2011 Fiscal Year Final Research Report

Neural Mechanism in Numerical Counting Processes of Presented Objects

Research Project

Project/Area Number	21500365
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Neurophysiology and muscle physiology
Research Institution	Tohoku University
Principal Investigator	SHIMA Keisetsu 東北大学, 大学院・医学系研究科, 助教 (60124583)
Project Period (FY)	2009 – 2011
Keywords	細胞活動 / カウンティング / サル / 認知課題 / 数的操作
Research Abstract	Previous b ehavioral studies in primates have suggested the existence of two distinct elements in numerical system, such as approximate and precise numerical systems. How the precise numerical system is operated in the monkey. We trained two monkeys to perform a numerosity-based operation task and examined the effect of numerosity on the performance level. Two distinct number systems exist with the critical object index-number of 4. The monkey was able to change the number of dots. The monkey was able to adjust device-use to change dot numbers toward a target number. Also, the monkey successfully switched to effective device-use, and the device-use chosen in the first step of each trial was become effective after several trials. It was suggested that intra-trial and inter-trial switching behavior may have different mechanisms.