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Titolo:
LUMINANCE AND SPATIAL ATTENTION EFFECTS ON EARLY VISUAL PROCESSING
Autore:
JOHANNES S; MUNTE TF; HEINZE HJ; MANGUN GR;
Indirizzi:
UNIV CALIF DAVIS,CTR NEUROSCI DAVIS CA 95616 UNIV CALIF DAVIS,CTR NEUROSCI DAVIS CA 95616 HANNOVER MED SCH,DEPT NEUROL HANNOVER GERMANY OTTO VONGUERICKE UNIV,DEPT CLIN NEUROPHYSIOL MAGDEBURG GERMANY UNIV CALIF DAVIS,DEPT PSYCHOL DAVIS CA 95616
Titolo Testata:
Cognitive brain research
fascicolo: 3, volume: 2, anno: 1995,
pagine: 189 - 205
SICI:
0926-6410(1995)2:3<189:LASAEO>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
EVENT-RELATED POTENTIALS; BILATERAL STIMULUS ARRAYS; INDEX FOCUSED ATTENTION; SELECTIVE ATTENTION; BRAIN POTENTIALS; EVOKED-POTENTIALS; ALLOCATION; LATENCY; SENSITIVITY; MODULATION;
Keywords:
SELECTIVE ATTENTION; SPATIAL ATTENTION; VISUAL ATTENTION; EVENT-RELATED POTENTIAL; ERP; LUMINANCE; TOPOGRAPHY; HUMAN;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
66
Recensione:
Indirizzi per estratti:
Citazione:
S. Johannes et al., "LUMINANCE AND SPATIAL ATTENTION EFFECTS ON EARLY VISUAL PROCESSING", Cognitive brain research, 2(3), 1995, pp. 189-205

Abstract

Event-related potentials (ERPs) were recorded from healthy subjects in response to unilaterally flashed high and low luminance bar stimuli presented randomly to left and right field locations. Their task was to covertly and selectively attend to either the left or right stimuluslocations (separate blocks) in order to detect infrequent shorter target bars of either luminance. Independent of attention, higher stimulus luminance resulted in higher ERP amplitudes for the posterior N95 (80-110 ms), occipital P1 (110-140 ms), and parietal N1 (130-180 ms). Brighter stimuli also resulted in shorter peak latency for the occipitalN1 component (135-220 ms); this effect was not observed for the N1 components over parietal, central or frontal regions. Significant attention-related amplitude modulations were obtained for the occipital P1, occipital, parietal and central N1, the occipital and parietal P2, andthe parietal N2 components; these components were larger to stimuli at the attended location. In contrast to the relatively short latenciesof both spatial attention and luminance effects, the first interaction between luminance and spatial attention effects was observed for theP3 component to the target stimuli (350-750 ms). This suggests that interactions of spatial attention and stimulus luminance previously reported for reaction time measures may not reflect the earliest stages of sensory/perceptual processing. Differences in the way in which luminance and attention affected the occipital P1, occipital N1 and parietal N1 components suggest dissociations among these ERPs in the mechanisms of visual and attentional processing they reflect, Nonetheless, scalp current density mappings of the attention effects throughout the latency ranges of the P1 and N1 components show the most prominent attention-related activity to be in lateral occipital scalp areas. Such a pattern is consistent with the spatially selective filtering of information into the ventral stream of visual processing which is responsiblefor complex feature analysis and object identification.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 22/09/20 alle ore 14:04:33