Jerry Fodor deemed informational encapsulation ‘the essence’ of a system’s modularity and argued that human perceptual processing comprises modular systems, thus construed. Nowadays, his conclusion is widely challenged. Often, this is because experimental work is seen to somehow demonstrate the cognitive penetrability of perceptual processing, where this is assumed to conflict with the informational encapsulation of perceptual systems. Here, I deny the conflict, proposing that cognitivepenetration need not have any straightforward bearing on (a) the conjecture that (...) perceptual processing is composed of nothing but informationally encapsulated modules, (b) the conjecture that each and every perceptual computation is performed by an informationally encapsulated module, and (c) the consequences perceptual encapsulation was traditionally expected to have for a perception-cognition border, the epistemology of perception and cognitive science. With these points in view, I propose that particularly plausible cases of cognitivepenetration would actually seem to evince the encapsulation of perceptual systems rather than refute/problematize this conjecture. (shrink)
If our experiences are cognitively penetrable, they can be influenced by our antecedent expectations, beliefs, or other cognitive states. Theorists such as Churchland, Fodor, Macpherson, and Siegel have debated whether and how our cognitive states might influence our perceptual experiences, as well as how any such influences might affect the ability of our experiences to justify our beliefs about the external world. This article surveys views about the nature of cognitivepenetration, the epistemological consequences of denying (...)cognitivepenetration, and the epistemological consequences of affirming cognitivepenetration. (shrink)
Cognitivepenetration of perception, broadly understood, is the influence that the cognitive system has on a perceptual system. The paper shows a form of cognitivepenetration in the visual system which I call ‘architectural’. Architectural cognitivepenetration is the process whereby the behaviour or the structure of the perceptual system is influenced by the cognitive system, which consequently may have an impact on the content of the perceptual experience. I scrutinize a study (...) in perceptual learning that provides empirical evidence that cognitive influences in the visual system produce neural reorganization in the primary visual cortex. The type of cognitivepenetration can be synchronic and diachronic. (shrink)
There are good, even if inconclusive, reasons to think that cognitivepenetration of perception occurs: that cognitive states like belief causally affect, in a relatively direct way, the contents of perceptual experience. The supposed importance of – indeed as it is suggested here, what is definitive of – this possible phenomenon is that it would result in important epistemic and scientific consequences. One interesting and intuitive consequence entirely unremarked in the extant literature concerns the perception of art. (...) Intuition has it that knowledge about art changes how one aesthetically evaluates artworks. A profound explanation of this intuitive fact is that perceptual experiences vary with artistic expertise. Cognitivepenetration provides an explanatory mechanism for this latter effect. What one knows or otherwise thinks about art may affect, in one of two ways sketched below, how one perceives art. Differences in aesthetic evaluation may follow, either because high-level aesthetic properties can be perceptually represented or because they causally depend on low-level perceptible properties. All of this lends credence to the hypothesis that the expert better judges art because she better perceives art. And she better perceives art because she better knows art. (shrink)
Cognitivepenetration of perception is the idea that what we see is influenced by such states as beliefs, expectations, and so on. A perceptual belief that results from cognitivepenetration may be less justified than a nonpenetrated one. Inferentialism is a kind of internalist view that tries to account for this by claiming that some experiences are epistemically evaluable, on the basis of why the perceiver has that experience, and the familiar canons of good inference provide (...) the appropriate standards by which experiences are evaluated. I examine recent defenses of inferentialism by Susanna Siegel, Peter Markie, and Matthew McGrath and argue that the prospects for inferentialism are dim. (shrink)
Perceptual dogmatism holds that if it perceptually seems to S that P, then S thereby has prima facie perceptual justification for P. But suppose Wishful Willy's desire for gold cognitively penetrates his perceptual experience and makes it seem to him that the yellow object is a gold nugget. Intuitively, his desire-penetrated seeming can't provide him with prima facie justification for thinking that the object is gold. If this intuitive response is correct, dogmatists have a problem. But if dogmatists have a (...) problem, you do too (well, most of you anyway). Reliabilists have denounced dogmatism's cognitivepenetration problems, but they have problems with cognitivepenetration that are even worse. (shrink)
Cognitive penetrability refers to the possibility that perceptual experiences are influenced by our beliefs, expectations, emotions, or other personal-level mental states. In this paper, I focus on the epistemological implication of cognitivepenetration and examine how exactly aetiologies matter to the justificatory power of perceptual experiences. I examine a prominent theory, according to which some cognitively penetrated perceptual experiences are like conclusions of bad inferences. Whereas one version of this theory is psychologically implausible, the other version has (...) sceptical consequences. In the second half of the paper, I suggest an alternative theory, drawing on recent empirical research on imagining-perception interaction and the epistemology of imagining. (shrink)
