Cortical regions associated with different aspects of object recognition performance.
In the present object recognition study, we examined the relationship between brain activation and four behavioral measures: error rate, reaction time, observer sensitivity, and response bias. Subjects perceptually matched object pairs in which structural similarity (SS), an index of structural differentiation, and exposure duration (DUR), an index of task difficulty, were manipulated. The SS manipulation affected the fMRI signal in the left anterior fusiform and parietal cortices, which in turn reflected a bias to respond same. Conversely, an SS-modulated fMRI signal in the right middle frontal gyrus reflected a bias to respond different. The DUR manipulation affected the fMRI signal in occipital and posterior fusiform regions, which in turn reflected greater sensitivity, longer reaction times, and greater accuracy. These findings demonstrate that the regions most strongly implicated in processing object shape (SS-modulated regions) are associated with response bias, whereas regions that are not directly involved in shape processing are associated with successful recognition performance.
Joseph
Jane E
JE
Department of Anatomy and Neurobiology, University of Kentucky Medical Center, 800 Rose Street, Davis-Mills Building, Room 308, Lexington, KY 40536, USA. jjoseph@uky.edu
Farley
Alison B
AB
D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D005260:Female; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008606:Mental Processes / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009778:Occipital Lobe / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology*; D012016:Reference Values; D013702:Temporal Lobe / Q000502:physiology*