Aphantasia, Hyperphantasia, and the Ecology of Internal Simulation

 

Abstract

Aphantasia and hyperphantasia are usually described as opposite extremes of mental imagery vividness, but this neuroecological framing underestimates their theoretical importance. This article argues that they represent contrasting cognitive strategies for simulating absent information. Hyperphantasia renders absent objects, scenes, actions, memories, and possible futures into sensory-rich internal representations that can be inspected, emotionally inhabited, and progressively modified. Aphantasia compresses absent information into concepts, spatial relations, verbal descriptions, procedural rules, affective meanings, and external scaffolds, allowing imagination and reasoning to proceed with reduced reliance on vivid sensory reconstruction. The present article proposes that aphantasia and hyperphantasia differ not merely in the strength of the mind’s eye, but in the degree to which internally generated sensory maps participate in progressive cognitive updating and association and affordance discovery. The resulting account reframes the aphantasia-hyperphantasia spectrum as a difference between compressed and rendered simulation, with implications for memory, selfhood, emotion, creativity, social cognition, trauma, problem solving, and theories of consciousness.

Keywords

Aphantasia; hyperphantasia; mental imagery; visual imagery; consciousness; working memory; affordances; internal simulation; progressive imagery modification; state-spanning coactivity; incremental change in state-spanning coactivity; icSSC; autobiographical memory; episodic memory; future simulation; imagination; sensory simulation gain; cognitive ecology; neuroecology; external scaffolding; predictive processing; default mode network; visual cortex; mental continuity.

Cite This Article As

Reser JE. Rendered affordances: Aphantasia, hyperphantasia, and the ecology of internal simulation. Manuscript in preparation; 2026.

1. Introduction: From imagery vividness to internal simulation strategy

Aphantasia and hyperphantasia are usually introduced as opposite extremes of visual mental imagery. Aphantasia refers to markedly reduced or absent conscious imagery, especially in the voluntary waking state, whereas hyperphantasia refers to unusually vivid imagery that may approach the richness of perception. Recent reviews characterize these conditions as genuine imagery-vividness extremes with behavioral, physiological, and neural correlates, rather than as simple differences in self-description. Zeman estimates that extreme aphantasia and hyperphantasia occur in roughly 1% and 3% of the population, respectively, although prevalence depends on measurement thresholds and sampling methods. (Cell) Milton and colleagues similarly describe aphantasia and hyperphantasia as recently characterized extremes of visual imagery vividness and report systematic differences in autobiographical memory, imagination, and neural connectivity across aphantasic, hyperphantasic, and mid-range imagery groups. (OUP Academic)

The present article approaches these conditions through a different question. Instead of asking only how vividly people can “see” in the mind, it asks how different minds simulate absent information. Human beings constantly reason about things that are not perceptually present: remembered places, future conversations, possible tools, hidden dangers, routes, social reactions, bodily movements, unfinished designs, causal mechanisms, and imagined worlds. Mental imagery is one way of making such absent information available to cognition. It can convert an abstract concept into a scene, a possible action into a rehearsed movement, or a verbal description into a quasi-perceptual field that can be inspected, modified, and emotionally evaluated.

This framing makes aphantasia and hyperphantasia more than a contrast between weak and strong pictures. They may reflect different strategies for managing absent affordances. An affordance is an action possibility specified by the relation between an organism and its environment. A chair affords sitting for a human body, a ledge affords climbing for one animal and shelter for another, and a social expression affords approach, avoidance, repair, or inquiry depending on context. Internally generated imagery may allow the brain to simulate affordances that are not currently available to perception. An imagined room can reveal possible routes through it; an imagined tool can reveal how it might fit the hand; an imagined conversation can reveal emotional risks; an imagined object can reveal missing parts, obstructions, or useful features.

Aphantasia and hyperphantasia can therefore be contrasted as compressed and rendered forms of simulation. In aphantasia, absent information may be represented more through concepts, words, spatial schemas, factual knowledge, procedural rules, affective tags, motor plans, or external scaffolds such as drawings and diagrams. In hyperphantasia, absent information is more readily rendered into sensory-rich scenes that can be inspected internally. The difference is not imagination versus no imagination. It is a difference in representational format and in the degree to which sensory reconstruction participates in ongoing thought.

