Influence of globus pallidus on arm movements in monkeys. II. Effects of stimulation

The effect of changing basal ganglia activity with electrical stimulation in and around the globus pallidus (GP) was studied in monkeys trained to make rapid arm-reaching movements to a visual target in a reaction time task. As was the case following kainic acid (KA) lesions of the globus pallidus (30), stimulation changed movement times (MT) without affecting the pattern of sequential activation of muscles involved in the task or, in most cases, the reaction times (RT). Stimulation in the ventrolateral internal segment of the globus pallidus (GPi) or in the ansa lenticularis reduced movement times, whereas stimulation at many sites in the external pallidal segment (GPe), dorsal GPi, and putamen increased movement times for the contralateral arm. These results are consistent with the hypothesis that arm movements are speeded up when the critical output of GPi is increased and arm movements are slowed down when critical GPi output is reduced, either by an inhibitory process (via stimulation-induced activation of inhibitory elements presynaptic to GPi) or by destroying GPi neurons (via kainic acid). The influence of the basal ganglia on the scaling of electromyographic (EMG) amplitude, as opposed to the spatiotemporal organization of EMG activation, is discussed.

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Influence of globus pallidus on arm movements in monkeys. I. Effects of kainic acid-induced lesions

Journal of Neurophysiology ◽

10.1152/jn.1984.52.2.290 ◽

1984 ◽

Vol 52 (2) ◽

pp. 290-304 ◽

Cited By ~ 118

Author(s):

F. B. Horak ◽

M. E. Anderson

Keyword(s):

Kainic Acid ◽

Globus Pallidus ◽

Movement Time ◽

Reaction Times ◽

Arm Movement ◽

Reaction Time Task ◽

Emg Activity ◽

Arm Reaching ◽

Sequential Organization ◽

Sequential Activation

The role of basal ganglia output via the globus pallidus (GP) was examined in monkeys trained to make rapid arm-reaching movements to a visual target in a reaction-time task. When neurons in the globus pallidus were destroyed by injection of kainic acid (KA) during task execution, contralateral arm movement times (MT) were increased significantly, with little or no change in reaction times (RT). The slowed movements were associated with a generalized depression in the amplitude and rate of rise of electromyographic (EMG) activity in all the contralateral muscles studied at the wrist, elbow, shoulder, and back, but there was no change in the sequential activation of these muscles. The most profound and persistent increases in movement time occurred when neurons were destroyed in the ventrolateral and caudal aspects of the internal as well as external pallidal segment. These results suggest a role for globus pallidus output in scaling the magnitude and/or buildup of EMG activity without affecting the initiation or the sequential organization of the programmed motor output.

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Globus pallidus dynamics reveal covert strategies for behavioral inhibition

10.1101/2020.03.03.975540 ◽

2020 ◽

Cited By ~ 1

Author(s):

Bon-Mi Gu ◽

Robert Schmidt ◽

Joshua D. Berke

Keyword(s):

Basal Ganglia ◽

State Space ◽

Globus Pallidus ◽

Behavioral Inhibition ◽

Reaction Times ◽

Proactive Inhibition ◽

Strategic Positioning ◽

Movement Initiation ◽

Population Activity ◽

Flexible Behavior

AbstractFlexible behavior requires restraint or cancellation of actions that are no longer appropriate. This behavioral inhibition critically relies on frontal cortex - basal ganglia circuits. A central node within the basal ganglia, the globus pallidus pars externa (GPe), has been hypothesized to mediate “proactive” inhibition: being prepared to stop an action if needed. Here we investigate the population dynamics of rat GPe neurons during preparation-to-stop, stopping, and going. Rats could selectively engage proactive inhibition towards one specific action, as shown by slowed reaction times (RTs) for that action. While proactive inhibition was engaged, GPe population activity occupied state-space locations farther from the trajectory followed during normal movement initiation. Furthermore, the specific state-space location was predictive of distinct types of errors: failures to stop, failures to go, and incorrect choices. The slowed RTs on correct proactive trials reflected a starting bias towards the alternative action, which was overcome before making progress towards action initiation. Our results demonstrate that rats can exert cognitive control via strategic positioning of their GPe network state.

