Neuronal activity in primary motor cortex differs when monkeys perform somatosensory and visually guided wrist movements

Liu, Yu; Denton, John M.; Nelson, Randall J.

doi:10.1007/s00221-005-0052-8

Cited by 13 publications

(19 citation statements)

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“…There was also a tendency over sessions for the exploration duration of NAT and UAT to decrease (see panel C of Figure 4.7 on page 69). These results indicate that ICMS feedback operates on a timescale of hundreds of milliseconds, which is comparable to the timescales of detection and discrimination of peripheral tactile stimuli (Lebedev et al, 1994;Liu et al, 2005).…”

Section: Active Touchmentioning

confidence: 66%

Brain-Machine-Brain Interface

O’Doherty¹

2015

Encyclopedia of Computational Neuroscience

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I first show that a direct intracortical signal can be used to instruct rhesus monkeys about the direction of a reach to make with a BMI. Rhesus monkeys placed an actuator over an instruction target and obtained, from the target's artificial texture, information about the correct reach path. Initially these somatosensory instructions took the form of vibrotactile stimulation of the hands. Next, ICMS of primary somatosensory cortex (S1) iv in one monkey and posterior parietal cortex (PPC) in another was substituted for this peripheral somatosensory signal. Finally, the monkeys made direct brain-controlled reaches using the activity of ensembles of primary motor cortex (M1) cells, conditional on the ICMS cues. The monkey receiving ICMS of S1 was able to achieve the same level of proficiency with ICMS as with the stimulus delivered to the skin of the hand. The monkey receiving ICMS of PPC was unable to perform the task above chance. This experiment indicates that ICMS of S1 can form the basis of an afferent prosthetic input to the brain for guiding brain-controlled prostheses.I next show that ICMS of S1 can provide feedback about the interactions of a virtualreality upper-limb avatar and virtual objects, enabling active touch. Rhesus monkeys initially controlled the avatar with the movements of their arms and used it to search through sets of up to three objects. Feedback in the form of temporal patterns of ICMS occurred whenever the avatar touched a virtual object. Monkeys learned to use this feedback to find the objects with particular artificial textures, as encoded by the ICMS patterns, and select those associated with reward while avoiding selecting the non-rewarded objects. Next, the control of the avatar was switched to direct brain-control and the monkeys continued to move the avatar with motor commands derived from the extracellular neuronal activity of M1 cells. The afferent and efferent modules of this BMBI were temporally interleaved, and as such did not interfere with each other, yet allowed effectively concurrent operation. Cortical motor neurons were measured while the monkey passively observed the movements of the avatar and were found to be modulated, a result that suggests that concurrent visual and artificial somatosensory feedback lead to the incorporation of the avatar into the monkey's internal brain representation. In summary, rhesus monkeys were augmented with a bidirectional neural interface that allowed them to make reaches to objects and discriminate them by their textures-all without making actual movements and without relying on somatic sensation from their real bodies. Both action and perception were mediated by the brain-machine-brain interface.I probed the sensitivity of the afferent leg of the interface to precise temporal patterns of ICMS. Moreover, I describe evidence that the BMBI controlled avatar was incorporated into the monkey's internal brain representation. These results suggest that future clinical neuroprostheses could implement realistic feedback about object-actuator in...

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Section: Active Touchmentioning

confidence: 66%

Brain-Machine-Brain Interface

O’Doherty¹

2015

Encyclopedia of Computational Neuroscience

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“…Our experimental design did not allow us to investigate specifically the types of fibers that carry the sensory signals from cutaneous or deep tissues. However, the source of vibratory input during the early RTPs might not involve the results of tendon-stretch because recorded profiles showed no changes in hand position (Liu et al 2005(Liu et al , 2007. The angular deflection of the plate that resulted during the vibration was less than 0.06°, which would be too small to cause significant joint movements.…”

Section: Vibration-entrained Si Neurons and Receptive Fieldsmentioning

confidence: 99%

“…Two adult male rhesus monkeys (Macaca mulatta, 9.5-10.5 kg) were trained to make wrist flexion and extension movements. The experimental apparatus and behavioral paradigm have been described previously (Liu et al 2005). Briefly, each monkey sat in an acrylic monkey chair with his right forearm on an armrest.…”

Section: Behavioral Paradigmmentioning

confidence: 99%

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Monkey primary somatosensory cortical activity during the early reaction time period differs with cues that guide movements

2008

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Vibration-related neurons in monkey primary somatosensory cortex (SI) discharge rhythmically when vibratory stimuli are presented. It remains unclear how functional information carried by vibratory inputs is coded in rhythmic neuronal activity. In the present study, we compared neuronal activity during wrist movements in response to two sets of cues. In the first, movements were guided by vibratory cue only (VIB trials). In the second, movements were guided by simultaneous presentation of both vibratory and visual cues (COM trials). SI neurons were recorded extracellularly during both wrist extensions and flexions. Neuronal activity during the instructed delay period (IDP) and the early reaction time period (RTP) were analyzed. A total of 96 cases from 48 neurons (each neuron contributed two cases, one each for extension and flexion) showed significant vibration entrainment during the early RTPs, as determined by circular statistics (Rayleigh test). Of these, 50 cases had cutaneous (CUTA) and 46 had deep (DEEP) receptive fields. The CUTA neurons showed lower firing rates during the IDPs and greater firing rate changes during the early RTPs when compared with the DEEP neurons. The CUTA neurons also demonstrated decreases in activity entrainment during VIB trials when compared with COM trials. For the DEEP neurons, the difference of entrainment between VIB and COM trials was not statistically significant. The results suggest that somatic vibratory input is coded by both the firing rate and the activity entrainment of the CUTA neurons in SI. The results also suggest that when vibratory inputs are required for successful task completion, the activity of the CUTA neurons increases but the entrainment degrades. The DEEP neurons may be tuned before movement initiation for processing information encoded by proprioceptive afferents.

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“…Determining NACs may be crucial when selecting individual neurons for further study either online or offline. Moreover, detecting the onset of NACs on a trial-by-trial basis is frequently needed in neurophysiological studies (DiCarlo and Maunsell, 2005;Liu et al, 2005;Ventura et al, 2005). Techniques available, however, are not always satisfactory for this purpose.…”

Section: Introductionmentioning

confidence: 99%