scholarly journals On the Boundaries between Decision and Action: Effector-selective Lateralization of Beta-frequency Power Is Modulated by the Lexical Frequency of Printed Words

2020 ◽  
Vol 32 (11) ◽  
pp. 2131-2144
Author(s):  
Michele Scaltritti ◽  
Remo Job ◽  
F.-Xavier Alario ◽  
Simone Sulpizio
Keyword(s):  
Motor Response ◽  
Motor Behavior ◽  
Lexical Frequency ◽  
Action Semantics ◽  
Discrete Processing ◽  
Beta Frequency ◽  
Choice Tasks ◽  
The Impact ◽  
Frequency Power ◽  
Response Activation

Current computational and neuroscientific models of decision-making posit a discrete, serial processing distinction between upstream decisional stages and downstream processes of motor-response implementation. We investigated this framework in the context of two-alternative forced-choice tasks on linguistic stimuli, words and pseudowords. In two experiments, we assessed the impact of lexical frequency and action semantics on two effector-selective EEG indexes of motor-response activation: the lateralized readiness potential and the lateralization of beta-frequency power. This allowed us to track potentially continuous streams of processing progressively mapping the evaluation of linguistic stimuli onto corresponding response channels. Whereas action semantics showed no influence on EEG indexes of motor-response activation, lexical frequency affected the lateralization of response-locked beta-frequency power. We argue that these observations point toward a continuity between linguistic processing of word input stimuli and implementation of corresponding choice in terms of motor behavior. This interpretation challenges the commonly held assumption of a discrete processing distinction between decisional and motor-response processes in the context of decisions based on symbolic stimuli.

scholarly journals Transient inhibition and long-term facilitation of locomotion by phasic optogenetic activation of serotonin neurons

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Patrícia A Correia ◽  
Eran Lottem ◽  
Dhruba Banerjee ◽  
Ana S Machado ◽  
Megan R Carey ◽  
...  
Keyword(s):  
Motor Behavior ◽  
Motor Impairment ◽  
Long Term Effects ◽  
Strong Suppression ◽  
Serotonin Neurons ◽  
Short And Long Term ◽  
Rapid Kinetics ◽  
Long Term Facilitation ◽  
The Impact

Serotonin (5-HT) is associated with mood and motivation but the function of endogenous 5-HT remains controversial. Here, we studied the impact of phasic optogenetic activation of 5-HT neurons in mice over time scales from seconds to weeks. We found that activating dorsal raphe nucleus (DRN) 5-HT neurons induced a strong suppression of spontaneous locomotor behavior in the open field with rapid kinetics (onset ≤1 s). Inhibition of locomotion was independent of measures of anxiety or motor impairment and could be overcome by strong motivational drive. Repetitive place-contingent pairing of activation caused neither place preference nor aversion. However, repeated 15 min daily stimulation caused a persistent increase in spontaneous locomotion to emerge over three weeks. These results show that 5-HT transients have strong and opposing short and long-term effects on motor behavior that appear to arise from effects on the underlying factors that motivate actions.

A critical period for the impact of vestibular sensation on ferret motor development

2007 ◽  
Vol 16 (4-5) ◽  
pp. 179-186
Author(s):  
S. Van Cleave ◽  
M.S. Shall
Keyword(s):  
Vestibular System ◽  
Motor Development ◽  
Critical Period ◽  
Motor Behavior ◽  
Fiber Development ◽  
Type I ◽  
Behavior Development ◽  
Sham Surgery ◽  
Walking Balance ◽  
The Impact

Children with hearing deficits and hypofunctioning vestibular receptors frequently have delayed motor development. This study focuses on when the vestibular system needs to be active for normal motor behavior development and the maturation of the soleus muscle in the ferret. Both vestibular labyrinths were removed from ferrets at Postnatal day 10 (P10), P21, or P45 and the resulting data were compared with ferrets that had undergone a sham surgery at the same ages. The animals were sacrificed at P120 (young adult ferret). The resulting data from these ferrets revealed that standing and walking balance was significantly affected when the vestibular system was eliminated at or before P21. The soleus of P10 and P21 animals generally had smaller diameter muscle fibers and proportionally less type I Myosin Heavy Chain (MHC) and more type IIX MHC. The twitch contraction time of the soleus of the P21 group was significantly slower than the other groups. It appears that the vestibular system is important to motor and muscle fiber development in the ferret during the period before P21. The eyes are still closed at that age and all of the vestibular receptors are not fully mature. These findings imply a "critical period" for vestibular sensation and the development of a muscle that is important to standing balance.

