Department of Psychology

On distinguishing human behavior by means of their mutual interference

Funded by the "Deutsche Forschungsgemeinschaft" (DFG; German Research Foundation) Grants Ja2307/1-1, 1-2

Humans show an enormous variety of behavior: From simple, unavoidable reflexes to complex actions, i.e.; behavior performed with a particular purpose and intention. Regarding the latter, psychologists have made an idealized distinction in stimulus- and goal-based action. At present, various approaches and ideas are discussed in relation to commonalities and distinctions of these action types. Yet, the evidence is mixed and leaves a controversial picture.

In different fields of human cognition, e.g. memory, the investigation of interference has been proven fruitful, and the present project aims to use the degree of interference as a means for an empirical distinction of various types of behavior. To this end, classical dual-task paradigms are employed, and combined with tasks that are commonly used to investigate reflexes and stimulus- or goal-based actions. Primary questions of the project are: Can reflexes be distinguished from action on the basis of (non-)existing interference? Do stimulus- and goal-based actions differ in their degree of interference? What are the causes for the reported differences in reaction times between stimulus- and goal-based actions?

Results so far show: First, in contrast to actions, reflexes do not show any signs of interference in a dual-task situation. Hence, the existence of an intention appears to be necessary for interference to occur. Secondly, there is little reason to assume differences in the degree of interference between two putatively different types of actions. Although the reaction time differences between forced- and free-choice tasks and common dual-task costs can be replicated, the amount of these costs (as an indicator for the degree of interference) was equal for both action types. Further, a study suggests a perceptual reason for the observed reaction time differences, such as a higher sensitivity for appropriate environmental conditions, as would be assumed against the background of Gollwitzer’s distinction between a goal intention and an implementation intention.

Recent publications:

Janczyk, M. (2016). Die Rolle von Handlungszielen bei der Entstehung von Doppelaufgabenkosten. Psychologische Rundschau, 67, 237-249.

Janczyk, M., Dambacher, M., Bieleke, M., & Gollwitzer, P.M. (2015). The benefit of no choice: Goal-directed plans enhance perceptual processing. Psychological Research, 79, 206-220.

Janczyk, M., Nolden, S. & Jolicoeur, P. (2015). No differences in dual-task costs between forced- and free-choice tasks. Psychological Research, 79, 463-477.

Janczyk, M., Pfister, R., Wallmeier, G., & Kunde, W. (2014). Exceptions from the PRP effect? A comparison of prepared and unconditioned reflexes. Journal of Experimental Psychology: Learning, Memory, and Cognition, 40, 776-786.