We use evidence from cognitive psychology and the history of science to examine the issue of the theory-ladenness of perceptual observation. This evidence shows that perception is theory-laden, but that it is only strongly theory-laden when the perceptual evidence is ambiguous or degraded, or when it requires a difficult perceptual judgment. We argue that debates about the theory-ladenness issue have focused too narrowly on the issue of perceptual experience, and that a full account of the scientific process requires an examination (...) of theory-ladenness in attention, perception, data interpretation, data production, memory, and scientific communication. We conclude that the evidence for theory-ladenness does not lead to a relativist account of scientific knowledge. (shrink)

The paper treats issues concerning the modular modelisation of musical mental processes. Some musical phenomena, like musical illusions, are explained in the framework of modularity and hypotheses are advanced in which the modular model seems very promising for the study of musical perception and cognition. In addition, arguments are proposed to distinguish between levels of abstraction and knowledge in musical cognitive processes.Moreover, some aspects about the theory of musical competence and the theory of musical processing are identified and the possibilities (...) for the integration of varying theoretical assertions are considered in light of these distinctions. (shrink)

The doctrine that the character of our perceptual knowledge is plastic, and can vary substantially with the theories embraced by the perceiver, has been criticized in a recent paper by Fodor. His arguments are based on certain experimental facts and theoretical approaches in cognitive psychology. My aim in this paper is threefold: (1) to show that Fodor's views on the impenetrability of perceptual processing do not secure a theory-neutral foundation for knowledge; (2) to show that his views on impenetrability are (...) almost certainly false; and (3) to provide some additional arguments for, and illustrations of, the theoretical character of all observation judgments. (shrink)

The present essay is addressed simultaneously to two distinct audiences.

High-level theory is the view that high-level properties—the property of being a dog, being a tiger, being an apple, being a pair of lips, etc.—can be represented in perceptual experience. Low-level theory denies this and claims that high-level properties are only represented at the level of perceptual judgment and are products of cognitive interpretation of low- level sensory information (color, shape, illumination). This paper discusses previous attempts to establish high-level theory, their weaknesses, and an argument for high-level theory that does (...) not have these weaknesses. (shrink)

In this paper I argue that because Churchland does not adequately address the distinction between high-level cognitive theories and low-level embodied theories, Churchland's claims for theory-laden perception lose their epistemological significance. I propose that Churchland and others debating the theory-ladenness of perception should distinguish carefully between two main ways in which perception is plastic: through modifying our high-level theories directly and through modifying our low-level theories using training experiences. This will require them to attend to two very different types of (...) constraints on the modification of our perceptions. (shrink)

The persistence of certain illusions has been used to argue that some theories cannot affect our perceptual experiences. Learning that one of these illusions is an illusion involves accepting theories. Nevertheless, the illusion does not go away. It seems then that these theories cannot affect our perceptual experiences. This paper contests an assumption of this argument: that the only way in which our perceptions can be affected by holding these theories is by the illusion going away.

The aim of this paper is to analyze a philosophical question (neutrality vs. theory-ladenness of observation) taking into consideration the empirical results of Cognitive Psychology (theories of perception). This is an important debate because the objectivity of science is at stake. In the Philosophy of Science there are two main positions with regard to observation, those of C. Hempel and N. R. Hanson. In the Philosophy of Mind there are also two important contrasting positions, those of J. Fodor and Paul (...) M. Churchland. I will analyze the consequences of recent theories of perception and vision developed within Cognitive Science for classical epistemological theses about observation. (shrink)

Churchland's paper "Perceptual Plasticity and Theoretical Neutrality" offers empirical, semantical and epistemological arguments intended to show that the cognitive impenetrability of perception "does not establish a theory-neutral foundation for knowledge" and that the psychological account of perceptual encapsulation that I set forth in The Modularity of Mind "[is] almost certainly false". The present paper considers these arguments in detail and dismisses them.

Several arguments are considered which purport to demonstrate the impossibility of theory-neutral observation. The most important of these infers the continuity of observation with theory from the presumed continuity of perception with cognition, a doctrine widely espoused in recent cognitive psychology. An alternative psychological account of the relation between cognition and perception is proposed and its epistemological consequences for the observation/theory distinction are then explored.

One of the most notable aspects of Fodor's work is that it articulates features not only of speculative cognitive architectures but also of current research in ...

