Aphantasia: Why “Blind Imagination” Could Be the Key to Understanding Consciousness

Source: Aphantasia: Why “Blind Imagination” Could Be the Key to Understanding Consciousness, Ihm Curious, 19:39, uploaded 2024-06-21, Watch Later position 847.

Ihm Curious begins with an apple. The viewer is asked to imagine one, close their eyes, and picture its colour. Most people can answer a follow-up question about the shade or shape they saw. Someone with aphantasia may think of the concept of an apple whilst experiencing no visual image at all. The condition gives the video a way to ask a harder question: can a person perform the work associated with a mental image without having the image as part of conscious experience?

From Galton’s observers to aphantasia

The video traces the first description of the condition to Francis Galton in 1880. Galton found that many scientists reported little or no mental imagery, which surprised him because scientific work seems to demand the manipulation of objects in the mind. The word aphantasia arrived much later. Hakwan Lau credits Adam Zeman with giving the condition its current name and with making the phenomenon systematic enough for current research.

The source gives a rough estimate of one per cent of the population. A person with aphantasia may understand what an apple is, remember its properties, and recognise a real apple whilst lacking a picture to compare against. Lau says that this absence seems selective. People who report no imagery can still activate visual cortex, hold material in working memory, and perform tasks that appear to involve visual manipulation. His interpretation is that the missing part is the conscious experience of imagery.

The distinction becomes visible through mental rotation. A classic experiment presents two objects and asks whether one is the same object viewed from another angle. People usually take longer as the angular difference grows. The video treats that increase as evidence that they rotate an object in the mind before answering. It then reports a study of 95 people with aphantasia. They could perform the task, and their reaction times also increased with the amount of rotation. Their performance therefore followed the pattern associated with seeing an object turn in the mind’s eye, even though they said that they experienced no such image.

That result gives aphantasia its use in consciousness research. Science tries to isolate the variable it wants to study. Consciousness research has a special difficulty because the target, subjective experience, often arrives together with the ability to respond to information. Aphantasia appears to separate a mental ability from the experience that researchers usually infer from its successful use. The separation remains a claim about a subset of people and a particular task. The video’s description adds that mental rotation can use analytic strategies, so Lau’s hypothesis needs only some aphantasic participants to rotate objects through unconscious imagery.

Two meanings of consciousness

Lau begins the interview by separating everyday consciousness from the subject studied in the neuroscience and philosophy of consciousness. In ordinary speech, a conscious person can respond meaningfully to stimulation. Someone who has drunk too much and lost consciousness has lost that ability. The same usage appears in some branches of social science, where consciousness can mean a rational awareness of one’s situation.

The research target is narrower. It concerns the qualities of subjective experience, such as the redness of red or the painfulness of pain. Those qualities are what a theory of consciousness has to explain. The ability to respond matters because researchers need evidence that a subject is awake and engaged, yet it also acts as a confound when the response itself becomes the evidence for experience.

Lau argues that the field keeps mixing the two meanings. Theories present themselves as accounts of subjective experience whilst drawing support from a person’s ability to respond. A study can show that a brain distinguishes a stimulus, reports it, or acts on it. Those results do not by themselves show what the stimulus feels like. Aphantasia offers a case in which the ability remains available whilst one type of experience seems to be absent.

An empirical version of the hard problem

The interviewer connects this dissociation to the hard problem of consciousness. A brain can process information and guide behaviour, yet the processing may still seem to leave a further question about why anything feels like anything. A robot with a camera could recognise objects and move through a room without there being anything it is like to be that robot.

Lau treats the philosophical problem with care. He points to David Chalmers’s zombie thought experiment, in which a creature behaves like a person whilst lacking subjective experience, then says that he prefers empirical cases. A philosophical zombie might be possible, or it might be an artefact of what a person can imagine. Imagination has weak authority: Lau gives the example of imagining that the square root of 124 is seven because he is poor at arithmetic. The imagined possibility remains false.