This article develops that contrast through the framework of progressive imagery modification. Reser’s 2016 model of state-spanning coactivity, SSC, and incremental change in state-spanning coactivity, icSSC, proposes that sustained coactivity in association cortex allows successive mental states to share overlapping representational content. That overlap enables mental continuity, iterative updating, and progressive transformation of working memory contents over time. The model explicitly links SSC and icSSC to the construction of interrelated topographic maps in sensory systems, such that sustained higher-order representations can guide successive rounds of imagery generation. Reser’s later cognitive architecture for machine consciousness and artificial superintelligence extends this account into an artificial intelligence framework, arguing that human-like thought can be modeled as the iterative updating of working memory, where successive states preserve part of the previous active set while adding new representations through associative search. (arXiv)

Within this framework, mental imagery is not merely the output of thought. It can also be an input to the next phase of thought. A higher-order concept can be held active, sent into sensory systems as a top-down specification, rendered into a topographic image, and then mined for new relations, constraints, details, and affordances. The resulting sensory map can return information to association cortex, where it changes the next working-memory state. Hyperphantasia may represent a high-gain version of this loop, in which sensory reconstruction contributes strongly to reasoning, memory, planning, creativity, and emotion. Aphantasia may represent a low-gain, altered-access, or more externally scaffolded version, in which thought proceeds with less reliance on vivid conscious sensory rendering.

The central thesis is that aphantasia and hyperphantasia reveal two cognitive ecologies of internal simulation. Hyperphantasia renders absent affordances into vivid internal worlds; aphantasia compresses absent affordances into nonvisual, schematic, linguistic, conceptual, procedural, or externally supported forms. Both strategies can support thought, planning, creativity, and selfhood, but they may differ in how they recruit memory, emotion, attention, and problem solving. The aphantasia-hyperphantasia spectrum therefore provides a valuable window into the architecture of consciousness because it shows that conscious cognition is not bound to a single representational format.

2. Theoretical foundation: Progressive imagery modification and icSSC

Reser’s 2016 model begins from the problem of mental continuity. A conscious train of thought does not usually consist of isolated, disconnected states. It progresses through overlapping configurations in which some representations are maintained while others drop out and new ones enter. The model introduces state-spanning coactivity, SSC, to refer to representations that remain coactive across consecutive brain states, and incremental change in state-spanning coactivity, icSSC, to describe the gradual turnover of that active set. Because some representations are conserved across successive states, each state is partially embedded in the previous one, allowing thought to proceed iteratively rather than as a sequence of unrelated snapshots.

This account is especially relevant to mental imagery because it separates two components of internally generated thought. Association areas maintain relatively enduring, higher-order representations: concepts, goals, objects, people, places, relations, task constraints, and contextual priorities. Sensory and motor systems construct more transient topographic maps: visual images, auditory imagery, spatial layouts, motor simulations, and other modality-specific or body-specific representations. Reser argues that higher-order representations held in SSC can act as sustained search parameters across multiple cycles of processing, while lower-order sensory systems generate successive images under their guidance.

Progressive imagery modification names the recursive interaction between these levels. Top-down association areas provide specifications to lower-order sensory systems; sensory systems integrate these specifications into a plausible topographic map; salient features of that map then feed forward into association cortex and alter the next active set. The next image is therefore not a fresh beginning. It is shaped by the concepts still held active from prior cycles and by new information extracted from the previous image. Reser describes this as a cyclical, nested flow in which each new topographic map is embedded in the previous one and guided by enduring representations in association cortex.

This process is important because internally generated imagery can do cognitive work that abstract concepts alone may not do as efficiently. Sensory systems have been trained directly by the structure of the perceptual world. They encode constraints involving shape, space, motion, texture, proportion, occlusion, bodily possibility, acoustic pattern, and object interaction. When higher-order representations are projected into these systems, the resulting map may contain information that was not explicit in the original concept. An image of a room may reveal that a path is blocked. An image of a face may suggest an emotional reaction. An image of a tool may reveal a better grip or a design flaw. An image of a future event may expose an overlooked risk or opportunity.

Reser’s 2016 article explicitly anticipates this generative role for sensory maps. It proposes that lower-order topographic images can depict and explore hypothetical relationships among higher-order specifications, with some contextual elements held constant while others change. This allows newly activated search terms to combine with search terms from the previous cycle, creating a progressive iterative process in which important representations “work” with newly introduced ones to interrogate the simulated situation. The same paper also argues that sensory areas may elaborate on top-down specifications with associated but unforeseen embellishments, thereby introducing new content into the stream of thought.

The 2022 cognitive architecture extends the same principle into a computational framework. In that article, thought is structured by the iterative updating of working memory. Each state preserves a proportion of the coactive representations from the previous state, while persistent activity spreads through a hierarchical network to search long-term memory for the next appropriate addition to the global workspace. The result is a chain of associatively linked intermediate states that can advance toward a solution or goal. (arXiv) This provides a useful bridge to the present article because aphantasia and hyperphantasia may differ in how much the iterative updating of working memory depends on vivid sensory reconstruction.

