scholarly journals Time for Action: Neural Basis of the Costs and Benefits of Temporal Predictability for Competing Response Choices

2021 ◽  
pp. 1-17
Author(s):  
Inga Korolczuk ◽  
Boris Burle ◽  
Jennifer T. Coull ◽  
Kamila Śmigasiewicz
Keyword(s):  
Motor Cortex ◽  
Onset Time ◽  
Incorrect Response ◽  
Response Conflict ◽  
Cortical Inhibition ◽  
Costs And Benefits ◽  
Neural Basis ◽  
Response Hand ◽  
Temporal Predictability ◽  
Choice Complexity

Abstract The brain can anticipate the time of imminent events to optimize sensorimotor processing. Yet, there can be behavioral costs of temporal predictability under situations of response conflict. Here, we sought to identify the neural basis of these costs and benefits by examining motor control processes in a combined electroencephalography–EMG study. We recorded electrophysiological markers of response activation and inhibition over motor cortex when the onset-time of visual targets could be predicted, or not, and when responses necessitated conflict resolution, or not. If stimuli were temporally predictable but evoked conflicting responses, we observed increased intertrial consistency in the delta range over the motor cortex involved in response implementation, perhaps reflecting increased response difficulty. More importantly, temporal predictability differentially modulated motor cortex activity as a function of response conflict before the response was even initiated. This effect occurred in the hemisphere ipsilateral to the response, which is involved in inhibiting unwanted actions. If target features all triggered the same response, temporal predictability increased cortical inhibition of the incorrect response hand. Conversely, if different target features triggered two conflicting responses, temporal predictability decreased inhibition of the incorrect, yet prepotent, response. This dissociation reconciles the well-established behavioral benefits of temporal predictability for nonconflicting responses as well as its costs for conflicting ones by providing an elegant mechanism that operates selectively over the motor cortex involved in suppressing inappropriate actions just before response initiation. Taken together, our results demonstrate that temporal information differentially guides motor activity depending on response choice complexity.

scholarly journals Brain mechanisms underlying neuropsychiatric symptoms in Alzheimer’s disease: a systematic review of symptom-general and –specific lesion patterns

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yaojing Chen ◽  
Mingxi Dang ◽  
Zhanjun Zhang
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Neuropsychiatric Symptoms ◽  
Onset Time ◽  
Anterior Cingulate ◽  
Neural Basis ◽  
Preclinical Ad ◽  
Disease Stages ◽  
Mild Cognitive Impairment Stage

AbstractNeuropsychiatric symptoms (NPSs) are common in patients with Alzheimer’s disease (AD) and are associated with accelerated cognitive impairment and earlier deaths. This review aims to explore the neural pathogenesis of NPSs in AD and its association with the progression of AD. We first provide a literature overview on the onset times of NPSs. Different NPSs occur in different disease stages of AD, but most symptoms appear in the preclinical AD or mild cognitive impairment stage and develop progressively. Next, we describe symptom-general and -specific patterns of brain lesions. Generally, the anterior cingulate cortex is a commonly damaged region across all symptoms, and the prefrontal cortex, especially the orbitofrontal cortex, is also a critical region associated with most NPSs. In contrast, the anterior cingulate-subcortical circuit is specifically related to apathy in AD, the frontal-limbic circuit is related to depression, and the amygdala circuit is related to anxiety. Finally, we elucidate the associations between the NPSs and AD by combining the onset time with the neural basis of NPSs.

P029 Direct evaluation of intra-cortical inhibition and facilitation balance in human motor cortex: an EEG-paired pulse TMS study

2008 ◽  
Vol 119 ◽  
pp. S78
Author(s):  
Florinda Ferreri ◽  
Patrizio Pasqualetti ◽  
David Ponzo ◽  
Sara Maatta ◽  
Fabio Ferrarelli ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Cortical Inhibition ◽  
Direct Evaluation ◽  
Human Motor Cortex ◽  
Paired Pulse ◽  
Human Motor

scholarly journals The influence of temporal predictability on express visuomotor responses

2020 ◽  
Author(s):  
Samuele Contemori ◽  
Gerald E. Loeb ◽  
Brian D. Corneil ◽  
Guy Wallis ◽  
Timothy J. Carroll
Keyword(s):  
Superior Colliculus ◽  
Onset Time ◽  
Surface Emg ◽  
Stimulus Onset ◽  
Target Motion ◽  
Target Velocity ◽  
Moving Target ◽  
Visuomotor Transformations ◽  
Shoulder Muscles ◽  
Temporal Predictability

