DOES PERCEPTION OUTSTRIP OUR CONCEPTS IN FINENESS OF GRAIN?

We seem perfectly able to perceive fine‐grained shades of colour even without possessing precise concepts for them. The same might be said of shapes. I argue that this is in fact not the case. A subject can perceive a colour or shape only if she possesses a concept of that type of colour or shape. I provide new justification for this thesis, and do not rely on demonstrative concepts such as THIS SHADE or THAT SHAPE, a move first suggested by John McDowell, but rejected by Christopher Peacocke and Richard Heck among others. 1     

The cost of thinking about false beliefs: evidence from adults' performance on a non-inferential theory of mind task

Much of what we know about other people's beliefs comes non-inferentially from what people tell us. Developmental research suggests that 3-year-olds have difficulty processing such information: they suffer interference from their own knowledge of reality when told about someone's false belief (e.g., [Wellman, H. M., & Bartsch, K. (1988). Young children's reasoning about beliefs. Cognition, 30, 239-277.]). The current studies examined for the first time whether similar interference occurs in adult participants. In two experiments participants read sentences describing the real colour of an object and a man's false belief about the colour of the object, then judged the accuracy of a picture probe depicting either reality or the man's belief. Processing costs for picture probes depicting reality were consistently greater in this false belief condition than in a matched control condition in which the sentences described the real colour of one object and a man's unrelated belief about the colour of another object. A similar pattern was observed for picture probes depicting the man's belief in most cases. Processing costs were not sensitive to the time available for encoding the information presented in the sentences: costs were observed when participants read the sentences at their own pace (Experiment 1) or at a faster or a slower pace (Experiment 2). This suggests that adults' difficulty was not with encoding information about reality and a conflicting false belief, but with holding this information in mind and using it to inform a subsequent judgement.     

Moral Luck and Liability Lotteries

Adversaries of Moral Luck (AMLs) are at pains to explain why wrongdoers are liable to bear burdens (punishment, compensation etc.) which are related to the harm they cause, because the consequences of what we do are a matter of luck. One attempt to solve this problem suggests that wrongdoers who cause more harm are liable to bear a greater burden not because they are more blameworthy but rather because they get the short straw in a liability lottery (represented by the apparently indeterminate causal process). In this paper I argue that this attempt fails on several grounds. Apart from the fact that it is hard to see how the implementation of liability lotteries can be motivated and the fact that such scheme presupposes a political order (whereas the notion of liability does not seem to presuppose one), detaching liability from the outcomes of a culpable action undermines whichever justifications there were for imposing liability in the first place. Moreover, relying on the determination of the causal process as a good indication of the wrongdoer’s degree of culpability is mistaken, because the luck brought about through the causal process is not necessarily the only element involved in cases of harmful conduct which lies beyond the wrongdoers’ control.     

Worldly Indeterminacy: A Rough Guide

This paper defends the idea that there might be vagueness or indeterminacy in the world itself--as opposed to merely in our representations of the world--against the charges of incoherence and unintelligibility. First we consider the idea that the world might contain vague properties and relations ; we show that this idea is already implied by certain well-understood views concerning the semantics of vague predicates (most notably the fuzzy view). Next we consider the idea that the world might contain vague objects ; we argue that an object is indeterminate in a certain respect (colour, size, etc.) just in case it is a borderline case of a maximally specific colour (size, etc.) property. Finally we consider the idea that the world as a whole might be indeterminate; we argue that the world is indeterminate just in case it lacks a determinate division into determinate objects.     

An analogy between colour and spatial coding

The early stages of colour coding are well established in that the trichromatic receptor stage is followed by a set of opponent colour channels. One interpretation of the sequence is that opponent channels carry unrelated aspects of the colour stimulus, unlike the cone channels. The overlap of the cone channels can be removed by decorrelating their spectral-sensitivity functions, and this procedure has been found to give opponent colour channels which match those found psychophysically. Since the known spatial-frequency channels also show considerable overlap, the question arises which aspects of the spatial stimulus are captured by decorrelating the spatial-frequency channels. The results of decorrelating the spatial-frequency channels are that the first decorrelated spatial filter acts as a broad bandpass filter which has a peak sensitivity at 7.9 cycles deg-1, and that the second decorrelated spatial filter acts as an opponent spatial-frequency channel, with a minimum output at a low (4.1 cycles deg-1) spatial frequency and a maximum output at a high (15.1 cycles deg-1) spatial frequency. The characteristics of the first decorrelated filter closely resemble the properties of the foveal perceptive field which have been used to explain the Hermann grid illusion. Thus, the decorrelation analysis produces a model for the functional organisation of the channel implementation at the neural and psychophysical levels, but which directly relates to the subjective appearance of the visual stimuli.     

