TEMPORAL PRIORITY OF PREMOTOR CORTEX OVER NEARBY AREAS IN RECEIVING VISUAL CUES IN PRIMATES

We examined neuronal activity in the dorsal and ventral premotor cortex (PMd and PMv, respectively) to explore the role of each motor area in processing visual signals for action planning. We recorded neuronal activity while monkeys performed a behavioral task during which two visual instruction cues were given successively with an intervening delay. One cue instructed the location of the target to be reached, and the other indicated which arm was to be used. We found that the properties of neuronal activity in the PMd and PMv differed in many respects. After the first cue was given, PMv neuron response mostly reflected the spatial position of the visual cue. In contrast, PMd neuron response also reflected what the visual cue instructed, such as which arm to be used or which target to be reached. After the second cue was given, PMv neurons initially responded to the cue's visuospatial features and later reflected what the two visual cues instructed, progressively increasing information about the target location. In contrast, the activity of the majority of PMd neurons responded to the second cue with activity reflecting a combination of information supplied by the first and second cues. Such activity, already reflecting a forthcoming action, appeared with short latencies (<400 ms) and persisted throughout the delay period. In addition, both the PMv and PMd showed bilateral representation on visuospatial information and motor-target or effector information. These results further elucidate the functional specialization of the PMd and PMv during the processing of visual information for action planning.

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Involvement of Human Thalamic Neurons in Internally and Externally Generated Movements

Journal of Neurophysiology ◽

10.1152/jn.00835.2003 ◽

2004 ◽

Vol 91 (2) ◽

pp. 1085-1090 ◽

Cited By ~ 16

Author(s):

M. L. MacMillan ◽

J. O. Dostrovsky ◽

A. M. Lozano ◽

W. D. Hutchison

Keyword(s):

Visual Cues ◽

Specific Activity ◽

Premotor Cortex ◽

Neuronal Firing ◽

Button Press ◽

Neural Pathways ◽

Means Testing ◽

Sequential Movements ◽

Motor Thalamus ◽

Post Hoc

Several anatomical studies support the existence of recurrent neural pathways from cortical motor areas to the thalamus via basal ganglia and back to the cortex. Neuronal responses to internally and externally generated sequential movements have been studied in the motor and premotor cortex of monkeys, but the involvement of subcortical motor structures such as the thalamus have not been studied in monkeys or humans. We examined the activity of neurons during a sequential button press task in motor thalamus of parkinsonian as well as chronic pain patients undergoing implantation of deep brain stimulating electrodes. Single and dual microelectrode recordings were carried out during an internally generated task with a memorized sequence (MEM) and an externally driven task with the sequence given during task performance (follow). Average histograms of neuronal firing were constructed for each task and aligned with respect to visual cues (ready, go) or button presses (P1, P2, P3). Sequential movements were monitored with surface electromyography and hand accelerometry, and cell responses were divided into movement-defined epochs for ANOVA and post hoc means testing. Of 52 neurons tested, 31 were found to have task-related responses and 10 were task-selective with 4 responding preferentially to MEM and 7 responding preferentially to follow (1 was both). Complex responses were found including preparatory, delay period, and phase- and task-specific activity. These kinds of responses suggest a role of the thalamus in both internally and externally cued arms movement and provide some evidence for a role in sequential movements.

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Changes in the Human Brain during Rhythm Learning

Journal of Cognitive Neuroscience ◽

10.1162/089892901753165863 ◽

2001 ◽

Vol 13 (7) ◽

pp. 952-966 ◽

Cited By ~ 79

Author(s):

N. Ramnani ◽

R. E. Passingham

Keyword(s):

Basal Ganglia ◽

Response Time ◽

Human Brain ◽

Parietal Cortex ◽

Visual Cues ◽

Premotor Cortex ◽

Temporal Cortex ◽

Motor Area ◽

Inferior Temporal Cortex ◽

External Cues

Subjects were scanned with PET while they learned a complex arbitrary rhythm, paced by visual cues. In the comparison condition, the intervals were varied randomly. The behavioral results showed that the subjects decreased their response time with training, thus becoming more accurate in responding to the pacing cues at the appropriate time. There were learning-related increases in the posterior lateral cerebellum (lobule HVIIa), intraparietal and medial parietal cortex, presupplementary motor area (pre-SMA), and lateral premotor cortex. Learning-related decreases were found in the prestriate and inferior temporal cortex, suggesting that with practice the subjects increasingly came to depend on internal rather than external cues to time their responses. There were no learning-related increases in the basal ganglia. It is suggested that it is the neocortical-cerebellar loop that is involved in the timing and coordination of responses.

