Numerical representation for action in the parietal cortex of the monkey

• Published in: Nature (London) Vol. 415; no. 6874; pp. 918 - 922
• Main Authors: Tanji, Jun, Sawamura, Hiromasa, Shima, Keisetsu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 21.02.2002; Nature Publishing Group
• Subjects: Animal behavior; Animals; Biological and medical sciences; Brain; Brain Mapping; Cognition - physiology; Fundamental and applied biological sciences. Psychology; Macaca; Monkeys & apes; Neurology; Parietal Lobe - physiology; Primates; Psychomotor Performance; Somesthesis and somesthetic pathways (proprioception, exteroception, nociception); interoception; electrolocation. Sensory receptors; Vertebrates: nervous system and sense organs; Somatosensory cortex; Vertebrata; Mammalia; Somesthetic pathway; Central nervous system; Parietal cortex; Body movement; Monkey; Primates; Arm; Brain (vertebrata)
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/415918a

The anterior part of the parietal association area in the cerebral cortex of primates has been implicated in the integration of somatosensory signals, which generate neural images of body parts and apposed objects and provide signals for sensorial guidance of movements. Here we show that this area is active in primates performing numerically based behavioural tasks. We required monkeys to select and perform movement A five times, switch to movement B for five repetitions, and return to movement A, in a cyclical fashion. Cellular activity in the superior parietal lobule reflected the number of self-movement executions. For the most part, the number-selective activity was also specific for the type of movement. This type of numerical representation of self-action was seen less often in the inferior parietal lobule, and rarely in the primary somatosensory cortex. Such activity in the superior parietal lobule is useful for processing numerical information, which is necessary to provide a foundation for the forthcoming motor selection.