I argue that discussions of cognitivepenetration have been insufficiently clear about what distinguishes perception and cognition, and what kind of relationship between the two is supposed to be at stake in the debate. A strong reading, which is compatible with many characterizations of penetration, posits a highly specific and directed influence on perception. According to this view, which I call the “internal effect view” a cognitive state penetrates a perceptual process if the presence of the (...)cognitive state causes a change to the computation performed by the process, with the result being a distinct output. I produce a novel argument that this strong reading is false. On one well-motivated way of drawing the distinction between perceptual states and cognitive states, cognitive representations cannot play the computational role posited for them by IEV, vis-à-vis perception. This does not mean, however, that there are not important causal relationships between cognitive and perceptual states. I introduce an alternative view of these relationships, the “external effect view”. EEV posits that each cognitive state is associated with a broad range of possible perceptual outcomes, and biases perception towards any of those perceptual outcomes without determining specific perceptual contents. I argue that EEV captures the kinds of cases philosophers have thought to be evidence for IEV, and a wide range of other cases as well. (shrink)
This paper concerns how extant theorists of predictive coding conceptualize and explain possible instances of cognitivepenetration. §I offers brief clarification of the predictive coding framework and relevant mechanisms, and a brief characterization of cognitivepenetration and some challenges that come with defining it. §II develops more precise ways that the predictive coding framework can explain, and of course thereby allow for, genuine top-down causal effects on perceptual experience, of the kind discussed in the context of (...)cognitivepenetration. §III develops these insights further with an eye towards tracking one extant criterion for cognitivepenetration, namely, that the relevant cognitive effects on perception must be sufficiently direct. Throughout these discussions, we extend the analyses of the predictive coding models, as we know them. So one open question that surfaces is how much of the extended analyses are genuinely just part of the predictive coding models, or something that must be added to them in order to generate these additional explanatory benefits. In §IV, we analyze and criticize a claim made by some theorists of predictive coding, namely, that (interesting) instances of cognitivepenetration tend to occur in perceptual circumstances involving substantial noise or uncertainty. It is here that our analysis is most critical. We argue that, when applied, the claim fails to explain (or perhaps even be consistent with) a large range of important and uncontroversially interesting possible cases of cognitivepenetration. We conclude with a general speculation about how the recent work on the predictive mind may influence the current dialectic concerning top-down effects on perception. (shrink)
Zenon Pylyshyn argues that cognitively driven attentional effects do not amount to cognitivepenetration of early vision because such effects occur either before or after early vision. Critics object that in fact such effects occur at all levels of perceptual processing. We argue that Pylyshyn’s claim is correct—but not for the reason he emphasizes. Even if his critics are correct that attentional effects are not external to early vision, these effects do not satisfy Pylyshyn’s requirements that the effects (...) be direct and exhibit semantic coherence. In addition, we distinguish our defense from those found in recent work by Raftopoulos and by Firestone and Scholl, argue that attention should not be assimilated to expectation, and discuss alternative characterizations of cognitive penetrability, advocating a kind of pluralism. (shrink)
The phenomenon of cognitivepenetration has received a lot of attention in recent epistemology, as it seems to make perceptual justification too easy to come by for experientialist theories of justification. Some have tried to respond to this challenge by arguing that cognitivepenetration downgrades the epistemic status of perceptual experience, thereby diminishing its justificatory power. I discuss two examples of this strategy, and argue that they fail on several grounds. Most importantly, they fail to realize (...) that cognitivepenetration is just an instance of a larger problem for experientialist theories of perceptual justification. The challenge does not lie in explaining how cognitivepenetration is able to downgrade the epistemic status of perceptual experience, the challenge lies in explaining why perceptual experience would have a special epistemic status to begin with. To answer this challenge, experientialists have to solve the distinctiveness problem: they have to explain what is so distinctive about perceptual experience that enables it to provide evidential justification without being in need of justification itself. Unfortunately, an internalist answer to this problem does not appear to be forthcoming, even though it would certainly help with explaining the problem of cognitivepenetration. (shrink)
Fiona Macpherson (2012) argues that various experimental results provide strong evidence in favor of the cognitivepenetration of perceptual color experience. Moreover, she proposes a mechanism for how such cognitivepenetration occurs. We argue, first, that the results on which Macpherson relies do not provide strong grounds for her claim of cognitive penetrability; and, second, that, if the results do reflect cognitive penetrability, then time-course considerations raise worries for her proposed mechanism. We base our (...) arguments in part on several of our own experiments, reported herein. (shrink)
