Aging but not arousal influences the effect of environmental noise on the span of attention.

In young samples environmental noise acts to reduce attention to low salience events. We asked whether noise would affect old individuals similarly. Furthermore, both aging and noise effects on performance have been attributed to changes in physiological arousal. Therefore, we also asked whether performance changes with noise and aging were necessarily associated with changes in physiological arousal. Young, middle-aged and older individuals (total N = 50) performed a dual task in the presence or absence of 90 dBA white noise. In noise relative to quiet, young and middle-aged but not older participants responded to low salience events less accurately. Neither self-report nor cardiovascular change unequivocally supported the view that general arousal induced the performance changes associated with noise or aging. Cardiovascular changes were controlled by engagement in the task, not by the presence or absence of noise. Age-related changes in preparation for infrequent events were related to vascular change. Alternatives to general arousal explanations were considered.