Training attention: Interactions between central cues and reflexive attention

Three experiments are reported in which we investigate whether the recently reported interactions between central cues (e.g., arrows) and reflexive attention are attributable to the overlearned spatial properties of certain central cues. In all three experiments, a nonpredictive cue with arbitrary spatial properties (a colour patch) is presented prior to a detection target in the left or right visual field. Reaction times to detect targets are compared before and after a training session in which participants are trained to associate each colour patch with left and right space, either via a target detection task in which colour predicts target location 100% of the time (Experiments 1 and 3), or via a left/right motor movement as a function of colour (Experiments 2 and 3). In the first two experiments, a small but highly significant training effect is observed. Participants are approximately 10 ms faster to detect targets at congruent locations relative to incongruent locations after training relative to before training, despite the fact that cue colour was nonpredictive during the test sessions. In Experiment 3, the length of the training session is increased and the magnitude of the training effect also increases as a result. Implications for the interaction between central cues and reflexive attention, as well as premotor theory of attention, are discussed.     

Heuristics and criterion setting during selective encoding in visual decision making: Evidence from eye movements

When making a decision, people spend longer looking at the option they ultimately choose compared to other options—termed the gaze bias effect—even during their first encounter with the options (Glaholt & Reingold, 2009a, 2009b; Schotter, Berry, McKenzie & Rayner, 2010). Schotter et al. (2010) suggested that this is because people selectively encode decision-relevant information about the options, online during the first encounter with them. To extend their findings and test this claim, we recorded subjects' eye movements as they made judgements about pairs of images (i.e., which one was taken more recently or which one was taken longer ago). We manipulated whether both images were presented in the same colour content (e.g., both in colour or both in black-and-white) or whether they differed in colour content and the extent to which colour content was a reliable cue to relative recentness of the images. We found that the magnitude of the gaze bias effect decreased when the colour content cue was not reliable during the first encounter with the images, but no modulation of the gaze bias effect in remaining time on the trial. These data suggest people do selectively encode decision-relevant information online.     

Colour cues or spatial cues? Context-dependent preferences in the European greenfinch (<Emphasis Type="Italic">Carduelis chloris</Emphasis>)

Using featural cues such as colour to identify ephemeral food can increase foraging efficiency. Featural cues may change over time however; therefore, animals should use spatial cues to relocate food that occurs in a temporally stable position. We tested this hypothesis by measuring the cue preferences of captive greenfinches Carduelis chloris when relocating food hidden in a foraging tray. In these standardised associative learning trials, greenfinches favoured colour cues when returning to a foraging context that they had encountered before only once (“one-trial test”) but switched to spatial cues when they had encountered that scenario on ten previous occasions (“repeated-trial test”). We suggest that repeated encounters generated a context in which individuals had a prior expectation of temporal stability, and hence context-dependent cue selection. Next, we trained birds to find food in the absence of colour cues but tested them in the presence of visual distracters. Birds were able to learn spatial cues after one encounter, but only when visual distracters were identical in colouration. When a colourful distracter was present in the test phase, cue selection was random. Unlike the first one-trial test, birds were not biased towards this colourful visual distracter. Together, these results suggest that greenfinches are able to learn both cue types, colour cue biases represent learning, not simply distraction, and spatial cues are favoured over colour cues only in temporally stable contexts.     

A Peircean examination of Gettier’s two cases

If we accept certain Peircean commitments, Gettier’s two cases are not cases of justified true belief because the beliefs are not true. On the Peircean view, propositions are sign substitutes, or “representamens.” In typical cases of thought about the world, propositions represent facts. In each of Gettier’s examples, we have a case in which a person S believes some proposition p, there is some fact F* such that were p to represent F* to S then p would be true, and yet p does not represent F* to S but some other fact F of which p is false. Since truth is a property of propositions with respect to their representational function, it follows that the belief is not true. Although an examination of Gettier’s two cases, this essay is not a defense of the justified true belief (JTB) analysis of knowledge, for there are objections to the JTB analysis other than Gettier’s two cases. Rather, Gettier’s two cases are of particular interest for the light they shed on the nature of truth and representation.

     

Taste and Acquaintance

The analogy between gustatory taste and critical or aesthetic taste plays a recurring role in the history of aesthetics. Our interest in this article is in a particular way in which gustatory judgments are frequently thought to be analogous to critical judgments. It appears obvious to many that to know how a particular object tastes we must have tasted it for ourselves; the proof of the pudding, we are all told, is in the eating. And it has seemed just as obvious to many philosophers that aesthetic judgment requires first‐person experience. In this article we argue that, despite its initial appeal, the claim that gustatory and critical judgments are analogous in this way is mistaken. The two sorts of judgments are, as a matter of fact, similar in their epistemology, but earlier theorists have got things entirely backward—neither gustatory judgment nor aesthetic judgment requires first‐hand acquaintance with their objects. Our particular focus in this article is on arguing that first‐person experience is not required to know how an item of food or drink tastes. In fact, there are a wide variety of ways in which we can acquire this knowledge.     