Reflection on the possibility of cases in which experience is cognitively penetrated has suggested to many that an experience's etiology can reduce its capacity to provide prima facie justification for believing its content below a baseline. This is epistemic downgrade due to etiology, and its possibility is incompatible with phenomenal conservatism. I develop a view that explains the epistemic deficiency in certain possible cases of cognitivepenetration but on which there is no epistemic downgrading below a baseline and (...) on which etiology plays no explanatory role. This view is not phenomenal conservatism exactly, but it does capture what’s right about phenomenal conservatism. (shrink)
We tend to think that perceptual experiences tell us about what the external world is like without being influenced by our own mind. But recent psychological and philosophical research indicates that this might not be true. Our beliefs, expectations, knowledge, and other personal-level mental states might influence what we experience. This kind of psychological phenomena is now called “cognitivepenetration.” The research of cognitivepenetration not only has important consequences for psychology and the philosophy of mind, (...) but also has interesting epistemological implications. According to the Downgrade Thesis, some cognitively penetrated perceptual experiences give their subjects less justification for believing their penetrated contents than perceptual experiences that are unpenetrated to represent those contents would usually give. In this paper, I propose an innovative argument for the Downgrade Thesis. First, I develop a positive account of how some cognitivepenetration works, according to which cognitive states influence perceptual experiences by triggering some imaginings. Second, I argue that imaginings do not give their subjects justification for believing their contents. I apply this epistemology of imagining to cognitivepenetration, and argue that because of the role that imaginings play, some cognitively penetrated experiences also give their subjects less justification for believing their penetrated contents. (shrink)
This is an excerpt from a report that highlights and explores five questions which arose from the workshop on perceptual learning and perceptual recognition at the University of Toronto, Mississauga on May 10th and 11th, 2012. This excerpt explores the question: What counts as cognitivepenetration?
Albert Newen and Petra Vetter argue that neurophysiological considerations and psychophysical studies provide striking evidence for cognitivepenetration. This commentary focuses mainly on the neurophysiological considerations, which have thus far remained largely absent in the philosophical debate concerning cognitivepenetration, and on the cognitivepenetration of perceptual experiences, which is the form of cognitivepenetration philosophers have debated about the most. It is argued that Newen and Vetter's evidence for cognitive (...) class='Hi'>penetration is unpersuasive because they do not sufficiently scrutinize the details of the empirical studies they make use of-the details of the empirical studies are crucial also when the studies are used in philosophical debates. The previous does not mean that cognitivepenetration could not occur. Quite the contrary, details of the feedback connections to the visual perceptual module and one of the candidates presented by Newen and Vetter suggest that cognitivepenetration can occur in rare cases. (shrink)
In The Principles of Psychology, William James (1981) has long ago suggested that attending to a stimulus can make it appear more ‘vivid and clear.’ Pre-cueing, the procedure in which a cue stimulus is presented to direct a subject’s attention to the location of a test stimulus, has been used to test James’ hypothesis (Posner, 1978; Carrasco et al., 2004; Carrasco, Loula, & Ho, 2006; Yeshurun & Rashal, 2010; Carrasco, 2011). One recent debate concerns whether the effects of pre-cueing and (...) other perceptual changes associated with covert attention are evidence for cognitivepenetration. In this paper, we argue that the pre-cueing effects associated with covert attention are similar to perceptual learning effects, despite the former having more transient effects than the latter. -/- . (shrink)
Cognitive and affective penetration of perception refers to the influence that higher mental states such as beliefs and emotions have on perceptual systems. Psychological and neuroscientific studies appear to show that these states modulate the visual system at the visuomotor, attentional, and late levels of processing. However, empirical evidence showing that similar consequences occur in early stages of visual processing seems to be scarce. In this paper, I argue that psychological evidence does not seem to be either sufficient (...) or necessary to argue in favour of or against the cognitivepenetration of perception in either late or early vision. In order to do that we need to have recourse to brain imaging techniques. Thus, I introduce a neuroscientific study and argue that it seems to provide well-grounded evidence for the cognitivepenetration of early vision in face perception. I also examine and reject alternative explanations to my conclusion. (shrink)
In this paper, I argue that visual attention is cognitively penetrated by intention. I present a detailed account of attention and its neural basis, drawing on a recent computational model of neural modulation during attention: divisive normalization. I argue that intention shifts computations during divisive normalization. The epistemic consequences of attentional bias are discussed.
