Irrelevant Stimuli and Action Control: Analyzing the Influence of Ignored Stimuli via the Distractor-Response Binding Paradigm

Summary

The distractor-response binding paradigm is described. It can be used to shed light on the influence irrelevant stimuli, competing with targets for a response, can have on human action. Both response retrieval effects and distractor inhibition effects can be analyzed within the paradigm.

Abstract

Selection tasks in which simple stimuli (e.g. letters) are presented and a target stimulus has to be selected against one or more distractor stimuli are frequently used in the research on human action control. One important question in these settings is how distractor stimuli, competing with the target stimulus for a response, influence actions. The distractor-response binding paradigm can be used to investigate this influence. It is particular useful to separately analyze response retrieval and distractor inhibition effects. Computer-based experiments are used to collect the data (reaction times and error rates). In a number of sequentially presented pairs of stimulus arrays (prime-probe design), participants respond to targets while ignoring distractor stimuli. Importantly, the factors response relation in the arrays of each pair (repetition vs. change) and distractor relation (repetition vs. change) are varied orthogonally. The repetition of the same distractor then has a different effect depending on response relation (repetition vs. change) between arrays. This result pattern can be explained by response retrieval due to distractor repetition. In addition, distractor inhibition effects are indicated by a general advantage due to distractor repetition. The described paradigm has proven useful to determine relevant parameters for response retrieval effects on human action.

Introduction

In order to maneuver our way through the endless stream of information to perceive, offering nearly infinite possibilities to behave in the world around us, our brain has to rely on a limited number of simple and efficient processes and mechanisms. One important mechanism is selective attention, that is, the ability to discriminate between relevant and irrelevant information. Once a stimulus is identified as being irrelevant, inhibition dampens the activation of the distractor representation¹ or blocks its access to the response system to reduce interference². Distractor inhibition is one of the core concepts of cognitive control³.

Another important characteristic of human behavior is that not each and every aspect of our actions can be intentionally controlled. Other mechanisms are necessary that translate intentional actions, resulting from a controlled and resource-demanding processing of information, into efficient behavioral routines. The retrieval of previous behavioral episodes might play an important role for such an automatization of behavior. According to recent instance based models, a specific stimulus can become integrated with a response that is executed in close temporal proximity to the occurrence of the stimulus. The compound of stimulus and response is then stored as an “instance”⁴ or “event file”^5,6 in episodic memory. Re-encountering the stimulus of such an event file leads to a retrieval of the entire episode from memory, including the associated response^4-8. This retrieval of previous actions operates fast and automatically, exerting efficient bottom up control of behavior by establishing stimulus driven behavioral routines. Recent evidence suggests that this mechanism can also be triggered by distractors, that is, distractor-based retrieval of previous episodes and responses has an impact on human action control as well⁹.

The paradigm of distractor-response binding was developed to specifically investigate the influence distractors that compete with a target stimulus for the response, have on action control. In particular, this technique allows to disentangle the two mechanisms that have been discussed in the context of distractor processing, namely distractor inhibition and distractor based retrieval of responses.

The distractor-response binding paradigm originates from research using the negative priming paradigm (for a review see Fox¹⁰). In a negative priming paradigm, prime distractors that are repeated as targets on the probe lead to slower response times or more errors as compared to probe responses to targets that did not appear on the prime (i.e. the negative priming effect). One difficulty with this paradigm has been that at least two different mechanisms can account for the negative priming effect. On the one hand it has been proposed that a prime distractor is inhibited at prime presentation, in order to enable responding to the prime target. Residual inhibition of the former distractor stimulus results in a disadvantage if a response to this inhibited stimulus is required on the probe^1,11. On the other hand, negative priming can be the result of retrieval mechanisms^12,13. For example, Neill assumed that the prime distractor is encoded together with a do-not-respond tag at the prime, which is then retrieved and in turn conflicts with responding to this stimulus if it is repeated as the probe target¹⁴.

More recently, the Stimulus Response Retrieval theory (SRR¹⁵) assumed that distractors are integrated with and can trigger the retrieval of responses. This opens new possibilities to investigate retrieval effects due to distractor repetition separately. Based on the Theory of Event Coding¹⁶, SRR proposes that target, distractor, and response features are encoded in one temporary episodic memory trace or event file. On the next encounter, any of these stimuli (i.e. also the distractor stimulus) can trigger the retrieval of the entire event file including the target response. These retrieval effects due to distractor repetition have been termed distractor-response binding. Distractor-response binding has been shown to influence performance in human reactions in the visual, the auditory, and the tactile modality^17-19. It also modulates responses in location selection²⁰. Various modulating factors of the effect evidence that distractor-response binding is not entirely automatic but influences behavior only under certain conditions^21-23.

The effect is evidenced in sequential selection tasks by the influence distractor repetition has on performance depending on response repetition. If the same response has to be given on the prime and probe, distractor repetition leads to better performance as compared to distractor change because the distractor retrieves a compatible response. In contrast, if a change of response is required, repeating the distractor hampers responding as the distractor retrieves an incompatible response. Thus, distractor-based retrieval is indicated by the interaction effect of response repetition × distractor repetition.

One advantage over the negative priming paradigm is that the paradigm of distractor-response binding can differentiate between effects of distractor inhibition and response retrieval²⁴. While retrieval effects are evidenced by an interaction of response repetition and distractor repetition, distractor inhibition is measured as the main effect of distractor repetition. That is, an inhibition account^1,25 would predict, that inhibiting the same stimulus two times in a row should always lead to benefits because after effects from distractor inhibition on the prime should facilitate distractor inhibition on the probe. This benefit effect of repeated distractors is, however, according to the inhibition theory independent of response repetition.

Further analyzing prerequisites and modulating factors of the distractor-response binding effect is important to get a better understanding of the way ignored objects in our everyday life influence human reaction. The present article gives a detailed description of the paradigm used to analyze the distractor-based retrieval and distractor inhibition.

Protocol

The protocol follows the ethical guidelines of the American Psychological Association and the World Medical Association (revised declaration of Helsinki, 1989). 1. General Experimental Setup Collect data, concerning distractor-response binding effects, in reaction time experiments via computer. 2. Preparation of the Experiment Use a standard experimental software to program the experiment. Most of the previous studies used E-Prime.</li…

Representative Results

In a 2 (Response Relation: repetition vs. change) × 2 (Distractor Relation: repetition vs. change) ANOVA on probe response times, a significant interaction of response relation and distractor relation indicates the effect of distractor-response binding. The advantage of distractor repetition is larger in response repetition than in response change trials. That is, the difference in mean response times between RR-DC and RR-DR trials is significantly larger than the difference in mean response times between RC-DC and …

Discussion

The paradigm of distractor-response binding is useful to investigate influences of distractors that compete with the target stimulus for a response execution. In particular, it can differentiate certain mechanisms that have been proposed to influence performance in selection tasks. Namely, both retrieval and inhibition effects concerning distractor stimuli can be analyzed separately. In addition, it is possible to manipulate the different aspects of distractor-response binding separately in this paradigm. If the effect a…

Materials

Standard PC			Various different models have been used in experiments investigating distractor-response binding
E-Prime	Psychology Software Tools		Both version 1.0 and version 2.0 have been used