ABSTRACTVolitional visuomotor responses in humans are generally thought to manifest 100ms or more after stimulus onset. Under appropriate conditions, however, much faster target-directed responses can be produced at upper limb and neck muscles. These “express” responses have been termed stimulus-locked responses (SLRs) and are proposed to be modulated by visuomotor transformations performed subcortically via the superior colliculus. Unfortunately, for those interested in studying SLRs, these responses have proven difficult to detect consistently across individuals. The recent report of an effective paradigm for generating SLRs in 100% of participants appears to change this. The task required the interception of a moving target that emerged from behind a barrier at a time consistent with the target velocity. Here we aimed to reproduce the efficacy of this paradigm for eliciting SLRs and to test the hypothesis that its effectiveness derives from the predictability of target onset time as opposed to target motion per se. In one experiment, we recorded surface EMG from shoulder muscles as participants made reaches to intercept temporally predictable or unpredictable targets. Consistent with our hypothesis, predictably timed targets produced more frequent and stronger SLRs than unpredictably timed targets. In a second experiment, we compared different temporally predictable stimuli and observed that transiently presented targets produced larger and earlier SLRs than sustained moving targets. Our results suggest that target motion is not critical for facilitating the expression of an SLR and that timing predictability does not rely on extrapolation of a physically plausible motion trajectory. These findings provide support for a mechanism whereby an internal timer, probably located in cerebral cortex, primes the processing of both visual input and motor output within the superior colliculus to produce SLRs.

scholarly journals Systematic examination of low-intensity ultrasound parameters on human motor cortex excitability and behavior

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Anton Fomenko ◽  
Kai-Hsiang Stanley Chen ◽  
Jean-François Nankoo ◽  
James Saravanamuttu ◽  
Yanqiu Wang ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Short Interval ◽  
Motor Evoked Potential ◽  
Cortical Inhibition ◽  
Transcranial Ultrasound ◽  
Human Motor Cortex ◽  
Low Intensity ◽  
Visuomotor Task ◽  
Motor Cortex Excitability ◽  
And Behavior

Low-intensity transcranial ultrasound (TUS) can non-invasively modulate human neural activity. We investigated how different fundamental sonication parameters influence the effects of TUS on the motor cortex (M1) of 16 healthy subjects by probing cortico-cortical excitability and behavior. A low-intensity 500 kHz TUS transducer was coupled to a transcranial magnetic stimulation (TMS) coil. TMS was delivered 10 ms before the end of TUS to the left M1 hotspot of the first dorsal interosseous muscle. Varying acoustic parameters (pulse repetition frequency, duty cycle, and sonication duration) on motor-evoked potential amplitude were examined. Paired-pulse measures of cortical inhibition and facilitation, and performance on a visuomotor task was also assessed. TUS safely suppressed TMS-elicited motor cortical activity, with longer sonication durations and shorter duty cycles when delivered in a blocked paradigm. TUS increased GABAA-mediated short-interval intracortical inhibition and decreased reaction time on visuomotor task but not when controlled with TUS at near-somatosensory threshold intensity.

scholarly journals Semantic Conflict and Response Conflict in the Stroop Task

2019 ◽  
Vol 6 (4) ◽  
pp. 24-38
Author(s):  
Alexey Starodubtsev ◽  
◽  
Mikhail Allakhverdov
Keyword(s):  
Stroop Effect ◽  
Word Meaning ◽  
Incorrect Response ◽  
Response Conflict ◽  
Response Level ◽  
Semantic Level ◽  
Semantic Conflict ◽  
Response Set ◽  
Different Color ◽  
Printed Word

The most common ways researchers explain the Stroop effect are either through semantic or through response conflict. According to the literature, there are several methods capable of disentangling these conflicts: to use words outside of the response set, to use associatively related colors and words, or to use a “2:1” paradigm (requiring the same response for two types of stimuli). However, we believe that these methods cannot entirely differentiate semantic and response conflicts. We propose the following alternative method: when naming the color of a printed word (e.g., red, yellow, etc.) in the Stroop test, participants were asked to use different color names for some colors. For example, the red-colored stimuli had to be named by the word “yellow”. This approach allowed us to create semantically congruent stimuli, but with the conflict at the response level (the word red appears in red, but the participants have to say “yellow” because of the rule). Some stimuli remain congruent at the response level, but with the conflict at the semantic level (the word yellow appears in red, and the participants have to say “yellow” because of the rule). The results showed that semantically congruent stimuli do not produce the Stroop effect even if the meaning of the word corresponds to an incorrect response. In turn, congruence at the response level reduces the interference effect, but interference remains significant. Thus, the response conflict affects the magnitude of the Stroop effect only when there is a semantic conflict. Our data do not correspond to models that assume direct activation of responses corresponding to word meaning

