Academic journal article Perception and Psychophysics

Impact of Contingency Manipulations on Accessory Stimulus Effects

Academic journal article Perception and Psychophysics

Impact of Contingency Manipulations on Accessory Stimulus Effects

Article excerpt

Accessory tone stimuli facilitate response performance despite being irrelevant for the current task. In order to investigate which processes are affected by accessory stimuli, we presented accessory tones in a simple response time (RT) task while varying the contingencies between accessory stimulation and either responses (Experiment 1) or stimulus conditions (Experiment 2). Accessory tones speeded up responding to a larger degree when they were conjointly presented within go compared with no-go trials. In contrast contingency variation with stimulus conditions did not alter the impact of accessory stimuli. Additionally, accessory tones increased response force. Thus, we conclude that in simple RT tasks accessory tones influence response-related stages such as response selection and response execution rather than perceptual processes.

One of the oldest questions in psychology is how information from different sensory modalities is combined. For example, Todd (1912) presented combinations of light tone, and electrical shock stimuli, instructing participants to respond whenever they detected any stimulus. Response times (RTs) were reduced when bimodal rather than unimodal stimuli were presented. Such intersensory facilitation effects are quite robust, and they have been replicated in many different settings. For example, intersensory facilitation has been reported in tasks such as Todd's, in which participants must respond to stimuli from any modality (e.g., Diederich & Colonius, 2004; Gondan, Niederhaus, Rosier, & Röder, 2005; Hershenson, 1962; Miller, 1991). Intersensory facilitation has also been reported when instructionally irrelevant accessory stimuli on one modality (i.e., stimuli to which participants need not respond) are presented simultaneously with relevant target stimuli on another modality, especially when the irrelevant accessories are auditory stimuli (Bernstein, 1970; Doyle & Snowden, 2001). Finally, intersensory facilitation has also been found when auditory warning signals are presented prior to visual target stimuli (FernandezDuque & Posner, 1997; Sanders, 1980; Ulrich & Mattes, 1996; Zeigler, Graham, & Hackley, 2001).


Intersensory facilitation seems to be especially surprising when the accessory stimulus is irrelevant for the task that participants must perform. For example, consider a recent task used by Hackley and Valle-Inclan (1999). In titis study, participants were asked to indicate by pressing a left or a right response key whether the letter S or T was presented. The target letters were presented in different colors and one of the colors (e.g., violet) instructed participants not to respond in this trial. In this choice/no-go paradigm, accessory tone stimuli were presented in 50% of all dials. Even though the tone stimuli were not related to any visual stimulus feature and were thus completely irrelevant for the task, participants responded 34 msec faster in trials with a tone than in those without one.

Despite the many studies of intersensory facilitation by accessory stimuli (e.g., Bernstein, 1970; Bernstein, Rose, & Ashe, 1970; Bertelson & Tisseyre, 1969; Dufft & Ulrich, 1999; Keuss, Van der Zee, & Van den Bree, 1990; Nakano, 1997, 2002; Nickerson, 1973; Schmidt Gielen, & Van den Heuvel, 1984; Stahl & Rammsayer, 2005), it is still unclear how the accessory stimulus facilitates responding. One of the major debates concerns tiie issue of which processing stages are influenced by an accessory tone (Hackley & Valle-Inclan, 1998, 1999, 2003; Miller, Franz, & Ulrich, 1999; Nakano, 2002; Stahl & Rammsayer, 2005). In principle, at least three different positions can be identified.

First there is evidence that irrelevant auditory stimuli alter perception processes; for example, the perceived intensity of a visual stimulus is affected by concurrent auditory stimulation (Stein, London, Wilkinson, & Price, 1996). …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.