The present article therefore treats imagery as a cognitive search space rather than as a static picture. In progressive imagery modification, a concept is not merely visualized and then observed by an inner spectator. It is transformed into a sensory or motor map that can reveal affordances, constraints, clues, and further associations. That map then helps determine the next state of thought. Aphantasia and hyperphantasia can be understood as variation in the gain, accessibility, or cognitive role of this recursive loop. Aphantasia may preserve high-order conceptual maintenance while reducing the conscious vividness or functional use of internally generated sensory maps. Hyperphantasia may amplify the sensory-rendering phase and allow the resulting imagery to contribute more strongly to memory, emotion, planning, and creative recombination.

This distinction also prevents a simple deficit interpretation of aphantasia. If thought depends only on vivid sensory imagery, then aphantasia would imply a major absence of imagination. The empirical literature does not support such a conclusion. People with aphantasia can reason, create, plan, remember, and solve visual-spatial problems, often by relying on different strategies. The more plausible interpretation is that aphantasia shifts cognition toward compressed simulation: concepts, schemas, language, spatial relations, external diagrams, motor procedures, and factual knowledge. Hyperphantasia shifts cognition toward rendered simulation: scene construction, sensory inspection, reliving, affective embodiment, and internal affordance discovery.

The article’s guiding mechanism can therefore be stated as follows: higher-order representations maintain the theme of thought; sensory systems render possible worlds from that theme; rendered worlds return new information to the higher-order system; and the cycle repeats. Aphantasia and hyperphantasia mark different positions along this rendering continuum. They are not simply variations in the brightness of the mind’s eye. They are variations in the extent to which internally generated sensory worlds participate in the ongoing construction of conscious thought.

3. The central framework: Compressed versus rendered affordances

The ecological significance of mental imagery becomes clearer when imagery is treated as a way of representing affordances in the absence of immediate perception. Gibson defined affordances as what the environment offers the animal, emphasizing that affordances belong to the relation between organism and environment rather than to either side in isolation. A surface affords walking only for a body that can move across it; an object affords grasping only for a hand or appendage with the relevant capacities; a social expression affords approach, repair, caution, or withdrawal depending on the perceiver’s goals, history, and bodily state. (Brown University Computer Science) Mental imagery extends this ecological relation inward. It allows absent objects, places, social situations, tools, dangers, and possible futures to be represented as if they were currently available for inspection and action.

The present article proposes that aphantasia and hyperphantasia differ in how absent affordances are represented. In aphantasia, affordances may be represented in compressed form: through concepts, verbal descriptions, spatial relations, factual knowledge, motor routines, emotional appraisals, external diagrams, or other nonvivid formats. In hyperphantasia, affordances are more readily rendered into sensory form: a person can internally construct a scene, inspect its features, feel its emotional tone, notice possible actions, and allow the image to suggest further modifications. The distinction concerns the format of simulation rather than the presence or absence of intelligence, imagination, or reasoning. Aphantasic cognition can remain highly capable while relying less on vivid sensory reconstruction; hyperphantasic cognition may rely more heavily on internally generated sensory worlds as working spaces.

This framework depends on a distinction between an affordance that is inferred and an affordance that is rendered. A compressed affordance is available to thought without being experienced as a vivid sensory image. A person may know that a door is too narrow for a couch, that a social remark would sound rude, or that a route would be inefficient without seeing the scene in the mind’s eye. A rendered affordance is discovered or clarified by constructing an internal sensory representation. A person may imagine the couch angled through the doorway and notice that the armrest catches on the frame, or imagine a conversation and sense that a particular phrase changes the emotional trajectory. Rendered affordances recruit the perceptual systems that normally organize sensory experience, allowing offline cognition to use some of the same constraints that structure online perception.

Reser’s 2016 model provides a mechanism for this distinction. In that account, higher-order representations held in state-spanning coactivity can guide the construction of lower-order topographic maps, while those maps can feed new features back into association cortex. The paper describes internally derived imagery as topographically organized because it is constructed by networks also involved in perceiving external stimuli; it further proposes that sensory areas function as an active canvas that can be driven by external input during perception or by top-down expectation during imagination. This allows imagery to serve as more than a depictive endpoint. The generated map can return constraints, relations, and clues to the higher-order system, thereby modifying the next cognitive state.

This is where progressive imagery modification becomes central. Sensory systems contain implicit knowledge about spatial fit, surface structure, object interaction, motion, proportion, occlusion, acoustic pattern, and bodily possibility. When higher-order concepts are projected into sensory systems, the resulting map may contain information that was not explicitly represented in the initiating concept. The 2016 model makes this point by arguing that lower-order topographic images can depict hypothetical relationships among higher-order specifications, with some contextual elements held constant while others change; successive images can then combine older search terms with newer ones in a progressive attempt to interrogate the simulated situation. The crucial implication is that imagery can discover affordances because sensory maps are constrained by the accumulated statistical structure of perception.

