scholarly journals TMS SMART – Scalp Mapping of Annoyance Ratings and Twitches caused by Transcranial Magnetic Stimulation

2017 ◽  
Author(s):  
Lotte Meteyard ◽  
Nicholas Holmes
Keyword(s):  
Reaction Time ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Reaction Time Task ◽  
Single Pulse ◽  
Muscle Fibres ◽  
Magnetic Pulse ◽  
Subjective Ratings ◽  
Time Task ◽  
Scalp Location

AbstractThe magnetic pulse generated during Transcranial magnetic stimulation [TMS] also stimulates cutaneous nerves and muscle fibres, with the most commonly reported side effect being muscle twitches and sometimes painful sensations. These sensations affect behaviour during experimental tasks, presenting a potential confound for ‘online’ single-pulse TMS studies. Our objective was to systematically map the degree of disturbance (ratings of annoyance, pain, and muscle twitches) caused by TMS at 43 locations across the scalp. Ten participants provided ratings whilst completing a choice reaction time task, and ten participants provided ratings whilst completing a ‘flanker’ reaction time task. TMS over frontal and inferior regions resulted in the highest ratings of annoyance, pain, and muscle twitches caused by TMS. In separate analyses we predicted the difference in reaction times (RT) under TMS by scalp location and subjective ratings. Frontal and inferior scalp locations showed the greatest cost to RTs under TMS (i.e., slowing), with midline sites showing no or minimal slowing. Increases in subjective ratings of disturbance predicted longer RTs under TMS. Critically, ratings were a better predictor of the cost of TMS than scalp location or scalp-to-cortex distance, and the more difficult ‘flanker’ task showed a greater effect of subjective disturbance. The peripheral sensations and discomfort caused by TMS pulses significantly and systematically influence RTs during single-pulse, online TMS experiments. We provide the data as an online resource (http://www.tms-smart.info) so that researchers can select control sites that account for the level of general interference in task performance caused by online single-pulse TMS.

Paired-Pulse Transcranial Magnetic Stimulation During Preparation for Simple and Choice Reaction Time Tasks

2010 ◽  
Vol 104 (3) ◽  
pp. 1392-1400 ◽  
Author(s):  
Oscar Soto ◽  
Josep Valls-Solé ◽  
Hatice Kumru
Keyword(s):  
Reaction Time ◽  
Transcranial Magnetic Stimulation ◽  
Inhibitory Control ◽  
Choice Reaction Time ◽  
Magnetic Stimulation ◽  
Short Interval ◽  
Single Pulse ◽  
Motor Preparation ◽  
Paired Pulse ◽  
Time Points

Motor preparation for execution of both simple and choice reaction time tasks (SRT and CRT) involves enhancement of corticospinal excitability (CE). However, motor preparation also implies changes in inhibitory control that have thus far been much less studied. Short-interval intracortical inhibition (SICI) has been shown to decrease before CE increases. Therefore we reasoned that, if SICI contributes to inhibitory control of voluntary movement during the preparatory phase, it would be larger in CRT than in SRT because of the need to keep the movement unreleased until the uncertainty resolves on which task is required. We measured changes in SICI and in CE at different time points preceding motor reaction in normal subjects. Single-pulse transcranial magnetic stimulation (spTMS) and paired-pulse transcranial magnetic stimulation (ppTMS) produced time-dependent changes in both SRT and CRT, with shortening when applied close to the presentation of the imperative signal (“early”) and lengthening when applied near the expected reaction (“late”). In addition, at all stimulation time points, reaction time was shorter with ppTMS than that with spTMS, but there was no consistent association between the amount of SICI and reaction time changes. At early stimulation time points, CE was reduced in CRT but not in SRT. However, SICI in CRT was not different from SICI in SRT. At late stimulation time points, SICI decreased just before enhancement of CE. Our findings indicate that inhibitory circuits other than SICI are responsible for setting the level of CE at earlier parts of the reaction time period. Although the decrease in SICI may contribute to the increase in CE at the last part of the premotor period, the two phenomena are not dependent on each other.

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

GeroPsych ◽  
2011 ◽  
Vol 24 (4) ◽  
pp. 169-176 ◽  
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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