092 Effect of the dual orexin receptor antagonist (DORA) daridorexant on behaviour upon awakening in rats and dogs

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A38-A39
Author(s):  
Giorgio Bergamini ◽  
Catherine Roch ◽  
Sean Durkin ◽  
Michel Steiner
Keyword(s):  
Grip Strength ◽  
Motor Skills ◽  
Muscle Weakness ◽  
Motor Behavior ◽  
Motor Impairment ◽  
Phase Behaviour ◽  
Fine Motor ◽  
Dependent Manner ◽  
The Impact ◽  
Time Point

Abstract Introduction The ability to be fast alert and to interact with the environment without motor impairment upon waking up, is a critical feature of natural sleep. DORAs represent a new class of insomnia medications that specifically inhibit the wake-promoting effects of orexin neuropeptides. Daridorexant is a potent and selective DORA under late stage development for the treatment of insomnia. Here, we assessed the impact of sleep-promoting doses of daridorexant on rats’ and dogs’ behaviour upon forced awakening. Zolpidem (a positive GABAA receptor modulator) was used as active comparator in rats because of its known negative impact on motor functions. Methods Rats were woken up at different time points after oral administration of daridorexant (10, 30, 100 mg/kg) or zolpidem (30, 100 mg/kg) during their inactive phase, and repeatedly subjected to two motor tasks: 1) the rotating rod test (lasting 120 sec, at each time point) assessing gross motor skills and coordination, and 2) the forepaw grip strength test assessing fine motor skills and muscle strength. Dogs were presented with food as an external, salient stimulus, three hours after administration of daridorexant in gelatin capsules (10, 30 or 90 mg/dog) during their active phase. Behaviour and signs of muscle weakness, after having woken up, were assessed by manual inspection of video recordings and concomitant electroencephalogram/electromyogram recordings. Results In both the rotarod and grip tests, daridorexant treatment had no effect on motor behavior at any dose or time point tested, while zolpidem significantly reduced the time spent on the rotarod and the grip strength in a dose and time-dependent manner (N=12/group; p<0.001;) (e.g. at 30 min post-dose, time spent on the rotarod was 84, 79–89 and 10–19 sec for vehicle, daridorexant and zolpidem, respectively). Dogs treated with daridorexant were able to wake up easily upon food presentation. They behaved and ate normally and did not show any signs of muscle weakness. Conclusion The type of sleep promoted by daridorexant is surmountable in rats and dogs and similar to physiological sleep. It allows animals to easily wake up, to behave normally without motor impairment and to respond efficiently to the environmental conditions. Support (if any) Funded by Idorsia Pharmaceuticals Ltd

Eye Movements of the Murine P/Q Calcium Channel Mutant Tottering, and the Impact of Aging

2006 ◽  
Vol 95 (3) ◽  
pp. 1588-1607 ◽  
Author(s):  
John S. Stahl ◽  
Robert A. James ◽  
Brian S. Oommen ◽  
Freek E. Hoebeek ◽  
Chris I. De Zeeuw
Keyword(s):  
Eye Movements ◽  
Calcium Channel ◽  
Motor Behavior ◽  
Motor Deficits ◽  
Ocular Motor ◽  
Gene Encoding ◽  
Optokinetic Reflex ◽  
Behavioral Abnormalities ◽  
Cross Axis ◽  
The Impact

Mice carrying mutations of the gene encoding the ion pore of the P/Q calcium channel (Cacna1a) are an instance in which cerebellar dysfunction may be attributable to altered electrophysiology and thus provide an opportunity to study how neuronal intrinsic properties dictate signal processing in the ocular motor system. P/Q channel mutations can engender multiple effects at the single neuron, circuit, and behavioral levels; correlating physiological and behavioral abnormalities in multiple allelic strains will ultimately facilitate determining which alterations of physiology are responsible for specific behavioral aberrations. We used videooculography to quantify ocular motor behavior in tottering mutants aged 3 mo to 2 yr and compared their performance to data previously obtained in the allelic mutant rocker and C57BL/6 controls. Tottering mutants shared numerous abnormalities with rocker, including upward deviation of the eyes at rest, increased vestibuloocular reflex (VOR) phase lead at low stimulus frequencies, reduced VOR gain at high stimulus frequencies, reduced gain of the horizontal and vertical optokinetic reflex, reduced time constants of the neural integrator, and reduced plasticity of the VOR as assessed in a cross-axis training paradigm. Unlike rocker, young tottering mutants exhibited normal peak velocities of nystagmus fast phases, arguing against a role for neuromuscular transmission defects in the attenuation of compensatory eye movements. Tottering also differed by exhibiting directional asymmetries of the gains of optokinetic reflexes. The data suggest at least four pathophysiological mechanisms (two congenital and two acquired) are required to explain the ocular motor deficits in the two Cacna1a mutant strains.

