Neuroanatomical variations as a function of experience in a complex daily task: A VBM and DTI study on driving experience.

Complex tasks require the learning and integration of multiple cognitive, sensory, and psychomotor skills for correct execution. Driving-related skills are developed step by step through the increase of mileage driven and the accumulation of practice in different traffic situations. The acquisition of these skills should be reflected in the brain structure. However, no previous studies have explored brain structural variations associated with driving experience. The aim of the present study was to investigate whether driving frequency, defined as average annual driving mileage, is related to neuroanatomical variations in gray matter (GM) volume and white matter (WM) integrity using voxel-based morphometry (VBM) and DTI-based fractional anisotropy (FA), respectively. We recruited 83 drivers with variable range of annual driving mileage and controlled for age, sex, handedness, IQ, time since the acquisition of driving license, use of motorcycles/mopeds and bicycles, perceived driving skills, and subjective probability of having an accident. Our results showed variations in white matter FA as a function of mileage driven. Driving experience was related to a significant increase of FA in parts of the right hemisphere superior and inferior longitudinal fasciculus, anterior thalamic radiation, forceps majors, inferior fronto-occipital fasciculus, and corticospinal tract. No significant differences were observed in gray matter volumes. FA variations were found in brain regions that have been associated with cognitive, visual, and motor processes necessary for skilled performance in driving. These results suggest that variations in white matter diffusivity can underlie the development of driving skills and safer driving.

Excessive body fat linked to blunted somatosensory cortex response to general reward in adolescents.

BACKGROUND AND AIMS: The brain reward system is key to understanding adolescent obesity in the current obesogenic environment, rich in highly appetising stimuli, to which adolescents are particularly sensitive. We aimed to examine the association between body fat levels and brain reward system responsivity to general (monetary) rewards in male and female adolescents. METHODS: Sixty-eight adolescents (34 females; mean age (s.d.)= 16.56 (1.35)) were measured for body fat levels with bioelectric impedance, and underwent a functional magnetic resonance imaging (fMRI) scan during the Monetary Incentive Delay (MID) task. The MID task reliably elicits brain activations associated with two fundamental aspects of reward processing: anticipation and feedback. We conducted regression analyses to examine the association between body fat and brain reward system responsivity during reward anticipation and feedback, while controlling for sex, age and socioeconomic status. We also analysed the moderating impact of sex on the relationship between fat levels and brain responsivity measures. Brain imaging analyses were corrected for multiple comparisons, with a cluster-defining threshold of P<0.001, and minimum cluster size of 38 contiguous voxels. RESULTS: Higher body fat levels were associated with lower activation of the primary somatosensory cortex (S1) and the supramarginal gyrus during reward feedback after controlling for key sociodemographic variables. Although we did not find significant associations between body fat and brain activations during reward anticipation, S1/supramarginal gyrus activation during feedback was linked to increased negative prediction error, that is, less reward than expected, in illustrative post hoc analyses. Sex did not significantly moderate the association between body fat and brain activation in the MID task. CONCLUSIONS: In adolescents, higher adiposity is linked to hypo-responsivity of somatosensory regions during general (monetary) reward feedback. Findings suggest that adolescents with excess weight have blunted activation in somatosensory regions involved in reward feedback learning.

Admission to Intensive Care for a trauma related to alcohol or drugs, a 'teachable moment' for the beginning of a change. / Ingreso en cuidados intensivos por un traumatismo relacionado con el consumo de alcohol o drogas, un «momento propicio de enseñanza¼ para el inicio del cambio.

OBJECTIVES: To estimate how many of the trauma patients admitted to ICU would be candidates for a secondary prevention programme for trauma related to alcohol or drug use by brief motivational intervention and to define what factors prevent that intervention being performed. METHODS: All 16-70year old trauma patients (n=242) admitted to ICU in 32 non-consecutive months (November 2011 to March 2015) were included in the study, coinciding with the implementation of a screening and brief motivational intervention programme for trauma patients related to substance consumption. The programme includes screening for exposure to substances at admission. Sociodemographic and clinical variables were collected prospectively. RESULTS: The screening for substances was not performed in 38 (15.7%) of all admitted patients. Of the patients screened, 101 (49.5%) were negative. The variables that in greater proportion impeded intervention between screening positive patients were neurological damage due to the trauma with 23 patients (37.1%) and prior psychiatric disorder with 18 (29%). Both variables were associated with substance consumption: negatives 9.9% vs positive 22.3% (P=.001) and negatives 3% vs positive 17.5% (P=.016) respectively. The number of candidates for motivational intervention was 41, 16.9% of all admitted patients. CONCLUSIONS: Almost 2 out of 10 patients were potential candidates. The factors that in a greater proportion precluded the intervention were the same as those associated with consumption. Mortality in ICU was associated with non-compliance with the screening protocol.