Sacha Behrend
Affiliation: Université Paris I Panthéon Sorbonne
Category: Philosophy
Keywords: Mental Imagery Bence Nanay Margherita Arcangeli
Date: Thursday 4th of September
Time: 17:30
Location: Maria Skłodowska-Curie Hall (123)
View the full session: Imagination
This paper addresses the surprisingly difficult task of defining mental imagery. It argues against recent influential definitions, those by Bence Nanay (2023) and Margherita Arcangeli (2020), and proposes an alternative definition that avoids their limitations.
Bence Nanay (2023) defines mental imagery as perceptual processing (i.e., processing in the primary sensory cortices V1, V2, V4/V8, MT) that is not triggered directly by sensory input. However, this definition faces several challenges. First, it is either too permissive or too restrictive (Green & Lande, 2024). If direct triggering by sensory input is interpreted loosely, then all perceptual states could qualify as mental imagery. Conversely, a stricter interpretation risks classifying many well-established cases of mental imagery as a form of perception. Second, Nanay’s definition fails to delineate a coherent natural kind, as the notion of indirect triggering applies to a heterogeneous set of phenomena that lack a unifying explanatory property (Green & Lande, 2024). Finally, it leads to the counterintuitive classification of amodal completion as a form of mental imagery. Green and Lande (2024) argue that this move lacks explanatory value, as amodal completion is better grouped with perceptual processes that are contextually influenced but still directly triggered by sensory input.
On the other hand, Margherita Arcangeli (2019) distinguishes two senses of mental imagery: as a psychological attitude and as a type of mental content. In the first sense, mental imagery refers to a re-creation or simulation of perception, producing mental experiences that are phenomenologically and/or functionally similar to perceptual ones. For example, imagining a flower involves forming a mental state that resembles actually seeing that flower, though this resemblance is only partial. Arcangeli identifies two key differences between perception and mental imagery: (1) phenomenological differences, such as variations in vividness and control over the experience, and (2) functional differences, particularly the fact that perception is constitutively related to truth, while mental imagery is not. Unlike perception, mental imagery does not inherently convey veridical information about the external world.
In its second sense, mental imagery refers to a specific type of content rather than a mode of mental processing. This perspective emphasizes that mental imagery mimics perceptual content by explicitly representing spatial and structural information, even when detached from sensory input. However, this content is less detailed and information-rich than perception, as it is based on stored representations or creative construction rather than direct sensory stimulation. Arcangeli follows previous theorists in arguing that this results in a loss of perceptual precision. Imagining a flower may include its general shape and color, but it lacks the fine-grained details provided by direct perception.
Despite these insights, Arcangeli’s account has several shortcomings. First, I argue that she misconstrues certain subpersonal processes as personal-level phenomena. In particular, the attitudinal sense of mental imagery is better understood as a subpersonal process rather than a conscious psychological attitude. Recognizing that key aspects of mental imagery operate at a subpersonal level reveals that the term “mental imagery” is used in three rather than two primary senses. Additionally, Arcangeli’s account does not provide a unified definition that would allow psychologists and neuroscientists to apply her framework in empirical research.
To address these limitations, I propose a new definitional approach to mental imagery. Building on Arcangeli’s approach, I first examine the varied uses of “mental imagery” in both philosophical and scientific literature. Psychological research refers to mental imagery in multiple ways, including afterimages, eidetic imagery, memory imagery, and imagination imagery (Richardson, 1969; Finke, 1989). By contrast, philosophers have used mental imagery to refer to phenomenal experience, neural representations, or intentional objects (Block, 1981; Arcangeli, 2020). These diverse uses reveal conceptual ambiguity, requiring a clearer theoretical framework.
I identify five key meanings in the various uses of mental imagery: (a) a phenomenal experience, (b) a format for mental representations, (c) a memory process, (d) an imaginative process, and (e) the persistence of a visual representation after a stimulus disappears.
However, I argue that these can be reduced to three core referents necessary for crafting a precise definition:
(a') Phenomenal experience, (b') A representational format, and (c') A mental/neural process.
Additionally, I challenge the assumption that phenomenal experience is either necessary or sufficient for defining mental imagery, although it often accompanies it. Based on this analysis, I propose the following definition:
Mental imagery is (i) a top-down, quasi-perceptual process (ii) producing analog/depictive mental representations.
This definition captures both the processual and representational aspects of mental imagery, ensuring it remains distinct from perception. By refining the concept in this way, this paper contributes to greater clarity in the theoretical and empirical literature on mental imagery, imagination and perception.