title: A spatially nonselective baseline signal in parietal cortex reflects the probability of a monkey's success on the current trial.
abstract: We recorded the activity of neurons in the lateral intraparietal area of two monkeys while they performed two similar visual search tasks, one difficult, one easy. Each task began with a period of fixation followed by an array consisting of a single capital T and a number of lowercase t's. The monkey had to find the capital T and report its orientation, upright or inverted, with a hand movement. In the easy task the monkey could explore the array with saccades. In the difficult task the monkey had to continue fixating and find the capital T in the visual periphery. The baseline activity measured during the fixation period, at a time in which the monkey could not know if the impending task would be difficult or easy or where the target would appear, predicted the monkey's probability of success or failure on the task. The baseline activity correlated inversely with the monkey's recent history of success and directly with the intensity of the response to the search array on the current trial. The baseline activity was unrelated to the monkey's spatial locus of attention as determined by the location of the cue in a cued visual reaction time task. We suggest that rather than merely reflecting the noise in the system, the baseline signal reflects the cortical manifestation of modulatory state, motivational, or arousal pathways, which determine the efficiency of cortical sensorimotor processing and the quality of the monkey's performance.
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning, Neuroscience Institute; and Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China, 100875; mingsha.zhang@bnu.edu.cn meg2008@columbia.edu.
authors.forename: Mingsha
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Mahoney-Keck Center for Brain and Behavior Research, Columbia Neuroscience, College of Physicians and Surgeons; and the New York State Psychiatric Institute, Columbia University Medical Center, Columbia University, New York, NY 10032;The Kavli Institute for Brain Science, Columbia University, New York, NY 10032; and.
authors.forename: Xiaolan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Mahoney-Keck Center for Brain and Behavior Research, Columbia Neuroscience, College of Physicians and Surgeons; and the New York State Psychiatric Institute, Columbia University Medical Center, Columbia University, New York, NY 10032;The Kavli Institute for Brain Science, Columbia University, New York, NY 10032; andDepartments of Neurology, Psychiatry, and Ophthalmology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 mingsha.zhang@bnu.edu.cn meg2008@columbia.edu.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Goldberg
mesh_terms: D000818:Animals; D001143:Arousal; D001288:Attention / Q000502:physiology; D001522:Behavior, Animal; D001931:Brain Mapping; D000882:Haplorhini; D009042:Motivation; D009474:Neurons / Q000378:metabolism / Q000502:physiology; D010296:Parietal Lobe / Q000473:pathology*; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D012438:Saccades; D014785:Vision, Ocular
keywords: LIP; modulatory systems; motivation