Perception and cognition can be understood either as conscious experience, thought, and behaviour or as bodily functions executed at the level of information processing. Whether or not they are cognitively penetrable depends on the level referred to. Selective attention is the mechanism by which cognition affects perception, theory influences observation and observational reports, culture biases experience, and current knowledge determines what inferences are made. Seeing must be distinguished from seeing as.

Paul Churchland has recently argued that empirical evidence strongly suggests that perception is penetrable to the beliefs or theories held by individual perceivers (1988). While there has been much discussion of the sorts of psychological cases he presents, little has been said about his arguments from neurology. I offer a critical examination of his claim that certain efferents in the brain are evidence against perceptual encapsulation. I argue that his neurological evidence is inadequate to his philosophical goals, both by itself (...) and taken in concert with his psychological evidence. (shrink)

Fodor claims that cognitive modules can be thought of as constituting a psychological natural kind in virtue of their possession of most or all of nine specified properties. The challenge to this considered here comes from synaesthesia. Synaesthesia is a type of cross-modal association: input to one sensory modality reliably generates an additional sensory output that is usually generated by the input to a distinct sensory modality. The most common form of synaesthesia manifests Fodor's nine specified properties of modularity, and (...) hence, according to Segal (1997), it should be understood as involving an extra module. Many psychologists believe that synaesthesia involves a breakdown in modularity. After outlining how both theories can explain the manifestation of the nine alleged properties of modularity in synaesthesia, I discuss the two concepts of function which initially motivate the respective theories. I argue that only a teleological concept of function is properly able to adjudicate between the two theories. The upshot is a further application of so-called externalist considerations to mental phenomena. (shrink)

Short-term memory, nonattentional task effects and nonspatial extraretinal representations in the visual system are signs of cognitive penetration. 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.

Pylyshyn could have strengthened his case by avoiding side issues and by taking a sterner, firmer line on the unresolved (and perhaps unresolvable) problems plaguing the sensitivity (d') measure of top-down, cognitive effects, as well as the general (nearly utter!) lack of convincing evidence provided by proponents of the cognitive penetrability of visual perception.

The Turing Test blurs the distinction between a model and irrelevant) instantiation details. Modeling only functional modules is problematic if these are interconnected and cognitively penetrable.

Is perception cognitively penetrable, and what are the epistemological consequences if it is? I address the latter of these two questions, partly by reference to recent work by Athanassios Raftopoulos and Susanna Seigel. Against the usual, circularity, readings of cognitive penetrability, I argue that cognitive penetration can be epistemically virtuous, when---and only when---it increases the reliability of perception.

Signal detection theory (SDT) is best known as a method for separating sensitivity from bias. If sensitivity reflects early sensory processing and bias later cognition, then SDT can be use to study penetrability by asking whether cognitive manipulations affect sensitivity. This assumption is too simple, but SDT can nonetheless be helpful in developing specific methods of how sensory and cognitive information combine. Two such approaches are described.

Can the phenomenal character of perceptual experience be altered by the states of one’s cognitive system, for example, one’s thoughts or beliefs? Ifone thinks that this can happen [at least in certain ways that are identWed in the paper] then one thinks that there can be cognitive penetration of perceptual experience; otherwise, one thinks that perceptual experience is cognitivelv impenetrable. I claim that there is one alleged case ofcognitive penetration that cannot be explained away by the standard strategies one can (...) typicallv use to explain away alleged cases. The case is one in which it seems subjects’ beliefs about the typical colour of objects ajfects their colour experience. I propose a two-step mechanism of indirect cognitive penetration that explains how cognitive penetration 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 cognitivelv penetrable will be less opposed to the idea when they come to consider this indirect mechanism and that those who are generallv sympathetic to the idea ofcognitive penetrability will welcome the elucidation ofthis plausible mechanism. (shrink)

Jerry Fodor has consistently cited the persistence of illusions--especially the M.