Aphantasia and hyperphantasia may therefore represent different positions along a sensory simulation gain continuum. Low sensory simulation gain would mean that higher-order concepts are maintained and manipulated without strongly recruiting vivid conscious sensory maps. The person may rely on conceptual compression, language, spatial schemas, symbolic structure, or external scaffolding. High sensory simulation gain would mean that higher-order concepts strongly recruit perceptual systems, generating detailed internal scenes that can feed back into thought. In this case, internally generated imagery becomes a cognitive search space. Hyperphantasia may therefore amplify the contribution of sensory systems to reasoning, memory, design, planning, emotional anticipation, and creative recombination.

This contrast also explains why aphantasia should not be treated as the absence of internal simulation. Recent reviews describe aphantasia as an imagery-vividness extreme, while also noting that people with aphantasia can retain many cognitive abilities and may use alternative representational strategies. (Cell) The present framework interprets this as evidence for multiple simulation formats. Aphantasic thought may remain rich in higher-order structure while relying less on conscious sensory rendering. Hyperphantasic thought may be richer in sensory instantiation, but that richness brings its own tradeoffs: more detail, stronger reliving, and greater emotional force, along with possible susceptibility to intrusive imagery, false perceptual embellishment, or excessive affective simulation.

The ecological interpretation is therefore pluralistic. Mental imagery allows the brain to make absent worlds actionable. Hyperphantasia does this by rendering absent affordances into vivid internal scenes that can be inspected, modified, and emotionally inhabited. Aphantasia does this by compressing absent affordances into concepts, rules, labels, spatial structures, bodily procedures, and external representations. Both strategies convert absence into usable cognition. They differ in whether the absent world is primarily rendered internally or represented in a more abstract and scaffolded form.

4. Memory and self: Knowing, reliving, and reconstructing the past

Autobiographical memory is one of the clearest domains in which the aphantasia-hyperphantasia contrast becomes psychologically significant. Remembering a past event can involve factual knowledge, narrative organization, emotional appraisal, bodily feeling, spatial structure, and sensory reliving. These components usually work together, but aphantasia reveals that they can dissociate. A person may know that an event occurred, know who was present, know what it meant, and know how it changed their life, while experiencing little or no visual re-entry into the scene. Hyperphantasia reveals the opposite tendency: past events may return with strong sensory presence, allowing memory to feel less like retrieval of information and more like partial reoccupation of a world.

Milton and colleagues compared individuals with aphantasia, hyperphantasia, and mid-range imagery, finding systematic differences in autobiographical memory and imagination across imagery-vividness groups. Their study reported that aphantasia was associated with subjective impairment in autobiographical memory and face recognition, while hyperphantasia occupied the opposite vividness pole. (OUP Academic) Dawes and colleagues similarly found that aphantasia was associated with diminished re-experiencing of the past and diminished simulation of the future, concluding that visual imagery is an important tool for the dynamic retrieval and recombination of episodic details during mental simulation. (PubMed) These findings support the view that vivid imagery contributes especially to the reliving component of autobiographical memory.

The distinction should be framed carefully. Aphantasia does not imply the absence of autobiographical knowledge. It suggests a change in the format of access. Aphantasic individuals may retrieve events through semantic memory, narrative summaries, emotional meanings, temporal ordering, verbal labels, spatial facts, or social knowledge. The remembered event may be accessible as a structured history rather than as a sensory scene. Hyperphantasic individuals may retrieve events through a more richly reconstructed sensory field, where lighting, color, faces, objects, spatial arrangement, and affective tone are more available to consciousness. The difference is therefore between autobiographical memory as organized knowledge and autobiographical memory as sensory reconstruction, with most people falling between these extremes.

Bainbridge and colleagues provide an especially useful empirical dissociation. In a drawing-from-memory study, individuals with aphantasia produced fewer objects and object details than controls when drawing remembered scenes, but their spatial placement was relatively preserved. The authors interpreted this as evidence for a dissociation between object and spatial content in memory representations. (ScienceDirect) This result is highly relevant to the present framework. It indicates that aphantasia does not simply erase internal structure. Spatial scaffolding can remain available even when sensory object detail is reduced. Aphantasic memory may preserve layout, relational geometry, and schematic organization while losing some of the perceptual richness that supports reliving.

This object-spatial dissociation fits the progressive imagery modification model. Reser’s 2016 article distinguishes enduring higher-order representations in association cortex from transient sensory maps in lower-order systems, and it argues that sensory areas integrate features into maps constrained by environmental regularities. In aphantasia, the higher-order elements of autobiographical memory may remain sufficiently organized to support identity, factual recall, and relational structure, while the sensory map contributes less vividly to conscious experience. In hyperphantasia, the same higher-order autobiographical representations may more strongly recruit sensory reconstruction, allowing the remembered event to become a detailed internal scene that can feed new affective and associative material back into the stream of thought.

