Time perception : the Stroop effect as an attentional variable

Four similar experiments were conducted to test cognitive hypotheses of time perception. Experiments I, II, and III utilized the duration judgment methods of Production (MP), Reproduction (MR), and Verbal Estimation (MVE) respectively, with 20 male and 20 female undergraduates in each experiment, while experiment IV had 4 subjects and was of a psychophysical nature. The design for experiments I, II, and III was a 2 X 4 split-plot factorial. Sex was the between-subject factor while the within factor was the conditions of No Strategy (A), Strategy (B), Colored-dot (C), and the Stroop (D). These four conditions were chosen such that the amount of attention and information processing required to work the tasks increased substantially from Condition A though Condition D. Ornstein’s storage size hypothesis (1969) predicts ascending duration judgments across conditions while an attentional model predicts descending duration judgments. Three hypotheses were tested: (1) A cognitive time-keeping strategy (Condition B) will yield more accurate duration judgments than a no-time keeping condition (Condition A). (2) Time duration judgments most closely approximate the attentional model and will thus follow a decreasing linear trend across conditions A through D. (#) Duration judgments will be more variable in the Stroop condition (D) than in the Colored-dot condition (C). Results showed a time-keeping strategy to be superior in accuracy to no strategy in experiments I, II, and III. Experiments I (MP) and II (MR) followed the attentional model in that a significant decreasing linear trend occurred across conditions A through D with no significant departure from linearity. However, even though Experiment III (MVE) showed a significant decreasing linear trend, it also had a significant quadratic component. Stroop condition (D) judgments were no more variable than Colored-dot condition (C) judgments. The method of estimation showed a significant effect in the psychophysical experiment (IV). The results were seen as generally favoring the attentional model of time perception.