This chapter critically assesses recent arguments that acquiring the ability to categorize an object as belonging to a certain high-level kind can cause the relevant kind property to be represented in visual phenomenal content. The first two arguments, developed respectively by Susanna Siegel (2010) and Tim Bayne (2009), employ an essentially phenomenological methodology. The third argument, developed by William Fish (2013), by contrast, is supported by an array of psychophysical and neuroscientific findings. I argue that while none of these arguments (...) ultimately proves successful, there is a substantial body of empirical evidence that information originating outside the visual system can nonetheless modulate the way an object’s low-level attributes visually appear. Visual phenomenal content, I show, is not only significantly influenced by crossmodal interactions between vision and other exteroceptive senses such as touch and audition, but also by interactions between vision and non-perceptual systems involved in motor planning and construction of the proprioceptive body-image. (shrink)
Can the phenomenal character of perceptual experience be altered by the states of one's cognitive system, for example, one's thoughts or beliefs? If one thinks that this can happen then one thinks that there can be cognitivepenetration of perceptual experience; otherwise, one thinks that perceptual experience is cognitively impenetrable. I claim that there is one alleged case of cognitivepenetration that cannot be explained away by the standard strategies one can typically use to explain (...) away alleged cases. The case is one in which it seems subjects' beliefs about the typical colour of objects affects their colour experience. I propose a two-step mechanism of indirect cognitivepenetration that explains how cognitivepenetration may occur. I show that there is independent evidence that each step in this process can occur. I suspect that people who are opposed to the idea that perceptual experience is cognitively penetrable will be less opposed to the idea when they come to consider this indirect mechanism and that those who are generally sympathetic to the idea of cognitive penetrability will welcome the elucidation of this plausible mechanism. (shrink)
Philosophers of mind and cognitive scientists have recently taken renewed interest in cognitivepenetration, in particular, in the cognitivepenetration of perceptual experience. The question is whether cognitive states like belief influence perceptual experience in some important way. Since the possible phenomenon is an empirical one, the strategy for analysis has, predictably, proceeded as follows: define the phenomenon and then, definition in hand, interpret various psychological data. However, different theorists offer different and apparently inconsistent (...) definitions. And so in addition to the usual problems (e.g., definitions being challenged by counterexample), an important result is that different theorists apply their definitions and accordingly get conflicting answers to the question “Is this a genuine case of cognitivepenetration?”. This hurdle to philosophical and scientific progress can be remedied, I argue, by returning attention to the alleged consequences of the possible phenomenon. There are three: theory-ladenness of perception in contexts of scientific theory choice, a threat to the general epistemic role of perception, and implications for mental architecture. Any attempt to characterize or define, and then empirically test for, cognitivepenetration should be constrained by these consequences. This is a method for interpreting and acquiring experimental data in a way that is agreeable to both sides of the cognitivepenetration debate. Put crudely, the question shifts to “Is this a cognitive-perceptual relation that results in (or constitutes) one or more of the relevant consequences?” In answering this question, relative to various data, it may turn out that there is no single unified phenomenon of cognitivepenetration. But this should be no matter, since it is the consequences that are of central importance to philosophers and scientists alike. (shrink)
This chapter concerns the cognitivepenetration of the visual experience of colour. Alleged cases of cognitively penetrated colour perception are of special import since they concern an uncontroversial type of visual experience. All theorists of perception agree that colour properties figure properly in the content or presentation of visual perception, even though not all parties agree that pine trees or causes or other "high-level" properties can figure properly in visual content or presentation. So an alleged case of this (...) kind does not require controversial commitments regarding the admissible contents of visual perception. The chapter clarifies this theoretical importance , identifying alleged empirical cases of cognitively penetrated colour perception, and then analyzing the implications of such cases for an epistemology of perception. (shrink)
