Search results for "Stimulus"
showing 10 items of 555 documents
Behavioral and electrophysiological correlates of cognitive control in ex-obese adults
2017
Impaired cognitive control functions have been documented in obesity. It remains unclear whether these functions normalize after weight reduction. We compared ex-obese individuals, who successfully underwent substantial weight loss after bariatric surgery, to normal-weight participants on measures of resistance to interference, cognitive flexibility and response inhibition, obtained from the completion of two Stroop tasks, a Switching task and a Go/NoGo task, respectively. To elucidate the underlying brain mechanisms, event-related potentials (ERPs) in the latter two tasks were examined. As compared to controls, patients were more susceptible to the predominant but task-irrelevant stimulus …
Does Observation of Postural Imbalance Induce a Postural Reaction?
2011
Import JabRef | WosArea Life Sciences and Biomedicine - Other Topics; International audience; Background: Several studies bring evidence that action observation elicits contagious responses during social interactions. However automatic imitative tendencies are generally inhibited and it remains unclear in which conditions mere action observation triggers motor behaviours. In this study, we addressed the question of contagious postural responses when observing human imbalance. Methodology/Principal Findings: We recorded participants' body sway while they observed a fixation cross (control condition), an upright point-light display of a gymnast balancing on a rope, and the same point-light di…
The impact of visual cues during visual word recognition in deaf readers: An ERP study
2021
Abstract Although evidence is still scarce, recent research suggests key differences in how deaf and hearing readers use visual information during visual word recognition. Here we compared the time course of lexical access in deaf and hearing readers of similar reading ability. We also investigated whether one visual property of words, the outline-shape, modulates visual word recognition differently in both groups. We recorded the EEG signal of twenty deaf and twenty hearing readers while they performed a lexical decision task. In addition to the effect of lexicality, we assessed the impact of outline-shape by contrasting responses to pseudowords with an outline-shape that was consistent (e…
''Motor Resonance Mechanisms Are Preserved In Alzheimer's Disease Patients''
2012
Bisio, A. | Casteran, M. | Ballay, Y. | Manckoundia, P. | Mourey, F. | Pozzo, T.; International audience; ''This study aimed to better characterize the sensorimotor mechanisms underlying motor resonance, namely the relationship between motion perception and movement production in patients suffering from Alzheimer's disease (AD). This work first gives a kinematic description of AD patients' upper limb movements, then it presents a simple paradigm in which a dot with different velocities is moved in front of the participant who is instructed to point to its final position when it stopped. AD patients' actions, as well as healthy elderly participants, were similarly influenced by the dot veloc…
Discrimination between cocaine-associated context and cue in a modified conditioned place preference paradigm: role of the nNOS gene in cue condition…
2009
The conditioned place preference (CPP) paradigm entails appetitive learning and is utilized to investigate the motivational effects of drug and natural reward in rodents. However, a typical CPP design does not allow dissociation between cue- and context-dependent appetitive learning. In humans, context and cues that had been associated with drug reward can elicit conditioned response and drug craving. Therefore, we investigated (a) methods by which to discriminate between cue- and context-dependent appetitive learning, and (b) the role of the neuronal nitric oxide synthase (nNOS) gene in appetitive learning. Wild-type (WT) and nNOS knockout (KO) mice were trained by cocaine (20 mg/kg) in a …
Spatial Properties of Mismatch Negativity in Patients with Disorders of Consciousness
2018
In recent decades, event-related potentials have been used for the clinical electrophysiological assessment of patients with disorders of consciousness (DOCs). In this paper, an oddball paradigm with two types of frequencydeviant stimulus (standard stimuli were pure tones of 1000 Hz; small deviant stimuli were pure tones of 1050 Hz; large deviant stimuli were pure tones of 1200 Hz) was applied to elicit mismatch negativity (MMN) in 30 patients with DOCs diagnosed using the JFK Coma Recovery ScaleRevised (CRS-R). The results showed that the peak amplitudes of MMN elicited by both large and small deviant stimuli were significantly different from baseline. In terms of the spatial properties of…
Multivariate analysis of the modifications induced by an environmental acoustic cue on rat exploratory behavior.
2007
The aim of the present paper is to study by means of a multivariate analysis the modifications induced by an environmental acoustic cue on the structure of rat exploratory behavior. Adult male Wistar rats were observed during the exploration of a soundproof observation box. Each rat was acoustically stimulated after 150 s from the beginning of the experimental session, lasting 300 s, and recorded through a digital videocamera. A frame by frame analysis was thereafter carried out using a professional video-recording system. Thirteen behavioral patterns were selected: immobility, immobile-sniffing, walking, rearing, climbing, chewing, paw-licking, face-grooming, body-grooming, head-turning, t…
Collaborative roles of Temporoparietal Junction and Dorsolateral Prefrontal Cortex in Different Types of Behavioural Flexibility
2017
AbstractBehavioural flexibility is essential for everyday life. This involves shifting attention between different perspectives. Previous studies suggest that flexibility is mainly subserved by the dorsolateral prefrontal cortex (DLPFC). However, although rarely emphasized, the temporoparietal junction (TPJ) is frequently recruited during flexible behaviour. A crucial question is whether TPJ plays a role in different types of flexibility, compared to its limited role in perceptual flexibility. We hypothesized that TPJ activity during diverse flexibility tasks plays a common role in stimulus-driven attention-shifting, thereby contributing to different types of flexibility, and thus the colla…
Phase-locked hippocampal theta-band responses are related to discriminative eyeblink conditioned responding
2013
Hippocampal electrophysiological oscillatory activity is undoubtedly related to learning and memory. The relative power of spontaneously occurring hippocampal theta (∼4-8 Hz) oscillations predicts how fast and how well an animal will learn: more theta predicts faster acquisition of the conditioned response in eyeblink conditioning in both rats and rabbits. Here, our aim was to study how hippocampal theta-band responses to conditioned stimuli elicited during very-long delay discrimination eyeblink conditioning relate to the accompanying conditioned behavior. We trained adult male New Zealand White rabbits using 1500-ms auditory stimuli as conditioned stimuli and a 100-ms airpuff as an uncond…
Nitric oxide induces muscular relaxation via cyclic GMP-dependent and -independent mechanisms in the longitudinal muscle of the mouse duodenum
2003
The aim of this study was to investigate, in mouse duodenum, the role of nitric oxide (NO) in the relaxation of longitudinal muscle evoked by nerve activation and the coupled action mechanism. Electrical field stimulation (EFS; 0.5ms, 10-s train duration, supramaximal voltage, at various frequencies) under nonadrenergic noncholinergic conditions evoked muscular relaxation occasionally followed, at the higher stimulus frequencies, by rebound contractions. Inhibition of the synthesis of NO by Nω-nitro-L-arginine methyl ester (L-NAME; 100μM) virtually abolished the evoked relaxation. The relaxation was reduced also by apamin (0.1μM) and by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 1μM)…