Current Issue : January - March Volume : 2014 Issue Number : 1 Articles : 4 Articles
Episodic memory refers to the capacity to bind multimodal memories to constitute a unique\r\npersonal event. Most developmental studies on episodic memory focused on one specific\r\ncomponent, i.e., the core factual information.The present study examines the relevance of a\r\nnovel episodic paradigm to assess its developmental trajectories in a more comprehensive\r\nway according to the type of association (item-feature, item-location, and item-sequence\r\nassociations) with measures of both objective and subjective recollection.We conducted\r\na behavioral study aimed at testing the effects of age in a large sample of 160 children,\r\nadolescents, and young adults (6ââ?¬â??23 years old).We confronted the behavioral data to the\r\nneural correlates in a subgroup of 30 children using voxel-based morphometry. Behavioral\r\ndata outlined differential developmental trajectories according to the type of association,\r\nwith a continuous increase of factual associative memory efficiency until 10 years, a linear\r\nincrease of performance in spatial associative memory that pursues until early adulthood\r\nand an abrupt increase in temporal associative memory efficiency between 9 and 10.\r\nRegarding recollection, measures showed a more pronounced enhancement from 9 to\r\n10 years. Hence, behavioral data highlight a peculiar period in late childhood (8ââ?¬â??10 years\r\nold) crucial for the developmental time course of episodic memory. Regarding structural\r\ndata, we found that the improvement of associative memory efficiency was related to a\r\ndecrease in gray matter volume in a large cerebral network including the dorsolateral and\r\nventrolateral prefrontal cortex (and superior and anterior temporal regions), and the hippocampus\r\nbilaterally. These data suggest that multimodal integration would probably be\r\nrelated to the maturation of temporal regions and modulated by a fronto-parietal network.\r\nBesides, our findings emphasize the relevance of the present paradigm to assess episodic\r\nmemory especially in the clinical setting...
Following the recognition of its role in sensory-motor coordination and learning, the\r\ncerebellum has been involved in cognitive, emotional, and even personality domains.\r\nThis study investigated the relationships between cerebellar macro- and micro-structural\r\nvariations and temperamental traits measured by Temperament and Character Inventory\r\n(TCI). High resolution T1-weighted, and Diffusion Tensor Images of 100 healthy subjects\r\naged 18ââ?¬â??59 years were acquired by 3 Tesla Magnetic Resonance scanner. In multiple\r\nregression analyses, cerebellar Gray Matter (GM) or White Matter (WM) volumes, GM\r\nMean Diffusivity (MD), and WM Fractional Anisotropy (FA) were used as dependent\r\nvariables, TCI scores as regressors, gender, age, and education years as covariates.\r\nNovelty Seeking scores were associated positively with the cerebellar GM volumes and\r\nFA, and negatively with MD. No significant association between Harm Avoidance, Reward\r\nDependence or Persistence scores and cerebellar structural measures was found. The\r\npresent data put toward a cerebellar involvement in the management of novelty....
Gambling is characterized by cognitive distortions in the processing of chance and skill\r\nthat are exacerbated in pathological gambling. Opioid and dopamine dysregulation is\r\nimplicated in pathological gambling, but it is unclear whether these neurotransmitters\r\nmodulate gambling distortions. The objective of the current study was to assess the\r\neffects of the opioid receptor antagonist naltrexone and the dopamine D2 receptor\r\nantagonist haloperidol on gambling behavior. Male recreational gamblers (n = 62) were\r\nassigned to receive single oral doses of naltrexone 50mg, haloperidol 2mg or placebo,\r\nin a parallel-groups design. At 2.5 h post-dosing, participants completed a slot machine\r\ntask to elicit monetary wins, ââ?¬Å?near-misses,ââ?¬Â and a manipulation of personal choice, and\r\na roulette game to elicit two biases in sequential processing, the gamblerââ?¬â?¢s fallacy and\r\nthe hot hand belief. Psychophysiological responses (electrodermal activity and heart rate)\r\nwere taken during the slot machine task, and plasma prolactin increase was assessed.\r\nThe tasks successfully induced the gambling effects of interest. Some of these effects\r\ndiffered across treatment groups, although the direction of effect was not in line with\r\nour predictions. Differences were driven by the naltrexone group, which displayed a\r\ngreater physiological response to wins, and marginally higher confidence ratings on\r\nwinning streaks. Prolactin levels increased in the naltrexone group, but did not differ\r\nbetween haloperidol and placebo, implying that naltrexone but not haloperidol may\r\nhave been functionally active at these doses. Our results support opioid modulation of\r\ncognition during gambling-like tasks, but did not support the more specific hypothesis that\r\nnaltrexone may act to ameliorate cognitive distortions....
Intermediate endophenotypes emerge as an important concept in the study of schizophrenia.\r\nAlthough research on phenotypes mainly investigated cognitive, metabolic or\r\nneurophysiological markers so far, some authors also examined the motor behavior anomalies\r\nas a potential trait-marker of the disease. However, no research has investigated social\r\nmotor coordination despite the possible importance of its anomalies in schizophrenia. The\r\naim of this study was thus to determine whether coordination modifications previously\r\ndemonstrated in schizophrenia are trait-markers that might be associated with the risk for\r\nthis pathology. Interpersonal motor coordination in 27 unaffected first-degree relatives of\r\nschizophrenia patients and 27 healthy controls was assessed using a hand-held pendulum\r\ntask to examine the presence of interpersonal coordination impairments in individuals at\r\nrisk for the disorder. Measures of neurologic soft signs, clinical variables and neurocognitive\r\nfunctions were collected to assess the cognitive and clinical correlates of social\r\ncoordination impairments in at-risk relatives. After controlling for potential confounding variables,\r\nunaffected relatives of schizophrenia patients had impaired intentional interpersonal\r\ncoordination compared to healthy controls while unintentional interpersonal coordination\r\nwas preserved. More specifically, in intentional coordination, the unaffected relatives of\r\nschizophrenia patients exhibited coordination patterns that had greater variability and in\r\nwhich relatives did not lead the coordination. These results show that unaffected relatives\r\nof schizophrenia patients, like the patients themselves, also present deficits in intentional\r\ninterpersonal coordination. For the first time, these results suggest that intentional interpersonal\r\ncoordination impairments might be a potential motor intermediate endophenotype\r\nof schizophrenia opening new perspectives for early diagnosis....
Loading....