VVIQ 35). A group difference was found in One Touch Stocking of Cambridge task for response time, but not accuracy, when the number of imagined moves that participants had to hold in their heads to complete the task increased. Similarly, a group difference in response time was apparent in the mental rotation task, but only in the subgroup of aphantasic participants who reported a severe deficit in visual imagery (VVIQ score of 16). Overall, this study raises questions about whether or not aphantasia represents a difference in cognitive function or in conscious experience.

This study examines the relationship of visual imagery to short term memory (STM) and hippocampal and primary visual cortex volumes, first in a large sample of healthy people across a large age range (N=229 behavioural data; N=56 MRI data in older participants) and then in patients with Alzheimer’s disease and Parkinson’s disease (N=19 in each group compared to 19 age-matched healthy controls).

This paper aims to address the scepticism surrounding aphantasia, the challenges in communicating about mental imagery, and the research methods used in cognitive sciences today through the lens of Wittgenstein’s philosophy. The paper argues that 1) communicating about mental imagery involves language games that persons with aphantasia may not be able to play (i.e., makes reference to expressions and concepts that are meaningless for them, such as ‘visualise,’ ‘form an image,’ etc.); 2) that as a consequence aphantasia, in present research, is only describable negatively (as lack or incapacity); 3) that rather than a cognitive or a psychological issue, aphantasia should be understood as a grammatical one; and 4) that we need to invent new language games in order to come to a better understanding of conditions such as aphantasia, and to be able to appreciate the rich diversity and variability of human experience.

Most self-reported aphantasics also reported weak or entirely absent auditory imagery; and participants lacking auditory imagery tended to be aphantasic. Similarly, vivid visual imagery tended to co-occur with vivid auditory imagery. Auditory representations and auditory imagery are thought to play a key role in a wide range of psychological domains, including working memory and memory rehearsal, prospective cognition, thinking, reading, planning, problem-solving, self-regulation, and music. Therefore, self-reports describing an absence of auditory imagery raise a host of important questions concerning the role of phenomenal auditory imagery in these domains.

Study finds that if you don't have visual imagery, you find a different (non sensory) strategy to hold visual info in short-term memory and performance will look the same as someone who uses a completely different strategy (imagery). If you have aphantasia, your working memory is just fine, even for visual objects! If you have imagery you tend to use it.

Recent work has shown that the pupil will adjust in response to illusory brightness. This study shows that the imagery pupillary light response correlates with objective measures of sensory imagery strength. It also demonstrates that there was no evidence for an imagery pupillary light response in a group of individuals without visual imagery (aphantasia). The first physiological validation of aphantasia.

Aphantasia, the loss of mental imagery, is a rare disorder and even more infrequent when acquired. No previous cases have been identified that were caused by transplant-related treatment. We describe a case of acquired aphantasia in a 62-year-old male with refractory IgG kappa multiple myeloma after receiving an autologous stem cell transplant (ASCT) following high-dose melphalan with a complicated hospital admission.

First systematic, wide-ranging neuropsychological and brain imaging study of people with aphantasia (n=24), hyperphantasia (n=25) and mid-range imagery vividness (n=20). These behavioral and neural signatures of visual imagery vividness extremes validate and illuminate this significant but neglected dimension of individual difference.