Washington: Researchers at the University of Illinois at Chicago have found that moderate intoxication helps a person notice minor changes in a visual scene.
During tests of "change blindness," the inability to notice minor changes, intoxicated participants detected as many changes as sober subjects and with shorter response times.
"Both the sober and drunk people find the same number of changes, but drunk people find them faster," said Jennifer Wiley, professor of psychology at UIC and senior author on the study.
Two experiments comprised the new study. First, 48 males were given a baseline task-set to make sure the drinking and non-drinking groups were equal at the outset.
The drinking group then watched an animated movie while consuming vodka and cranberry juice until they reached approximately .08 percent blood alcohol content-legal intoxication. The nondrinking group watched the same movie.
Researchers then challenged each group using a flicker paradigm (going back and forth between two versions of the same image with one small change) in eight rounds of the test. Each round featured an everyday setting, such as a farmers market or an office. Participants had to indicate when they noticed an item change, and identify it.
"Our suspicion is that the sober people are using a more systematic, methodical strategy, and the drunk people are waiting for the `pop out,`" Wiley said.
A second experiment, using working memory tasks-which require focused attention-proved more difficult for the intoxicated group. These tests require remembering sequences of letters or shapes while performing another task, such as solving a math problem, at the same time.
"These tests require you to go back and forth between two tasks, which means you need to be directing your attention. So there is a lot of updating, and a lot of back and forth. Drunk people are less able to do this, and they did 15 to 30 percent worse on these tasks," Wiley said.
Co-author Gregory Colflesh, now a postdoctoral researcher at the University of Maryland, said the findings "nicely supplement our previous research illustrating that moderate intoxication improved creativity."
In that study, Wiley, Colflesh, and UIC graduate student Andrew Jarosz found that participants who were slightly under the .08 percent legal limit for blood alcohol outperformed sober subjects in solving word association problems.
Wiley stated for some tasks, like change detection and creative problem-solving, "you are sometimes better off not trying to direct yourself to find an answer."
The study was published online in the journal Consciousness and Cognition.