Moral paternalism,virtue, and autonomy

According to colour irrealism, material objects do not have colour; they only appear to have colour. The appeal of this view, prominent among philosophers and scientists alike, stems in large part from the conviction that scientific explanations of colour facts do not ascribe colour to material objects. To explain why objects appear to have colour, for instance, we need only appeal to surface reflectance properties, properties of light, the neurophysiology of observers, etc.

Typically attending colour irrealism is the error theory of ordinary colour judgement: ordinary judgements in which colour is ascribed to a material object are, strictly speaking, false. In this paper, I claim that colour irrealists who endorse the error theory cannot explain how we acquire colour concepts (yellow, green, etc.), concepts they must acknowledge we do possess. Our basic colour concepts, I argue, could not be phenomenal concepts that we acquire by attending to the colour properties of our experience. And, I explain, all other plausible explanations render colour concepts such that our ordinary colour judgements involving them are often true. Given the explanatory considerations upon which the irrealist's position is based, this is a severe problem for colour irrealism.     

High-spatial-frequency tritanopia: S-filling-in or S-filtering-out?

It has long been an accepted fact that a small test field presented against a large background may change its colour appearance because the test-field background contrast is attenuated by the receptor colour channels unequally (Willmer, 1944 Nature 153 774-775; Hartridge, 1947 Philosophical Transactions of the Royal Society of London, Series B 232 519-671). Such an effect is usually called small-field tritanopia. However, as shown in the present report, a similar colour illusion can be achieved with a large test field as well, provided its spatial-frequency content is high enough to reveal the differential drop of contrast sensitivity for the receptor colour channels (high-spatial-frequency tritanopia). A few demonstrations are presented which show that a traditional explanation of high-spatial-frequency tritanopia (including small-field tritanopia), based on the hypothetical process of filling-in, is not correct. An alternative account, based on spatial filtering within the receptor colour channels, is put forward.     

Psycholphysical 'measurement' of cortical colour mechanisms: reply of Meyer.

In a paper recently published in this journal, Meyer criticised our study on relationships between channels for colour and spatial frequence for not being able to demonstrate a size aftereffect not specific to colour, a McCollough effect not specific to size, or the functions of cortical colour mechanisms. In fact, our study attempted none of these demonstrations in the sense suggested by Meyer because the first would have been impossible for empirical reasons, the second for conceptual reasons, and the third for methodological reasons. Instead, our study yielded evidence that at least three different types of perceptual channel underlie our capacity to perceive the size and colour of objects.     

On describing colours

This paper attempts to refute the familiar sceptical argument based upon the theoretical possibility of systematic transpositions of colours in different observers’ colour‐vision. The force of this argument lies in its apparent demonstration that cases of transposed colour‐vision would be on a quite different cognitive footing from ordinary cases of colour‐blindness; since colour transposition, unlike colour‐blindness, could not possibly have any effect on the use of language by a person who suffered from it. It is argued (1) that this demonstration works only if we assume the truth of a certain theory of the logical nature of our colour vocabulary, and (2) that this theory is false.     

Episodic representation of diagnostic and nondiagnostic object colour

In three experiments, we investigated transsaccadic object file representations. In each experiment, participants moved their eyes from a central fixation cross to a saccade target located between two peripheral objects. During the saccade, this preview display was replaced with a target display containing a single object to be named. On trials in which the target identity matched one of the preview objects, its colour either matched or did not match the previewed object colour. The results indicated that colour changes disrupt perceptual continuity, but only for the class of objects for which colour is diagnostic of object identity. When the colour is not integral to identifying an object (for example, when the object is a letter or an object without a characteristic colour), object continuity is preserved regardless of changes to the object's colour. These results suggest that object features that are important for defining the object are incorporated into its episodic representation. Furthermore, the results are consistent with previous work showing that the quality of a feature's representation determines its importance in preserving continuity.     

Self-awareness and self-deception: a Sartrean perspective

In spite of the fact that many find Jean-Paul Sartre’s account of la mauvaise foi puzzling, unclear and troublesome, he remains a recurring figure in the debate about self-deception. Indeed, Sartre’s exposition of self-deception is as puzzling as it is original. The primary task of my paper will be to expose why this is the case and to thereby correct a recurrent misunderstanding of Sartre’s theory of consciousness. In the end, will we see that Sartre offers the following theory: self-deception is to be accounted for by assuming that there are intrinsically self-deceptive epistemic states. The latter are self-deceptive in so far as they claim certainty while nevertheless being accompanied by an inbuilt and incorruptible awareness of being unwarranted. For Sartre, developing this rather peculiar account of self-deception, is, as we will see, not primarily intended as an end in itself. Rather, Sartre thereby hopes to illuminate the nature of self-awareness as (i.) epistemically super-secure, (ii.) pre-reflexive, (iii.) non-positional and “embryonic” knowledge that (iv.) does not necessitate but can still ground epistemically super-secure reflexive knowledge, and (v.) that can replace Freud’s notion of unconscious knowledge. As an account of self-deception, Sartre’s suggestion, however, comes at a high price. Apart from the presuppositions Sartre makes in the theory of consciousness and intentionality, his account is deflationist with regard to local cases of self-deception.     

