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Titolo:
Context-sensitive binding by the laminar circuits of V1 and V2: A unified model of perceptual grouping, attention, and orientation contrast
Autore:
Raizada, RDS; Grossberg, S;
Indirizzi:
Boston Univ, Dept Cognit & Neural Syst, Boston, MA 02215 USA Boston Univ Boston MA USA 02215 ognit & Neural Syst, Boston, MA 02215 USA
Titolo Testata:
VISUAL COGNITION
fascicolo: 3-5, volume: 8, anno: 2001,
pagine: 431 - 466
SICI:
1350-6285(200106/10)8:3-5<431:CBBTLC>2.0.ZU;2-A
Fonte:
ISI
Lingua:
ENG
Soggetto:
PRIMARY VISUAL-CORTEX; MACAQUE STRIATE CORTEX; LATERAL GENICULATE-NUCLEUS; CLASSICAL RECEPTIVE-FIELD; OBJECT-BASED ATTENTION; NEURAL DYNAMICS; HORIZONTAL CONNECTIONS; INTRINSIC CONNECTIONS; ILLUSORY CONTOURS; PYRAMIDAL NEURONS;
Tipo documento:
Review
Natura:
Periodico
Settore Disciplinare:
Social & Behavioral Sciences
Citazioni:
130
Recensione:
Indirizzi per estratti:
Indirizzo: Grossberg, S 677 Beacon St, Boston, MA 02215 USA 677 Beacon St Boston MA USA 02215 n St, Boston, MA 02215 USA
Citazione:
R.D.S. Raizada e S. Grossberg, "Context-sensitive binding by the laminar circuits of V1 and V2: A unified model of perceptual grouping, attention, and orientation contrast", VIS COGN, 8(3-5), 2001, pp. 431-466

Abstract

A detailed neural model is presented of how the laminar circuits of visualcortical areas V1 and V2 implement context-sensitive binding processes such as perceptual grouping and attention. The model proposes how specific laminar circuits allow the responses of visual cortical neurons to be determined not only by the stimuli within their classical receptive fields, but also to be strongly influenced by stimuli in the extra-classical surround. This context-sensitive visual processing can greatly enhance the analysis of visual scenes, especially those containing targets that are low contrast, partially occluded, or crowded by distractors. We show how interactions of feedforward, feedback, and horizontal circuitry can implement several types of contextual processing simultaneously, using shared laminar circuits. In particular, we present computer simulations that suggest how top-down attention and preattentive perceptual grouping, two processes that are fundamental for visual binding, can interact, with attentional enhancement selectively propagating along groupings of both real and illusory contours, thereby showing how attention can selectively enhance object representations. These simulations also illustrate how attention may have a stronger facilitatory effect on low contrast than on high contrast stimuli, and how pop-out from orientation contrast may occur. The specific functional roles which the model proposes for the cortical layers allow several testable neurophysiological predictions to be made. The results presented here simulate only the boundary grouping system of adult cortical architecture. However, we also discuss how this model contributes to a larger neural theory of vision that suggests how intracortical and intercortical feedback help to stabilize development and learning within these cortical circuits. Although feedback plays a key role, fast feedforward processing is possible in response to unambiguous information. Model circuits are capable of synchronizing quickly, but context-sensitive persistence of previous events can influence how synchronydevelops. Although these results focus on how the interblob cortical processing stream controls boundary grouping and attention, related modelling ofthe blob cortical processing stream suggests how visible surfaces are formed, and modelling of the motion stream suggests how transient responses to scenic changes can control long-range apparent motion and also attract spatial attention.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 23/01/20 alle ore 12:20:48