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Stopping eyes and hands: evidence for non-independence of stop and go processes and for a separation of central and peripheral inhibition.

Gulberti A, Arndt PA, Colonius H - Front Hum Neurosci (2014)

Bottom Line: Saccadic reaction times revealed some significant violations of the model's basic assumption of independent go and inhibition processes for all six participants.Saccades that escaped an early stop signal were systematically slower and had smaller amplitudes compared to saccades without a stop signal.Moreover, the analysis of concomitant electromyographic responses recorded from the upper arm suggests the existence of two separate inhibitory mechanisms: a slow, selective, central inhibitory mechanism and a faster, highly efficient, peripheral one, which is probably ineffective for saccades.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf Hamburg, Germany.

ABSTRACT
In the stop-signal paradigm, participants perform a primary reaction task, for example a visual or auditory discrimination task, and have to react to a go stimulus as quickly as possible with a specified motor response. In a certain percentage of trials, after presentation of the stimulus (go signal), another stimulus (stop signal) is presented with a variable stop-signal delay. Whenever a stop signal occurs, the participant is asked to inhibit the execution of the response. Here, an extended test of the popular horse race model for this task (Logan and Cowan, 1984) is presented. Responses for eye and hand movements in both single-task and dual-task conditions were collected. Saccadic reaction times revealed some significant violations of the model's basic assumption of independent go and inhibition processes for all six participants. Saccades that escaped an early stop signal were systematically slower and had smaller amplitudes compared to saccades without a stop signal. Moreover, the analysis of concomitant electromyographic responses recorded from the upper arm suggests the existence of two separate inhibitory mechanisms: a slow, selective, central inhibitory mechanism and a faster, highly efficient, peripheral one, which is probably ineffective for saccades.

No MeSH data available.


Related in: MedlinePlus

The probability of inhibition in stop trials is plotted as a function of the stop-signal delay for eye, hand, and dual task, for each participant.
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Figure 3: The probability of inhibition in stop trials is plotted as a function of the stop-signal delay for eye, hand, and dual task, for each participant.

Mentions: Before beginning with the main experiment, each participant carried out an intensive training phase. The aim of the training and response-rate tracking phase was to determine individual SSDs for the three condition blocks. About 10–12 training sessions were required for each participant in order to stabilize their performance at approximately 50% of successfully inhibited responses. At the same time, four individual SSDs were determined for each of the participants in order to obtain inhibition probabilities of approximately 90, 70, 40, and 20% for the main experiment (see Figure 3 and Table 1).


Stopping eyes and hands: evidence for non-independence of stop and go processes and for a separation of central and peripheral inhibition.

Gulberti A, Arndt PA, Colonius H - Front Hum Neurosci (2014)

The probability of inhibition in stop trials is plotted as a function of the stop-signal delay for eye, hand, and dual task, for each participant.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3927451&req=5

Figure 3: The probability of inhibition in stop trials is plotted as a function of the stop-signal delay for eye, hand, and dual task, for each participant.
Mentions: Before beginning with the main experiment, each participant carried out an intensive training phase. The aim of the training and response-rate tracking phase was to determine individual SSDs for the three condition blocks. About 10–12 training sessions were required for each participant in order to stabilize their performance at approximately 50% of successfully inhibited responses. At the same time, four individual SSDs were determined for each of the participants in order to obtain inhibition probabilities of approximately 90, 70, 40, and 20% for the main experiment (see Figure 3 and Table 1).

Bottom Line: Saccadic reaction times revealed some significant violations of the model's basic assumption of independent go and inhibition processes for all six participants.Saccades that escaped an early stop signal were systematically slower and had smaller amplitudes compared to saccades without a stop signal.Moreover, the analysis of concomitant electromyographic responses recorded from the upper arm suggests the existence of two separate inhibitory mechanisms: a slow, selective, central inhibitory mechanism and a faster, highly efficient, peripheral one, which is probably ineffective for saccades.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf Hamburg, Germany.

ABSTRACT
In the stop-signal paradigm, participants perform a primary reaction task, for example a visual or auditory discrimination task, and have to react to a go stimulus as quickly as possible with a specified motor response. In a certain percentage of trials, after presentation of the stimulus (go signal), another stimulus (stop signal) is presented with a variable stop-signal delay. Whenever a stop signal occurs, the participant is asked to inhibit the execution of the response. Here, an extended test of the popular horse race model for this task (Logan and Cowan, 1984) is presented. Responses for eye and hand movements in both single-task and dual-task conditions were collected. Saccadic reaction times revealed some significant violations of the model's basic assumption of independent go and inhibition processes for all six participants. Saccades that escaped an early stop signal were systematically slower and had smaller amplitudes compared to saccades without a stop signal. Moreover, the analysis of concomitant electromyographic responses recorded from the upper arm suggests the existence of two separate inhibitory mechanisms: a slow, selective, central inhibitory mechanism and a faster, highly efficient, peripheral one, which is probably ineffective for saccades.

No MeSH data available.


Related in: MedlinePlus