Prefrontal unit activity during delayed conditional discriminations in the monkey

Single unit activity was recorded from the prefrontal cortex (principalis, arcuate and inferior convexity areas) of the monkey while the animal was performing a delayed conditional discrimination task. Sequential events of the task were as follows: instructional cue presentation, 1st delay, presentation of two pattern stimuli on left and right windows respectively as a discriminative cue, 2nd delay and choice response to the left or right window. The positive pattern was dependent on the instructional cue. In total, 424 units obtained from two monkeys showed a correlation with some aspects of the task. Of these 424 task-related units, 169 differential between the instructional cues and/or the discriminative cues. The majority of these differential units (n = 123) were found to be related to spatial information processing (related to the side of the response) while 19 differential units were related to non-spatial information processing (related to the color or pattern configuration of the cue). The activity of the remaining 27 differential units was considered to be related to both spatial and non-spatial information processing (related to both the instructional cue and the side of the response) and this type of unit was shown to be involved in conditional information processing. The results indicate that prefrontal units may be related to the meaning of the stimulus independent of its physical properties.

[1]  H. Niki,et al.  Prefrontal cortical unit activity and delayed alternation performance in monkeys. , 1971, Journal of neurophysiology.

[2]  H Niki,et al.  Prefrontal unit activity during delayed alternation in the monkey. II. Relation to absolute versus relative direction of response. , 1974, Brain research.

[3]  J. Fuster.  Unit activity in prefrontal cortex during delayed-response performance: neuronal correlates of transient memory. , 1973, Journal of neurophysiology.

[4]  E. Evarts.  A technique for recording activity of subcortical neurons in moving animals. , 1968, Electroencephalography and clinical neurophysiology.

[5]  M L Wolbarsht,et al.  Glass Insulated Platinum Microelectrode , 1960, Science.

[6]  M. Azuma,et al.  Prefrontal neuronal activity during gazing at a light spot in the monkey , 1977, Brain Research.

[7]  H Niki,et al.  Prefrontal unit activity during delayed alternation in the monkey. I. Relation to direction of response. , 1974, Brain research.

[8]  Joaquin M. Fuster,et al.  Single cell activity in ventral prefrontal cortex of behaving monkeys , 1981, Brain Research.

[9]  K. Kubota,et al.  Visuokinetic activities of primate prefrontal neurons during delayed-response performance. , 1974, Journal of neurophysiology.

[10]  Mark R. Rosensweig.  Neurobiological basis of learning and memory , 1981 .

[11]  D. Perrett,et al.  Responses of neurons in area 7 of the parietal cortex to objects of different significance , 1979, Brain Research.

[12]  D. Robinson,et al.  Parietal association cortex in the primate: sensory mechanisms and behavioral modulations. , 1978, Journal of neurophysiology.

[13]  D. B. Bender,et al.  Activity of inferior temporal neurons in behaving monkeys , 1979, Neuropsychologia.

[14]  A. Mikami,et al.  Neuronal activity in the monkey dorsolateral prefrontal cortex during a discrimination task with delay , 1980, Brain Research.

[15]  Masataka Watanabe,et al.  Prefrontal unit activity during delayed conditional discrimination in the monkey , 1979, Neuroscience Letters.

[16]  H. Niki.  Differential activity of prefrontal units during right and left delayed response trials. , 1974, Brain research.

[17]  Masataka Watanabe,et al.  Prefrontal unit activity and delayed response: Relation to cue location versus direction of response , 1976, Brain Research.

[18]  S. Kojima.  Prefrontal unit activity in the monkey: Relation to visual stimuli and movements , 1980, Experimental Neurology.

[19]  E. T. Rolls,et al.  Activity of neurones in the inferotemporal cortex of the alert monkey , 1977, Brain Research.

[20]  Masataka Watanabe,et al.  Prefrontal and cingulate unit activity during timing behavior in the monkey , 1979, Brain Research.