Recreational Cocaine Use May Reduce Attentional Scope

The recreational use of cocaine has rapidly increased over the past few years becoming Europe’s second preferred recreational drug habit after smoking cannabis.

Cocaine is no longer considered an “elite” drug but is affordable for all, especially for recreational use. It is therefore likely that the recreational use of cocaine will become a public health issue in the next few years.  


Researchers at Leiden University and the University of Amsterdam, led by Lorenza Colzato, employed the “global-local task” to measure whether recreational cocaine users and cocaine-free controls differ systematically with respect to their attentional scope. The task requires participants to respond to either global or local characteristics of hierarchically constructed visual stimuli (e.g., larger shapes made of smaller shapes), so that the efficiency of global and local processing can be compared. The results show that recreational cocaine users attend more to the local aspects of perceived events than controls do, indicating a reduced scope of visual attention.

The study is the first of its kind to systematically investigate the attentional scope in recreational users, i.e. those who don’t meet the criteria for abuse or dependency but who take cocaine (usually by snorting) on a monthly basis (1 to 4 grams). Given the seemingly small quantities of cocaine involved, the findings of this study are rather worrying. Everyday behavior requires an “open” scope of attention in order to be able to adapt and to restructure in response to changing environmental demands. Moreover, a reduced scope of attention may be associated with the perpetuation of the use of the drug, and may help explaining why it is so difficult for cocaine users to change their compulsive drug-related habits and to enter and stay in rehabilitation therapy.

Read more in the study published June 25 in the online, open-access journal .

Last Modified: 19-07-2010