Covert signs of expectancy in serial reaction time tasks revealed by event-related potentials

Author(s): Leuthold, H., Soetens, E.

Journal/Book: Percept Psychophys. 1999; 61: 1710 Fortview Rd, Austin, TX 78704, USA. Psychonomic Soc Inc. 342-353.

Abstract: Choice reaction time is strongly determined by the sequence of preceding stimuli. With long response-stimulus intervals (RSIs), a cost-benefit pattern is observed, which has been related to expectancy, whereas with short RSIs a benefit-only pattern emerges, possibly because of automatic facilitation. In the present study, event-related potentials were recorded while subjects performed serial choice responses to visual and auditory stimuli at long and short RSIs. As expected, reaction times displayed cost-benefit and benefit-only patterns at long and short RSIs, respectively. In contrast, sequential effects in event-related potential amplitudes displayed a cost-benefit pattern, unaffected by the RSI. The results demonstrate that an expectancy-like mechanism is always active in serial tasks but appears to influence performance only when the RSI is long.

Note: Article Sommer W, Humboldt Univ, Inst Psychol, Hausvogteipl 5-7, D-10117 Berlin, GERMANY

Keyword(s): DIRECT PARAMETER SPECIFICATION; 2-CHOICE REACTION-TIME; STIMULUS SEQUENCE; POP-OUT; ATTENTION

Zurück | Weiter