Abstract
The activity of single neurons was recorded in area 5 while monkeys made parallel arm movements within different parts of space in an instructed-delay reaching task. In this task: (1) extrinsic variables, such as the direction of movement, were dissociated from intrinsic ones, such as the joint configuration used to perform the movements; and (2) the early neural events related to the presentation of the visual stimulus concerning movement direction were dissociated in time from the later events linked to the execution of movement. Under these experimental conditions, cell activity in area 5 changed so that the population of preferred direction vectors of parietal neurons rotated in space in a way which predicted the rotation of the arm necessary to perform the task. This rotation occurred both during the “instructed-delay time,” when the monkey waited for the “go-signal,” and during the time interval surrounding the onset of movement. This suggests that reaching to visual targets in area 5 is coded by a mechanism combining somatic and visually derived information within a shoulder- or body-centered coordinate system and that instructed-delay time activity in area 5 reflects not only the composition of the direction signal for reaching but also the spatial configuration of the arm.
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References
Bauswein E, Fromm C (1992) Activity in the precentral motor areas after presentation of targets for delayed reaching movements varies with the initial arm position. Eur J Neurosci 4:1407–1410
Burnod Y, Grandguillaume P, Otto I, Ferraina S, Johnson PB, Caminiti R (1992) Visuomotor transformations underlying arm movements toward visual targets: a neural network model of cerebral cortical operations. J Neurosci 12:1435–1453
Caminiti R, Johnson PB, Urbano A (1990) Making arm movements within different parts of space: dynamic aspects in the primate motor cortex. J Neurosci 10:2039–2058
Caminiti R, Johnson PB, Galli C, Ferraina S, Burnod Y (1991) Making arm movements within different parts of space: the premotor and motor cortical representation of a coordinate system for reaching to visual targets. J Neurosci 11:1182–1197
Crammond DJ, Kalaska JF (1989) Neuronal activity in primate parietal area 5 varies with intended movement direction during an instructed-delay period. Exp Brain Res 76:458–462
Efron B (1979) Bootstrap methods: another look at the jackknife. Ann Stat 7:1–26
Georgopoulos AP, Schwartz AB, Kettner RE (1986) Neuronal population coding of movement direction. Science 233:1416–1419
Jupp PE, Mardia KV (1980) A general correlation coefficient for directional data and related regression problems. Biometrika 67:163–173
Kalaska JF, Caminiti R, Georgopoulos AP (1983) Cortical mechanisms related to the direction of two-dimensional arm movements: relations in parietal area 5 and comparison with motor cortex. Exp Brain Res 51:347–260
Mountcastle VB, Lynch JC, Georgopoulos AP, Sakata H, Acuna C (1975) Posterior parietal association cortex of the monkey: command functions for operations within extrapersonal space. J Neurophysiol 38:871–908
Seal J, Gross C, Doudet D, Bioulac B (1983) Instructed-related changes in neuronal activity in area 5 during a simple forearm movement in the monkey. Neurosci Lett 36:145–150
Soechting JF, Flanders M (1989) Sensorimotor representations for pointing to targets in three-dimensional space. J Neurophysiol 62:582–594
Watson GS (1983) Statistics on spheres. Wiley, New York
Wise SP, Di Pellegrino G, Boussaoud D (1992) Primate premotor cortex: dissociation of visuomotor from sensory signals. J Neurophysiol 68:969–972
Zar JH (1984) Biostatistical analysis, 2nd edn. Prentice-Hall, Englewood Cliffs NJ
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Ferraina, S., Bianchi, L. Posterior parietal cortex: functional properties of neurons in area 5 during an instructed-delay reaching task within different parts of space. Exp Brain Res 99, 175–178 (1994). https://doi.org/10.1007/BF00241423
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DOI: https://doi.org/10.1007/BF00241423