Real-time Tracking of Motor Response Activation and Response Competition in a Stroop Task in Young Children: A Lateralized Readiness Potential Study

2009 ◽  
Vol 21 (11) ◽  
pp. 2195-2206 ◽  
Author(s):  
Dénes Szűcs ◽  
Fruzsina Soltész ◽  
Donna Bryce ◽  
David Whitebread
Keyword(s):  
Real Time ◽  
Stroop Task ◽  
Motor Response ◽  
Response Competition ◽  
Real Life ◽  
Lateralized Readiness Potential ◽  
Readiness Potential ◽  
Motor Inhibition ◽  
Motor Activation ◽  
Response Activation

The ability to select an appropriate motor response by resolving competition among alternative responses plays a major role in cognitive performance. fMRI studies suggest that the development of this skill is related to the maturation of the frontal cortex that underlies the improvement of motor inhibition abilities. However, fMRI cannot characterize the temporal properties of motor response competition and motor activation in general. We studied the development of the time course of resolving motor response competition. To this end, we used the lateralized readiness potential (LRP), an ERP measure, for tracking correct and incorrect motor cortex activation in children in real time. Fourteen children and 14 adults took part in an animal-size Stroop task where they selected between two animals, presented simultaneously on the computer screen, which was larger in real life. In the incongruent condition, the LRP detected stronger and longer lasting incorrect response activation in children than in adults. LRP results could explain behavioral congruency effects, the generally longer RT in children than in adults and the larger congruency effect in children than in adults. In contrast, the peak latency of ERP waves, usually associated with stimulus processing speed, could explain neither of the above effects. We conclude that the development of resolving motor response competition, relying on motor inhibition skills, is a crucial factor in child development. Our study demonstrates that the LRP is an excellent tool for studying motor activation in children.

scholarly journals Real-Time Quality Index to Control Data Loss in Real-Life Cardiac Monitoring Applications

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5357
Author(s):  
Gaël Vila ◽  
Christelle Godin ◽  
Sylvie Charbonnier ◽  
Aurélie Campagne
Keyword(s):  
Heart Rate ◽  
Quality Index ◽  
Real Life ◽  
Motion Artifacts ◽  
Cardiac Monitoring ◽  
Data Loss ◽  
Median Error ◽  
Monitoring Applications ◽  
The Impact ◽  
Frequency Power

Wearable cardiac sensors pave the way for advanced cardiac monitoring applications based on heart rate variability (HRV). In real-life settings, heart rate (HR) measurements are subject to motion artifacts that may lead to frequent data loss (missing samples in the HR signal), especially for commercial devices based on photoplethysmography (PPG). The current study had two main goals: (i) to provide a white-box quality index that estimates the amount of missing samples in any piece of HR signal; and (ii) to quantify the impact of data loss on feature extraction in a PPG-based HR signal. This was done by comparing real-life recordings from commercial sensors featuring both PPG (Empatica E4) and ECG (Zephyr BioHarness 3). After an outlier rejection process, our quality index was used to isolate portions of ECG-based HR signals that could be used as benchmark, to validate the output of Empatica E4 at the signal level and at the feature level. Our results showed high accuracy in estimating the mean HR (median error: 3.2%), poor accuracy for short-term HRV features (e.g., median error: 64% for high-frequency power), and mild accuracy for longer-term HRV features (e.g., median error: 25% for low-frequency power). These levels of errors could be reduced by using our quality index to identify time windows with few or no data loss (median errors: 0.0%, 27%, and 6.4% respectively, when no sample was missing). This quality index should be useful in future work to extract reliable cardiac features in real-life measurements, or to conduct a field validation study on wearable cardiac sensors.

Psychomotor retardation in major depressive disorder: A dimension to be rediscovered?

2014 ◽  
Vol 29 (S3) ◽  
pp. 579-579
Author(s):  
T. Mauras
Keyword(s):  
Motor Behavior ◽  
Brain Structures ◽  
Incentive Motivation ◽  
Psychomotor Retardation ◽  
Point Of View ◽  
Therapeutic Interventions ◽  
Psychomotor Slowing ◽  
Psychomotor Activity ◽  
The One ◽  
The Impact

Psychomotor activity is one of the traits we most immediately perceive in others. Psychomotor slowing, which can be easily noticed on a first medical examination, is a symptom which may be prodromal of psychic disturbances.Historically, psychomotor retardation is a characteristic attached to depression, especially melancholia. Some studies show that psychomotor retardation is associated with good therapeutic prognosis, including positive response to electro-convulsivo-therapy. The cluster of non-verbal symptoms includes both basic aspects related to motor behavior such as attitudes and movements and more complex aspects such as goal-directed behaviors. We will see that this intuitive and fundamental dimension of clinical depression is not homogeneous. From a motor point of view, hypo-bradykinesia in depression may be compared to the one found in cortico-subcortical syndromes such as Parkinson's disease. This comparison suggests that key brain structures such as the basal ganglia could be involved in depression.Moreover, the loss of vital energy is the dominant psychopathological explanation linked to psychomotor retardation. From a phenomenological point of view, this interpretation seems to be relevant but appears disappointing as an experimental variable. However, motivation, understood as the factor that energizes the behavior seems to be an interesting and promising concept.Experimentally, it is possible to measure how much an individual is able to invest energy in order to achieve a goal.The impact of depression on the process of incentive motivation will be analyzed before turning to a description of therapeutic interventions related to psychomotor field such as sports or sensorimotor stimulations that appear to be promising tracks for clinical improvement.

scholarly journals Neural mechanisms underlying the impact of daylong cognitive work on economic decisions

2016 ◽  
Vol 113 (25) ◽  
pp. 6967-6972 ◽  
Author(s):  
Bastien Blain ◽  
Guillaume Hollard ◽  
Mathias Pessiglione
Keyword(s):  
Real Life ◽  
Limited Resource ◽  
Self Control ◽  
Economic Decisions ◽  
Common Resource ◽  
Order Of Magnitude ◽  
Considerable Controversy ◽  
Carry Over ◽  
Choice Tasks ◽  
The Impact

The ability to exert self-control is key to social insertion and professional success. An influential literature in psychology has developed the theory that self-control relies on a limited common resource, so that fatigue effects might carry over from one task to the next. However, the biological nature of the putative limited resource and the existence of carry-over effects have been matters of considerable controversy. Here, we targeted the activity of the lateral prefrontal cortex (LPFC) as a common substrate for cognitive control, and we prolonged the time scale of fatigue induction by an order of magnitude. Participants performed executive control tasks known to recruit the LPFC (working memory and task-switching) over more than 6 h (an approximate workday). Fatigue effects were probed regularly by measuring impulsivity in intertemporal choices, i.e., the propensity to favor immediate rewards, which has been found to increase under LPFC inhibition. Behavioral data showed that choice impulsivity increased in a group of participants who performed hard versions of executive tasks but not in control groups who performed easy versions or enjoyed some leisure time. Functional MRI data acquired at the start, middle, and end of the day confirmed that enhancement of choice impulsivity was related to a specific decrease in the activity of an LPFC region (in the left middle frontal gyrus) that was recruited by both executive and choice tasks. Our findings demonstrate a concept of focused neural fatigue that might be naturally induced in real-life situations and have important repercussions on economic decisions.

Application of Fitts' Law to Individuals with Cerebral Palsy

2002 ◽  
Vol 94 (3) ◽  
pp. 883-895 ◽  
Author(s):  
Alison Gump ◽  
Miriam Legare ◽  
Deborah L. Hunt
Keyword(s):  
Cerebral Palsy ◽  
Linear Models ◽  
Motor Behavior ◽  
Error Rates ◽  
Subject Group ◽  
Full Data ◽  
Data Set ◽  
Fitts Law ◽  
The Impact ◽  
Speed Accuracy

Cerebral palsy is a condition that results in motor abnormalities as a direct consequence of injury to the developing brain. Fitts' law, which describes a speed-accuracy tradeoff in visually guided movements, has been shown to characterize the motor behavior of normal subjects during aiming tasks. To assess whether Fitts' law can also describe the aimed movements of persons with cerebral palsy, eight cerebral palsied adults participated in an aimed movement study. 12 targets were used with Indices of Difficulty ranging from 2.19 to 6.00 bits. The impact of Gan and Hoffmann's 1988 ballistic movement factor, A, and Fitts' 1954 Index of Difficulty on subject's movement and reaction times was examined using multivariate linear models. The analysis of the full data set yielded a significant effect of A on movement times and no significant adherence to Fitts' law. However, high error rates that could be the result of oculomotor problems among the subject group were noted, and the method of handling errors had a large effect on the results. Tracking eye position during a Fitts' law task would provide information regarding the effect of oculomotor difficulties on aiming tasks in the cerebral palsied subject group.

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