No abstract

Even an irrelevant distractor stimulus is integrated into event files. Subsequently repeating the distractor triggers retrieval of the event file; however, an unresolved issue concerns the question of what is retrieved by the distractor. While recent studies predominantly assume that the distractor retrieves the previous response, it is also possible that distractor repetition triggers retrieval of the previous target stimulus. In 3 experiments, we dissociated distractor-response and distractor-target binding processes using a sequential distractor-to-distractor repetition paradigm. In Experiment 1, response relation and target relation were manipulated orthogonally; results yielded independent evidence for both mechanisms. Experiment 2 provided distinct evidence for distractor-target binding and retrieval by avoiding response repetitions of any kind. Experiment 3 provided distinct evidence for distractor-response binding and retrieval by eliminating target stimuli. We conclude that both distractor-target and distractor-response binding reflect independent processes in the service of behavior automatization.

Distractor inhibition and distractor-response binding were investigated in two experiments by analyzing distractor repetition benefits and their interaction with response repetition effects in a sequential-priming paradigm. Distractor repetition benefits were larger for distractors that were incompatible with the to-be-executed response (task-related distractors) than for distractors that were not assigned to a response (neutral distractors), indicating that the strength of distractor inhibition was a function of response interference for the distractors. In contrast, the distractor-response bindings were found to be of equal strength for both task-related and neutral distractors. Thus, differences in the strengths of distractor inhibition did not affect the integration of distractors with responses into event files. Instead, our results suggest that distractor-response binding and distractor inhibition are independent mechanisms that are recruited for the automatization of behavior and action control.

A habit is a regularity in automatic responding to a specific situation. Classical learning psychology explains the emergence of habits by an extended learning history during which the response becomes associated to the situation (learning of stimulus-response associations) as a function of practice ("law of exercise") and/or reinforcement ("law of effect"). In this paper, we propose the "law of recency" as another route to habit acquisition that draws on episodic memory models of automatic response regulation. According to this account, habitual responding results from (a) storing stimulusresponse episodes in memory, and (b) retrieving these episodes when encountering the stimulus again. This leads to a reactivation of the response that was bound to the stimulus (c) even in the absence of extended practice and reinforcement. As a measure of habit formation, we used a modified color-word contingency learning (CL) paradigm, in which irrelevant stimulus features (i.e., word meaning) were predictive of the to-be-executed color categorization response. The paradigm we developed allowed us to assess effects of global CL and of an instance-based episodic response retrieval simultaneously within the same experiment. Two experiments revealed robust CL as well as episodic response retrieval effects. Importantly, these effects were not independent: Controlling for response retrieval effects eliminated effects of CL, which supports the claim that habit formation can be mediated by episodic retrieval processes, and that short-term binding effects are not fundamentally separate from long-term learning processes. Our findings have theoretical and practical implications regarding (a) models of long-term learning, and (b) the emergence and change of habitual responding.

The learning of contingent regularities between events is fundamental for interacting with our world. We are also heavily influenced by recent experiences, as frequently studied in the stimulus-response binding literature. According to one view (“unitary view”), the learning of regularities across many events and the influence of recent events on current performance can coherently be explained with one high-learning rate memory mechanism. That is, contingency learning effects and binding effects are essentially the same thing, only studied at different timescales. On the other hand, there may be more to a contingency effect than just the summation of the influence of past events (e.g., an additional impact of learned regularities). To test these possibilities, the current report reanalyses a number of datasets from the colour-word contingency learning paradigm. It is shown that the weighted sum of binding effects accumulated across many previous trials (with especially strong influence of very recent events) does explain a large chunk of the contingency effect, but not all of it. In particular, the asymptote towards which the contingency effect decreases by accounting for an increasing number of previous-trial binding effects is robustly above zero. On the other hand, we also observe evidence for higher-order interactions between binding effects at differing lags, suggesting that a mere linear accumulation of binding episodes might underestimate their influence on contingency learning. Accordingly, focusing only on episodic stimulus-response binding effects that are due to the last occurrence of a stimulus rendered contingency learning effects non-significant. Implications for memory models are discussed.