The puzzle of cross‐modal shape experience

Abstract

The puzzle of cross-modal shape experience is the puzzle of reconciling the apparent differences between our visual and haptic experiences of shape with their apparent similarities. This paper proposes that we can resolve the cross-modal puzzle by reflecting on another puzzle. The puzzle of perspectival character challenges us to reconcile the variability of shape experience through shifts in perspective with its constancy. An attractive approach to the latter puzzle holds that shape experience is complex, involving both perspectival aspects and constant aspects. I argue here that parallel distinctions between perspectival and constant aspects of shape experience arise in sight and touch, and that perspectival aspects are modality-specific while at least some constant aspects are constitutively multisensory. I then address a powerful challenge to the idea that aspects of spatial phenomenology are shared cross-modally.

Empirical evidence for perspectival similarity.

“…If Burge and Burge find our claim obvious, so be it; this means only that our experiments were not designed for them. If anything, they or anyone else with that feeling could see our results as complementary to their views, providing additional empirical support for a position they accept but that others reject (as in Green, 2021). 13…”

“…We think this omission matters, because it leads Burge and Burge to misinterpret our claims and criticize views we do not hold. Instead of reading us as other scholars have (e.g., Cheng, 2022; Cohen, 2021; Daoust, 2021; Hill, 2022; and especially Green, 2021, who reviews the same sources and context and then characterizes our views accurately and as intended: “visual experiences of the slanted circle and head-on ellipse are similar in some respect”), Burge and Burge exoticize our claims, attributing to us the proposal that “a new entity” should be introduced into the science of perception and interpreting this entity as being located “in some intermediate position(s) between the distal shape and the retinal image.” This is not our claim. It is possible that some philosophers conceive of perspectival appearance along these lines (perhaps, e.g., in Hill, 2016’s discussion of “Thouless properties”; though even Hill suggests that what we are aware of are viewpoint-dependent relational properties of the perceived object , not some intermediate, separate entity located between the perceiver and the object).…”

Spatial representations in sensory modalities

“…Cf.,Green (2021a): "I argue here that parallel distinctions between perspectival and constant aspects of shape…”

“…The first is the view he is recommending, called the ‘type identity view’, according to which ‘vision and touch generate tokens of the same representation type’ (p. 3). The second is called the ‘rational link view’ (Evans, 1985), according to which ‘vision and touch generate distinct representation types that are … rationally linked’ (Green, 2021a, 2021b, p. 3). And finally, the ‘structural correspondence view’ has it that ‘vision and touch generate distinct representation types that, while not rationally linked, exhibit a structural correspondence that enables the subject to make reasonable inferences about whether seen and felt shapes are the same [Cheng, 2019, 2020; Leibniz, 1765/1981]’ (Green, 2021b, p. 3).…”

Philosophy of Perception in the Psychologist’s Laboratory

“…This finding too has fed back into philosophical discussions, with some arguing that "perspectival similarity is real and efficacious" (Green, 2021), others questioning the theoretical implications (see, e.g., Burge and Burge, 2022, and replies by Morales andFirestone, 2023 andCheng et al, 2022), and still others suggesting follow-up experiments to explore this issue further (Cheng, 2022).…”