496 research outputs found
Relationships between substance use and hypomanic symptoms in a non-clinical sample
No full textPrevious work has demonstrated high levels of comorbidity between bipolar disorders and substance use disorders. There appears to be a relationship between substance use and hypomanic symptoms within the general population, but there has been little research in the area. The aim of the study was to examine relationships between substance use variables and hypomanic symptoms in a non-clinical sample. An international sample of 400 undergraduate students completed the 32-item hypomania checklist (HCL-32) and an author-constructed measure of substance use. Scores on the HCL-32 were significantly higher for those who were currently using amphetamines, and were approaching signifiance for those currently using cannabis, 3,4-methylenedioxymethamphetamine (MDMA), and cocaine. Those with a lifetime history of cocaine and amphetamine use had significantly higher scores, and there was a non-significant trend for the same effect with lifetime MDMA use. Statistically significant correlations were found between scores on the HCL-32 subscales and age of first use of cannabis and amphetamines. There were significant correlations or non-significant trends for a relationship between higher hypomanic symptoms and greater consumption of cannabis and MDMA in the past year and higher lifetime use of cannabis, cocaine and amphetamines. The present study concluded that substance use is related to hypomania in non-clinical populations. Further research using longitudinal designs is required to understand better the causal mechanisms involved in such a relationship
Learning and memory deficits in ecstasy users and their neural correlates during a face-learning task
No full textIt has been consistently shown that ecstasy users display impairments in learning and memory performance. In addition, working memory processing in ecstasy users has been shown to be associated with neural alterations in hippocampal and/or cortical regions as measured by functional magnetic resonance imaging (fMRI). Using functional imaging and a face-learning task, we investigated neural correlates of encoding and recalling face?name associations in 20 recreational drug users whose predominant drug use was ecstasy and 20 controls. To address the potential confounding effects of the cannabis use of the ecstasy using group, a second analysis included 14 previously tested cannabis users (Nestor, L., Roberts, G., Garavan, H., Hester, R., 2008. Deficits in learning and memory: parahippocampal hyperactivity and frontocortical hypoactivity in cannabis users. Neuroimage 40, 1328?1339). Ecstasy users performed significantly worse in learning and memory compared to controls and cannabis users. A conjunction analysis of the encode and recall phases of the task revealed ecstasy-specific hyperactivity in bilateral frontal regions, left temporal, right parietal, bilateral temporal, and bilateral occipital brain regions. Ecstasy-specific hypoactivity was evident in the right dorsal anterior cingulated cortex (ACC) and left posterior cingulated cortex. In both ecstasy and cannabis groups brain activation was decreased in the right medial frontal gyrus, left parahippocampal gyrus, left dorsal cingulate gyrus, and left caudate. These results elucidated ecstasy-related deficits, only some of which might be attributed to cannabis use. These ecstasy-specific effects may be related to the vulnerability of isocortical and allocortical regions to the neurotoxic effects of ecstasy
The effects of subordinates’ use of upward influence tactics on their supervisors’ job performance evaluations in Saudi Arabia: the significance of loyalty
No full textMost research examining the effects of subordinates’ use of upward influence tactics on supervisor job performance evaluations has been conducted in Western countries. In these contexts, it has been suggested that upward influence tactics bias supervisor ratings because they affect the quality of the relationship between supervisors and subordinates. This has primarily been explained in terms of supervisor liking. We suggest instead, that the particular cultural context in Saudi
Arabia emphasises loyalty as the primary indicator of relationship quality. Based on data we obtained from 389 matched
supervisor–subordinate dyads in Saudi Arabia, we found that five upward influence tactics; rational persuasion, ingratiation,
self-promotion, coalition and upward appeal had indirect effects on supervisor job performance ratings through subordinate loyalty. Our findings suggest cultural contexts can emphasise differing aspects of relational quality between supervisors and subordinates that potentially explain bias in supervisor job performance evaluations
Vintimille, le Calais italien, Maryline Baumard, lemonde.fr, 20/08/2016
No full textinfographie Le Monde, OIM (...) "Ces neuf migrants étaient tous montés dans le train de 9 h 33 à Vintimille, destination Cannes (Alpes-Maritimes). Ils étaient contents d’avoir déjoué la vigilance des policiers italiens qui empêchent la montée à bord. Mais à la gare de Menton-Garavan, juste après la frontière, les CRS français ont investi les wagons, contrôlé l’identité des personnes présentes et fait descendre les seuls passagers à la peau foncée. Ces derniers ont été alignés dehors pour êtr..
