Christian O. Scholz

Aphantasia, the strong diminution or complete absence of mental imagery, challenges long-standing views of imagery as central to cognition. Competing accounts variously explain the phenomenon as a failure of sensory reactivation or as unconscious mental imagery. Here, we propose a new framework, the integration model of aphantasia, which argues that reactivated sensory information must undergo multi-stage integration to yield imagery experience. Against unconscious imagery accounts, we argue that the neural activations observed in aphantasics are not imagery but sensory precursors: rudimentary sensory codes that lack perceptual status. Only when sensory precursors are locally integrated do they become perceptual representations, and only when these are further integrated with interoceptive signals do they give rise to conscious imagery experience. We present the integration model as a dual-stream framework that unifies recent attention- and interoception-based accounts, situate it within existing theories of mental imagery and aphantasia, and highlight its clinical relevance. In doing so, we reframe the debate on unconscious imagery and draw attention to the role of multi-stage integration as a key mechanism underlying mental imagery and its absence across different subtypes of aphantasia.

In his recent book Mental imagery: Philosophy, psychology, neuroscience, Nanay presents a far-reaching empirically grounded account of mental imagery. This commentary focuses on Nanay's proposal that individuals with aphantasia, a cognitive norm variant characterized by an absence of imagery experience, have unconscious mental imagery. Recent empirical findings on aphantasia are reviewed, and evidence both for and against voluntary and involuntary unconscious mental imagery in aphantasia is discussed in the context of Nanay's general account of mental imagery and its taxonomy. It is argued that people with aphantasia, contrary to Nanay's proposal, do not possess unconscious mental imagery.

Aphantasia, namely the inability to voluntarily form visual mental imagery, does not, counterintuitively, impair the affected from successfully performing mental imagery tasks. One way of explaining this finding is to posit that aphantasics, despite their claim to the contrary, can form visual imagery, a position here referred to as aphantasia skepticism. This article outlines and rejects two types of aphantasia skepticism and argues that the position results from what is coined the visualizer’s fallacy, namely the false belief that visual mental imagery is necessary to carry out mental imagery tasks. Furthermore, it is argued that the visualizer’s fallacy and the resulting aphantasia skepticism are not only potentially harmful to aphantasics but may also lead to an impoverished view of the dynamics of cognition in general.

Aphantasia, i.e., the inability to voluntarily form visual mental images, affects approximately 2 to 5 percent of the population and plays an important role in a more general debate revolving around the role of imagery for our cognition. This thesis investigates aphantasia by means of an interdisciplinary approach, combining insights from contemporary neuroscientific research with historical philosophical arguments, with a specific focus on the later philosophy of Ludwig Wittgenstein. A new theoretical concept, meta-imagination, is developed and it is argued that the concept can explain why aphantasics perform successfully on a wide range of visual imagery tasks, thus providing important implications for the more general debate about the connection between imagery and cognition.