Prefrontal cortex and working memory processes.
Working memory is a mechanism for short-term active maintenance of information as well as for processing maintained information. The dorsolateral prefrontal cortex has been known to participate in working memory. The analysis of task-related dorsolateral prefrontal cortex activity while monkeys performed a variety of working memory tasks revealed that delay-period activity is a neural correlate of a mechanism for temporary active maintenance of information, because this activity persisted throughout the delay period, showed selectivity to a particular visual feature, and was related to correct behavioral performances. Information processing can be considered as a change of the information represented by a population of neural activities during the progress of the trial. Using population vectors calculated by a population of task-related dorsolateral prefrontal cortex activities, we demonstrated the temporal change of information represented by a population of dorsolateral prefrontal cortex activities during performances of spatial working memory tasks. Cross-correlation analysis using spike firings of simultaneously isolated pairs of neurons reveals widespread functional interactions among neighboring neurons, especially neurons having delay-period activity, and their dynamic modulation depending on the context of the trial. Functional interactions among neurons and their dynamic modulation could be a mechanism of information processing in the dorsolateral prefrontal cortex.
Funahashi
S
S
Department of Cognitive and Behavioral Sciences, Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan. h50400@sakura.kudpc.kyoto-u.ac.jp
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D006801:Humans; D008570:Memory, Short-Term / Q000502:physiology*; D023421:Models, Animal; D009415:Nerve Net / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology