Neural Responses during Interception of Real and Apparent Circularly Moving Stimuli in Motor Cortex and Area 7a

Abstract

We recorded the neuronal activity in the arm area of the motor cortex and parietal area 7a of two monkeys during interception of stimuli moving in real and apparent motion. The stimulus moved along a circular path with one of five speeds (180-540 degrees/s), and was intercepted at 6 o'clock by exerting a force pulse on a semi-isometric joystick which controlled a cursor on the screen. The real stimuli were shown in adjacent positions every 16 ms, whereas in the apparent motion situation five stimuli were flashed successively at the vertices of a regular pentagon. The results showed, first, that a group of neurons in both areas above responded not only during the interception but also during a NOGO task in which the same stimuli were presented in the absence of a motor response. This finding suggests these areas are involved in both the processing of the stimulus as well as in the preparation and production of the interception movement. In addition, a group of motor cortical cells responded during the interception task but not during a center --> out task, in which the monkeys produced similar force pulses towards eight stationary targets. This group of cells may be engaged in sensorimotor transformations more specific to the interception of real and apparent moving stimuli. Finally, a multiple regression analysis revealed that the time-varying neuronal activity in area 7a and motor cortex was related to various aspects of stimulus motion and hand force in both the real and apparent motion conditions, with stimulus-related activity prevailing in area 7a and hand-related activity prevailing in motor cortex. In addition, the neural activity was selectively associated with the stimulus angle during real motion, whereas it was tightly correlated to the time-to-contact in the apparent motion condition, particularly in the motor cortex. Overall, these observations indicate that neurons in motor cortex and area 7a are processing different parameters of the stimulus depending on the kind of stimulus motion, and that this information is used in a predictive fashion in motor cortex to trigger the interception movement.

A dynamical neural network for hitting an approaching object

“…As it stands, there are only very little neurophysiological data on interceptive actions Port et al 2001;Merchant et al 2004), and to our knowledge neurophysiological data on hitting (i.e., the control ofẊ ip ) are completely lacking. Although the original formulation of the RVITE model (Dessing et al 2002; see also Beek et al 2003) was consistent with available neurophysiological data, the hit-RVITE model makes predictions for future neurophysiological observations.…”

Contributions of the Human Temporoparietal Junction and MT/V5+ to the Timing of Interception Revealed by Transcranial Magnetic Stimulation

“…Best-fitting was 136 and 114 ms in control and TMS-perturbed trials, respectively. After we account for the neuromechanical delay between motor cortex activation and button-press response (ϳ75 ms, see Materials and Methods), we estimate the additional processing time to be ϳ40 -60 ms, compatible with processing delays between visual-motion regions and motor cortex in target tracking or interception (Kruse et al, 2002;Merchant et al, 2004;Senot et al, 2008).…”

“…In primates, several brain regions contribute the necessary visual and motor information (Merchant et al, 2004;Indovina et al, 2005;Miller et al, 2008;Senot et al, 2008). Recordings in monkey motor cortex and area 7a showed firing patterns timed to either the target or the hand movement (Port et al, 2001;Merchant et al, 2004).…”

Adaptations of lateral hand movements to early and late visual occlusion in catching

“…While only few studies have directly addressed the neural basis of visuomotor transformations for interception (Ilg and Schumann 2007;Lee et al 2001;Merchant et al 2004;Port et al 2001;Schenk et al 2005), a vast number of behavioral studies on interception have been performed. A large part of these studies focused on the predictive control of movement timing (Bootsma and van Wieringen 1990;Fitch and Turvey 1978;Lee et al 1983;McLeod 1987;Savelsbergh et al 1991;Tyldesley and Whiting 1975), while others focused more on the vision-based movement adjustments used to reach the right place at the right time (Brenner et al 1998;Dessing et al 2005;Jacobs and Michaels 2006;Montagne et al 1999;Peper et al 1994;Smeets and Brenner 1995).…”