This has consequences for selfhood. A self built with less sensory reliving may be organized more strongly around facts, values, interpretations, commitments, roles, and narrative summaries. A self built with highly vivid imagery may be organized more strongly around relivable episodes, sensory scenes, emotional re-entry, and richly simulated futures. This is a hypothesis rather than an established typology, but it follows naturally from the existing memory literature. Aphantasia may encourage a more semantic or interpretive autobiographical style, while hyperphantasia may encourage a more episodic and scene-saturated autobiographical style.

The ecological function of autobiographical memory is preparation rather than storage alone. Past events are useful because they allow the organism to extract patterns, anticipate recurrence, avoid danger, repeat success, understand others, and maintain continuity of identity over time. Hyperphantasia may support this function by allowing past scenes to be re-entered and recombined into vivid future simulations. Aphantasia may support the same function through abstraction: extracting lessons, rules, causal relations, and social meanings without requiring sensory reliving. Each style has possible strengths. Reliving can make the past emotionally instructive and future action more concrete. Abstraction can protect against unnecessary re-exposure, reduce distracting detail, and preserve generalizable knowledge.

The contrast becomes especially important when memory feeds future thought. The same systems used to reconstruct the past are involved in simulating possible futures, and the aphantasia literature suggests that reduced imagery can affect both directions of mental time travel. (PubMed) In hyperphantasia, the future may be pre-experienced as a scene with sensory and emotional force. In aphantasia, the future may be represented as a plan, rule, sequence, probability, intention, or verbal proposition. Both forms can guide behavior. The difference lies in whether future affordances are rendered into an internal world or compressed into an actionable structure.

5. Emotion, threat, and social simulation

Mental imagery is a powerful emotional amplifier because it can make absent events feel present. A threat that is described verbally remains abstract until it is converted into a scene with sensory, bodily, and affective structure. A future embarrassment becomes more potent when one can imagine the room, the faces, the silence, and the social consequences. A remembered loss becomes more immediate when the person, place, or moment is reconstructed in sensory detail. Hyperphantasia may strengthen this conversion from meaning to felt presence, while aphantasia may weaken one major route through which verbal or conceptual content becomes emotionally embodied.

The clearest experimental evidence comes from fear imagery. Wicken, Keogh, and Pearson found that people with aphantasia showed significantly reduced physiological fear responses, measured by skin conductance, while reading frightening scenarios. Their responses to perceptually presented frightening images were not similarly reduced, indicating that the effect was specific to internally generated imagery rather than to fear responsiveness in general. This finding supports a central claim of the present article: sensory imagery can function as an affective bridge between abstract knowledge and embodied response.

In ecological terms, imagery allows the organism to respond emotionally to absent affordances. A predator that is no longer present, a future social risk, a remembered injury, or a possible opportunity can be simulated with enough sensory detail to recruit bodily preparation. This capacity has obvious adaptive value, because organisms must often prepare for events before they occur and learn from events after they have passed. Hyperphantasia may intensify this preparation by rendering absent dangers and opportunities as quasi-perceptual fields. Aphantasia may reduce the affective force of absent scenes, while preserving other routes to emotion, such as conceptual appraisal, interoception, moral judgment, verbal meaning, and learned associations.

This emotional contrast should not be reduced to emotional richness versus emotional poverty. Aphantasic individuals can experience strong emotion, and hyperphantasic individuals need not be emotionally dysregulated. The difference concerns one pathway into emotion: the conversion of internally generated content into sensory-like simulation. A person with aphantasia may feel fear because a situation is understood as dangerous, because the body is already aroused, or because the concept has learned emotional value. A person with hyperphantasia may feel fear because the danger is understood and because it is vividly rendered in a form that recruits perceptual and bodily systems.

This distinction has implications for worry, desire, shame, grief, nostalgia, and trauma. Hyperphantasia may make future possibilities more emotionally actionable by allowing them to be pre-experienced. That can support planning, empathy, artistic immersion, and social anticipation, but it may also increase the force of intrusive imagery, anticipatory anxiety, craving, regret, or rumination. Aphantasia may limit visual intrusions or reduce the sensory vividness of imagined harm, while still allowing distress to occur through verbal, bodily, semantic, or affective channels. PTSD and trauma-related imagery should therefore be approached carefully: imagery vividness may shape the form of intrusive experience, but it should not be treated as a simple shield or risk factor on its own.

Social simulation provides a further extension of the same mechanism. Human social life requires the anticipation of absent minds: what another person might say, how a facial expression might change, how a room might feel, how a gesture might be interpreted, and how an apology or accusation might unfold. Hyperphantasia may support scene-like social rehearsal, allowing the person to internally stage possible conversations and detect emotional affordances within them. Aphantasia may support social anticipation through scripts, rules, explicit perspective taking, verbal reasoning, bodily feeling, and past-learned social knowledge. Both strategies can be effective, but they provide different kinds of information to consciousness.

