Search results for "cognitive"
showing 10 items of 10389 documents
Low-frequency rTMS inhibitory effects in the primary motor cortex: Insights from TMS-evoked potentials
2014
The neuromodulatory effects of repetitive transcranial magnetic stimulation (rTMS) have been mostly investigated by peripheral motor-evoked potentials (MEPs). New TMS-compatible EEG systems allow a direct investigation of the stimulation effects through the analysis of TMS-evoked potentials (TEPs).We investigated the effects of 1-Hz rTMS over the primary motor cortex (M1) of 15 healthy volunteers on TEP evoked by single pulse TMS over the same area. A second experiment in which rTMS was delivered over the primary visual cortex (V1) of 15 healthy volunteers was conducted to examine the spatial specificity of the effects. Single-pulse TMS evoked four main components: P30, N45, P60 and N100. M…
How to improve reading skills in dyslexics: the effect of high frequency rTMS.
2013
The latest progress in understanding remediation of dyslexia underlines how some changes in brain are a necessary mechanism of improvement. We wanted to determine whether high frequency repetitive transcranial magnetic stimulation (hf-rTMS) over areas that are underactive during reading in dyslexics, would improve reading of dyslexic adults. We applied 5Hz-TMS over both left and right inferior parietal lobule (IPL) and superior temporal gyrus (STG) prior to word, non-word and text reading aloud. Results show that hf-rTMS stimulation over the left IPL improves non-word reading accuracy and hf-rTMS stimulation over the left STG increases word reading speed and text reading accuracy. Moreover …
The what and how of observational learning
2007
Abstract Neuroimaging evidence increasingly supports the hypothesis that the same neural structures subserve the execution, imagination, and observation of actions. We used repetitive transcranial magnetic stimulation (rTMS) to investigate the specific roles of cerebellum and dorsolateral prefrontal cortex (DLPFC) in observational learning of a visuomotor task. Subjects observed an actor detecting a hidden sequence in a matrix and then performed the task detecting either the previously observed sequence or a new one. rTMS applied over the cerebellum before the observational training interfered with performance of the new sequence, whereas rTMS applied over the DLPFC interfered with performa…
Facilitation of bottom-up feature detection following rTMS-interference of the right parietal cortex
2010
In visual search tasks the optimal strategy should utilize relevant information ignoring irrelevant one. When the information at the feature and object levels are in conflict, un-necessary processing at higher level of object shape can interfere with detection of lower level orientation feature. We explored the effects of inhibitory trains of transcranial magnetic stimulation (rTMS) on the right and left parietal cortex in healthy subjects performing two visual search tasks. One task (Task A) was characterised by an object-to-feature interference. The other task (Task B) was without such interference. We found that rTMS of the right parietal cortex significantly reduced reaction times (RTs)…
New perspectives on the manipulation of opiate urges and the assessment of cognitive effort associated with opiate urges
2000
Behavioral models of drug urges assume that conditioned urges are strongly associated with drug consumption. An alternative, cognitive model assumes that urges represent the operation of cognitively demanding processes devoted to either supporting or blocking the automatized drug-use behavior. In Study 1, the effect of verbal drug cues and mood induction on self-reported opiate urges were examined. Twenty-four opiate addicts were either instructed to listen to verbal drug cures or neutral cues. Negative mood induction was applied on 12 addicts. Study 2 examined the cognitive processes underlying these urges. In a dual task paradigm, participants responded to a probe stimulus and listened si…
A meta-analysis of cognitive performance in melancholic versus non-melancholic unipolar depression
2016
Abstract Background Recently there is increasing recognition of cognitive dysfunction as a core feature of Major Depressive Disorder (MDD). The goal of the current meta-analysis was to review and examine in detail the specific features of cognitive dysfunction in Melancholic (MEL) versus Non-Melancholic (NMEL) MDD. Methods An electronic literature search was performed to find studies comparing cognitive performance in MEL versus NMEL. A meta-analysis of broad cognitive domains ( processing speed , reasoning/problem solving , verbal learning , visual learning , attention/working memory ) was conducted on all included studies (n=9). Sensitivity and meta-regression analyses were also conducted…
Animacy matters: ERP evidence for the multi-dimensionality of topic-worthiness in Chinese
2013
Abstract An event-related potential (ERP) study was conducted to investigate how animacy interacts with givenness during topic processing. Both animacy and givenness have been considered as within-discourse factors that contribute to an element׳s potential to form an optimal topic (i.e., topic-worthiness). ERPs were recorded while participants read question–answer pairs, of which the target sentence induced either a continuation or an alternation of a previously introduced topic (i.e., given vs. new). Depending on the context, a potential topic further differed in its animacy from the preceding one (i.e., animate vs. inanimate). The data revealed a robust givenness effect with an N400 reduc…
Object switching within working memory is reflected in the human event-related brain potential
2008
In two experiments applying a memory updating task subjects are asked to perform several arithmetic operations on stored numbers. From a trial-to-trial perspective these operations could be either performed on a previously processed item or on a new item which requires an object switch in working memory. Object switching results in prolonged operation times; these operation time costs reflect the switch of the focus of attention to the relevant information. Event-related brain potentials obtained in object switch trials show an increased P3a around 300 ms and a late, central negative component between 400 ms and 500 ms. The data suggest that the P3a may reflect the unhitching of the focus o…
Is an attention-based associative account of adjacent and nonadjacent dependency learning valid?
2014
Pacton and Perruchet (2008) reported that participants who were asked to process adjacent elements located within a sequence of digits learned adjacent dependencies but did not learn nonadjacent dependencies and conversely, participants who were asked to process nonadjacent digits learned nonadjacent dependencies but did not learn adjacent dependencies. In the present study, we showed that when participants were simply asked to read aloud the same sequences of digits, a task demand that did not require the intentional processing of specific elements as in standard statistical learning tasks, only adjacent dependencies were learned. The very same pattern was observed when digits were replace…
The context congruency effect is face specific
2013
There is evidence that faces are processed by specialized and independent modules that treat them as global configurations, or wholes (Axelrod & Yovel, 2010; Kanwisher, McDermott, & Chun, 1997). The holistic nature of face perception has been demonstrated with several experimental paradigms designed to examine whether facial parts interact, or are accessed independently. A recently introduced paradigm (Meinhardt-Injac, Persike, & Meinhardt, 2010) measures the strength of contextual interaction among internal and external facial features in congruent and incongruent target/no-target relationships. For this paradigm it is shown that the context congruency effect is indeed face specific: A str…