On the absence of response interference in choice reaction time tasks: Higher probable events

Two experiments are reported which investigated the possibility that the ‘higher probable’ to two stimulus-response (SR) events avoids the latency enhancing influence of pre-stimulus (Ex.1) or post-stimulus (Ex.2) response interference (RI) in choice reaction time (RT) tasks. The level of predictability associated with the higher probable event (0.6, 0.8), and the degree of competing response similarity (i.e., Hand Condition), were examined as possible factors which might influence RI avoidance. The results obtained indicated SR events which fall into the category of higher probable escape the influence of both pre-stimulus and post-stimulus RI provided their associated predictability level is high (0.8). This RI avoidance is not evident when predictability is low (0.6) [exception: between-hand finger responses, pre-stimulus RI] or for the ‘lesser probable’ SR events (0.4, 0.2). Generally, Hand Condition did not influence RI avoidance, nor did it alter RT size. Some implications are highlighted.