Forschungsprojekt ::

Interplay of cognitive control in behavioral and neurophysiological correlates: Towards an understanding of control in human behavior

Projektbeschreibung

Our society increasingly requires us to be multitaskers in everyday life, such as answering a phone call while driving or scheduling meetings during cooking. Due to this, we encounter frequent situations in which we face multiple conflicts at the same time that require rapid decisions regarding how to react according to our current goals. To resolve these concurrent conflicts, we implement cognitive control processes. Cognitive/executive control is among the core cognitive processes because it allows us to adapt to environmental changes in a fast and flexible way. The processes behind such adaptability include focusing attention on the relevant information as well as inhibiting competing alternatives or habitual responses. Investigating the question of how cognitive control processes are implemented and how they interact is, therefore, an important pre-requisite towards understanding human behavior. The purpose of this project is to contribute to this endeavor. In cognitive psychology, control processes are investigated by presenting incongruent stimuli (i.e., stimuli which induce a conflict between response alternatives). For instance, a stimulus is incongruent when the color word “green” is printed in red (Stroop), when the stimulus is associated with a left key-press but is presented on the right side of the screen (Simon), or when the relevant stimulus is flanked by irrelevant characters (Flanker). Responding to incongruent trials requires us to activate goal-relevant features (e.g., the color “red”, the left key-press or the central stimulus, respectively) and inhibit irrelevant ones (i.e., the word meaning “green”, the right side, or the irrelevant characters, respectively). Recent research has highlighted different inhibition processes (Stahl et al., 2014). However, it is unclear how these different inhibition processes interact to allow a rapid and goal-appropriate adjustment of control when multiple conflicts are presented concurrently. So far, only a few studies have addressed this question by combining two conflict tasks. For example, the Stoop task was paired with a Simon task by presenting the color words on either the right or left side (e.g., Hommel, 1997, Kornblum, 1997, Wendt, Kluwe, & Peters, 2006). The results were mixed. Some studies found no interaction between the control processes deployed to solve the two conflicts (e.g., Hommel, 1997; Kornblum, 1994). In contrast, other studies found an interaction such that inhibiting the irrelevant information of one conflict facilitates the processing of the other conflict (Hommel, 1997, Wendt et al., 2006). Critically, when the stimulus set size for each task was large enough to discourage the use of episodic memory processes to perform the task, the results revealed an interaction between the conflicts, irrespective of the conflict combination (i.e., Stroop with Flanker, Stroop with Simon, or Flanker with Simon; see Rey-Mermet & Gade, 2016). The purpose of the present project is to use behavioral measures as well as event-related potentials (ERPs) in order to investigate how responding to multiple conflicts within the same trial results in an interaction of control processes. To this end, the first part of the project is designed to determine to what extent this interaction results from a temporal, verbal or spatial overlap in the processes underlying task performance. In the second part, the aim is to discover the processes responsible for the interplay of cognitive control. Specifically, the focus will be on disentangling the impact of conflict detection and control implementation by means of ERPs, then on the contribution of stimulus/response frequency, and finally on the precise role of inhibitory processes. In sum, the overall goal is to advance our understanding of flexible adjustments of cognitive control processes, especially in situations that require handling of multiple conflicts at the same time.