The cognitive penetrability of perceptual experiences has been a long-standing topic of disagreement among philosophers and psychologists. Although the notion of cognitive penetrability itself has also been under dispute, the debate has mainly focused on the cases in which cognitive states allegedly penetrate perceptual experiences. This paper concerns the plausibility of two prominent cases. The first one originates from Susanna Siegel’s claim that perceptual experiences can represent natural kind properties. If this is true, then the concepts we (...) possess change the way things appear to us. The second candidate for cognitivepenetration is Fiona Macpherson’s claim that, in addition to concepts, our beliefs can penetrate perceptual experiences. It is argued that neither candidate is a case of cognitivepenetration. In doing so, I provide an explanation to both that is based on perceptual learning, a non-cognitive phenomenon where relatively slow and long-lasting modifications to an organism’s perceptual system bring about changes in perception. This explanation is theoretically more plausible and remains closer to the empirical data than the explanations based on cognitivepenetration. (shrink)
It has been argued that just as, say, prejudice or wishful thinking can generate ill-founded beliefs, the same is true of experiences. The idea is that the etiology of cognitively penetrated experiences can downgrade their justificatory force. This view, known as the Downgrade Principle, seems to be compatible with both internalist and externalist conceptions of epistemic justification. An assessment of the credentials of the Downgrade Principle is particularly important in view of the fact that not all cases of cognitive (...)penetration are epistemically malignant. There are good and bad cases of cognitivepenetration. I argue that a proper assessment of the Downgrade Principle will have to address two fundamental questions. I identify two general ways of responding to these questions and show why they fail. It will be maintained that an explanationist conception of justification has a better chance of accounting for the distinction between good and bad cases of cognitivepenetration. The Downgrade Principle is then discussed in the context of the extended cognition thesis. In particular, I look at the sensorimotor theory of perception, as a way of broadening the scope of to include conscious perceptual experience, that sees senses as ways of exploring the environment mediated by different patterns of sensorimotor contingency. I suggest possible ways in which one could distinguish between good and bad cases of cognitivepenetration on such a view compatible with the explanationist view of epistemic justification. (shrink)
The thesis of cognitive penetrability, according to which cognitive states can affect perceptual experiences, remains the topic of intense debate among philosophers. A new candidate for a case of cognitivepenetration is presented and defended. The candidate is based on studies involving suggestions that something is a certain way, which are usually given under hypnosis, rather than mere request to imagine that things are a certain way.
Short-term memory, nonattentional task effects and nonspatial extraretinal representations in the visual system are signs of cognitivepenetration. All of these have been found physiologically, arguing against the cognitive impenetrability of vision as a whole. Instead, parallel subcircuits in the brain, each subserving a different competency including sensory and cognitive (and in some cases motor) aspects, may have cognitively impenetrable components.
Visualizing and mental imagery are thought to be cognitive states by all sides of the imagery debate. Yet the phenomenology of those states has distinctly visual ingredients. This has potential consequences for the hypothesis that vision is cognitively impenetrable, the ability of visual processes to ground perceptual warrant and justification, and the distinction between cognitive and perceptual phenomenology. I explore those consequences by describing two forms of visual ambiguity that involve visualizing: the ability to visually experience a picture (...) surface as flat after it has caused volumetric nonconceptual contents, and the ability to use a surface initially perceived as flat to visualize three-dimensional scenes. In both cases, the visual processes which extract viewer-centered volumetric shapes have to rely solely on monocular depth cues in the absence of parallax and stereopsis. Those processes can be cognitively penetrated by acts of visualizing, including ones that draw on conceptual information about kinds. However, the penetrability of the visual processes does not weaken their ability to provide perceptual warrant and justification for beliefs. The reason is that picture perceptions—whether they are stimulus -driven or based on acts of visualizing—are different to object perceptions both phenomenologically and in terms of their functional roles as states. Thus, although the penetrability of the visual processes does mean that subjects can have visual experiences with contradictory contents, perceptual belief is adopted at most towards one set of contents, and questions of warrant and justification are raised only for those contents. A rule-proving exception is provided by trompe-l’oeils. (shrink)
Advancing a radically enactive account of cognition, we provide arguments in favour of the possibility that cultural factors permeate rather than penetrate cognition, such that cognition extensively and transactionally incorporates cultural factors rather than there being any question of cultural factors having to break into the restricted confines of cognition. The paper reviews the limitations of two classical cognitivist, modularist accounts of cognition and a revisionary, new order variant of cognitivism – a Predictive Processing account of Cognition, or PPC. It (...) argues that the cognitivist interpretation of PPC is conservatively and problematically attached to the idea of inner models and stored knowledge. In abandoning that way of understanding PPC, it offers a radically enactive alternative account of how cultural factors matter to cognition – one that abandons all vestiges of the idea that cultural factors might contentfully communicate with basic forms of cognition. In place of that idea, the possibility that culture permeates cognition is promoted. (shrink)
