Neural correlates of intrusion of emotion words in a modified Stroop task

Behavioural studies have demonstrated that the emotional Stroop task is a valuable tool for investigating emotion-attention interactions in a variety of healthy and clinical populations, showing that participants are typically more distracted by negative stimuli as compared to neutral or positive stimuli. The main aim of this study was to find and examine the neural correlates of this greater intrusion from negative emotional stimuli. Reliable reaction time (RT) and event-related potential (ER-P) data were collected from 23 participants who performed a manual emotional Stroop, task with short (40 ins) and long (500 ms) inter-trial intervals. In the short interval condition, participants were found to produce longer RTs for negative than neutral words, suggesting that these stimuli were more difficult to ignore. This RT effect disappeared in the long interval condition, although larger PI amplitudes were found for the negative words. This suggests that differences in early attention allocation may be unrelated to the degree of intrusion at the behavioural level. In addition, a larger negative slow wave around 300-700 ms post-stimulus was observed in the long interval condition, but only for those negative words that produced prolonged RTs as compared to their matched controls. This late and broadly distributed effect is believed to reflect suppression of meaning representations

Changes in recognition memory over time: an ERP investigation into vocabulary learning

Although it seems intuitive to assume that recognition memory fades over time when information is not reinforced, some aspects of word learning may benefit from a period of consolidation. In the present study, event-related potentials (ERP) were used to examine changes in recognition memory responses to familiar and newly learned (novel) words over time. Native English speakers were taught novel words associated with English translations, and subsequently performed a Recognition Memory task in which they made old/new decisions in response to both words (trained word vs. untrained word), and novel words (trained novel word vs. untrained novel word). The Recognition task was performed 45 minutes after training (Day 1) and then repeated the following day (Day 2) with no additional training session in between. For familiar words, the late parietal old/new effect distinguished old from new items on both Day 1 and Day 2, although response to trained items was significantly weaker on Day 2. For novel words, the LPC again distinguished old from new items on both days, but the effect became significantly larger on Day 2. These data suggest that while recognition memory for familiar items may fade over time, recognition of novel items, conscious recollection in particular may benefit from a period of consolidation

A global experiment on motivating social distancing during the COVID-19 pandemic

Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

Towards a competitive learning model of mirror effects in yes/no recognition memory tests

Manipulations of encoding strength and stimulus class can lead to a simultaneous increase in hits and decrease in false alarms for a given condition in a yes/no recognition memory test. Based on signal detection theory, the strength-based `mirror effect' is thought to involve a shift in response criterion/threshold (Type I), whereas the stimulus class effect derives from a specific ordering of the memory strength signals for presented items (Type II). We implemented both suggested mechanisms in a simple, competitive feed-forward neural network model with a learning rule related to Bayesian inference. In a single-process approach to recognition, the underlying decision axis as well as the response criteria/thresholds were derived from network activation. Initial results replicated findings in the literature and are a first step towards a more neurally explicit model of mirror effects in recognition memory tests

The influence of encoding intention on electrophysiological indices of recognition memory

The main aim of this study was to further specify the encoding and retrieval conditions that determine the success of an ERP-based memory assessment procedure, originally derived from lie detection studies. We examined whether event-related brain potentials (ERPs) recorded during successful and unsuccessful retrieval would vary according to intentional (study) and incidental (repetition) encoding conditions. Participants (N=20) were asked to indicate recognition of previously studied words (learned targets, p=0.2) and words that were used as distractors in a preceding recognition task (repeated targets, p=0.2). Words that were recognised elicited a P3 component, which was largely absent for new words and words that failed to be recognised. Encoding intention was found to increase the P3 amplitude slightly but had no influence on P3 scalp distribution, suggesting that the differently encoded targets were similarly processed during retrieval but to a different extent. The amplitude difference was explained in terms of variance in memory trace strength and decision confidence. With respect to negative findings for repeated items in our earlier study (Van Hooff, J.C., Golden, S. 2002. Validation of an event-related potential memory assessment procedure: Intentional learning as opposed to simple repetition. J. Psychophysiol., 16, 12–22.), it was suggested that the instruction to actively retrieve the repeated words was essential for obtaining reliable indications of the presence or absence of weak memory traces

Validation of an Event-related Potential memory assessment procedure: Effects of incidental and intentional learning

The main aim of this study was to investigate whether an ERP-based memory assessment procedure (van Hooff et al., 1996) could be used to detect memories for items that (1) did not receive a behavioural recognition response and (2) were not intentionally learned. Participants were first required to study a short list of "neutral," semantically unrelated words that were subsequently tested for recognition. Next, participants studied a second, different word list, which again was tested for recognition (learned targets) in a following test. In this second test, the distractors consisted of the words that were studied prior to - and had to be recognized in - the first test (learned nontargets), words that were used as distractors in the first test (repeated nontargets), and words that had not been learned or presented before (new words). Targets and both types of nontargets were presented less frequently than the new words, so essentially this test had an oddball character. Results showed that learned targets as well as learned nontargets elicited a P300 component that was largely absent for the new words and for the repeated nontargets. These results seem to imply that successful use of the ERP-based memory assessment procedure did not rely on behavioural indications of recognition, but did depend on the level of contemplation during initial study/presentation

A Systematic Investigation of Same and Cross Modality Priming Using Written and Spoken Responses

Effects of presentation modality and response format were investigated using visual and auditory versions of the word stem completion task. Study presentation conditions (visual, auditory, non-studied) were manipulated within participants, while test conditions (visual/written, visual/spoken, auditory/written, auditory/spoken, recall-only) were manipulated between participants. Results showed evidence for same modality and cross modality priming on all four word stem completion tasks. Words from the visual study list led to comparable levels of priming across all test conditions. In contrast, words from the auditory study list led to relatively low levels of priming in the visual/written test condition and high levels of priming in the auditory/spoken test condition. Response format was found to influence priming performance following auditory study in particular. The findings confirm and extend previous research and suggest that, for implicit memory studies that require auditory presentation, it may be especially beneficial to use spoken rather than written responses

Using event-related potentials to distinguish mirror effect types: Evidence from a modified directed forgetting procedure (item-method) {A}bstract.

Mirror effects --- simultaneous increases in recognition accuracy for old and new items in a given condition --- provide an important benchmark for memory models, but only if they arise from memory-related differences between conditions. We present a novel approach to distinguish between decision-related (type I) and memory-related (type II) mirror effects in simple yes/no recognition paradigms using event-related potentials (ERPs). We modified a directed forgetting procedure (item-method) to specify and test a relationship between encoding differences (as measured by study phase ERPs), mirror effects (as measured by behavioural data) and ERP retrieval set effects (as measured by test phase ERPs) from the perspective of a strength-based signal detection model of recognition memory. New words were once blocked with old words cued to-be-forgotten (forget retrieval context) and once with old words cued to-be-remembered (remember retrieval context), which produced a mirror effect. In the forget retrieval context, recognition accuracy decreased and ERPs for correctly identified new words were less negative-going in the \overline{\mbox{N400}} time-window (300--500~ms). This ERP retrieval set effect was unrelated to response-criterion shifts between conditions and may instead reflect changes in retrieval orientation, implying a type II mirror effect. Our results suggest that combining behavioural and ERP data can arbitrate between different theoretical explanations of mirror effects and thus memory models