J. J. Gibson

Bio: J. J. Gibson is an academic researcher. The author has contributed to research in topics: Adaptation (eye) & Visual perception. The author has an hindex of 1, co-authored 1 publications receiving 563 citations.

Humans integrate visual and haptic information in a statistically optimal fashion.

Abstract: When a person looks at an object while exploring it with their hand, vision and touch both provide information for estimating the properties of the object. Vision frequently dominates the integrated visual-haptic percept, for example when judging size, shape or position, but in some circumstances the percept is clearly affected by haptics. Here we propose that a general principle, which minimizes variance in the final estimate, determines the degree to which vision or haptics dominates. This principle is realized by using maximum-likelihood estimation to combine the inputs. To investigate cue combination quantitatively, we first measured the variances associated with visual and haptic estimation of height. We then used these measurements to construct a maximum-likelihood integrator. This model behaved very similarly to humans in a visual-haptic task. Thus, the nervous system seems to combine visual and haptic information in a fashion that is similar to a maximum-likelihood integrator. Visual dominance occurs when the variance associated with visual estimation is lower than that associated with haptic estimation.

Principles of neurodynamics. perceptrons and the theory of brain mechanisms

Abstract: : Part I attempts to review the background, basic sources of data, concepts, and methodology to be employed in the study of perceptrons. In Chapter 2, a brief review of the main alternative approaches to the development of brain models is presented. Chapter 3 considers the physiological and psychological criteria for a suitable model, and attempts to evaluate the empirical evidence which is available on several important issues. Chapter 4 contains basic definitions and some of the notation to be used in later sections are presented. Parts II and III are devoted to a summary of the established theoretical results obtained to date. Part II (Chapters 5 through 14) deals with the theory of three-layer series-coupled perceptrons, on which most work has been done to date. Part III (Chapters 15 through 20) deals with the theory of multi-layer and cross-coupled perceptrons. Part IV is concerned with more speculative models and problems for future analysis. Of necessity, the final chapters become increasingly heuristic in character, as the theory of perceptrons is not yet complete, and new possibilities are continually coming to light.

Visual dominance: an information-processing account of its origins and significance.

Abstract: In many situations, visual input tends to dominate other modalities in perceptual and memorial reports and in speeded responses. Visual dominance appears to be related to the relatively weak capacity of visual inputs to alert the organism to their occurrence. In response to this reduced alerting, subjects tend to keep their attention tuned to the visual modality. This bias works via prior entry to allow vision to control the mechanisms that subserve conscious reports. The study of visual dominance provides a model situation in which chronometric and phenomenological techniques can be brought together to produce a more complete picture of the relation between information processing and awareness. Process models of perceptual phenomena (Chase, 1973) usually emphasize the flow of information within and between such systems as visual and acoustic analyzers, short- and long-term memories, and decision and response systems. Most often, some form of mental chronometry (Posner, in press), such

A Neural Theory of Binocular Rivalry

Abstract: When the two eyes view discrepant monocular stimuli, stable single vision gives way to alternating periods of monocular dominance; this is the well-known but little understood phenomenon of binocular rivalry. This article develops a neural theory of binocular rivalry that treats the phenomenon as the default outcome when binocular correspondence cannot be established. The theory posits the existence of monocular and binocular neurons arrayed within a functional processing module, with monocular neurons playing a crucial role in signaling the stimulus conditions instigating rivalry and generating inhibitory signals to implement suppression. Suppression is conceived as a local process happening in parallel over the entire cortical representation of the binocular visual field. The strength of inhibition causing suppression is related to the size of the pool of monocular neurons innervated by the suppressed eye, and the duration of a suppression phase is attributed to the strength of excitation generated by the suppressed stimulus. The theory is compared with three other contemporary theories of binocular rivalry. The article closes with a discussion of some of the unresolved problems related to the theory.