Alcohol and cognitive function: assessment in everyday life and laboratory settings using mobile phones.

BACKGROUND

Mobile phone (cellphone) technology makes it practicable to assess cognitive function in a natural setting. We assessed this method and compared impairment of performance due to alcohol in everyday life with measurements made in the laboratory.

METHODS

Thirty-eight volunteers (20 male, aged 18-54 years) took part in the everyday study, completing assessments twice a day for 14 days following requests sent by text messages to the mobile phone. Twenty-six of them (12 male, aged 19-54) took part in a subsequent two-period crossover lab study comparing alcohol with no alcohol (placebo).

RESULTS

Everyday entries with 5 or more units of alcohol consumed in the past 6 hours (inferred mean blood alcohol concentration 95 ml/100 ml) showed higher scores for errors in tests of attention and working memory compared with entries with no alcohol consumed that day. Response times were impaired for only 1 test, sustained attention to response. The laboratory comparison of alcohol (mean blood alcohol concentration 124 mg/100 ml) with placebo showed impairment to both reaction time and error scores for all tests. A similar degree of subjective drunkenness was reported in both settings.

CONCLUSIONS

We found that mobile phones allowed practical research on cognitive performance in an everyday life setting. Alcohol impaired function in both laboratory and everyday life settings at relevant doses of alcohol.