Stop and Go: The Neural Basis of Selective Movement Prevention

2009 ◽  
Vol 21 (6) ◽  
pp. 1193-1203 ◽  
Author(s):  
James P. Coxon ◽  
Cathy M. Stinear ◽  
Winston D. Byblow
Keyword(s):  
Motor Cortex ◽  
Right Hemisphere ◽  
Inferior Frontal Gyrus ◽  
Middle Finger ◽  
Neural Basis ◽  
Movement Initiation ◽  
Stop And Go ◽  
Inferior Parietal Cortex ◽  
Supplementary Motor Cortex ◽  
The Right

Converging lines of evidence show that volitional movement prevention depends on the right prefrontal cortex (PFC), especially the right inferior frontal gyrus (IFG). Selective movement prevention refers to the rapid prevention of some, but not all, movement. It is unknown whether the IFG, or other prefrontal areas, are engaged when movement must be selectively prevented, and whether additional cortical areas are recruited. We used rapid event-related fMRI to investigate selective and nonselective movement prevention during performance of a temporally demanding anticipatory task. Most trials involved simultaneous index and middle finger extension. Randomly interspersed trials required the prevention of one, or both, finger movements. Regions of the right hemisphere, including the IFG, were active for selective and nonselective movement prevention, with an overlap in the inferior parietal cortex and the middle frontal gyrus. Selective movement prevention caused a significant delay in movement initiation of the other digit. These trials were associated with activation of the medial frontal cortex. The results provide support for a right-hemisphere network that temporarily “brakes” all movement preparation. When movement is selectively prevented, the supplementary motor cortex (SMA/pre-SMA) may participate in conflict resolution and subsequent reshaping of excitatory drive to the motor cortex.

Mechanisms underlying long-interval cortical inhibition in the human motor cortex: a TMS-EEG study

2013 ◽  
Vol 109 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Nigel C. Rogasch ◽  
Zafiris J. Daskalakis ◽  
Paul B. Fitzgerald
Keyword(s):  
Motor Cortex ◽  
Motor Evoked Potentials ◽  
Cortical Inhibition ◽  
Human Motor Cortex ◽  
Paired Pulse ◽  
Small Hand ◽  
Human Motor ◽  
Hand Muscle ◽  
Underlying Mechanisms ◽  
Eeg Conditioning

Long-interval cortical inhibition (LICI) refers to suppression of neuronal activity following paired-pulse transcranial magnetic stimulation (TMS) with interstimulus intervals (ISIs) between 50 and 200 ms. LICI can be measured either from motor-evoked potentials (MEPs) in small hand muscles or directly from the cortex using concurrent electroencephalography (EEG). However, it remains unclear whether EEG inhibition reflects similar mechanisms to MEP inhibition. Eight healthy participants received single- and paired-pulse TMS (ISI = 100 ms) over the motor cortex. MEPs were measured from a small hand muscle (first dorsal interosseus), whereas early (P30, P60) and late (N100) TMS-evoked cortical potentials (TEPs) were measured over the motor cortex using EEG. Conditioning and test TMS intensities were altered, and modulation of LICI strength was measured using both methods. LICI of MEPs and both P30 and P60 TEPs increased in strength with increasing conditioning intensities and decreased with increasing test intensities. LICI of N100 TEPs remained unchanged across all conditions. In addition, MEP and P30 LICI strength correlated with the slope of the N100 evoked by the conditioning pulse. LICI of early and late TEP components was differentially modulated with altered TMS intensities, suggesting independent underlying mechanisms. LICI of P30 is consistent with inhibition of cortical excitation similar to MEPs, whereas LICI of N100 may reflect presynaptic autoinhibition of inhibitory interneurons. The N100 evoked by the conditioning pulse is consistent with the mechanism responsible for LICI, most likely GABAB-mediated inhibition of cortical activity.

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