ABSTRACT

Drugs, fatigue, illness, shift-work, noise, depression, stress, and unusual environments such as space or the deep sea affect one's ability to think, learn, remember, decide, and react. More succinctly, environmental and physiological stressors, such as these, affect cognition. We know this from anecdotes: Coffee makes us alert; alcohol slows us down; noise makes it difficult to focus. We also know this from controlled studies in which individuals are repeatedly tested on a battery of behavioral measures (e.g., Kennedy, Turnage, Wilkes, & Dunlap, 1993). In such studies, changes in performance on the battery coincide with changes in the level of the stressors. For example, the reaction time of deep-sea clivers slows with the air mixture (Logie & Baddeley, 1983). Fatigue leads to increased memory lapses, and a general slowing down (Koslowsky & Babkoff, 1993).