Cling together, swing together? Assessing indirect retrieval of stimulus-response bindings for associated stimuli.

When a stimulus is paired with a response, a stimulus-response (SR) binding (or event file) is formed. Subsequent stimulus repetition retrieves the SR binding from memory, which facilitates (impedes) performance when the same (a different) response is required. We aimed to explore whether indirect retrieval of SR bindings by a newly learnt associated stimulus is possible. Participants first went through a learning task to acquire novel stimulus-stimulus associations. The same stimulus pairs were then presented in a prime-probe task to assess direct and indirect retrieval effects. Participants responded by classifying word color in prime and probe trials. Probe words were either identical to prime words (test for direct retrieval) or corresponded to the associated stimulus (test for indirect retrieval) or were unrelated words (baseline). Independently of word relation, response relation (repetition vs. change) across prime and probe trials was manipulated. In two highly powered preregistered studies (total N = 260) using different types of stimulus associations, we obtained evidence for direct retrieval due to identical word repetition in the probe. Crucially, evidence for indirect retrieval upon presentation of an associated probe word was absent. Controlling for memory of each stimulus-stimulus association did not alter the findings. Our results show that indirect retrieval through newly acquired associations does not occur at the level of SR bindings, at least not for recently acquired stimulus-stimulus associations. Our study illustrates the scope of binding principles and highlights boundary conditions for the stimulus properties that can elicit automatic response retrieval.

Imagined object files: Visual imagery produces partial repetition costs where perception does not.

The present study explored whether object (or event) files can be formed that integrate color imagery and perceptual location features. To assess this issue, a cue-target procedure was used whereby color imagery was cued to be generated at a particular location in space, which was then followed by a perceptual color discrimination task. Partial repetition costs (PRCs) were then measured by varying the overlap of the color and location features of the cue and target to evaluate whether an object/event file was formed. Robust PRCs were observed when imagery was generated at a location, supporting the idea that imagery and perception can be incorporated into a common event file. It was also revealed that the PRC effects for perceptual color cues were tenuous-they did not reach significance in the present study. Overall, the present study indicates that imagery can produce stronger binding effects than perception, offering important insights into the role that active engagement plays in the formation of object/event files.

Emotional arousal does not modulate stimulus-response binding and retrieval effects.

The adaptation-by-binding account and the arousal-biased competition model suggest that emotional arousal increases binding effects for transient links between stimuli and responses. Two highly-powered, pre-registered experiments tested whether transient stimulus-response bindings are stronger for high versus low arousing stimuli. Emotional words were presented in a sequential prime-probe design in which stimulus relation, response relation, and stimulus arousal were orthogonally manipulated. In Experiment 1 (N = 101), words with high and low arousal levels were presented individually in prime and probe displays. In Experiment 2 (N = 170), a high arousing affective word was presented simultaneously with a neutral word during the prime display; in the subsequent probe display, either the arousing or the neutral word repeated or a different high versus low arousal word was shown. Data from both experiments did not demonstrate a modulation of SRBR effects by stimulus arousal and SRBR effects were of equal magnitude for word stimuli of high and low arousal levels. These null results are not in line with binding accounts that hypothesise a modulatory influence of emotional arousal on perception-action binding.

Reluctance against the machine: Retrieval of observational stimulus-response episodes in online settings emerges when interacting with a human, but not with a computer partner.

Observing how another person responds to a stimulus creates stimulus-response (SR) episodes. These can be retrieved from memory on later occasions, which means that observed responses are utilized for regulating one's own actions. Until now, evidence for storage and retrieval of observationally acquired SR episodes was limited to dyadic face-to-face interactions between two partners who respond in an alternating fashion. In two preregistered studies (total N = 252), we demonstrate for the first time that observational SR episodes can also be acquired in online interactions: Robust retrieval effects emerged when observers believe to be interacting with another person. In turn, retrieval effects were absent when observers believe to be interacting with a computer. Our findings show that feature-based binding and retrieval principles are pervasive and also apply to social interactions, even under purely virtual conditions. We discuss implications of our findings for different explanatory accounts of social modulations of automatic imitation.

Smaller Than Expected.

In two pre-registered studies, we investigated whether processes of imitative action regulation are facilitated after experiencing an episode of social exclusion. We reasoned that imitative action regulation effects should be more pronounced for participants who were socially excluded, providing them with an "automatic means" to socially reconnect with others. Participants played a virtual ball-tossing game to experimentally induce social exclusion or inclusion experiences. Subsequently, pairs of two participants engaged in an observational stimulus-response (SR) binding paradigm modeled after Giesen et al. (2014): Participants observed color categorization responses in their interaction partner (trialn-1) and then executed (in)compatible responses in the subsequent trial (trialn), with observation and responding occurring in alternation. Stimulus relation (repetition vs. change) from trialn-1 to trialn was orthogonally manipulated. In both studies, stimulus-based retrieval effects of observationally acquired SR bindings were descriptively larger in socially excluded (compared with socially included) participants. However, none of the effects were statistically significant. Even a joint analysis of both experiments did not show the expected modulation. We discuss the implications of our findings for research on social exclusion effects on imitative action regulation processes.

