Online research in philosophy

There are currently two main philosophical theories of perception - Direct Realism and the Representative Theory. The former is supported by most contemporary philosophers, whereas the latter forms the groundwork for most scientific theories in this area. The paper describes a recent experiment involving retinal and cortical rivalry that provides strong empirical evidence that the Direct Realist theory is incorrect. There are of course a large number of related experiments on visual perception that would tend to lead us to the same conclusion, but the experiment described in this paper does so in a singularly direct and straightforward manner. Often the most telling experiments are the simplest.

In a target article that appeared in this journal, Thomas Stoffregen 2000 questions the possibility of ecological event perception research. This paper describes an experiments performed to examine the perception of the disappearance of gap-crossing affordances, a variety of event as defined by Chemero 2000. We found that subjects reliably perceive both gap-crossing affordances and the disappearance of gap-crossing affordances. Our findings provide empirical evidence in favor of understanding events as changes in the layout of affordances, shoring up event perception research in ecological psychology.

This paper is part of a series in which we had worked in the last 6 months, and, specifically, intend to investigate the notion of timbre through the ecological perspective proposed by James Gibson in his Theory of Direct Perception. First of all, we discussed the traditional approach to timbre, mainly as developed in acoustics and psychoacoustics. Later, we proposed a new conception of timbre that was born in concepts of ecological approach. The ecological approach to perception proposed by Gibson (1966, 1979) presupposes a level of analysis of perceptual stimulated that includes, but is quite broader than the usual physical aspect. Gibson suggests as focus the relationship between the perceiver and his environment. At the core of this approach, is the notion of affordances, invariant combinations of properties at the ecological level, taken with reference to the anatomy and action systems of species or individual, and also with reference to its biological and social needs. Objects and events are understood as relates to a perceiving organism by the meaning of structured information, thus affording possibilities of action by the organism. Event perception aims at identifying properties of events to specify changes of the environment that are relevant to the organism. The perception of form is understood as a special instance of event perception, which is the identity of an object depends on the nature of the events in which is involved and what remains invariant over time. From this perspective, perception is not in any sense created by the brain, but is a part of the world where information can be found. Consequently, an ecological approach represents a form of direct realism that opposes the indirect realist based on predominant approaches to perception borrowed from psychoacoustics and computational approach.

When philosophers speak of direct perceptual knowledge, they obviously mean to suggest that such knowledge is unmediated ? but unmediated by what? This is where we find evidence of violent disagreement. To clarify matters, I want to identify and briefly describe several important senses of "direct" that have helped shape our understanding of perceptual knowledge. They are (1) "Direct" as Non-Inferential Perception; (2) "Direct" as Unmediating by Objects of Perception; (3) "Direct" as Conceptually Unmediated Perception; (4) "Direct" as Independent Verification of Perceptual Beliefs; and (5) "Direct" as Perception of What is Epistemically Prior.

When philosophers speak of direct perceptual knowledge, they obviously mean to suggest that such knowledge is unmediated ? but unmediated by what? This is where we find evidence of violent disagreement. To clarify matters, I want to identify and briefly describe several important senses of "direct" that have helped shape our understanding of perceptual knowledge. They are (1) "Direct" as Non-Inferential Perception; (2) "Direct" as Unmediating by Objects of Perception; (3) "Direct" as Conceptually Unmediated Perception; (4) "Direct" as Independent Verification of Perceptual Beliefs; and (5) "Direct" as Perception of What is Epistemically Prior.

Thomas Reid's distinction between original and acquired perception is not merely metaphysical; it has psychological and phenomenological stories to tell. Psychologically, acquired perception provides increased sensitivity to features in the environment. Phenomenologically, Reid's theory resists the notion that original perception is exhaustive of perceptual experience. James Van Cleve has argued that most cases of acquired perception do not count as perception and so do not pose a threat to Reid's direct realism. I argue that acquired perception is genuine perception and as direct as original perception. Perception is grounded in a productive and developing relationship between the mind and world.

In her essay --?Information, Perception and Action--, Claire Michaels reaches two conclusions that run very much against the grain of ecological psychology. First, she claims that affordances are not perceived, but simply acted upon; second, because of this, perception and action ought to be conceived separately. These conclusions are based upon a misinterpretation of empirical evidence which is, in turn, based upon a conflation of two proper objects of perception: objectively with properties and affordances.

In the course of his discussion of perception, Searle criticizes representative theories in general. In this paper I will argue that, even though his criticisms may be adequate regarding a certain form of these theories, perhaps the most frequently defended by philosophers of perception, a version I will outline here escapes to them. A second issue I raise concerns Searle's claim that his theory of perception is a form of direct realism. I will raise difficulties for Searle's attempt to maintain at the same time a "token-reflexive" theory of perception and the thesis of direct realism.

In his ecological approach to perception, james gibson introduced the concept of affordance to refer to the perceived meaning of environmental objects and events. this paper examines the relational and causal character of affordances, as well as the grounds for extending affordances beyond environmental features with transcultural meaning to include those features with culturally-specific meaning. such an extension is seen as warranted once affordances are grounded in an intentional analysis of perception. toward this end, aspects of merleau-ponty's treatment of perception are explored. finally, a resolution of the apparent tension between the relational and perceiver-independent nature of affordances is presented.

Using hypersets as an analytic tool, we compare traditionally Gibsonian (Chemero 2003; Turvey 1992) and representationalist (Sahin et al. this issue) understandings of the notion ‘affordance’. We show that representationalist understandings are incompatible with direct perception and erect barriers between animal and environment. They are, therefore, scarcely recognizable as understandings of ‘affordance’. In contrast, Gibsonian understandings are shown to treat animal-environment systems as unified complex systems and to be compatible with direct perception. We discuss the fruitful connections between Gibsonian affordances and dynamical systems explanation in the behavioral sciences and point to prior fruitful application of Gibsonian affordances in robotics. We conclude that it is unnecessary to re-imagine affordances as representations in order to make them useful for researchers in robotics.