http://repub.eur.nl/res/aut/23046/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/34907/ 2012-01-01T00:00:00Z Endophenotypes are intermediate phenotypes on the putative causal pathway from genotype to phenotype and can aid in discovering the genetic etiology of a disorder. There are currently very few suitable endophenotypes available for substance use disorders (SUD). The amplitude of the P300 event-related brain potential is a possible candidate. The present study determined whether the P300 amplitude fulfils two fundamental criteria for an endophenotype: (1) an association with the disorder (disease marker), and (2) presence in unaffected biological relatives of those who have the disorder (vulnerability marker). For this purpose, two separate meta-analyses were performed. Meta-analysis 1 investigated the P300 amplitude in relation to SUD in 39 studies and Meta-analysis 2 investigated P300 amplitude in relation to a family history (FH+) of SUD in 35 studies. The findings indicate that a reduced P300 amplitude is significantly associated with SUD (d=0.51) and, though to a lesser extent, with a FH+ of SUD (d=0.28). As a disease maker, the association between reduced P300 amplitude and SUD is significantly larger for participants that were exclusively recruited from treatment facilities (d=0.67) than by other methods (i.e., community samples and family studies; d=0.45 and 0.32, respectively), and larger for abstinent SUD patients (d=0.71) than for current substance users (d=0.37). Furthermore, in contrast to FH+ males, a P300 amplitude reduction seems not to be present in FH+ females (d=-0.07). Taken together, these results suggest that P300 amplitude reduction can be both a useful disease and vulnerability marker and is a promising neurobiological endophenotype for SUD, though only in males. Implications and future directions are discussed. http://repub.eur.nl/res/pub/25979/ 2011-04-08T00:00:00Z Rationale: Although risky decision-making is one of the hallmarks of alcohol use disorders, relatively little is known about the acute psychopharmacological effects of alcohol on decision-making processes. Objective: The present study investigated the acute effects of alcohol on neural mechanisms underlying feedback processing and outcome evaluation during risky decision-making, using event-related brain potentials (ERPs). Methods: ERPs elicited by positive and negative feedback were recorded during performance of a modified version of the Balloon Analogue Risk Task in male participants receiving either a moderate dose of alcohol (0.65 g/kg alcohol; n = 32) or a non-alcoholic placebo beverage (n = 32). Results: Overall, there was no significant difference in the mean number of pumps between the alcohol and the placebo condition. However, when analyzing over time, it was found that the alcohol group made more riskier choices at the beginning of the task than the placebo group. ERPs demonstrated that alcohol consumption did not affect early processing of negative feedback, indexed by the feedback-related negativity. By contrast, alcohol-intoxicated individuals showed significantly reduced P300 amplitudes in response to negative feedback as compared to sober controls, suggesting that more elaborate evaluation to losses was significantly diminished. Conclusions: These results suggest that alcohol consumption does not influence the ability to rapidly evaluate feedback valence, but rather the ability to assign sufficient attention to further process motivationally salient outcomes. Blunted P300 amplitudes may reflect poor integration of feedback across trials, particularly adverse ones. Consequently, alcohol may keep people from effectively predicting the probability of future gains and losses based on their reinforcement history. http://repub.eur.nl/res/pub/19390/ 2010-04-01T00:00:00Z Starting from an addiction model of obesity, the present study examined differences in attention for food-related stimuli and food intake between overweight/obese and normal-weight women under conditions of hunger and satiety. Twenty-six overweight/obese (BMI: 30.00 ± 4.62) and 40 normal-weight (BMI: 20.63 ± 1.14) females were randomly assigned to a condition of hunger or satiety. Three indexes of attention were employed, all including pictures of food items: an eye-tracking paradigm (gaze direction and duration), a visual probe task (reaction times), and a recording of electrophysiological brain activity (amplitude of the P300 event-related potential). In addition, the acute food intake of participants was assessed using a bogus taste task. In general, an attentional bias towards food pictures was found in all participants. No differences between groups or conditions were observed in the eye-tracking data. The visual probe task revealed an enhanced automatic orientation towards food cues in hungry versus satiated, and in overweight/obese versus normal-weight individuals, but no differences between groups or conditions in maintained attention. The P300 amplitude showed that only in normal-weight participants the intentional allocation of attention to food pictures was enhanced in hunger versus satiety. In hungry overweight/obese participants, the P300 bias for food pictures was not clearly present, although an increased food intake was observed especially in this group. In conclusion, various attention-related tasks yielded various results, suggesting that they measure different underlying processes. Strikingly, overweight/obese individuals appear to automatically direct their attention to food-related stimuli, to a greater extent than normal-weight individuals, particularly when food-deprived. Speculatively, hungry overweight/obese individuals also appear to use cognitive strategies to reduce a maintained attentional bias for food stimuli, perhaps in an attempt to prevent disinhibited food intake. However, in order to draw firm conclusions, replication studies are needed.