A single dose of cocaine enhances prospective memory performance

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychopharmacology

Background:

• Prospective memory, the ability to remember future intentions, is known to be impaired by cannabis.
• The acute effects of cocaine on prospective memory remain largely uninvestigated.
• It is unclear if observed memory changes stem from specific memory alterations or broader cognitive effects like attention and arousal.

Purpose of the Study:

• To investigate the specific effects of cocaine and cannabis on prospective memory.
• To determine if drug-induced changes in prospective memory are memory-specific or linked to general cognitive changes in attention and arousal.

Main Methods:

• A placebo-controlled, three-way, cross-over study was conducted with 15 regular poly-drug users.
• Participants received oral cocaine (300 mg), vaporized cannabis (300+150 µg/kg), or placebo.
• Prospective memory was assessed using an event-based task, attention via a divided attention task, and arousal via the Profile of Mood States questionnaire.

Main Results:

• Cocaine significantly enhanced prospective memory, attention, and subjective arousal.
• Cannabis impaired prospective memory and attention, with the lowest performance and arousal levels observed under this condition compared to placebo and cocaine.
• Prospective memory performance showed only a weak positive association with attention and arousal measures.

Conclusions:

• Cocaine's enhancement of prospective memory is not solely attributable to increased attention or arousal.
• The findings suggest that cocaine directly impacts the neural networks underlying prospective memory.
• Cannabis, in contrast, appears to impair prospective memory, attention, and arousal.