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Learning to search. The importance of eye movements in the decrease of response times during a visual choice reaction time task

Journal of Eye Movement Research ◽

10.16910/jemr.9.5.5 ◽

2016 ◽

Vol 9 (5) ◽

Author(s):

Aleksandra Kroll ◽

Monika Mak ◽

Jerzy Samochowiec

Keyword(s):

Eye Movements ◽

Reaction Time ◽

Choice Reaction Time ◽

Visual Target ◽

Response Times ◽

Reaction Times ◽

Reaction Time Task ◽

Visual Tasks ◽

Target Searching

Reaction times are often used as an indicator of the efficiency of the processes in thecentral nervous system. While extensive research has been conducted on the possibleresponse time correlates, the role of eye movements in visual tasks is yet unclear. Here wereport data to support the role of eye movements during visual choice reaction time training.Participant performance, reaction times, and total session duration improved. Eyemovementsshowed expected changes in saccade amplitude and resulted in improvementin visual target searching.

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Globus pallidus dynamics reveal covert strategies for behavioral inhibition

eLife ◽

10.7554/elife.57215 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 2

Author(s):

Bon-Mi Gu ◽

Robert Schmidt ◽

Joshua D Berke

Keyword(s):

Basal Ganglia ◽

State Space ◽

Globus Pallidus ◽

Behavioral Inhibition ◽

Reaction Times ◽

Proactive Inhibition ◽

Movement Initiation ◽

Population Activity ◽

Occupied State ◽

Flexible Behavior

Flexible behavior requires restraint of actions that are no longer appropriate. This behavioral inhibition critically relies on frontal cortex - basal ganglia circuits. Within the basal ganglia, the globus pallidus pars externa (GPe) has been hypothesized to mediate selective proactive inhibition: being prepared to stop a specific action, if needed. Here we investigate population dynamics of rat GPe neurons during preparation-to-stop, stopping, and going. Rats selectively engaged proactive inhibition towards specific actions, as shown by slowed reaction times (RTs). Under proactive inhibition, GPe population activity occupied state-space locations farther from the trajectory followed during normal movement initiation. Furthermore, the state-space locations were predictive of distinct types of errors: failures-to-stop, failures-to-go, and incorrect choices. Slowed RTs on correct proactive trials reflected starting bias towards the alternative action, which was overcome before progressing towards action initiation. Our results demonstrate that rats can exert cognitive control via strategic adjustments to their GPe network state.

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Testing Basal Ganglia Motor Functions Through Reversible Inactivations in the Posterior Internal Globus Pallidus

Journal of Neurophysiology ◽

10.1152/jn.01010.2007 ◽

2008 ◽

Vol 99 (3) ◽

pp. 1057-1076 ◽

Cited By ~ 50

Author(s):

M. Desmurget ◽

R. S. Turner

Keyword(s):

Basal Ganglia ◽

Globus Pallidus ◽

Reaction Times ◽

Movement Direction ◽

Visually Guided ◽

Movement Initiation ◽

Internal Globus Pallidus ◽

On Line ◽

Motor Loop ◽

Target Locations

To test current hypotheses on the contribution of the basal ganglia (BG) to motor control, we examined the effects of muscimol-induced inactivations in the skeletomotor region of the internal globus pallidus (sGPi) on visually directed reaching. Injections were made in two monkeys trained to perform four out-and-back reaching movements in quick succession toward four randomly selected target locations. Following sGPi inactivations the following occurred. 1) Peak velocity and acceleration were decreased in nearly all sessions, whereas movement duration lengthened inconsistently. 2) Reaction times were unaffected on average, although minor changes were observed in several individual sessions. 3) Outward reaches showed a substantial hypometria that correlated closely with bradykinesia, but directional accuracy was unaffected. 4) Endpoint accuracy was preserved for the slow visually guided return movements. 5) No impairments were found in the rapid chaining of out-and-back movements, in the selection or initiation of four independent reaches in quick succession or in the quick on-line correction of initially misdirected reaches. 6) Inactivation-induced reductions in the magnitude of movement-related muscle activity (EMG) correlated with the severity of slowing and hypometria. There was no evidence for inactivation-induced alterations in the relative timing of EMG bursts, excessive cocontraction, or impaired suppression of antagonist EMG. Therefore disconnecting the BG motor pathway consistently produced bradykinesia and hypometria, but seldom affected movement initiation time, feedback-mediated guidance, the capacity to produce iterative reaches, or the ability to abruptly reverse movement direction. These results are discussed with reference to the idea that the BG motor loop may regulate energetic expenditures during movement (i.e., movement “vigor”).

