Search results for "Motor"
showing 10 items of 3137 documents
Dynamics of brain activity underlying working memory for music in a naturalistic condition
2014
We aimed at determining the functional neuroanatomy of working memory (WM) recognition of musical motifs that occurs while listening to music by adopting a non-standard procedure. Western tonal music provides naturally occurring repetition and variation of motifs. These serve as WM triggers, thus allowing us to study the phenomenon of motif tracking within real music. Adopting a modern tango as stimulus, a behavioural test helped to identify the stimulus motifs and build a time-course regressor of WM neural responses. This regressor was then correlated with the participants' (musicians') functional magnetic resonance imaging (fMRI) signal obtained during a continuous listening condition. In…
Frontal–posterior theta oscillations reflect memory retrieval during sentence comprehension
2015
Abstract Successful working-memory retrieval requires that items be retained as distinct units. At the neural level, it has been shown that theta-band oscillatory power increases with the number of to-be-distinguished items during working-memory retrieval. Here we hypothesized that during sentence comprehension, verbal-working-memory retrieval demands lead to increased theta power over frontal cortex, supposedly supporting the distinction amongst stored items during verbal-working-memory retrieval. Also, synchronicity may increase between the frontal cortex and the posterior cortex, with the latter supposedly supporting item retention. We operationalized retrieval by using pronouns, which r…
Reduced Threshold for Inhibitory Homeostatic Responses in Migraine Motor Cortex? A tDCS/TMS Study
2014
Background and Objective Neurophysiological studies in migraine have reported conflicting findings of either cortical hyper- or hypoexcitability. In migraine with aura (MwA) patients, we recently documented an inhibitory response to suprathreshold, high-frequency repetitive transcranial magnetic stimulation (hf-rTMS) trains applied to the primary motor cortex, which is in contrast with the facilitatory response observed in the healthy subjects. The aim of the present study was to support the hypothesis that in migraine, because of a condition of basal increased cortical responsivity, inhibitory homeostatic-like mechanisms of cortical excitability could be induced by high magnitude stimulati…
Visual inference of arm movement is constrained by motor representations
2015
International audience; Several studies support the idea that motion inference is strongly motor dependent. In the present study, we address the role of biomechanical constraints in motion prediction and how this implicit knowledge can interfere in a spatial prediction task. Right-handed (RHS) and left-handed subjects (LHS) had to estimate the final position of a horizontal arm movement in which the final part of the trajectory was hidden. Our study highlighted a direction effect: end point prediction accuracy was better to infer the final position of horizontal motion directed toward the median line of human body. This finding suggests that the spatial prediction of end point is mapped ont…
Physical activity, healthy behaviors and its motivational correlates: exploring the spillover effect through stages of change
2022
On the basis of the spillover or transfer effect and the transtheoretical model of change, this study assessed the association between amount of physical activity, healthy and unhealthy weight control behaviors, and motivational types, as well as their variability across stages of change. A total of 1219 randomly selected Mexican adults from 18 to 65 years old, representative of the city of Monterrey (México), participated in the study. Correlation analyses, differences by gender, and multivariate analyses of variance, controlling for age, were performed. We found that in the maintenance stage, there is higher frequency of physical activity more healthy weight control behaviors, as well as …
Modulation of cortical motor outputs by the symbolic meaning of visual stimuli.
2010
Abstract The observation of an action modulates motor cortical outputs in specific ways, in part through mediation of the mirror neuron system. Sometimes we infer a meaning to an observed action based on integration of the actual percept with memories. Here, we conducted a series of experiments in healthy adults to investigate whether such inferred meanings can also modulate motor cortical outputs in specific ways. We show that brief observation of a neutral stimulus mimicking a hand does not significantly modulate motor cortical excitability (Study 1) although, after prolonged exposure, it can lead to a relatively nonspecific modulation (Study 2). However, when such a neutral stimulus is p…
Developing motor planning over ages
2009
International audience; Few studies have explored the development of response selection processes in children in the case of object manipulation. In the current research, we studied the end-state comfort effect, the tendency to ensure a comfortable position at the end rather than at the beginning of simple object manipulation tasks. We used two versions of the unimanual bar transport task. In Experiment 1, only 10-year-olds reached the same level of sensitivity to end-state comfort as adults, and 8-year-olds were less efficient than 6-year-olds. In each age group, children’s sensitivity did not increase during a session: i.e., either clearly showed the sensitivity or showed no sensitivity a…
Impaired control of an action after supplementary motor area lesion: A case study
2000
The kinematics of the action formed by reaching-grasping an object and placing it on a second target was studied in a patient who suffered from an acute vascular left brain lesion, which affected the Supplementary Motor Area proper (SMA-proper) (Matelli M, Luppino G. Thalamic input to mesial and superior area 6 in the macaque monkey. Journal of Comparative Neurology 1996;372:59-87, Matelli M, Luppino G, Fogassi L, Rizzolatti G. Thalamic input to inferior area 6 and area 4 in the macaque monkey. Journal of Comparative Neurology 1989;280:468-488), and in five healthy control subjects. The reach kinematics of the controls was affected by the positions of both the reaching-grasping and the plac…
Daily modulation of the speed–accuracy trade-off
2017
International audience; Goal-oriented arm movements are characterized by a balance between speed and accuracy. The relation between speed and accuracy has been formalized by Fitts’ law and predicts a linear increase in movement duration with task constraints. Up to now this relation has been investigated on a short-time scale only, that is during a single experimental session, although chronobiological studies report that the motor system is shaped by circadian rhythms. Here, we examine whether the speed–accuracy trade-off could vary during the day. Healthy adults carried out arm-pointing movements as accurately and fast as possible toward targets of different sizes at various hours of the …
Context-dependent neuroelectric responses during motor control
2015
Abstract Research on brain responses during motor control is usually performed under typical laboratory settings. However, everyday life and the laboratory differ in many aspects, such as purposeful and motivated behavior; and there's no awareness of “being measured” in everyday life. In the laboratory, movements are usually explicitly instructed, overtly measured and follow no intrinsic motivated purpose. Therefore, here we present a new method to measure and reliably analyze neuroelectric brain responses by EEG, as well as kinematics during the performance of grasping movements in two different behavioral contexts. One context (L) simulates a typical laboratory task and another context (E…