Aging and Vigilance: Who Has the Inhibition Deficit?

Abstract

The present study compared 18 younger (M = 21.00 years) and 17 older adults (M = 64.29 years) in a modified vigilance task that required the inhibition of a routinized response. The task was a 50-min simulation of industrial inspection, wherein observers were presented with simple displays labeled “good” and “bad” parts. General linear modeling indicated that younger adults showed a doubling of inhibition failures over time (from 19% to 43%); older adults' inhibition failures held constant at approximately 17.5%. In both age groups, those who responded most quickly were also most error-prone. A control experiment, using the traditional vigilance task requiring a response to infrequent “bad” parts, found only small age differences in accuracy and these also favored older adults. This research suggests that younger adults may demonstrate larger inhibition failures when the routinized responses on simple tasks must be suppressed. There are several implications for theory, industrial design, and cognitive assessment.

The authors would like to offer sincere thanks to David Stewart, who helped with programming this experiment, support for which was provided by grants from the Natural Science and Engineering Research Council of Canada and the Canadian Institutes for Health Research.

Notes

¹In a control experiment, 12 younger adults (M = 23.67 years, SD = 5.37 years) and 12 older adults (M = 64.41 years, SD = 7.53 years) completed a conventional vigilance task. The task was identical to that described earlier with one exception: people responded to “bad” parts that had a probability of .05. Results indicated that RTs were longer than in the main experiment, likely because responses were rare. More importantly, both younger and older adults were quite accurate in responses to “bad” parts, with average accuracy near 98%. Older adult were more accurate on “good” parts; that is, they made fewer false alarms. There was no interaction of age and time on task for any variable. These results replicate the aging literature to date, in demonstrating no age deficits in traditional vigilance tasks.