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Modeling Within-Person Variance in Reaction Time Data of Older Adults

GeroPsych ◽

10.1024/1662-9647/a000045 ◽

2011 ◽

Vol 24 (4) ◽

pp. 169-176 ◽

Cited By ~ 4

Author(s):

Philippe Rast ◽

Daniel Zimprich

Keyword(s):

Reaction Time ◽

Cognitive Aging ◽

Reaction Times ◽

Reaction Time Task ◽

Reaction Time Data ◽

Scale Model ◽

Time Data ◽

Time Task ◽

The Mean ◽

Second Wave

In order to model within-person (WP) variance in a reaction time task, we applied a mixed location scale model using 335 participants from the second wave of the Zurich Longitudinal Study on Cognitive Aging. The age of the respondents and the performance in another reaction time task were used to explain individual differences in the WP variance. To account for larger variances due to slower reaction times, we also used the average of the predicted individual reaction time (RT) as a predictor for the WP variability. Here, the WP variability was a function of the mean. At the same time, older participants were more variable and those with better performance in another RT task were more consistent in their responses.

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Manipulations of the Response-Stimulus Intervals as a Factor Inducing Controlled Amount of Reaction Time Intra-Individual Variability

Brain Sciences ◽

10.3390/brainsci11050669 ◽

2021 ◽

Vol 11 (5) ◽

pp. 669

Author(s):

Paweł Krukow ◽

Małgorzata Plechawska-Wójcik ◽

Arkadiusz Podkowiński

Keyword(s):

Reaction Time ◽

Simple Reaction Time ◽

Reaction Times ◽

Reaction Time Task ◽

Assessment Method ◽

Individual Variability ◽

Simple Reaction Time Task ◽

Stimulus Interval ◽

Simple Reaction ◽

Response Stimulus

Aggrandized fluctuations in the series of reaction times (RTs) are a very sensitive marker of neurocognitive disorders present in neuropsychiatric populations, pathological ageing and in patients with acquired brain injury. Even though it was documented that processing inconsistency founds a background of higher-order cognitive functions disturbances, there is a vast heterogeneity regarding types of task used to compute RT-related variability, which impedes determining the relationship between elementary and more complex cognitive processes. Considering the above, our goal was to develop a relatively new assessment method based on a simple reaction time paradigm, conducive to eliciting a controlled range of intra-individual variability. It was hypothesized that performance variability might be induced by manipulation of response-stimulus interval’s length and regularity. In order to verify this hypothesis, a group of 107 healthy students was tested using a series of digitalized tasks and their results were analyzed using parametric and ex-Gaussian statistics of RTs distributional markers. In general, these analyses proved that intra-individual variability might be evoked by a given type of response-stimulus interval manipulation even when it is applied to the simple reaction time task. Collected outcomes were discussed with reference to neuroscientific concepts of attentional resources and functional neural networks.

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Morphological Abnormalities in the Basal Ganglia of Dystonia Patients

Stereotactic and Functional Neurosurgery ◽

10.1159/000512599 ◽

2021 ◽

pp. 1-12

Author(s):

Xi Bai ◽

Peter Vajkoczy ◽

Katharina Faust

Keyword(s):

