Expectation mismatch: differences between self-generated and cue-induced expectations

Action-outcome delays modulate the temporal expansion of intended outcomes

The phenomenon of intentional binding pertains to the perceived connection between a voluntary action and its anticipated result. When an individual intends an outcome, it appears to subjectively extend in time due to a pre-activation of the intended result, particularly evident at shorter action-outcome delays. However, there is a concern that the operationalisation of intention might have led to a mixed interpretation of the outcome expansion attributed to the pre-activation of intention, given the sensitivity of time perception and intentional binding to external cues that could accelerate the realisation of expectations. To investigate the expansion dynamics of an intended outcome, we employed a modified version of the temporal bisection task in two experiments. Experiment 1 considered the action-outcome delay as a within-subject factor, while experiment 2 treated it as a between-subject factor. The results revealed that the temporal expansion of an intended outcome was only evident under the longer action-outcome delay condition. We attribute this observation to working memory demands and attentional allocation due to temporal relevancy and not due to pre-activation. The discrepancy in effects across studies is explained by operationalising different components of the intentional binding effect, guided by the cue integration theory. Moreover, we discussed speculative ideas regarding the involvement of specific intentions based on the proximal intent distal intent (PIDI) theory and whether causality plays a role in temporal binding. Our study contributes to the understanding of how intention influences time perception and sheds light on how various methodological factors, cues, and delays can impact the dynamics of temporal expansion associated with an intended outcome.

Sirtuins, a key regulator of ageing and age-related neurodegenerative diseases

Sirtuins are Nicotinamide Adenine Dinucleotide (NAD+) dependent class ІΙΙ histone deacetylases enzymes (HDACs) present from lower to higher organisms such as bacteria (Sulfolobus solfataricus L. major), yeasts (Saccharomyces cerevisiae), nematodes (Caenorhabditis elegans), fruit flies (Drosophila melanogaster), humans (Homo sapiens sapiens), even in plants such as rice (Oryza sativa), thale cress (Arabidopsis thaliana), vine (Vitis vinifera L.) tomato (Solanum lycopersicum). Sirtuins play an important role in the regulation of various vital cellular functions during metabolism and ageing. It also plays a neuroprotective role by modulating several biological pathways such as apoptosis, DNA repair, protein aggregation, and inflammatory processes associated with ageing and neurodegenerative diseases. In this review, we have presented an updated Sirtuins and its role in ageing and age-related neurodegenerative diseases (NDDs). Further, this review also describes the therapeutic potential of Sirtuins and the use of Sirtuins inhibitor/activator for altering the NDDs disease pathology.

Development of Low-Fidelity Virtual Replicas of Products for Usability Testing

Designers perform early-stage formative usability tests with low-fidelity prototypes to improve the design of new products. This low-tech prototype style reduces the manufacturing resources but limits the functions that can be assessed. Recent advances in technology enable designers to create low-fidelity 3D models for users to engage in a virtual environment. Three-dimensional models communicate design concepts and are not often used in formative usability testing. The proposed method discusses how to create a virtual replica of a product by assessing key human interaction steps and addresses the limitations of translating those steps into a virtual environment. In addition, the paper will provide a framework to evaluate the usability of a product in a virtual setting, with a specific emphasis on low-resource online testing in the user population. A study was performed to pilot the subject’s experience with the proposed approach and determine how the virtual online simulation impacted the performance. The study outcomes demonstrated that subjects were able to successfully interact with the virtual replica and found the simulation realistic. This method can be followed to perform formative usability tests earlier and incorporate subject feedback into future iterations of their design, which can improve safety and product efficacy.

Hyperreactivity to uncertainty is a key feature of subjective cognitive impairment

