Fast ballistic arm movements triggered by visual, auditory, and somesthetic stimuli in the monkey. I. Activity of precentral cortical neurons

Abstract

Single-unit recordings from motor cortex (area 4) were obtained in two monkeys trained to perform simple flexion and extension movements of the arm in response to somesthetic, visual, and auditory signals. All neurons tested showed movement-related responses that were identical for equivalent movements irrespective of the modality of the triggering stimulus. Progressively longer reaction times were always associated with progressively longer latencies of unit responses. When visual and auditory stimuli were presented simultaneously, the intensity and the duration of both motor and unitary responses remained unchanged as if only one stimulus (auditory) had been given. When the auditory stimulus was appropriately delayed with respect to the visual one, shortening of motor reaction time was observed with a corresponding shortening of the latency of unit responses. In addition to movement-related responses, some neurons showed sensory-related responses mainly to the somesthetic stimulus (37%) and more rarely to the auditory (11%) and visual stimuli (3%). These "sensory" responses preceded and were independent of the movement-related responses; they showed no obvious correlation with the reaction time. Whenever tested, the somatosensory responses persisted after extinction of the motor responses. These findings suggest that, in our experimental conditions, area 4 neurons of the monkey are not involved in the early processing of sensory information required for the initiation of simple, triggered movements. Rather, they appear to generate signals that are mainly related to the characteristics of the motor responses.

Perceptual Basis of Redundancy Gains in Visual Pop-out Search

“…This phenomenon is well established (e.g., Todd, 1912) and has been reported in a wide range of experimental paradigms (e.g., Koene & Zhaoping, 2007;Mohr, Endrass, Hauk, & Pulvermuller, 2007;Schroter, Ulrich, & Miller, 2007;Gondan, Lange, Rösler, & Röder, 2004;Iacoboni & Zaidel, 2003;Forster, Cavina-Pratesi, Aglioto, & Berlucchi, 2002;Lamarre, Busby, & Spidalieri, 1983). These paradigms can be classified along several criteria: (a) spatial origin of the signals (same or different locations), (b) modality of the signals (visual, auditory, or haptic), (c) number of relevant modalities (one or two), and (d) depth of signal processing necessary to determine the appropriate motor response (onset, feature contrast, or target identity).…”

Multisensory Facilitation of Behavior in Monkeys: Effects of Stimulus Intensity

“…The extent to which nonhuman primates, specifically macaque monkeys, exhibit an RSE in their manual RTs (RTs) to auditory-visual multisensory stimuli is unresolved and was the focus of the present study. Prior research in monkeys observed an RSE only for manual RTs when stimuli were presented asynchronously, although it is noteworthy that such was not statistically validated (Miller, Ulrich, & Lamarre, 2001;Lamarre, Busby, & Spidalieri, 1983). By contrast, studies in humans have successfully used synchronously presented stimuli to elicit an RSE (e.g., Cappe, Thut, et al, 2009;Romei et al, 2009;Martuzzi et al, 2007;Romei, Murray, Merabet, & Thut, 2007;Molholm et al, 2002;Giard & Peronnet, 1999).…”

“…The assessment of whether RT facilitation exceeded levels predicted by probability summation allowed us to determine whether integrative processes need to be invoked to account for behavioral improvements. Given the pattern of results obtained by Miller et al (2001) and Lamarre et al (1983), who failed to observe an RSE with synchronously presented and suprathreshold auditory and visual stimuli, and given the fact that studies in humans routinely obtain an RSE with synchronously presented auditory-visual stimuli, we parametrically varied the efficacy of auditory stimuli. We hypothesized that multisensory stimulus presentation facilitates detection near threshold and shortens RT as compared with unisensory stimulus presentation (cf.…”

Comparison of neuronal activity in the supplementary motor area and primary motor cortex

“…Another difference is the presence or absence of a selective relationship to a movement initiated differently. In MI neurons, the movement-related activity is similar, regardless of whether the movement is triggered by a visual, auditory or tactile signal [32,68]. In contrast, the activity of SMA neurons are often selective.…”