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Complementary encoding of priors in monkey frontoparietal network supports a dual process of decision-making

eLife ◽

10.7554/elife.47581 ◽

2019 ◽

Vol 8 ◽

Cited By ~ 6

Author(s):

Lalitta Suriya-Arunroj ◽

Alexander Gail

Keyword(s):

Decision Making ◽

Visual Cues ◽

Free Choice ◽

Premotor Cortex ◽

Action Planning ◽

Dual Process ◽

Action Goal ◽

Preferred Direction ◽

Frontoparietal Network ◽

Parietal Cortices

Prior expectations of movement instructions can promote preliminary action planning and influence choices. We investigated how action priors affect action-goal encoding in premotor and parietal cortices and if they bias subsequent free choice. Monkeys planned reaches according to visual cues that indicated relative probabilities of two possible goals. On instructed trials, the reach goal was determined by a secondary cue respecting these probabilities. On rarely interspersed free-choice trials without instruction, both goals offered equal reward. Action priors induced graded free-choice biases and graded frontoparietal motor-goal activity, complementarily in two subclasses of neurons. Down-regulating neurons co-encoded both possible goals and decreased opposite-to-preferred responses with decreasing prior, possibly supporting a process of choice by elimination. Up-regulating neurons showed increased preferred-direction responses with increasing prior, likely supporting a process of computing net likelihood. Action-selection signals emerged earliest in down-regulating neurons of premotor cortex, arguing for an initiation of selection in the frontal lobe.

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Two Distinct Systems Represent Contralateral and Ipsilateral Sensorimotor Processes in the Human Premotor Cortex: A Dense TMS Mapping Study

Cerebral Cortex ◽

10.1093/cercor/bhz237 ◽

2019 ◽

Vol 30 (4) ◽

pp. 2250-2266 ◽

Cited By ~ 1

Author(s):

Carlotta Lega ◽

Leonardo Chelazzi ◽

Luigi Cattaneo

Keyword(s):

Visual Cues ◽

Premotor Cortex ◽

Cortical Region ◽

Functional Specialization ◽

Stimulus Side ◽

Motor Information ◽

Dense Grid ◽

Motor Representations ◽

Sensorimotor Mechanisms ◽

Sensorimotor Processes

Abstract Animal brains contain behaviorally committed representations of the surrounding world, which integrate sensory and motor information. In primates, sensorimotor mechanisms reside in part in the premotor cortex (PM), where sensorimotor neurons are topographically clustered according to functional specialization. Detailed functional cartography of the human PM is still under investigation. We explored the topographic distribution of spatially dependent sensorimotor functions in healthy volunteers performing left or right, hand or foot, responses to visual cues presented in the left or right hemispace, thus combining independently stimulus side, effector side, and effector type. Event-related transcranial magnetic stimulation was applied to single spots of a dense grid of 10 points on the participants’ left hemiscalp, covering the whole PM. Results showed: (1) spatially segregated hand and foot representations, (2) focal representations of contralateral cues and movements in the dorsal PM, and (3) distributed representations of ipsilateral cues and movements in the ventral and dorso-medial PM. The present novel causal information indicates that (1) the human PM is somatotopically organized and (2) the left PM contains sensory-motor representations of both hemispaces and of both hemibodies, but the hemispace and hemibody contralateral to the PM are mapped on a distinct, nonoverlapping cortical region compared to the ipsilateral ones.

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Supporting the Use of Rudimentary Vocalizations

Perspectives on Augmentative and Alternative Communication ◽

10.1044/aac23.3.132 ◽

2014 ◽

Vol 23 (3) ◽

pp. 132-139 ◽

Cited By ~ 1

Author(s):

Lauren Zubow ◽

Richard Hurtig

Keyword(s):

Rett Syndrome ◽

Visual Cues ◽

Acoustic Analysis ◽

Eye Gaze ◽

Research Question ◽

Primary Research ◽

Multiple Modalities ◽

Face To Face ◽

Perceptual Judgments ◽

The Face

Children with Rett Syndrome (RS) are reported to use multiple modalities to communicate although their intentionality is often questioned (Bartolotta, Zipp, Simpkins, & Glazewski, 2011; Hetzroni & Rubin, 2006; Sigafoos et al., 2000; Sigafoos, Woodyatt, Tuckeer, Roberts-Pennell, & Pittendreigh, 2000). This paper will present results of a study analyzing the unconventional vocalizations of a child with RS. The primary research question addresses the ability of familiar and unfamiliar listeners to interpret unconventional vocalizations as “yes” or “no” responses. This paper will also address the acoustic analysis and perceptual judgments of these vocalizations. Pre-recorded isolated vocalizations of “yes” and “no” were presented to 5 listeners (mother, father, 1 unfamiliar, and 2 familiar clinicians) and the listeners were asked to rate the vocalizations as either “yes” or “no.” The ratings were compared to the original identification made by the child's mother during the face-to-face interaction from which the samples were drawn. Findings of this study suggest, in this case, the child's vocalizations were intentional and could be interpreted by familiar and unfamiliar listeners as either “yes” or “no” without contextual or visual cues. The results suggest that communication partners should be trained to attend to eye-gaze and vocalizations to ensure the child's intended choice is accurately understood.

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