Location-response binding and inhibition of return in a detection task.

In the present study, we investigated the binding of location and response in a detection task of the target-target paradigm of inhibition of return (IOR). Results showed a cost of responding to a target at the repeated location (IOR) when the response was not repeated and an effect of facilitation of return (FOR) when the response was repeated. These findings suggest that when responding to a target, its location and the response to it are integrated together. In addition, an analysis of the Vincentized cumulative response time (RT) distribution further showed that memory retrieval of event representations requires time to operate. These findings were discussed according to the theoretical framework of event files.

Decoding Stimulus-Response Representations and Their Stability Using EEG-Based Multivariate Pattern Analysis.

Goal-directed actions require proper associations between stimuli and response. This has been delineated by cognitive theory, for example, in the theory of event coding framework, which proposes that event files represent such bindings. Yet, how such event file representations are coded on a neurophysiological level is unknown. We close this gap combining temporal electroencephalography (EEG) signal decomposition methods and multivariate pattern analysis (MVPA). We show that undecomposed neurophysiological data is unsuitable to decode event file representations because different aspects of information coded in the neurophysiological signal reveal distinct and partly opposed dynamics in the representational content. This is confirmed by applying MVPA to temporal decomposed EEG data. After intermixed aspects of information in the EEG during response selection have been separated, a reliable examination of the event file's representational content and its temporal stability was possible. We show that representations of stimulus-response bindings are activated and decay in a gradual manner and that event file representations resemble distributed neural activity. Especially representations of stimulus-response bindings, as well as stimulus-related representations, are coded and reveal temporal stability. Purely motor-related representations are not found in neurophysiological signals during event coding.

Stimulus-response recoding during inhibitory control is associated with superior frontal and parahippocampal processes.

Inhibitory control is affected by perceptual processes, but the mechanisms how perceptual features affect response inhibition are poorly understood. Theoretical frameworks detailing how variations in stimulus features that create overlaps between response categories can affect action control, like the Theory of Event Coding (TEC), have not been transferred to inhibitory control. We present a novel Go/Nogo paradigm in which we varied stimulus feature overlap between Go and Nogo trials. To examine what cognitive-neurophysiological subprocesses and functional neuroanatomical structures are modulated by stimulus-response feature overlap and recoding during inhibitory control, we combine event-related potential (ERP) recordings with source localization analyses. We show that response inhibition was compromised when stimulus features overlapped between Go and Nogo trials. The EEG data show that the recoding of stimulus-response mappings induced by such a stimulus feature overlaps affects subprocesses from perceptual gating/categorization (P1 ERP-component) to pre-motor inhibition (Nogo-N2 ERP-component) and motor inhibition (Nogo-P3 ERP-component). Although these are distinct processes, overlapping neuronal structures are associated with these modulations. The cascade of processes starts in the superior frontal cortex and is associated with perceptual categorization mechanisms. Subsequently, pre-motor inhibition or stimulus-response unbinding processes are modulated in parahippocampal structures before stimulus-response rebinding and motor inhibition is accomplished in parahippocampal and superior frontal structures. The study shows how perceptual processes can affect response inhibition using a theoretical framework, which has, until now, not been brought into connection with inhibitory control and establishes links between neurophysiology and functional neuroanatomy of inhibitory control with the TEC framework.

The Law of Recency: An Episodic Stimulus-Response Retrieval Account of Habit Acquisition.

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 stimulus-response 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.

Intimacy Effects on Action Regulation: Retrieval of Observationally Acquired Stimulus-Response Bindings in Romantically Involved Interaction Partners Versus Strangers.

Previous research has shown that stimulus-response (SR) binding and retrieval processes also occur when responses are only observed in another person (Giesen et al., 2014). Importantly, this effect depends on the two individuals interacting interdependently during the task (e.g., competition or cooperation). Interdependence, however, must not necessarily result from task-related demands, but can also reflect an intrinsic feature of a given relationship. The present study examines whether observing responses of one's romantic partner also produces stimulus-based retrieval of observed responses even if the task itself does not involve interdependence. Participants performed a task pairwise, either with their romantic partner or with a stranger. In a sequential prime-probe design, both participants of a pair gave color responses themselves (actors) or merely observed these (observers) in alternating fashion. As expected, stimulus-based retrieval of observationally acquired SR-bindings occurred only in romantically involved pairs; participants interacting with a stranger showed no retrieval effects. We conclude that mental representations of self and other are more closely intertwined in romantic couples, which produces automatic retrieval of observationally acquired SR binding effects even independently of the task itself.