Reser’s progressive imagery modification model gives a useful mechanistic interpretation of this process. Higher-order representations can be held active while lower-order sensory systems generate topographic maps, and those maps can return new features, constraints, and associations to the next cognitive state. The model explicitly proposes that sensory areas may elaborate top-down specifications with unforeseen but associated embellishments, adding new material to the stream of thought. In emotional and social cognition, those embellishments may include a remembered facial expression, a threatening posture, a comforting tone of voice, a spatial cue, or an anticipated reaction. The image thereby becomes a source of affective and social inference.

This leads to a broader ecological interpretation. Hyperphantasia renders absent social and emotional affordances, allowing them to be inspected and felt before direct action. Aphantasia compresses those affordances into concepts, meanings, bodily responses, scripts, and external cues. Hyperphantasia may therefore increase the emotional availability of absent worlds, while aphantasia may reduce sensory reliving and place greater emphasis on abstract appraisal and present perception. The difference matters because emotion is partly a preparation for action, and imagery is one way the brain prepares for action toward things that are not currently there.

6. Attention, problem solving, creativity, and external scaffolding

Mental imagery can function as an attentional template. When a person searches for a lost object, imagines the shape of a tool, anticipates the layout of a room, or mentally rehearses a gesture, internally generated sensory content can bias perception toward relevant features. In this role, imagery is an instrument for active search. It prepares the perceptual system for what might be encountered, and it can make absent affordances temporarily available to attention before the environment supplies them directly.

This function is supported by visual-search findings. Monzel and colleagues examined whether aphantasic individuals show reduced attentional guidance from visual imagery and reported evidence that visual imagery can influence visual search, with aphantasic participants showing less benefit under task conditions designed to depend on imagery-based guidance. A later hidden-object study, “Where’s Wanda?”, likewise examined visual search in relation to imagery vividness and found that imagery vividness can matter for search speed in complex pictures. These studies suggest that mental images can serve as functional search templates, guiding attention toward anticipated perceptual structure.

Aphantasia therefore provides evidence for strategy substitution. When vivid internal templates are unavailable or weak, the person can still search, reason, remember, design, and solve problems, but may rely more heavily on other formats. These can include verbal labels, semantic features, spatial rules, categorical distinctions, motor routines, explicit checklists, external diagrams, written notes, sketches, measurements, or direct perceptual sampling. Aphantasic cognition may therefore move some of the work normally done by internal sensory maps into language, structure, action, and the external world.

Working-memory findings are consistent with this interpretation. Keogh and colleagues found no group differences between aphantasic individuals and controls in visual, general-number, or spatial working-memory capacity, while reporting differences in the strategies participants used to perform the tasks. This is important because it shows that vivid imagery is not required for successful performance on many tasks that appear visually mediated. The aphantasic mind may solve such tasks through alternative representational routes, using compressed or relational formats in place of conscious sensory rendering.

Mental rotation gives a similar message. A 2024 study reported that aphantasic participants were slower but more accurate on classic mental-rotation tasks, with evidence for differences in strategy use. This pattern is compatible with the distinction between sensory immersion and structural computation. Hyperphantasic individuals may manipulate a quasi-perceptual object internally, whereas aphantasic individuals may rely more on rules, spatial relations, motor transformations, or stepwise reasoning. The performance outcome may be similar or even superior under some conditions, while the cognitive route differs.

Creativity can be understood in the same way. Hyperphantasia may support internal sketching, cinematic imagination, scene construction, visual recombination, and repeated inspection of internally rendered possibilities. A writer may see the scene before describing it; an architect may inspect a room before drawing it; a musician may internally hear variations before externalizing them; a designer may visualize how parts fit together before building a prototype. Such imagery can participate in progressive imagery modification by returning clues, constraints, and affordances to the next cycle of thought.

Aphantasic creativity may be more externalized, iterative, symbolic, or procedural. The aphantasic artist, scientist, engineer, or writer may discover structure through marks on paper, diagrams, equations, models, physical manipulation, language, analogy, or interaction with tools. This should be treated as a different creative ecology, not as an impoverished version of visual creativity. Zeman’s 2024 review notes that aphantasia has been variably associated with scientific occupations and that the absence or reduction of imagery does not entail absence of imagination.

Reser’s 2016 model provides a useful mechanism for this contrast. The model proposes that higher-order representations held in state-spanning coactivity can guide the construction of topographic sensory maps, and that these maps can feed salient features back into the evolving stream of thought. Hyperphantasia may therefore increase the role of internally generated sensory maps as problem-solving spaces. Aphantasia may shift more of that problem-solving burden toward compressed representations and external scaffolds. In both cases, cognition remains iterative, but the working medium differs.

