Reasoning deficits among illicit drug users are associated with aspects of cannabis use.

Deficits in deductive reasoning have been observed among ecstasy/polydrug users. The present study seeks to investigate dose-related effects of specific drugs and whether these vary with the cognitive demands of the task. One hundred and five participants (mean age 21.

Fuzzy risk perception: correlates of "fuzzy" and specific measures of outcome likelihood in young drinkers.

Promoting informed choices about alcohol use requires understanding the nature of drinkers' risk perceptions and how these influence decision-making. Fuzzy trace theory states that people use imprecise "fuzzy" risk representations, which are based on the broad cognitive and affective meanings of risk-related experiences, whereas traditionally used measures request precise unitary estimations. Fuzzy representations may be less affected by defensive self-enhancement biases inherent in unitary estimates and better predictors of decision outcomes because they better reflect risk-related affect.

Risk perception, fuzzy representations and comparative optimism.

Rather than a unitary value, individuals may represent health risk as a fuzzy entity that permits them to make a number of specific possible estimates. Comparative optimism might be explained by people flexibly, using such a set to derive optimistic risk estimates. Student participants were asked to rate the likelihood of eight harmful alcohol-related outcomes occurring to themselves and to an average student.