Basal Ganglia ◽

Globus Pallidus ◽

Trajectory Planning ◽

Matched Control ◽

Young Patients ◽

Control Population ◽

Pathogenic Role ◽

Target Region ◽

Morphological Abnormalities ◽

Primary Dystonia

Objective: The pathophysiology of dystonia is poorly understood. As opposed to secondary forms of dystonia, primary dystonia has long been believed to lack any neuroanatomical substrate. During trajectory planning for DBS, however, conspicuous T2-hyperinstensive signal alterations (SA) were registered within the target region, even in young patients, where ischemia is rare. Methods: Fifty MRIs of primary dystonia patients scheduled for DBS were analyzed. Total basal ganglia (BG) volumes, as well as proportionate SA volumes, were measured and compared to 50 age-matched control patients. Results: There was a 10-fold preponderance of percentaged SA within the globus pallidus (GP) in dystonia patients. The greatest disparity was in young patients <25 years. Also, total BG volume differences were observed with larger GP and markedly smaller putamen and caudate in the dystonia group. Conclusions: BG morphology in primary dystonia differed from a control population. Volume reductions of the putamen and caudate may reflect functional degeneration, while volume increases of the GP may indicate overactivity. T2-hyperintensive SA in the GP of young primary dystonia patients, where microvascular lesions are highly unlikely, are striking. Their pathogenic role remains unclear.

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Lateralization of attention in adults with ADHD: Evidence of pseudoneglect

European Psychiatry ◽

10.1192/j.eurpsy.2020.68 ◽

2020 ◽

Vol 63 (1) ◽

Author(s):

Bartosz Helfer ◽

Stefanos Maltezos ◽

Elizabeth Liddle ◽

Jonna Kuntsi ◽

Philip Asherson

Keyword(s):

Reaction Time ◽

Visual Field ◽

Reaction Times ◽

Study Participant ◽

Reaction Time Task ◽

Right Visual Field ◽

Time Variability ◽

Incentive Condition ◽

Reaction Time Variability ◽

The Right

Abstract Background. We investigated whether adults with attention-deficit/hyperactivity disorder (ADHD) show pseudoneglect—preferential allocation of attention to the left visual field (LVF) and a resulting slowing of mean reaction times (MRTs) in the right visual field (RVF), characteristic of neurotypical (NT) individuals —and whether lateralization of attention is modulated by presentation speed and incentives. Method. Fast Task, a four-choice reaction-time task where stimuli were presented in LVF or RVF, was used to investigate differences in MRT and reaction time variability (RTV) in adults with ADHD (n = 43) and NT adults (n = 46) between a slow/no-incentive and fast/incentive condition. In the lateralization analyses, pseudoneglect was assessed based on MRT, which was calculated separately for the LVF and RVF for each condition and each study participant. Results. Adults with ADHD had overall slower MRT and increased RTV relative to NT. MRT and RTV improved under the fast/incentive condition. Both groups showed RVF-slowing with no between-group or between-conditions differences in RVF-slowing. Conclusion. Adults with ADHD exhibited pseudoneglect, a NT pattern of lateralization of attention, which was not attenuated by presentation speed and incentives.

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Regionalization within the mammalian telencephalon is mediated by changes in responsiveness to Sonic Hedgehog

Development ◽

10.1242/dev.125.24.5079 ◽

1998 ◽

Vol 125 (24) ◽

pp. 5079-5089 ◽

Cited By ~ 15

Author(s):

J.D. Kohtz ◽

D.P. Baker ◽

G. Corte ◽

G. Fishell

Keyword(s):

Basal Ganglia ◽

Globus Pallidus ◽

Sonic Hedgehog ◽

Adult Brain ◽

Ganglionic Eminence ◽

Lateral Ganglionic Eminence ◽

Expression Characteristic ◽

Sonic Hedgehog Gene ◽

Embryonic Structure ◽

Sequential Induction

The cortex and basal ganglia are the major structures of the adult brain derived from the embryonic telencephalon. Two morphologically distinct regions of the basal ganglia are evident within the mature ventral telencephalon, the globus pallidus medially, and the striatum, which is positioned between the globus pallidus and the cortex. Deletion of the Sonic Hedgehog gene in mice indicates that this secreted signaling molecule is vital for the generation of both these ventral telencephalic regions. Previous experiments showed that Sonic Hedgehog induces differentiation of ventral neurons characteristic of the medial ganglionic eminence, the embryonic structure which gives rise to the globus pallidus. In this paper, we show that later in development, Sonic Hedgehog induces ventral neurons with patterns of gene expression characteristic of the lateral ganglionic eminence. This is the embryonic structure from which the striatum is derived. These results suggest that temporally regulated changes in Sonic Hedgehog responsiveness are integral in the sequential induction of basal telencephalic structures.

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