Perception purports to help you gain knowledge of the world even if the world is not the way you expected it to be. Perception also purports to be an independent tribunal against which you can test your beliefs. It is natural to think that in order to serve these and other central functions, perceptual representations must not causally depend on your prior beliefs and expectations. In this paper, I clarify and then argue against the natural thought above. All perceptual systems (...) must solve an under-determination problem: the sensory data they receive could be caused by indefinitely many arrangements of distal objects and properties. Using a Bayesian approach to perceptual processing, I argue that in order to solve the under-determination problem, perceptual capacities must rely on prior beliefs or expectations of some kind. I then argue that perceptual states or processes can help ground knowledge of the world whether the ‘beliefs’ necessary for perceptual processing are encoded as sub-personal states within a perceptual system or cognitive states, such as person-level beliefs. My argument has two main parts. First, I give a preliminary argument that cognitive influence on perception can be appropriate, and I respond to three lines of objection. Second, I argue that cognitively influenced perceptual states can be instances of seeing that p, which makes the relevant states well suited to help ground knowledge that p. I conclude that a cognitively penetrated perceptual state or process can help ground knowledge under some circumstances. (shrink)
Cognition can influence action. Your belief that it is raining outside, for example, may cause you to reach for the umbrella. Perception can also influence cognition. Seeing that no raindrops are falling, for example, may cause you to think that you don’t need to reach for an umbrella. The question that has fascinated philosophers and cognitive scientists for the past few decades, however, is whether cognition can influence perception. Can, for example, your desire for a rainy day cause you (...) to see, hear, or feel raindrops when you walk outside? More generally, can our cognitive states influence the way we see the external world? In this paper, I discuss three experiments on memory colour effects. In these experiments, subjects systematically made different colour matches or adjustments for object-patches representing objects that have prototypical colours and neutral object-patches. I argue that these differences are not merely differences in judgments but are best explained in terms of phenomenology. However, I show that these differences in phenomenology can be explained without reference to cognitive states such as colour concepts or beliefs. (shrink)
This is an excerpt of a report that highlights and explores five questions that arose from the Network for Sensory Research workshop on perceptual learning and perceptual recognition at the University of York in March, 2012. This portion of the report explores the question: Can perceptual experience be modified by reason?
The Macpherson :24–62, 2012) argued that the perceptual experience of colors is cognitively penetrable. Macpherson also thinks that perception has nonconceptual content because this would provide a good explanation for several phenomena concerning perceptual experience. To have both, Macpherson must defend the thesis that the CP of perception is compatible with perception having NCC. Since the classical notion of CP of perception does not allow perception to have NCC, Macpherson proposes CP-lite. CP-lite makes room for an experience to have content (...) determined by concepts because the perceptual processes that produce the experience are affected by concepts rendering the experience, CP, while the same type of experience could have been had without any conceptual influences, in which case it would be CI. Macpherson then proceeds to show that CP-lite is compatible with some of the definitions of NCC. To do so, she argues that even when an experience is CP owing to the fact that it is produced by means of the mechanism posited by CP-lite, that is, through the interaction between bottom–up pure perception and top–down perceptual imagery, its content is NCC because it has the basic properties that characterize NCC. Based on this, Macpherson proceeds to criticize and undermine the definitions of NCC that are incompatible with CP-lite. In this paper, I argue that the possibility of CP-lite rests on the erroneous assumption that a state with conceptual content and a state with NCC can have the same phenomenology or content, and that the compatibility of CP-lite with NCC presupposes a view of NCC that does not conform to the usual construal of NCC. (shrink)
On page 3653, there is a mistake in the explanation of the Cornsweet illusion. In fact, the explanation is that the panel perceived as darker is facing towards the light source—in the case of this figure the light is coming from the right.
How can the impenetrability hypothesis be empirically tested? We comment on the role of signal detection measures, suggesting that context effects on discriminations for which post-perceptual cues are irrelevant, or on neural activity associated with early vision, would challenge impenetrability. We also note the great computational power of the proposed pre-perceptual attention processes and consider the implications for testability of the theory.