Flexible goal imitation: Vicarious feedback influences stimulus-response binding by observation.

This study investigated whether vicarious feedback influences binding processes between stimuli and observed responses. Two participants worked together in a shared color categorization task, taking the roles of actor and observer in turns. During a prime trial, participants saw a word while observing the other person executing a specific response. Automatic binding of words and observed responses into stimulus-response (S-R) episodes was assessed via word repetition effects in a subsequent probe trial in which either the same (compatible) or a different (incompatible) response had to be executed by the participants in response to the same or a different word. Results showed that vicarious prime feedback (i.e., the feedback that the other participant received for her or his response in the prime) modulated S-R retrieval effects: After positive vicarious prime feedback, typical S-R retrieval effects emerged (i.e., performance benefits for stimulus repetition probes with compatible responses, but performance costs for stimulus repetition probes with incompatible responses emerged). Notably, however, S-R-retrieval effects were reversed after vicarious negative prime feedback (meaning that stimulus repetition in the probe resulted in performance costs if prime and probe responses were compatible, and in performance benefits for incompatible responses). Findings are consistent with a flexible goal imitation account, according to which imitation is based on an interpretative and therefore feedback-sensitive reconstruction of action goals from observed movements. In concert with earlier findings, this data support the conclusion that transient S-R binding and retrieval processes are involved in social learning phenomena.

A systems neurophysiology approach to voluntary event coding.

Mechanisms responsible for the integration of perceptual events and appropriate actions (sensorimotor processes) have been subject to intense research. Different theoretical frameworks have been put forward with the "Theory of Event Coding (TEC)" being one of the most influential. In the current study, we focus on the concept of 'event files' within TEC and examine what sub-processes being dissociable by means of cognitive-neurophysiological methods are involved in voluntary event coding. This was combined with EEG source localization. We also introduce reward manipulations to delineate the neurophysiological sub-processes most relevant for performance variations during event coding. The results show that processes involved in voluntary event coding included predominantly stimulus categorization, feature unbinding and response selection, which were reflected by distinct neurophysiological processes (the P1, N2 and P3 ERPs). On a system's neurophysiological level, voluntary event-file coding is thus related to widely distributed parietal-medial frontal networks. Attentional selection processes (N1 ERP) turned out to be less important. Reward modulated stimulus categorization in parietal regions likely reflecting aspects of perceptual decision making but not in other processes. The perceptual categorization stage appears central for voluntary event-file coding.

Not all errors are created equally: specific ERN responses for errors originating from distractor-based response retrieval.

The binding of stimulus (S) and response (R) features into S-R episodes or 'event files' is a basic process for the regulation of behavior. Recent studies have shown that even irrelevant information is bound into event files. Associating distractors with responses leads to more efficient behavior if irrelevant and relevant stimuli are correlated, but leads to erroneous or inadequate behavior if irrelevant stimuli do not predict relevant ones. In this study, we investigated a control mechanism that is triggered by errors resulting from distractor-based response retrieval. We tested whether the error-related negativity (ERN) differs depending on the error source. In particular, we compared errors due to distractor-based response retrieval with random errors. Errors originating from distractor-based response retrieval elicited a stronger (more negative) ERN than did other types of errors, suggesting that the cognitive system responds in a unique way to this kind of error. This control mechanism is adaptive because it prevents the emergence of inadequate response routines.

Negative emotion does not modulate rapid feature integration effects.

Emotional arousal at encoding is known to facilitate later memory recall. In the present study, we asked whether this emotion-modulation of episodic memory is also evident at very short time scales, as measured by "feature integration effects," the moment-by-moment binding of relevant stimulus and response features in episodic memory. This question was motivated by recent findings that negative emotion appears to potentiate first-order trial sequence effects in classic conflict tasks, which has been attributed to emotion-modulation of conflict-driven cognitive control processes. However, these effects could equally well have been carried by emotion-modulation of mnemonic feature binding processes, which were perfectly confounded with putative control processes in these studies. In the present experiments, we tried to shed light on this question by testing explicitly whether feature integration processes, assessed in isolation of conflict-control, are in fact susceptible to negative emotion-modulation. For this purpose, we adopted a standard protocol for assessing the rapid binding of stimulus and response features in episodic memory (Experiment 1) and paired it with the presentation of either neutral or fearful background face stimuli, shown either at encoding only (Experiment 2), or at both encoding and retrieval (Experiment 3). Whereas reliable feature integration effects were observed in all three experiments, no evidence for emotion-modulation of these effects was detected, in spite of significant effects of emotion on response times. These findings suggest that rapid feature integration of foreground stimulus and response features is not subject to modulation by negative emotional background stimuli and further suggest that previous reports of emotion-modulated trial-transition effects are likely attributable to the effects of emotion on cognitive control processes.