This distinction has ecological significance. Internal imagery can allow an organism to search a possible environment before entering it, test a plan before acting, or evaluate an affordance before it becomes perceptually present. External scaffolding can accomplish similar work through drawing, writing, measuring, manipulating, and building. Hyperphantasia may favor internal laboratories; aphantasia may favor external laboratories. Both strategies transform possibilities into usable constraints for thought and action.

7. Mechanisms and contested questions: Conscious imagery, unconscious imagery, and sensory gain

The mechanisms underlying aphantasia and hyperphantasia remain contested. The simplest interpretation would place them on a single vividness scale, with aphantasia reflecting weak imagery and hyperphantasia reflecting strong imagery. That description is useful, but it does not fully explain the range of findings. Aphantasia may involve weak top-down drive from association cortex to sensory cortex, weak sensory reconstruction, reduced feedback from sensory maps into higher-order thought, altered conscious access to internally generated sensory activity, or differences in metacognitive reporting. Hyperphantasia may involve stronger top-down recruitment, stronger sensory stabilization, stronger feedback, or greater conscious integration of internally generated sensory representations.

Physiological work supports the view that imagery vividness has measurable bodily correlates. Kay, Keogh, and Pearson found that typical imagers showed pupillary responses when imagining bright versus dark objects, while individuals with aphantasia showed no significant imagery-driven pupillary light response despite normal perceptual pupil responses and cognitive-load-related dilation. This finding is important because it links visual imagery to sensory physiology. It suggests that in typical imagery, imagined light and darkness can recruit visual-system processes strongly enough to influence the pupil, while in aphantasia this route is greatly weakened or unavailable.

At the same time, recent neural evidence complicates the claim that aphantasia means a complete absence of sensory-format activity. Chang and colleagues reported that early visual cortex activity during attempted imagery could contain decodable information in aphantasic participants, introducing the idea of “imageless imagery.” The result suggests that some internally generated visual information may exist without ordinary conscious visual experience. This possibility is especially important for theories of consciousness because it separates sensory representation from vivid subjective access.

This creates several mechanistic possibilities. In one account, aphantasia arises because higher-order concepts do not strongly activate sensory maps. In another, sensory maps are generated but lack sufficient strength, stability, or recurrent integration to become vivid. In a third, sensory activity exists but does not feed back into the evolving conscious stream with enough force to be experienced as imagery. In a fourth, imagery exists in a transformed format, such as spatial, semantic, motoric, affective, or nonvisual representation, and is therefore not reported as visual experience. These accounts are not mutually exclusive, and aphantasia may include multiple subtypes.

Reser’s icSSC framework is useful because it separates the maintenance of higher-order content from the rendering of lower-order topographic maps. The 2016 article describes mental continuity as the incremental updating of a set of coactive representations, and the 2022 arXiv article extends the same principle into a cognitive architecture in which working memory is updated iteratively through partially preserved and newly recruited active representations. In this framework, aphantasia can be interpreted as a reduction in the conscious sensory-rendering contribution to iterative thought, while hyperphantasia can be interpreted as an amplification of that contribution. The central mechanism is not simple visual cortex activity; it is the degree to which sensory reconstruction enters, enriches, and redirects the ongoing working-memory cycle.

The concept of simulation gain can organize these mechanisms. Simulation gain refers to the strength with which higher-order representations recruit, stabilize, and integrate lower-order sensory reconstructions. Low conscious sensory simulation gain would produce aphantasic cognition: concepts, plans, memories, and spatial relations remain available, while vivid topographic rendering contributes little to conscious thought. High conscious sensory simulation gain would produce hyperphantasic cognition: concepts and memories strongly recruit sensory systems, producing vivid internal scenes that can be inspected, modified, emotionally inhabited, and used for affordance discovery.

A second contested issue concerns voluntary and involuntary imagery. Many people with aphantasia report dreams or other spontaneous imagery despite weak voluntary waking imagery, although reviews caution that the voluntary-involuntary distinction is more complex than early descriptions suggested. Voluntary imagery may depend more heavily on deliberate top-down specification from association cortex, whereas dreams, flashbacks, and spontaneous images may rely more strongly on hippocampal, affective, sensory, or associative generative processes. This distinction could explain why an individual may be unable to call up a visual image intentionally while still experiencing imagery in sleep or under unusual states.

A third contested issue concerns whether vividness implies accuracy. Hyperphantasic imagery may feel perceptually rich, but vividness does not guarantee veridical detail. Imagined scenes can contain embellishments, distortions, emotional exaggerations, and false perceptual confidence. Aphantasic imagery may contain fewer sensory details, but this could reduce some forms of false visual embellishment while preserving schematic or semantic accuracy. The drawing-from-memory literature, where aphantasic participants produced fewer object details but preserved spatial placement, supports the broader principle that visual richness and structural organization can dissociate.

