Effects of nonspatial selective and divided visual attention on fMRI BOLD responses
| Autor: | Riklef Weerda, Mark W. Greenlee, Roland M. Rutschmann, Ignacio Vallines, James P. Thomas |
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| Rok vydání: | 2006 |
| Předmět: |
Adult
Male genetic structures media_common.quotation_subject Posterior parietal cortex Prefrontal Cortex Fixation Ocular Stimulus (physiology) Extrastriate cortex Perception Parietal Lobe medicine Humans 570 Biowissenschaften Biologie Attention Prefrontal cortex Size Perception media_common Brain Mapping medicine.diagnostic_test Working memory General Neuroscience Magnetic Resonance Imaging Visual cortex medicine.anatomical_structure Stimulus uncertainty Visual attention Colour discrimination Shape perception Functional MRI 150 Psychologie Visual Perception ddc:150 Female ddc:570 Functional magnetic resonance imaging Psychology Color Perception Photic Stimulation Cognitive psychology |
| DOI: | 10.5283/epub.41234 |
| Popis: | Using an uncertainty paradigm and functional magnetic resonance imaging (fMRI) we studied the effect of nonspatial selective and divided visual attention on the activity of specific areas of human extrastriate visual cortex. The stimuli were single ovals that differed from an implicit standard oval in either colour or width. The subjects’ task was to classify the current stimulus as one of two possible alternatives per stimulus dimension. Three different experimental conditions were conducted: “colour-certainty”, “shape-certainty” and “uncertainty”. In all experimental conditions, the stimulus differed in only one stimulus dimension per trial. In the two certainty conditions, the subjects knew in advance which dimension this would be. During the uncertainty condition they had no such previous knowledge and had to monitor both dimensions simultaneously. Statistical analysis of the fMRI data (with SPM2) revealed a modest effect of the attended stimulus dimension on the neural activity in colour sensitive area V4 (more activity during attention to colour) and in shape sensitive area LOC (more activity during attention to shape). Furthermore, cortical areas known to be related to attention and working memory processes (e.g., lateral prefrontal and posterior parietal cortex) exhibit higher activity during the condition of divided attention (“uncertainty”) than during that of selective attention (“certainty”). |
| Databáze: | OpenAIRE |
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