Alison Springle (University of Pittsburgh), Alessandra Buccella (University of Pittsburgh)
Sometimes, perception seems to present the same thing in different ways – a phenomenon we will refer to as phenomenal variation. Several philosophers have argued that some phenomenal variation is systematic on the basis of certain empirical findings. Some of these findings strongly suggest the attention impacts phenomenal character. For instance, Carrasco et al. (1998, 2004) found that subjects’ perceived contrast of a Gabor patch differs systematically depending on whether or not a patch is being foveated (attended). In addition, Sperling (1960) showed that cueing attention after a grid of alphanumeric characters is presented for about 0.5 seconds influences how many characters are correctly identified and reported by subjects. But attention isn’t the only phenomenology-impacting factor. Bouma (1970) demonstrated that phenomenal character can change in response to the so-called “crowding effect”: the more “crowded” a perceptual scene, the less precise or determinate are the properties subjects report, and vice versa.
Ned Block (2010, 2012, 2015) argues that systematic phenomenal variation as demonstrated in these experiments poses a serious challenge to representational accounts of perceptual phenomenology. According to representationalism, perceptual phenomenology is fully determined by representational content (e.g. Harman 1990; Tye 1995, 2000, 2009; Dretske, 1995). Block’s argument goes as follows:
(1) According to representationalism, phenomenal variation is directly explained (and determined) by changes in representational content.
(2) Phenomenal variation can be satisfactorily explained by changes in representational contents only if such contents are conceived as “intervallic” (Block 2015, 3), that is, if they specify a range, where the actual value is within the represented range in order to preserve veridicality.
(3) However, phenomenal character is more determinate than any range content (i.e. there is always a single way something looks, even if the subject cannot always report it.)
(4) Therefore, intervallic contents do not fully explain phenomenal variation in terms of representational content.
(5) From (1), (2), and (4) it follows that, more generally, phenomenology cannot be fully determined by representational content, and thus representationalism is false.
A number of representationalists have attempted to resist Block’s argument by developing accounts of intervallic contents that they claim are the right kind of tool to accommodate phenomenal variation. We will consider two classes of proposals that have emerged. The first appeals to notions like “perceptual precision” or “determinable/determined properties” (Nanay 2010, Stazicker 2011). The second appeals to notions of probabilistic percepts (e.g. Morrison 2016).
Our principal aim is to clarify problematic ambiguities in these proposals concerning what part of perceptual representation explains phenomenology. We 1) identify the components of perceptual representations (content, vehicle, force) depending on how representation is conceived (e.g. Russellian vs. Fregean), 2) identify for each component how it might plausibly contribute to perceptual phenomenology, and 3) interpret the intervallic proposals according to these components. In light of what this clarificatory analysis, we argue that it is ultimately the phenomenal vehicle of the representation rather than the content that most plausibly explains phenomenal variation. Consequently, the prospects for the intervallic replies to Block’s argument are poor.