The strongest mechanistic conclusion is therefore pluralistic. Aphantasia and hyperphantasia probably do not differ along a single axis alone. They involve variation in top-down drive, sensory reconstruction, feedback integration, conscious access, metacognitive report, strategy use, and reliance on external scaffolding. The useful theoretical contrast is between low and high participation of sensory maps in progressive cognitive updating. Hyperphantasia renders concepts into sensory worlds that can return new affordances to thought. Aphantasia reduces reliance on that rendered loop and shifts cognition toward other representational economies.

8. Ecological synthesis, predictions, and conclusion

The ecological question is why internal imagery exists at all. Mental imagery allows absent things to become actionable. It permits organisms to anticipate danger, remember routes, prepare tool use, rehearse social behavior, imagine consequences, compare alternatives, and simulate futures before acting. In this sense, imagery is offline perception: a way of constructing provisional affordance fields when the relevant environment is absent, hidden, delayed, or hypothetical.

Aphantasia and hyperphantasia may be two strategies for solving this problem. Hyperphantasia renders absent affordances into vivid internal scenes. It allows internally generated worlds to be inspected, emotionally felt, and progressively modified. Aphantasia compresses absent affordances into concepts, relations, language, rules, spatial schemas, bodily procedures, and external scaffolds. It allows absent worlds to guide action without requiring vivid sensory reliving.

This contrast generates several predictions. In autobiographical memory, aphantasia should be associated with more semantic, factual, narrative, or interpretive recall, while hyperphantasia should be associated with richer sensory reliving and more detailed episodic reconstruction. In future thought, aphantasia should favor contingency planning, verbal structure, and abstract sequencing, while hyperphantasia should favor pre-experiencing possible futures as scenes. In emotion, aphantasia should show weaker imagery-driven amplification of absent threats or desires, while hyperphantasia should show stronger affective responses to imagined scenes. In visual search and design, aphantasia should rely more on rules, labels, external marks, and direct perception, while hyperphantasia should rely more on internal visual templates and scene inspection.

The article also predicts different vulnerabilities. Hyperphantasia may increase the intensity of intrusive imagery, anticipatory anxiety, shame, craving, nostalgia, grief, or trauma-related sensory reliving when internally generated scenes become affectively powerful. Aphantasia may reduce visual intrusions or weaken one route to imagery-based fear, while leaving other distress pathways intact, including verbal rumination, bodily arousal, semantic threat appraisal, and affective memory. These differences should be studied without treating aphantasia as protection or hyperphantasia as pathology. They are differences in how absent information becomes present to consciousness.

Research should therefore measure more than vividness ratings. Studies should distinguish voluntary and involuntary imagery, visual and nonvisual modalities, object detail and spatial structure, imagery vividness and imagery accuracy, internal and external strategy use, emotional embodiment, attentional-template strength, and metacognitive access. Physiological measures such as pupillary response, neural decoding, psychophysics, eye tracking, actigraphy of behavior during problem solving, and ecological momentary reports could all help determine how imagery contributes to real-world cognition. The most informative studies would compare not simply whether participants can form images, but whether sensory reconstruction changes what they notice, remember, feel, infer, and do.

This approach also reframes the relation between aphantasia and creativity. Hyperphantasia may support creativity through internal rendering, inspection, recombination, and sensory exploration. Aphantasia may support creativity through abstraction, conceptual compression, externalization, and iterative interaction with tools and marks. The latter route may be especially important in science, engineering, mathematics, writing, design, and any domain where external representations can serve as working surfaces. The cognitive ecology differs, but both forms can generate novelty.

The broader implication concerns consciousness. The aphantasia-hyperphantasia spectrum shows that conscious thought is not bound to one representational format. A person can think consciously through words, meanings, spatial relations, motor tendencies, bodily feelings, external marks, and abstract concepts, as well as through vivid sensory imagery. Reser’s 2016 and 2022 models help explain this plurality by distinguishing sustained higher-order representations from the lower-order maps that may be recruited during iterative working-memory updating. Sensory rendering is one powerful route through which concepts become actionable, but it is not the only route.

The final synthesis is that aphantasia and hyperphantasia are cognitive ecologies of internal simulation. Hyperphantasia uses rendered scenes to discover affordances, embody emotion, reconstruct memory, and rehearse possible futures. Aphantasia uses compressed representations and external scaffolds to achieve many of the same goals with less conscious sensory rendering. The difference is not imagination versus absence of imagination. It is a difference in how the mind transforms concepts into usable possibilities for thought and action.