Context-Specific Grasp Movement Representation in the Macaque Anterior Intraparietal Area

Abstract

To perform grasping movements, the hand is shaped according to the form of the target object and the intended manipulation, which in turn depends on the context of the action. The anterior intraparietal cortex (AIP) is strongly involved in the sensorimotor transformation of grasping movements, but the extent to which it encodes context-specific information for hand grasping is unclear. To explore this issue, we recorded 571 single-units in AIP of two macaques during a delayed grasping task, in which animals were instructed by an external context cue (LED) to perform power or precision grips on a handle that was presented in various orientations. While 55% of the recorded neurons encoded the object orientation from the cue epoch on, the number of cells encoding the grip type increased from 25% during the cue epoch to 58% during movement execution. Furthermore, a classification of cells according to the time of their tuning onset revealed differences in the function and anatomical location of early-versus late-tuned cells. In a cue separation task, when the object was presented first, neurons representing power or precision grips were activated simultaneously until the actual grip type was instructed. In contrast, when the grasp type instruction was presented before the object, type information was only weakly represented in AIP, but was strongly encoded after the grasp target was revealed. We conclude that AIP encodes context specific hand grasping movements to perceived objects, but in the absence of a grasp target, the encoding of context information is weak.

Context-Specific Grasp Movement Representation in Macaque Ventral Premotor Cortex

“…Context-specific, or rule-based, information has been demonstrated in frontal cortex (White and Wise, 1999;Hoshi et al, 2000;Wallis et al, 2001;Amemori and Sawaguchi, 2006) and in parietal cortex (Gottlieb and Goldberg, 1999;Kalaska et al, 2003;Gail and Andersen, 2006;Scherberger and Andersen, 2007). Recently, we demonstrated such context-specific grasp movement signals in AIP (Baumann et al, 2009). Since AIP and F5 are intimately connected, we hypothesize that F5 also contains contextspecific information that might contribute, in addition to sensory information, to grasp movement preparation.…”

“…The ventral premotor cortex (PMv) in the frontal cortex, specifically area F5, participates in such visuomotor transformations for grasping (Gentilucci et al, 1983;Murata et al, 1997;Fogassi et al, 2001;Cerri et al, 2003;Umilta et al, 2007). Anatomically, area F5 is strongly and reciprocally connected to the parietal cortex, in particular to the anterior intraparietal area (AIP) (Matelli et al, 1986;Luppino et al, 1999;Tanné-Gariépy et al, 2002;Borra et al, 2008), which also contains hand grasping signals (Taira et al, 1990;Sakata et al, 1995;Murata et al, 2000;Baumann et al, 2009). At the motor output side, F5 has direct projections to the hand area of primary motor cortex (Matsumura and Kubota, 1979;Muakkassa and Strick, 1979;Matelli et al, 1986;Dum and Strick, 2005) and to the spinal cord (Dum and Strick, 1991;He et al, 1993;Borra et al, 2010).…”

Eye Position Encoding in Three-Dimensional Space: Integration of Version and Vergence Signals in the Medial Posterior Parietal Cortex

“…To assess the relative effects of vergence and/or version and their interaction on the discharge of the cell during FIX, we performed a two-way ANOVA with vergence as factor 1 (three levels: near, intermediate, far) and version as factor 2 (three levels: ipsilateral, central, contralateral) ( p Ͻ 0.05). Neurons with mean firing rate Ͻ5 spikes/s were excluded from the analysis (Baumann et al, 2009). In the cells with a significant excitatory effect, we calculated the response latency for each LED position.…”

Morphological patterns of the intraparietal sulcus and the anterior intermediate parietal sulcus of Jensen in the human brain

“…By contrast, in the monkey, it is a relatively simple furrow and its functional organization has been clarified by elegant single-neuron recording studies. The anterior intraparietal sulcal cortex (area AIP) has been shown to be involved in complex sensorimotor integration [2][3][4][5], whereas its more central and caudal parts (lateral, medial and caudal intraparietal areas) play critical roles in visuospatial and attentional processing [6][7][8][9][10][11][12][13][14][15]. More recently, there have been several attempts to explore the functional organization of the intraparietal sulcal cortex in the human brain using functional neuroimaging methods [16 -24] (for reviews, see [25][26][27]).…”