Mazviita Chirimuuta

Colours appear to instantiate a number of structural properties: for instance, they stand in distinctive relations of similarity and difference, and admit of a fundamental distinction into unique and binary. Accounting for these structural properties is often taken to present a serious problem for physicalist theories of colour. This paper argues that a prominent attempt by Byrne and Hilbert to account for the structural properties of the colours, consistent with the claim that colours are types of surface spectral reflectance, is unsuccessful. Instead, it is suggested that a better account of the structural properties of the colours is provided by a form of non-reductive physicalism about colour: a naïve realist theory of colour, according to which colours are superficial mind-independent properties

Reflectance realism is an important position in the philosophy of colour. This paper is an examination of David R. Hilbert’s case for there being scientific support for the theory. The specific point in question is whether colour science has shown that reflectance is recovered by the human visual system. Following a discussion of possible counter-evidence in the recent scientific literature, I make the argument that conflicting interpretations of the data on reflectance recovery are informed by different theoretical assumptions about the nature of
colour, and of perception. If this is so, there cannot be neutral empirical
evidence on this point, and this does seem to undermine Hilbert’s claim for
empirical support. In the end, I suggest alternative ways of thinking about the relationship between colour ontology and empirical work on colour.

What is colour vision for? In the popular imagination colour vision is for “seeing the colours” — adding hue to the achromatic world of shape, depth and motion. On this view colour vision plays little more than an ornamental role, lending glamour to an otherwise monochrome world. This idea has guided much theorising about colour within vision science and philosophy. However, we argue that a broader approach is needed. Recent research in the psychology of colour demonstrates that colour vision is integral to a variety of visual processes, helping us to perform many types of visual tasks. We discuss some of this research and consider its implications for philosophical theories of colour

While introspective methods went out of favour with the decline of Titchener’s analytic school, many important questions concern the rehabilitation of introspection in contemporary psychology. Hatfield rightly points out that introspective methods should not be confused with analytic ones, and goes on to describe their “ineliminable role” in perceptual psychology. Here I argue that certain methodological conventions within psychophysics reflect a continued uncertainty over appropriate use of subjects’ perceptual observations and the reliability of their introspective judgements. My first claim is that different psychophysical methods do not rely equally on the introspective capabilities of experimental subjects. I contrast “minimally-introspective” tasks with “introspection-heavy” ones. It is only in the latter, I argue, that introspection can be said to have a non-trivial role in the subjects’ performance. My second claim is that my rough-and-ready distinction maps onto a number of important “dichotomies” in vision science. Not coincidentally, the introspection-heavy categorisation captures many of the tasks typically considered less able to yield useful information regarding the processes underlying visual sensation.

The concept of the receptive field, first articulated by Hartline, is central to visual neuroscience. The receptive field of a neuron encompasses the spatial and temporal properties of stimuli that activate the neuron, and, as Hubel and Wiesel conceived of it, a neuron’s receptive field is static. This makes it possible to build models of neural circuits and to build up more complex receptive fields out of simpler ones. Recent work in visual neurophysiology is providing evidence that the classical receptive field is an inaccurate picture. The receptive field seems to be a dynamic feature of the neuron. In particular, the receptive field of neurons in V1 seems to be dependent on the properties of the stimulus. In this paper, we review the history of the concept of the receptive field and the problematic data. We then consider a number of possible theoretical responses to these data.

This article examines three candidate cases of non-causal explanation in computational neuroscience. I argue that there are instances of efficient coding explanation that are strongly analogous to examples of non-causal explanation in physics and biology, as presented by Batterman, Woodward, and Lange. By integrating Lange’s and Woodward’s accounts, I offer a new way to elucidate the distinction between causal and non-causal explanation, and to address concerns about the explanatory sufficiency of non-mechanistic models in neuroscience. I also use this framework to shed light on the dispute over the interpretation of dynamical models of the brain. _1_ Introduction _1.1_ Efficient coding explanation in computational neuroscience _1.2_ Defining non-causal explanation _2_ Case I: Hybrid Computation _3_ Case II: The Gabor Model Revisited _4_ Case III: A Dynamical Model of Prefrontal Cortex _4.1_ A new explanation of context-dependent computation _4.2_ Causal or non-causal? _5_ Causal and Non-causal: Does the Difference Matter?