2012 年 24 巻 3+4 号 p. 45-51
It is generally admitted that alcohol drinking elicits the decline of cognitive function. There was little literature mentioned about the relationship between cognitive level and alcohol intake in a quantitative way. The P300 is one of the event related potentials (ERP) and can be used for the indicator of cognitive function. The P300 evoked by auditory Odd-ball task was measured in 10 volunteers. After baseline measurement, the subjects drank alcohol, equivalent to 350 mL of beer (17.5mL of ethanol). Five minutes later, the breath alcohol concentration was checked, and P300 was recorded. If needed, the additional 350mL of beer or equivalent ethanol containing beverages was taken, and P300 was measured repeatedly until the breath concentration reached 1mg⁄L or the participants or⁄and researchers felt that volunteers got drunk enough for the safety. After alcohol loading, the latencies of P300 were significantly prolonged (p<0.001). This phenomenon means a delay of the recognition. Also, the amplitudes of P300 were significantly reduced (p<0.005). This indicates a fall of the cognitive level. Moreover, the positive relationship between the breath alcohol concentrations and delays of P300 latency was clearly observed (p<0.05). This relation was also admitted in the declines of P300 amplitude and breath alcohol levels (p<0.05). It was confirmed that cognitive function decreased in proportion to the amount of the alcohol drinking.
