Latent inhibition (LI) is a preconscious gating mechanism that allows animals with complex nervous systems to ignore stimuli previously experienced as irrelevant. Decreased LI has been associated with dopaminergic agonist intoxication and schizophrenic conditions. We previously demonstrated reductions in LI among individuals characterized by higher levels of trait Openness and Extraversion. This study replicates our previous findings, using another university student sample (Total N=79). Participants characterized by decreased LI (N=23) were significantly more Open (Mean=36.7, S.D.=5.4; N=23) and Extraverted (Mean=31.4, S.D.=7.1) than those who manifested intact LI (N=54; Openness Mean=33.7, S.D.=7.1, t=1.80, P < 0.04, d=0.44; Extraverted Mean=28.2, S.D.=6.6, t=1.85, P < 0.04, d=0.46). The two groups were better differentiated, however, by the simple additive combination of z-scored Extraversion and Openness, deemed Plasticity (P < 0.01, d=0.57). Differences between the two groups also emerged with regards to Gough's Creative Personality Scale [J. Pers. Soc. Psychol. 37 (1979) 1398], with the Low LI group scoring higher than the High LI group (P < 0.03, d=0.46).

No abstract

Binge drinking is associated with impaired cognitive functioning, but the relationship of cognitive impairments and white matter integrity is less known. We used diffusion tensor imaging (DTI) to investigate the relationships of binge drinking, whole brain white matter integrity and cognitive performance during young adulthood (18 to 25 years), a period of continued brain development in two sessions 1 year apart. Binge drinkers (n = 20) and non-binge drinkers (n = 20) underwent DTI and completed measures of spatial working memory and motor impulsivity. Fractional anisotropy (FA), a measure derived from DTI, was estimated from whole brain and from five segments of the corpus callosum (CC): prefrontal, premotor/supplementary motor, motor, (SMA) sensory and parietal/temporal/occipital (PTO). FA was lower for binge than for non-binge men but not women at Session 1 and 2 for all measurements except for FA in the motor segment, which was significantly increased from Session 1 to Session 2. Lower FA in the prefrontal and PTO CC segments was associated with higher binge score, whereas lower FA in all five segments was associated with greater drug use in men and worse spatial working memory both in men and women. These findings extend the literature by showing that in early adulthood, binge drinking and drug use are linked with degradations in neural white matter and that compromised white matter at this period of brain development is linked with impaired cognitive functioning.