One Standard for All: Uniform Scale for Comparing Individuals and Groups in Hierarchical Bayesian Evidence Accumulation Modeling.

In recent years, a growing body of research uses Evidence Accumulation Models (EAMs) to study individual differences and group effects. This endeavor is challenging because fitting EAMs requires constraining one of the EAM parameters to be equal for all participants, which makes a strong and possibly unlikely assumption. Moreover, if this assumption is violated, differences or lack thereof may be wrongly found. To overcome this limitation, in this study, we introduce a new method that was originally suggested by van Maanen & Miletic (2021), which employs Bayesian hierarchical estimation. In this new method, we set the scale at the population level, thereby allowing for individual and group differences, which is realized by de facto fixing a population-level hyper-parameter through its priors. As proof of concept, we ran two successful parameter recovery studies using the Linear Ballistic Accumulation model. The results suggest that the new method can be reliably used to study individual and group differences using EAMs. We further show a case in which the new method reveals the true group differences whereas the classic method wrongly detects differences that are truly absent.

Bumpy ride ahead: Anticipated effort as emotional evidence?

Conscious reportable (un)pleasantness feelings were shown to be successfully described by a process in which evidence favoring pleasant and unpleasant feelings accumulates until one response wins the race. This approach is challenged by (a) insufficient specification of "evidence," and (b) incomplete verification that participants report their truly experienced (un)pleasant feelings and not what they expect to feel. In each trial in this preregistered experiment, the (un)pleasant feeling reports regarding emotion evoking pictures was embedded in a period when participants expected a low-effort task (feature visual search) or a high-effort task (feature-conjunction search). Fitting the Linear Ballistic Accumulator model to the feeling report data shows that anticipated effort was associated with a higher rate of unpleasant evidence accumulation, but only when the emotion evoking pictures were normatively unpleasant and not when they were normatively pleasant. These results suggest that anticipated effort may be one source of "evidence," but only given a certain interpretation of the findings, and that genuinely felt emotions contribute to the emotion reports, assuming that participants intended to react to the pictures, as instructed, and not to the anticipated effort.

Both pleasant and unpleasant emotional feelings follow Weber's law but it depends how you ask.

It remains unclear how we become aware of our emotions. The perceptual theory argues that emotions are a form of perception and reach awareness just like simple sensations. The theory was recently supported by Berkovich and Meiran (2023) showing, using evidence accumulation modeling of pleasantness reports, that pleasant emotional feelings follow one of the most basic psychophysical laws, Weber's Law, as nearly all sensations do. Contrary to predictions, this was true for pleasantness and not for unpleasantness. In this work, of which data were collected at the end of 2022, we employed the same experimental approach and successfully replicated the results but only when pleasantness was probed directly (emotions described as either "positive feeling" or "positive vs. negative feeling"). We unexpectedly found that the results flipped when we probed unpleasantness directly (i.e., "negative feeling") where we found that unpleasantness followed Weber's Law while pleasantness did not. Thus, Weber's Law holds for both pleasant and unpleasant feelings when probed directly, thereby providing an even stronger support for the perceptual theory. This in turn suggests that Weber's Law contributes to phenomena such as the unsuccessful pursuit of happiness and why psychotherapy is especially effective in leading to felt improvement when focusing on enhancing positive emotions and not on reducing negative emotions. The findings are limited by the fact that the participants were nondepressed undergraduate students. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Pleasant emotional feelings follow one of the most basic psychophysical laws (weber's law) as most sensations do.