Mathematics. A Science of Patterns?

The present article aims at showing that it is possible to construct a realist philosophy of mathematics which commits one neither to dream the dreams of Platonism nor to reduce the word 'realism' to mere noise.It is argued that mathematics is a science of patterns, where patterns are not objects (or properties of objects), but aspects, or aspects of aspects, etc. of objects. (The notion of aspect originates from ideas sketched by Wittgenstein in the Philosophical Investigations.)The philosophical importance of this contribution is mainly in the successfulness of the attempt made to justify a view of mathematics which, holding on to a Tarskian/Aristotelian conception of mathematical truth, does not involve the postulation of entities which are beyond the bounds of experience.     

The effect of name category and discriminability on the search characteristics of colour sets

Within (and between) cultures, people tend to agree on which parts of colour space are easiest to name and what the names for these regions are. Therefore it is likely that the manipulation of ease of naming (nameability) of colours should change performance in tasks where categorisation by colour name is important. More specifically? highly 'nameable' colour sets should lead to better performance than metrically equivalent but less categorically distinct sets, when the task requires categorisation. This hypothesis was investigated by testing observers on a name-based task, the naming and subsequent identification by name of colour sets with up to sixteen members. These sets were designed to be easy to name (nameable), maximally discriminable, or matched discriminable. The first were derived from previously generated data, the second by a standard algorithm to space colours widely in colour space, and the latter by closely matching their metric characteristics to those of an easy-to-name colour set. This final condition was metrically (but not categorically) equivalent to the nameable set. It was found that sets designed to be nameable did indeed lead to superior performance as measured by response times, confidence ratings, and response accuracy. Perceptual colour similarity, measured by a AE metric, did not predict errors. Nameability may thus be a valid, manipulable, aspect of sets of colours, and one which is not otherwise duplicated in the metric characteristics of such sets.     

Colour perception changes with basic colour word comprehension

Recent work has investigated the origin of infant colour categories, showing pre-linguistic infants categorise colour even in the absence of colour words. These infant categories are similar but not identical to adult categories, giving rise to an important question about how infant colour perception changes with the learning of colour words. Here we present two novel paradigms in which 12- and 19-month-old participants learning English as their first language were assessed on their perception of colour, while data on their colour word comprehension were also collected. Results indicate that participants' perception of colours close to the colour category boundaries dramatically change after colour word learning. The results highlight the shift made from infant colour categories to adult-like linguistically mediated colour categories that accompanies colour word learning.

Research Highlights

• We aimed to test whether colour perception is linguistically mediated in infants.
• We used novel eye-tracking and pupillometry paradigms to test infant colour perception either side of learning colour words.
• Infants' discrimination of colour changes after learning colour words, suggesting a shift due to colour word learning.
• A shift from pre-linguistic colour representation to linguistically mediated colour representation is discussed.

     

Recognising the forest, but not the trees: an effect of colour on scene perception and recognition

Colour has been shown to facilitate the recognition of scene images, but only when these images contain natural scenes, for which colour is 'diagnostic'. Here we investigate whether colour can also facilitate memory for scene images, and whether this would hold for natural scenes in particular. In the first experiment participants first studied a set of colour and greyscale natural and man-made scene images. Next, the same images were presented, randomly mixed with a different set. Participants were asked to indicate whether they had seen the images during the study phase. Surprisingly, performance was better for greyscale than for coloured images, and this difference is due to the higher false alarm rate for both natural and man-made coloured scenes. We hypothesized that this increase in false alarm rate was due to a shift from scrutinizing details of the image to recognition of the gist of the (coloured) image. A second experiment, utilizing images without a nameable gist, confirmed this hypothesis as participants now performed equally on greyscale and coloured images. In the final experiment we specifically targeted the more detail-based perception and recognition for greyscale images versus the more gist-based perception and recognition for coloured images with a change detection paradigm. The results show that changes to images are detected faster when image-pairs were presented in greyscale than in colour. This counterintuitive result held for both natural and man-made scenes (but not for scenes without nameable gist) and thus corroborates the shift from more detailed processing of images in greyscale to more gist-based processing of coloured images.