Coffee can ’t fix all the cognitive impairments caused by a bad night’s sleep

In this study, the participants had to keep track of where they were in a seven-step screen-based task. The participants were initially trained in how to complete the steps correctly, in the right order, and then expected to remember this information. Every so often, they were interrupted part-way through a sequence and asked to complete another brief task. They then went back to the original task. To resume correctly, and complete the steps in the right order, they had to remember where they’d broken off. The researchers counted the number of mistakes that they made. After this, some participants were sent home to sleep as normal while the others were kept awake overnight in the lab. The next morning, the sleepers came back in, and all were given a capsule that contained either 200mg of caffeine or a placebo. Then they completed a second round of visual vigilance and place-keeping tests. The differences in the results were clear. Sleep deprivation (without caffeine) impaired performance on both tasks, as expected. With caffeine, though, sleep-deprived people did just as well on the visual vigilance task as those who’d had a good night’s sleep (without morning caffeine). Caffeine clearly worked very well to fix this particular deficit. (Though those who’d slept and consumed caffeine did best of all.) However, this wasn’t the case for the place-keeping task. A few did get some benefit from caffeine — the people who were worst at the task. But most of the s...
Source: BPS RESEARCH DIGEST - Category: Psychiatry & Psychology Authors: Tags: Drugs Sleep and dreaming Source Type: blogs