Perception and knowledge

Knowledge concerning the object, scene, or event in a conscious propositional form generally does not affect perception. By and large, perception is autonomous with respect to thought. That is because perception is stimulus bound and is based on mental contents, lawful principles and rules that are unconscious and in a form very different from such consciously represented propositional knowledge. Exceptions to this generalization can occur if the stimulus is ambiguous and can support a cued or suggested interpretation or one in line with what is known to be present as well as it can support the perception that occurs spontaneously. How the representation of the given, consciously apprehended knowledge can enter into the unconscious events that govern perception is not known, but it is suggested that such knowledge accesses memories and it is these memories that can affect perception.Since knowledge of this kind can affect perception, it is important to ensure that subjects in experiments are naive. Otherwise we will confuse spontaneous perceptions with those that only occur when suggested and the distinction is theoretically important. In certain cases, knowledge leads to an intentional intervention in the process of achieving a percept, the mechanism of which is not known. However, this kind of effect may be based on a process of imagining or visualizing of objects or events that dovetails with the proximal stimulus and it is the imagining that leads to the perception.Knowledge in the form of stored representations of past visual experience (or of phylogenetic ‘experience’) can affect perception in various ways: it enables recognition and interpretation to occur; it enables perceptual discrimination among similar members of a category to occur; it can lead to perceptual enrichment effects; it provides internal solutions which can then be accessed in cases where perceptual problem solving occurs; it provides rules or laws concerning geometrical optics on the basis of which phenomena such as perceptual constancy and the like can be achieved; it can lead to the recalibration of tactual or visual sensation. However, before such top-down effects of past experience can occur bottom-up processes must first achieve a preliminary perception. That perception provides the bridge to the relevant stored representations which are accessed on the basis of similarity.     

Perception and practical knowledge

According to G.E.M. Anscombe, an agent's knowledge of his own intentional actions differs from his knowledge of his unintended behaviors as well as the knowledge others can have of what he intentionally does, in being known “without observation”. I begin by posing a problem for any conception of this theory according to which non-observational knowledge must be independent of sense perception, and criticize several recent attempts to get around the problem. Having done this, I develop an alternative account of non-observational knowledge according to which it consists in the particular causal role of an agent's self-awareness in bringing his intentional actions about.     

Perception, Causation, and Supervenience

What relation between an experience and a physical object makes the experience a perception of the object?¹ One common answer is that it is a certain kind of causal relation. The idea is that to perceive an object is just to undergo an experience appropriately caused by the object. This answer is incorrect. The reason is that perceiving an object does not supervene on the causal connection the object bears to the perceiver's experience. Whether or not a person perceives an object depends, in part, on conditions that could obtain or fail to obtain without variation in the causal processes (if any) by which the object causes the person's experience. In what follows, I explain and defend these claims.     

Perception,meaning, and mind

Earlier versions of this paper were read in the Philosophy department at the University of Helsinki, in the Institute for Advanced Studies in the Humanities at the University of Edinburgh, at Vanderbilt University, at the Indiana Philosophical Association, and at the Institute for Logic and Cognitive Science at the University of Houston. I am grateful for very helpful comments on each of these occasions, and I am especially appreciative to John Haugeland, Mark Johnson, and George McClure for their comments and suggestions. Thanks, too, to Robert Solomon who urged me to amplify my claims about perceptual meaning.     

Perception of racial discrimination and psychopathology across three U.S. ethnic minority groups

To examine the association between the perception of racial discrimination and the lifetime prevalence rates of psychological disorders in the three most common ethnic minorities in the United States, we analyzed data from a sample consisting of 793 Asian Americans, 951 Hispanic Americans, and 2,795 African Americans who received the Composite International Diagnostic Interview through the Collaborative Psychiatric Epidemiology Studies. The perception of racial discrimination was associated with the endorsement of major depressive disorder, panic disorder with agoraphobia, agoraphobia without history of panic disorder, posttraumatic stress disorder, and substance use disorders in varying degrees among the three minority groups, independent of the socioeconomic status, level of education, age, and gender of participants. The results suggest that the perception of racial discrimination is associated with psychopathology in the three most common U.S. minority groups.     