A Developmental Perspective on Facets of Impulsivity and Brain Activity Correlates from Adolescence to Adulthood
No full textEnduring alterations in response patterns in rats exposed to lead (Pb) during early development: I. Two-choice olfactory serial reversal task.
No full textExecutive "brake failure" following deactivation of human frontal lobe
No full textIn the course of daily living, humans frequently encounter situations in which a motor activity, once initiated, becomes unnecessary or inappropriate. Under such circumstances, the ability to inhibit motor responses can be of vital importance. Although the nature of response inhibition has been studied in psychology for several decades, its neural basis remains unclear. Using transcranial magnetic stimulation, we found that temporary deactivation of the pars opercularis in the right inferior frontal gyrus selectively impairs the ability to stop an initiated action. Critically, deactivation of the same region did not affect the ability to execute responses, nor did it influence physiological arousal. These findings confirm and extend recent reports that the inferior frontal gyrus is vital for mediating response inhibition
Artifactual fMRI group and condition differences driven by performance confounds
No full textAnalysis techniques comparing groups or conditions that vary in performance are open to a possible confound driven by those performance differences, if these errors are ignored. Disproportionate numbers of errors may either introduce noise into the signal of interest or confound the signal of interest with additional signal associated with specific error-related processes. Two inhibitory task datasets were reanalysed, one comparing young and elderly groups, the other comparing high and low conflict conditions within the same group of subjects. The data were analysed twice using event-related techniques, one treating correct and error responses separately, the other treating error responses as if they were correct. It was found that the activation maps differed considerably, with the inclusion of errors leading to many false positive and false negative activation clusters. Using performance as a covariate, analyses of covariance (ANCOVA) were used to try to correct these differences without success. Data simulations that varied the number of errors included in the analyses found that surprisingly few errors could significantly alter activation maps. Consequently, brain-imaging investigations that do not accommodate error contributions to functional signals are at risk of misinterpreting activation patterns
IMAGEN_DIS_Supplemental_Material_final – Supplemental material for Extending the Construct Network of Trait Disinhibition to the Neuroimaging Domain: Validation of a Bridging Scale for Use in the European IMAGEN Project
No full textSupplemental material, IMAGEN_DIS_Supplemental_Material_final for Extending the Construct Network of Trait Disinhibition to the Neuroimaging Domain: Validation of a Bridging Scale for Use in the European IMAGEN Project by Sarah J. Brislin, Christopher J. Patrick, Herta Flor, Frauke Nees, Angela Heinrich, Laura E. Drislane, James R. Yancey, Tobias Banaschewski, Arun L. W. Bokde, Uli Bromberg, Christian Büchel, Erin Burke Quinlan, Sylvane Desrivières, Vincent Frouin, Hugh Garavan, Penny Gowland, Andreas Heinz, Bernd Ittermann, Jean-Luc Martinot, Marie-Laure Paillère Martinot, Dimitri Papadopoulos Orfanos, Luise Poustka, Juliane H. Fröhner, Michael N. Smolka, Henrik Walter, Robert Whelan, Patricia Conrod, Argyris Stringaris, Maren Struve, Betteke van Noort, Yvonne Grimmer, Tahmine Fadai, Gunter Schumann, and Jens Foell in Assessment</p
The role of the pre-supplementary motor area in the control of action
No full textAlthough regions within the medial frontal cortex are known to be active during voluntary movements their precise role remains unclear. Here we combine functional imaging localisation with psychophysics to demonstrate a strikingly selective contralesional impairment in the ability to inhibit ongoing movement plans in a patient with a rare lesion involving the right pre-supplementary motor area (pre-SMA), but sparing the supplementary motor area (SMA). We find no corresponding delay in simple reaction times, and show that the inhibitory deficit is sensitive to the presence of competition between responses. The findings demonstrate that the pre-SMA plays a critical role in exerting control over voluntary actions in situations of response conflict. We discuss these findings in the context of a unified framework of pre-SMA function, and explore the degree to which extant data on this region can be explained by this function alone
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