Input-output properties of hand-related cells in the ventral cingulate cortex in the monkey.

1. Neurons with proprioceptive or cutaneous receptive fields associated with the hand were identified in the ventral bank of the cingulate sulcus in the monkey. Cells with proprioceptive fields outnumbered cells receiving cutaneous afferents by more than three to one. No cells were encountered that received convergent proprioceptive and cutaneous input. The high concentration of these neurons in the lateral depth of the cingulate sulcus establishes that a distinct hand representation exists within the rostral part of area 23c. 2. Hand-related neurons in area 23c exhibited strong activity modulations during grasping, lifting, and holding an object with the contralateral thumb and index finger. Force pulse perturbations applied to the object elicited excitatory responses at latencies of approximately 45 ms. The modulation of the cellular activity and the input-output properties of these cingulate neurons suggest that, like neurons of primary motor and sensory cortex, these cingulate neurons are also involved in the sensorimotor control of finger movements.