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Titolo:
Cooperative and competitive spatial interactions in motion integration
Autore:
Lorenceau, J; Zago, L;
Indirizzi:
Coll France, CNRS, Lab Physiol Percept & Act, F-75005 Paris, France Coll France Paris France F-75005 ol Percept & Act, F-75005 Paris, France
Titolo Testata:
VISUAL NEUROSCIENCE
fascicolo: 4, volume: 16, anno: 1999,
pagine: 755 - 770
SICI:
0952-5238(199907/08)16:4<755:CACSII>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
CAT VISUAL-CORTEX; AREA MT; NEURONAL RESPONSES; LUMINANCE CONTRAST; CORTICAL NETWORKS; COHERENT MOTION; MACAQUE MONKEY; STRIATE CORTEX; PERCEPTION; PATTERNS;
Keywords:
collinearity; spatial discontinuities; motion integration; segmentation; long-range lateral interactions;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
78
Recensione:
Indirizzi per estratti:
Indirizzo: Lorenceau, J Coll France, CNRS, Lab Physiol Percept & Act, 11 Pl M Berthellot, F-75005 Paris, France Coll France 11 Pl M Berthellot Paris France F-75005 , France
Citazione:
J. Lorenceau e L. Zago, "Cooperative and competitive spatial interactions in motion integration", VIS NEUROSC, 16(4), 1999, pp. 755-770

Abstract

Recovering the velocity of objects moving in the visual field requires both the integration and segmentation of local neuronal responses elicited by moving stimuli in primary visual cortex. Herein, we investigate the effectsof the contrast, density, spatial proximity, spatial frequency, and spatial configuration of component motions on these complementary processes. Measuring the ability of human observers to discriminate the global direction of motion displays composed of spatially distributed patches of drifting gratings whose motion is locally ambiguous, we provide psychophysical evidencethat linking component motion across space is facilitated at low contrast and high patch density. Furthermore, direction discrimination depends on the spatial frequency of component gratings and is more accurate for spatial configurations that contain; "virtual" L junctions as compared to configurations composed of "virtual" T junctions. We suggest that the conditions yielding global motion coherence can be accounted for by the existence of anisotropic cooperative/competitive, contrast-dependent, long-range interactions among oriented direction-selective units. In addition, we bring evidence that motion segmentation processes rely upon the processing of moving localspatial discontinuities. The results are discussed in the light of recent psychophysical and physiological evidence that long-range excitatory and inhibitory interactions within primary visual cortex modulate perceptual linking.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/11/20 alle ore 04:16:11