Anesthetic drugs show the problem with a common experimental comparison. When a person is anesthetised, subjective experience disappears alongside much of their thinking, movement, and ability to respond. A study that compares an awake brain with an anesthetised brain therefore finds many differences. It cannot say which difference belongs to consciousness and which belongs to the general loss of cognition and behaviour.

Blindsight and aphantasia seem more useful because they leave more function in place. Lau calls them near-ideal empirical zombie states. In both cases, the researcher may find a mental or perceptual ability that operates whilst its accompanying experience is missing. Aphantasia provides a case of imagery without the conscious feeling of seeing the image. Blindsight provides a case of responding to visual information without ordinary visual awareness. The aim is to find a selective change in subjective experience whilst keeping the relevant ability intact.

That is the practical form of the hard problem in this interview. Researchers need cases in which experience can vary independently of the behaviour used to measure it. The problem becomes a demand for better controls rather than an invitation to settle the metaphysics through thought experiments.

Global workspace and the confounded experiment

The final section turns to Global Neuronal Workspace Theory, which the video presents as one of the most respected theories of consciousness. The theory says that information becomes conscious when the brain broadcasts it globally, making it available to many regions and systems. Lau’s objection concerns the evidence used to support that idea.

One line of evidence comes from coma patients and anesthetised people. A brain that works effectively has more activity and communication than a brain that has largely shut down, so global broadcasting will appear in the comparison. The result shows that global broadcasting helps a brain function. It does not isolate the part of functioning that constitutes subjective experience.

Another line comes from backward masking. The technique can remove a person’s conscious experience of seeing a stimulus, yet Lau says it also removes perception in a broader sense. If the subject receives less usable information, global broadcasting may be required for that perception. The experiment still leaves open whether global broadcasting produces the feeling of seeing.

Lau compares the problem with height. A critic might say that a researcher who studies tall and short people cannot control for the length of their bones because bone length constitutes height. Lau accepts that relation as a genuine impossibility, then says that subjective experience and meaningful response do not have the same relation. Aphantasia and blindsight already show that the two can come apart in living subjects. Researchers therefore can try to control for response when they study subjective experience, even though the field often treats that control as absurd.

He says he has raised this issue for two decades. In his teaching, students quickly understand why confounded evidence cannot carry the theory built on it. Researchers who have invested in a theory have more reason to defend the existing studies. The video leaves the theory’s fate with that methodological dispute. If its strongest evidence measures general function, perception, or response alongside consciousness, then the theory has yet to test the experience it claims to explain.

Limits of the case

This note follows the complete English caption track, the video description, chapters, and downloaded metadata. The captions mishear several names and terms, including Francis Galton, Adam Zeman, Hakwan Lau, David Chalmers, blindsight, and Global Neuronal Workspace Theory. The corrected forms follow the context and the description where it supplies them.

The video reports the one-per-cent estimate, the study of 95 people, the mental-rotation result, and Lau’s interpretation of imagery without giving the original study citations. The description corrects an over-simple reading of mental rotation: people use several strategies, and Lau’s proposal needs only a subset of aphantasic participants to use unconscious mental imagery. The source presents this as a promising way to separate ability from experience. It does not establish that every person with aphantasia lacks all mental imagery, or that aphantasia provides a complete model of consciousness.

The description links the book In Consciousness We Trust and identifies the two image sets used in the video. Those links document the source material for the pictures. They do not independently support the interview’s central claims about aphantasia, blindsight, or consciousness research. The video’s critique of Global Neuronal Workspace Theory remains Lau’s account in this interview, with its evidence and objections requiring the underlying studies for a full assessment.

Further reading / references

• Hakwan Lau, In Consciousness We Trust: The Cognitive Neuroscience of Subjective Experience, Oxford University Press, 2022.
• Jarosław M. Michałowski and colleagues, “The Set of Fear Inducing Pictures (SFIP): Development and validation in fearful and nonfearful individuals”, Behavior Research Methods, 2017. The source uses the SFIP for the spider and rooster images.
• Benedek Kurdi, Shayn Lozano, and Mahzarin R. Banaji, “Introducing the Open Affective Standardized Image Set (OASIS)”, Behavior Research Methods, 2017. The source uses OASIS for the dog-in-a-teacup image.