The object advantage can be eliminated under equiluminant conditions

• Published in: Psychonomic bulletin & review Vol. 21; no. 6; pp. 1459 - 1464
• Main Authors: Brown, James M., Guenther, Benjamin A., Narang, Shruti, Siddiqui, Aisha P., Foley, Nicholas C.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.12.2014; Springer; Springer Nature B.V
• Subjects: Activity levels. Psychomotricity; Attention - physiology; Behavioral Science and Psychology; Biological and medical sciences; Brief Report; Cognitive Psychology; Edinger-Westphal Nucleus - physiology; Experiments; Fundamental and applied biological sciences. Psychology; Humans; Lighting; Oculomotor Nuclear Complex - physiology; Pattern Recognition, Visual - physiology; Psychology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychophysics; Reaction Time - physiology; Retina - physiology; Software; Vigilance. Attention. Sleep; Visual Pathways - physiology; Visual task performance; Object-based attention; Perception; Attention systems; Cognitive neuroscience; Space-based attention; Human; Visual parvocellular pathway; Spatial attention; Visual magnocellular pathway; Cognition; Experimental study; Vision; Object; Visual attention
• ISSN: 1069-9384; 1531-5320
• DOI: 10.3758/s13423-014-0630-5

A key phenomenon supporting the existence of object-based attention is the object advantage, in which responses are faster for within-object, relative to equidistant between-object, shifts of attention. The origins of this effect have been variously ascribed to low-level “bottom-up” sensory processing and to a cognitive “top-down” strategy of within-object attention prioritization. The degree to which the object advantage depends on lower-level sensory processing was examined by differentially stimulating the magnocellular (M) and parvocellular (P) retino-geniculo-cortical visual pathways by using equiluminant and nonequiluminant conditions. We found that the object advantage can be eliminated when M activity is reduced using psychophysically equiluminant stimuli. This novel result in normal observers suggests that the origin of the object advantage is found in lower-level sensory processing rather than a general cognitive process, which should not be so sensitive to differential activation of the bottom-up P and M pathways. Eliminating the object advantage while maintaining a spatial-cueing advantage with reduced M activity suggests that the notion of independent M-driven spatial attention and P-driven object attention requires revision.