With an increasingly ageing global population, more people are presenting with concerns about their cognitive function, but not all have an underlying neurodegenerative diagnosis. Subjective cognitive impairment (SCI) is a common condition describing self-reported deficits in cognition without objective evidence of cognitive impairment. Many individuals with SCI suffer from depression and anxiety, which have been hypothesised to account for their cognitive complaints. Despite this association between SCI and affective features, the cognitive and brain mechanisms underlying SCI are poorly understood. Here, we show that people with SCI are hyperreactive to uncertainty and that this might be a key mechanism accounting for their affective burden. Twenty-seven individuals with SCI performed an information sampling task, where they could actively gather information prior to decisions. Across different conditions, SCI participants sampled faster and obtained more information than matched controls to resolve uncertainty. Remarkably, despite their ‘urgent’ sampling behaviour, SCI participants were able to maintain their efficiency. Hyperreactivity to uncertainty indexed by this sampling behaviour correlated with the severity of affective burden including depression and anxiety. Analysis of MRI resting functional connectivity revealed that SCI participants had stronger insular-hippocampal connectivity compared to controls, which also correlated with faster sampling. These results suggest that altered uncertainty processing is a key mechanism underlying the psycho-cognitive manifestations in SCI and implicate a specific brain network target for future treatment.

Central and Peripheral Fatigue in Physical Exercise Explained: A Narrative Review

The study of the origin and implications of fatigue in exercise has been widely investigated, but not completely understood given the complex multifactorial mechanisms involved. Then, it is essential to understand the fatigue mechanism to help trainers and physicians to prescribe an adequate training load. The present narrative review aims to analyze the multifactorial factors of fatigue in physical exercise. To reach this aim, a consensus and critical review were performed using both primary sources, such as scientific articles, and secondary ones, such as bibliographic indexes, web pages, and databases. The main search engines were PubMed, SciELO, and Google Scholar. Central and peripheral fatigue are two unison constructs part of the Integrative Governor theory, in which both psychological and physiological drives and requirements are underpinned by homeostatic principles. The relative activity of each one is regulated by dynamic negative feedback activity, as the fundamental general operational controller. Fatigue is conditioned by factors such as gender, affecting men and women differently. Sleep deprivation or psychological disturbances caused, for example, by stress, can affect neural activation patterns, realigning them and slowing down simple mental operations in the context of fatigue. Then, fatigue can have different origins not only related with physiological factors. Therefore, all these prisms must be considered for future approaches from sport and clinical perspectives.

Differential effects of cue-based and sequence knowledge-based predictability on multitasking performance

Everyday multitasking often is characterized by predictable sequences. While such sequential regularities are present in setups using the Serial Reaction Time Task (SRTT), many laboratory studies on dual-tasking performance use random sequences of stimuli in either of the two tasks. In the current study, following single-task training on the SRTT, participants completed trials where they were confronted with an additional visual-manual task with either a random (Experiment 1) or a partially predictable (Experiment 2) stimulus sequence. In the SRTT, we cued participants with respect to which of the four stimulus options were yet to occur (before a new round with all four options would start). We randomly mixed a sequence to be practiced with random sequences of the same length and with the same constraint. Thus, we were able to vary predictability of upcoming stimuli (from chance to 100%) as well as sequence knowledge (practiced vs. random sequence) in order to assess how cueing and sequence knowledge, as two potential bases of prediction, would affect performance in single- and dual-tasking. Results suggest that both cueing and sequence knowledge-based prediction can lead to shorter RTs in dual-tasking. In previous studies, the disruption of sequence learning by adding a task with a random stimulus sequence has been linked to the effects of automatic prediction between events in the two tasks. In line with these studies, dual-task performance did not impede usage of sequence knowledge when a task with a predictable (rather than random) sequence of stimuli was added to the SRTT.

Intended outcome expands in time

Intentional agents desire specific outcomes and perform actions to obtain those outcomes. However, whether getting such desired (intended) outcomes change our subjective experience of the duration of that outcome is unknown. Using a temporal bisection task, we investigated the changes in temporal perception of the outcome as a function of whether it was intended or not. Before each trial, participants intended to see one of two possible outcomes but received the intended outcome only in half of the trials. Results showed that intended outcomes were perceived as longer than unintended outcomes. Interestingly, this temporal expansion was present only when the intended outcome appeared after short action-outcome delays (250 ms-Exp 1 and 500 ms-Exp 2), but not when it appeared after long action-outcome delay (1000 ms-Exp 3). The effect was absent when participants did not intend and performed instruction-based action (Exp 4). Finally, Exp 5 (verbal estimation task) revealed that intention induced temporal expansion occurs via altering the gating or switch mechanism and not the pacemaker speed. Results are explained based on intention-induced pre-activation resulting in extended temporal experience. Our study not only suggests inclusion of intention as a potential factor influencing time perception but also indicates a close link between intentional binding and the intention induced temporal expansion of its outcome.

