Neural mechanisms of spatial- and feature-based attention: A quantitative analysis

• Published in: Brain research Vol. 1181; pp. 51 - 60
• Main Authors: Stoppel, Christian Michael, Boehler, Carsten Nicolas, Sabelhaus, Clemens, Heinze, Hans-Jochen, Hopf, Jens Max, Schoenfeld, Mircea Ariel
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 21.11.2007; Amsterdam Elsevier; New York, NY
• Subjects: Adult; Analysis of Variance; Anatomical correlates of behavior; Attention - physiology; Behavioral psychophysiology; Biological and medical sciences; Brain Mapping; Cerebral Cortex - physiology; Color; Eye Movements - physiology; Feature-based attention; Female; Field Dependence-Independence; Fixation, Ocular - physiology; fMRI; Form Perception - physiology; Fundamental and applied biological sciences. Psychology; Humans; Magnetic Resonance Imaging; Motion; Neurology; Photic Stimulation; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Reaction Time - physiology; Space Perception - physiology; Spatial attention; fMRI; Motion; Feature-based attention; Spatial attention; Color; Human; Cognition; Space perception; Nuclear magnetic resonance imaging; Quantitative analysis; Functional imaging
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2007.07.019

Attentional selection can be based on spatial locations, non-spatial stimulus features, or entire objects as integrated feature ensembles. Several studies reported attentional modulations in those regions that process the constituent features of the presented stimuli. Here we employed functional magnetic resonance imaging (fMRI) to directly compare the magnitude of space- and/or feature-based attentional modulations while subjects directed their attention to a particular color (red or green) of a transparent surface and at the same time to a spatial location (left or right visual field). The experimental design made it possible to disentangle and quantify the hemodynamic activity elicited by identical physical stimuli when attention was directed to spatial locations and/or stimulus features. The highest modulations were observed when the attentional selection was based on spatial location. Attended features also elicited a response increase relative to unattended features when their spatial location was attended. Importantly, at unattended locations, a response increase upon feature-based selection was observed in motion-sensitive but not in color-related areas. This suggests that compared to color, motion stimuli are more effective in capturing attention at unattended locations leading to a competitive advantage. These results support the idea of a high biological relevance of the feature motion in the visual world.