Although the study of visual perception has made more progress in the past 40 years than any other area of cognitive science, there remain major disagreements as to how closely vision is tied to general cognition. This paper sets out some of the arguments for both sides (arguments from computer vision, neuroscience, Psychophysics, perceptual learning and other areas of vision science) and defends the position that an important part of visual perception, which may be called early vision or just vision, (...) is prohibited from accessing relevant expectations, knowledge and utilities - in other words it is cognitively impenetrable. That part of vision is complex and articulated and provides a representation of the 3-D surfaces of objects sufficient to serve as an index into memory, with somewhat different outputs being made available to other systems such as those dealing with motor control. The paper also addresses certain conceptual and methodological issues, including the use of signal detection theory and event-related potentials to assess cognitive penetration of vision. A distinction is made among several stages in visual processing. These include, in addition to the inflexible early-vision stage, a pre-perceptual attention allocation stage and a post-perceptual evaluation, memory-accessing, and inference stage which provide several different highly constrained ways in which cognition can affect the outcome of visual perception. The paper discusses arguments that have been presented in both computer vision and psychology showing that vision is "intelligent" and involves elements of problem solving". It is suggested that these cases do not show cognitive penetration, but rather they show that certain natural constraints on interpretation, concerned primarily with optical and geometrical properties of the world, have been compiled into the visual system. The paper also examines a number of examples where instructions and "hints" are alleged to affect. (shrink)

The chapters in this book address directly the issue of the cognitive penetrability of perception.

In this paper I argue for the cognitive impenetrability of perception by undermining the argument from reentrant pathways. To do that I will adduce psychological and neuropsychological evidence showing that (a) early vision processing is not affected by our knowledge about specific objects and events, and (b) that the role of the descending pathways is to enable the early-vision processing modules to participate in higher-level visual or cognitive functions. My thesis is that a part of observation, which I will call (...) perception, is bottom-up and theory neutral. As such, perception could play the role of common ground on which a naturalized epistemology can be built and relativism avoided. (shrink)

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.

The basic problem of perceptual change is how to account for both variation and constancy in perceiving the world. Is order learned? How deep does plasticity go in that respect? I argue that different kinds of perceptual plasticity have been confused in recent debates, notably between J. Fodor and P. M. Churchland. By focusing on changes in the use of concepts, the issues in the Fodor-Churchland debate can be resolved. Beyond that debate, I propose a generalized encoding approach to perception (...) as a way of accounting for a significant form of perceptual change. (shrink)

Pylyshyn acknowledges that cognition intervenes in determining the nature of perception when attention is allocated to locations or properties prior to the operation of early vision. I present evidence that scale perception (one function of early vision) is cognitively penetrable and argue that Pylyshyn's criterion covers not a few, but many situations of recognition. Cognitive penetrability could be their modus operandi.

The distinction between top-down and bottom-up effects is widely relied on in experimental psychology. However, there is an important problem with the way it is normally defined. Top-down effects are effects of previously-stored information on processing the current input. But on the face of it that includes the information that is implicit in the operation of any psychological process – in its dispositions to transition from some types of representational state to others. This paper suggests a way to distinguish information (...) stored in that way from the kind of influence of prior information that psychologists are concerned to classify as a top-down effect. So-drawn, the distinction is not just of service to theoretical psychology. Asking about the extent of top-down processing is one way to pose some of the questions at issue in philosophical debates about cognitive penetrability – about the extent of the influence of cognitive states on perception. The existence of a theoretically-useful perception-cognition distinction has come under pressure, but even if it has to be abandoned, some of the concerns addressed in the cognitive penetrability literature can be recaptured by asking about the extent of top-down influences on any given psychological process. That formulation is more general, since it can be applied to any psychological process, not just those that are paradigmatically perceptual. (shrink)

In this paper I argue that it's possible that the contents of some visual experiences are influenced by the subject's prior beliefs, hopes, suspicions, desires, fears or other mental states, and that this possibility places constraints on the theory of perceptual justification that 'dogmatism' or 'phenomenal conservativism' cannot respect.

In this paper I offer a theory of what makes certain influences on visual experiences by prior mental states (including desires, beliefs, moods, and fears) reduce the justificatory force of those experiences. The main idea is that experiences, like beliefs, can have rationally assessable etiologies, and when those etiologies are irrational, the experiences are epistemically downgraded.

Expert perceivers may learn more than just where to apply visual processing, or which part of the output from the visual system to attend to. Their early visual system may be modified, as a result of their specific needs, through a process of early visual learning. We argue that this is, in effect, a form of long-term, indirect cognitive penetration of early vision.