Tied to expectations: Predicting features speeds processing even under adverse circumstances

When participants predict the upcoming stimulus in a randomized choice reaction task, a match between prediction and stimulus increases processing speed at a level similar to that observed in cueing studies with highly valid cues. This might be taken to suggest that people cannot help but fully use their self-generated, verbalized predictions for preparing task processing. Thus, we tested how flexibly participants can control formation and implementation of predictions. In Experiment 1, we varied validity and response-relevance of predictions. We observed that prediction effects on RT can be boosted by increasing validity, but prevail under adverse circumstances. This was not the case in a control group who read rather than predicted the feature words, suggesting that the effect was specific to predictions as such. Experiment 2 provided further evidence for limited control of participants over implementing and forming predictions. Participants were provided with practice on stimuli occurring with varying frequency, but neither learned to strategically choose predictions to maximize the number of match trials, nor did they reduce the amount of prediction-based preparation when predicting an infrequent stimulus. As sequential aftereffects of prediction match did not vary with validity, they were identified as an independent effect of verbalizing a response-relevant stimulus feature. The results are consistent with the view that the predicted stimulus feature is represented in the focus of attention in working memory and that the amount of implementation can be subject to weighting.

Expectations and Decisions in the Volunteer's Dilemma: Effects of Social Distance and Social Projection

In a Volunteer’s Dilemma (VoD) one individual needs to bear a cost so that a public good can be provided. Expectations regarding what others will do play a critical role because they would ideally be negatively correlated with own decisions; yet, a social-projection heuristic generates positive correlations. In a series of 2-person-dilemma studies with over 1,000 participants, we find that expectations are indeed correlated with own choice, and that people tend to volunteer more than game-theoretic benchmarks and their own expectations would allow. We also find strong evidence for a social-distance heuristic, according to which a person’s own probability to volunteer and the expectation that others will volunteer decrease as others become socially more remote. Experimentally induced expectations make opposite behavior more likely, but respondents underweight these expectations. As a result, there is a small but systematic effect of over-volunteering among psychologically close individuals.

Can Psychological Expectation Models Be Adapted for Placebo Research?

Placebo responses contribute substantially to the effect and clinical outcome of medical treatments. Patients' expectations have been identified as one of the major mechanisms contributing to placebo effects. However, to date a general theoretical framework to better understand how patient expectations interact with features of medical treatment has not been developed. In this paper we outline an expectation model that can be used as framework for experimental studies on both placebo and nocebo mechanisms. This model is based on psychological concepts of expectation development, expectation maintenance, and expectation change within the typical paradigms used in placebo research. This theoretical framework reflects the dynamic aspects of the interaction between expectations and medical treatment, and offers a platform to combine psychological and neurophysiological research activities. Moreover, this model can be used to identify important future research questions. For example, we argue that the dynamic processes of expectation maintenance vs. expectation changes are not sufficiently addressed in current research on placebo mechanisms. Therefore, the question about how to change and optimize patients' expectations prior to treatment should be a special focus of future clinical research.

Guessing versus Choosing an Upcoming Task

We compared the effects of guessing vs. choosing an upcoming task. In a task-switching paradigm with four tasks, two groups of participants were asked to either guess or choose which task will be presented next under otherwise identical conditions. The upcoming task corresponded to participants’ guesses or choices in 75 % of the trials. However, only participants in the Choosing condition were correctly informed about this, whereas participants in the Guessing condition were told that tasks were determined at random. In the Guessing condition, we replicated previous findings of a pronounced reduction of switch costs in case of incorrect guesses. This switch cost reduction was considerably less pronounced with denied choices in the Choosing condition. We suggest that in the Choosing condition, the signaling of prediction errors associated with denied choices is attenuated because a certain proportion of denied choices is consistent with the overall representation of the situation as conveyed by task instructions. In the Guessing condition, in contrast, the mismatch of guessed and actual task is resolved solely on the level of individual trials by strengthening the representation of the actual task.