Perception,illusion, and hallucination

Patrick Suppes' set-theoretical approach to the analysis of theories, and Joseph D. Sneed's metatheory are briefly outlined. The notions of observation, illusion and hallucination are reconstructed according to these approaches. It is argued that the terms ‘perception’ and ‘truth’ are theoretical with respect to observation but nontheoretical with respect to illusion and hallucination. Hallucination is construed as a special kind of illusion.     

Concepts,Attention, and Perception

Abstract

According to the conceptualist view in the philosophy of perception, we must possess concepts for all the objects, properties and relations which feature in our perceptual experiences. In this paper, I investigate the possibility of developing an argument against the conceptualist view by appealing to the notion of attention.

In Part One, I begin by setting out an apparently promising version of such an argument, a version which appeals to a link between attention and perceptual demonstrative concept possession. In Part Two, however, I show how the conceptualist can challenge what appears to be the key premise of the argument, and I go on to describe, in Part Three, an important further difficulty which we face if we attempt to overcome this challenge in a particular way. My conclusion will be that the conceptualist's challenge to the argument is convincing and hence that the argument remains inconclusive.     

Perception, Color, and Realism

One reason philosophers have addressed the metaphysics of color is its apparent relevance to the sciences concerned with color phenomena. In the light of such thinking, this paper examines a pairing of views that has received much attention: color physicalism and externalism about the content of perceptual experience. It is argued that the latter is a dubious conception of the workings of our perceptual systems. Together with flawed appeals to the empirical literature, it has led some philosophers to grant color physicalism a scientific legitimacy it does not merit. This discussion provides a useful entry into broader points pertaining to debates about color realism and the relationship between philosophical theories of color and the relevant empirical literatures. A sketch of a novel form of color realism is offered, as is an example that fills in some details of that sketch.     

Perception, Content and Rationality

Anil Gupta's Empiricism and Experience is a stylish and stimulating contribution to our subject. My expectation is that those who disagree with some of its central theses will, like me, learn greatly from thinking through where and why they part company with Gupta's lucidly presented position. For the purposes of a Symposium, I select three points of disagreement. Each point in one way or another concerns the epistemic role of the content of experience.     

Timing, remembering, and discrimination

Four pigeons were first trained in a timing procedure. In one condition, each trial began with the presentation of an X on the center key, followed by a delay (short or long), after which two side keys were lit. If the delay was short, pecks to the red side key were reinforced. If the delay was long, pecks to the green side key were reinforced. In a second condition, the opposite contingencies applied following presentation of a square on the center key. Choice responses were then tested at 10 time intervals ranging from short to long (1 to 4 s and 4 to 7 s in different conditions). The two timing conditions were combined to create a remembering condition in which correct responding depended upon discrimination of both the sample stimulus (X or square) and the delay interval (short or long). Choices varied systematically across delay in timing conditions, but in remembering conditions, accurate choice at the training delays did not initially generalize to intermediate delays. However, with prolonged training in the remembering task, the response pattern began to resemble that of the timing conditions. Generalization gradients were asymmetrical, in accordance with Weber's Law, in that greater generalization occurred with longer delays than with shorter delays.     

Moral Imagination,Perception, and Judgment

This paper develops an account of moral imagination that identifies the ways in which imaginative capacities contribute to our ability to make reason practical in the world, beyond their roles in moral perception and moral judgment. In section 1, I explain my understanding of what it means to qualify imagination as ‘moral,’ and go on in section 2 to identify four main conceptions of moral imagination as an aspect of practical reason in philosophical ethics. I briefly situate these alternative ideas in relation to standard accounts of moral perception and judgment with reference to some guiding examples. In section 3, I argue that the fourth conception of moral imagination, moral imagination understood as the capacity to generate new possibilities for morally good action, is not well accounted for within the standard categories of practical reason. Section 4 clarifies the scope and importance of this capacity and defends its claim to increased theoretical attention.