Dissociable effects of a single dose of ecstasy (MDMA) on psychomotor skills and attentional performance.

Ecstasy (3,4-methylenedioxymethamphetamine, MDMA) is a psychoactive recreational drug widely used by young people visiting dance parties, and has been associated with poor cognitive function. The current study assessed the influence of a single dose of MDMA 75 mg and alcohol 0.5 g/kg on cognition, psychomotor performance and driving-related task performance. Twelve healthy recreational ecstasy users participated in an experimental study conducted according to a double-blind, double-dummy, placebo-controlled three-way cross-over design. MDMA improved psychomotor performance, such as movement speed and tracking performance in a single task, as well as in a divided attention task. MDMA impaired the ability to predict object movement under divided attention. However, the inability to accurately predict object movement after MDMA may indicate impairment of particular performance skills relevant to driving. There was no effect of MDMA on visual search, planning or retrieval from semantic memory.

An age-embedding effect: time sensitivity and time insensitivity when pricing health benefits.

Benefits are often extended over time. One determinant of this benefit duration is how long a person will live to enjoy them. In four studies, we investigated whether people are sensitive to age when pricing benefits that will last for the remainder of one's life. In Study 1 drivers gave their willingness-to-pay (WTP) to cure a medical condition which would stop them from driving. Results showed an age-embedding effect: WTP was unrelated to the estimated number of driving years left. Study 2 tested whether age-embedding arose because people have a lot of information about themselves which dilutes the impact of age on their valuations. In Studies 3 and 4 we investigated whether people believed that age was an important consideration, or if they failed to properly incorporate it into their judgment. Results indicate that little weight is given to age when making individual pricing decisions, although people did not believe it was normatively irrelevant.