The Context Matters: Outcome Probability and Expectation Mismatch Modulate the Feedback Negativity When Self-Evaluation of Response Correctness Is Possible

Individuals typically evaluate whether their performance and the obtained feedback match. Previous research has shown that feedback negativity (FN) depends on outcome probability and feedback valence. It is, however, less clear to what extent previous effects of outcome probability on FN depend on self-evaluations of response correctness. Therefore, we investigated the effects of outcome probability on FN amplitude in a simple go/no-go task that allowed for the self-evaluation of response correctness. We also investigated effects of performance incompatibility and feedback valence. In a sample of N = 22 participants, outcome probability was manipulated by means of precues, feedback valence by means of monetary feedback, and performance incompatibility by means of feedback that induced a match versus mismatch with individuals' performance. We found that the 100% outcome probability condition induced a more negative FN following no-loss than the 50% outcome probability condition. The FN following loss was more negative in the 50% compared to the 100% outcome probability condition. Performance-incompatible loss resulted in a more negative FN than performance-compatible loss. Our results indicate that the self-evaluation of the correctness of responses should be taken into account when the effects of outcome probability and expectation mismatch on FN are investigated.

The benefit of expecting no conflict--Stronger influence of self-generated than cue-induced conflict expectations on Stroop performance

The role of expectations in sequential adaptation to cognitive conflict has been debated controversially in prior studies. On the one hand, a sequential congruency effect (SCE) has been reported for trials in which participants expect a repetition of conflict level. On the other hand, conflict level expectations vs. the SCE have been shown to develop differentially across runs of trials with the same conflict level, arguing against the theory that the SCE is purely driven by expectation. The current verbal Stroop experiment addresses this controversy by two means. First, we tested which specific type of expectation (cue-induced expectations vs. self-generated predictions) might affect the SCE. Second, we assessed the impact of expectation on the SCE as well as the development of SCE and expectation with congruency level run length in one design. We observed a dissociation between expectations and SCE, demonstrating that the SCE is not exclusively driven by expectations. At the same time, we found evidence that (self-generated) expectations do have an impact on the SCE. Our data document especially high performance for one specific combination of task events: congruent trial accompanied by congruent prediction and conflict level repetition. Our results are in line with theories attributing conflict adaptation effects to the "adaption to the lack of conflict". We discuss our results in a broader context of theories about conflict monitoring.

Incorrect predictions reduce switch costs

In three experiments, we combined two sources of conflict within a modified task-switching procedure. The first source of conflict was the one inherent in any task switching situation, namely the conflict between a task set activated by the recent performance of another task and the task set needed to perform the actually relevant task. The second source of conflict was induced by requiring participants to guess aspects of the upcoming task (Exps. 1 & 2: task identity; Exp. 3: position of task precue). In case of an incorrect guess, a conflict accrues between the representation of the guessed task and the actually relevant task. In Experiments 1 and 2, incorrect guesses led to an overall increase of reaction times and error rates, but they reduced task switch costs compared to conditions in which participants predicted the correct task. In Experiment 3, incorrect guesses resulted in faster performance overall and to a selective decrease of reaction times in task switch trials when the cue-target interval was long. We interpret these findings in terms of an enhanced level of controlled processing induced by a combination of two sources of conflict converging upon the same target of cognitive control.

Transferring control demands across incidental learning tasks - stronger sequence usage in serial reaction task after shortcut option in letter string checking

After incidentally learning about a hidden regularity, participants can either continue to solve the task as instructed or, alternatively, apply a shortcut. Past research suggests that the amount of conflict implied by adopting a shortcut seems to bias the decision for vs. against continuing instruction-coherent task processing. We explored whether this decision might transfer from one incidental learning task to the next. Theories that conceptualize strategy change in incidental learning as a learning-plus-decision phenomenon suggest that high demands to adhere to instruction-coherent task processing in Task 1 will impede shortcut usage in Task 2, whereas low control demands will foster it. We sequentially applied two established incidental learning tasks differing in stimuli, responses and hidden regularity (the alphabet verification task followed by the serial reaction task, SRT). While some participants experienced a complete redundancy in the task material of the alphabet verification task (low demands to adhere to instructions), for others the redundancy was only partial. Thus, shortcut application would have led to errors (high demands to follow instructions). The low control demand condition showed the strongest usage of the fixed and repeating sequence of responses in the SRT. The transfer results are in line with the learning-plus-decision view of strategy change in incidental learning, rather than with resource theories of self-control.