ターゲットに対する反応回数は遂行成績並びに視覚的注意に影響するのか

抄録

Visual attention refers to cognitive functions for selecting task-relevant information and filtering out task-irrelevant information. Psychological research on visual attention has utilized congruency effects observed in Stimulus-Response compatibility paradigms, such as the Stroop task, the Flanker task, and the Simon task as the benchmark for investigating cognitive control. A number of studies (e.g., Egner, 2007) have demonstrated that the congruency effect is larger when congruent trials appear frequently within a given block than when they appear infrequently. This phenomenon is termed the proportion congruency (PC) effect, which is considered to reflect fluctuations in visual selectivity. Recently, however, a number of researchers have challenged the view that the PC effect reflects the modulation of visual selectivity. Schmidt (2013) for example argued that the PC effect is driven by performance improvements based on learning predictive relationships between stimuli and responses, rather than by the modulation of visual selectivity. It is notably unclear whether performance improvements are caused by increased contingency of a specific stimulus-response, or high response frequency resulting from the increased contingency in a block. This study was designed to examine the effect of response frequency on Simon task performance by manipulating the number of responses (pushing response buttons) to a target in the Simon task. More specifically, right-handed undergraduate and graduate students (N = 16) were requested to press a key once for a specific target (e.g., red circle) and press the key twice for the other target (e.g., green circle). Our results demonstrated that reaction times and error rates were not dependent on the number of reactions. This finding suggests that performance improvement is caused by contingency learning of stimulus-response pairs and not by the high response frequency.