In a series of recent papers, Jane Heal (1994, 1995a, 1995b, 1996a, 1996b) has developed her own quite distinctive version of simulation theory and offered a detailed critique of the arguments against simulation theory that we and our collaborators presented in earlier papers. Heal's theory is clearly set out and carefully defended, and her critique of our arguments is constructive and well informed. Unlike a fair amount of what has been written in this area in recent years, her work is (...) refreshingly free of obscurity; it generates more light than heat. While we have many disagreements with Heal, we also find much that we can agree with and learn from. In this paper we hope to advance the discussion by saying where we agree and how we think we can build on that agreement. We'll also explain where we disagree and why. (shrink)

This paper considers an orectic penetration hypothesis which says that desires and desire-like states may influence perceptual experience in a non-externally mediated way. This hypothesis is clarified with a definition, which serves further to distinguish the interesting target phenomenon from trivial and non-genuine instances of desire-influenced perception. Orectic penetration is an interesting possible case of the cognitive penetrability of perceptual experience. The orectic penetration hypothesis is thus incompatible with the more common thesis that perception is cognitively impenetrable. It is of (...) importance to issues in the philosophy of mind and cognitive science, epistemology, and general philosophy of science. The plausibility of orectic perception can be motivated by some classic experimental studies, and some new experimental research inspired by those same studies. The general suggestion is that orectic penetration thus defined, and evidenced by the relevant studies, cannot be deflected by the standard strategies of the cognitive impenetrability theorist. (shrink)

Modular architectures of the mind can vary both with respect to the strength of the notion of modularity and the scope of the modularity of mind. We propose a dilemma for modular architectures, no matter how they vary along these two dimensions. First, if a modular theory commits to the informational encapsulation of modules, then modules are on this account impenetrable. However, there are plausible cases of the cognitive penetrability of perception. And so any strongly modular theory of perception is (...) threatened. Second, many recent massive modularity theories weaken the strength of the notion of module, while broadening the scope of modularity. These theories do not require any robust informational encapsulation, and thus avoid the incompatibility with cognitive penetrability. However, the weakened commitment to informational encapsulation significantly weakens the explanatory force of the theory and, ultimately, is conceptually incompatible with the core of modularity. We conclude by proposing a non-modular, but explanatorily sufficient, notion of functionally independent system. (shrink)

Pylyshyn claims that if a system is cognitively penetrable, its function depends in a semantically coherent way to the organism's goals and beliefs. He rejects evidence of attentional modulation observed in neurons within the visual system, claiming that any modulation seen is not logically related to goals and behavior. I present some of this evidence and claim that it is connected in exactly the way Pylyshyn requires and thus it refutes his main thesis.

In this paper we focus on the modularity of visual functions in the human visual cortex, that is, the specific problems that the visual system must solve in order to achieve recognition of objects and visual space. The computational theory of early visual functions is briefly reviewed and is then used as a basis for suggesting computational constraints on the higher-level visual computations. The remainder of the paper presents neurological evidence for the existence of two visual systems in man, one (...) specialized for spatial vision and the other for object vision. We show further clinical evidence for the computational hypothesis that these two systems consist of several visual modules, some of which can be isolated on the basis of specific visual deficts which occur after lesions to selected areas in the visually responsive brain. We will provide examples of visual modules which solve information processing tasks that are mediated by specific anatomic areas. We will show that the clinical data from behavioral studies of monkeys (Ungerleider and Mishkin 1984) supports the distinction between two visual systems in monkeys, the 'what' system, involved in object vision, and the 'where' system, involved in spatial vision. (shrink)

It is argued that the alleged cases of cognitive penetration of visual modules actually arise from the integration of information among different modules. This would reflect a general computational strategy according to which constraints to a particular module would be provided by information coming from different modules. Examples are provided from the integration of stereopsis and occlusion and from computation of motion direction.

We offer an ecological (Gibsonian) alternative to cognitive (im)penetrability. Whereas Pylyshyn explains cognitive (im)penetrability by focusing solely on computations carried out by the nervous system, according to the ecological approach the perceiver as a knowing agent influences the entire animal-environmental system: in the determination of what constitutes the environment (affordances), what constitutes information, what information is detected and, thus, what is perceived.

A number of studies in the apparent motion literature were examined using the cognitive penetrability criterion to determine the extent to which beliefs affect the perception of apparent motion. It was found that the interaction between the perceptual processes mediating apparent motion and higher order processes appears to be limited. In addition, perceptual and inferential beliefs appear to have different effects on perceived motion optimality and direction. Our findings suggest that the system underlying apparent motion perception has more than one (...) stage and is informationally encapsulated from cognitive factors. (shrink)