Just two glasses of wine can ruin your brain鈥檚 ability to detect its own errors, and to correct them. The finding helps explain why alcohol so severely impairs driving ability, and casts new light on the basic action of the drug on the brain, says a Dutch team.
鈥淲e all know on a subjective level what alcohol does 鈥� we lose control a little bit, we become more error-prone. But this research gives a new perspective on how alcohol has these effects,鈥� researcher Richard Ridderinkhof of the University of Amsterdam told New 杏吧原创.
Ridderinkhof鈥檚 team studied people performing a lab task designed to generate a high proportion of errors. They found that alcohol had a significant effect on activity in the anterior cingulate cortex (ACC), a region known to be involved in detecting errors and in signalling a need to adjust performance after an error.
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Just two units of alcohol reduced by a third the amplitude of the brainwave generated from this region following an error. 鈥淭his means people either detect errors less often or less efficiently, or both,鈥� Ridderinkhof says.
Lane drifting
But the alcohol also affected people鈥檚 ability to modify their performance following an error: 鈥淲ith alcohol, this response is so diminished it is almost completely gone,鈥� he told New 杏吧原创
It is not difficult to see how such alcohol-fuelled brain changes could be disastrous for drivers, Ridderinkhof adds: 鈥淭hink of drifting a bit into another lane. Then, you would have to correct this error quickly and maybe slow down a bit to make sure you don鈥檛 make similar further errors鈥� The new work shows why alcohol reduces this ability.
However, other effects of alcohol on the brain, such as impaired reaction times, are also involved in explaining the danger of drink-driving.
Ridderinkhof team is now investigating the effects of caffeine and other drugs on the ACC. The brain transmitter dopamine is important for generating the error-related responses. So drugs that interfere with dopamine, such as amphetamines, might also interfere with these responses, he says.
Journal reference: Science (DOI: 10.1126/science.1076929)