Decision-makers effortlessly balance the need for urgency against the need for caution. Theoretical and neurophysiological accounts have explained this tradeoff solely in terms of the "quantity" of evidence required to trigger a decision (the "threshold"). This explanation has also been used as a benchmark test for evaluating…

Discusses changes occurring in two-, four-, and six-month-old infants' visual attention span, through a series of experiments examining their ability to orient to peripheral visual stimuli. The results obtained were consistent with the hypothesis that infants get faster with age in shifting attention to a spatial location. (AA)