Emotion episodes may include a conscious aspect of the emotion, namely being aware of our own emotional experience. Despite explosion in research over previous years, it remains unclear how emotions reach awareness and become feelings. Already in 1884, William James argued that emotional feelings resemble ordinary sensations in this respect. Here, using a novel model-based ratio scale of emotion intensity, we provide one of the strongest pieces of evidence supporting James' perceptual theory by showing that emotion awareness obeys one of the most fundamental laws of perception, Weber's law. According to this law, stimulus encoding accuracy decreases with intensity. In this work, we asked participants to provide binary pleasant-versus-unpleasant reports of their experience when watching normed emotion-eliciting pictures (NAPS; Marchewka et al., 2014). The results validate our model's measure of emotion intensity by showing its monotonous relation to picture norms. Most importantly, they show, for the first time, that in humans, pleasant emotion experiences follow Weber's classical psychophysical law-indicating decreased encoding precision with increasing pleasantness. This result supports James' theory, suggesting that (pleasant) emotions reach awareness just as ordinary sensations do. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Can Feelings "Feel" Wrong? Similarities Between Counter-Normative Emotion Reports and Perceptual Errors.

In popular belief, emotions are regarded as deeply subjective and thus as lacking truth value. Is this reflected at the behavioral or brain level? This work compared counter-normative emotion reports with perceptual-decision errors. Participants (university students; N = 29, 16, 40, and 60 in Experiments 1-4, respectively) were given trials comprising two tasks and were asked to (a) report their pleasant or unpleasant feelings in response to emotion-invoking pictures (emotion report) and (b) indicate the gender of faces (perceptual decision). Focusing on classical error markers, we found that the results of both tasks indicated (a) post-error slowing, (b) speed/accuracy trade-offs, (c) a heavier right tail of the reaction time distribution for errors or counter-normative responses relative to correct or normative responses, and (d) inconclusive evidence for error-related negativity in electroencephalograms. These results suggest that at both the behavioral and the brain levels, the experience of reporting counter-normative emotions is remarkably similar to that accompanying perceptual-decision errors.

The effect of a high-polyphenol Mediterranean diet (Green-MED) combined with physical activity on age-related brain atrophy: the Dietary Intervention Randomized Controlled Trial Polyphenols Unprocessed Study (DIRECT PLUS).

BACKGROUND: The effect of diet on age-related brain atrophy is largely unproven. OBJECTIVES: We aimed to explore the effect of a Mediterranean diet (MED) higher in polyphenols and lower in red/processed meat (Green-MED diet) on age-related brain atrophy. METHODS: This 18-mo clinical trial longitudinally measured brain structure volumes by MRI using hippocampal occupancy score (HOC) and lateral ventricle volume (LVV) expansion score as neurodegeneration markers. Abdominally obese/dyslipidemic participants were randomly assigned to follow 1) healthy dietary guidelines (HDG), 2) MED, or 3) Green-MED diet. All subjects received free gym memberships and physical activity guidance. Both MED groups consumed 28 g walnuts/d (+440 mg/d polyphenols). The Green-MED group consumed green tea (3-4 cups/d) and Mankai (Wolffia-globosa strain, 100 g frozen cubes/d) green shake (+800 mg/d polyphenols). RESULTS: Among 284 participants (88% men; mean age: 51 y; BMI: 31.2 kg/m2; APOE-ε4 genotype = 15.7%), 224 (79%) completed the trial with eligible whole-brain MRIs. The pallidum (-4.2%), third ventricle (+3.9%), and LVV (+2.2%) disclosed the largest volume changes. Compared with younger participants, atrophy was accelerated among those ≥50 y old (HOC change: -1.0% ± 1.4% compared with -0.06% ± 1.1%; 95% CI: 0.6%, 1.3%; P < 0.001; LVV change: 3.2% ± 4.5% compared with 1.3% ± 4.1%; 95% CI: -3.1%, -0.8%; P = 0.001). In subjects ≥ 50 y old, HOC decline and LVV expansion were attenuated in both MED groups, with the best outcomes among Green-MED diet participants, as compared with HDG (HOC: -0.8% ± 1.6% compared with -1.3% ± 1.4%; 95% CI: -1.5%, -0.02%; P = 0.042; LVV: 2.3% ± 4.7% compared with 4.3% ± 4.5%; 95% CI: 0.3%, 5.2%; P = 0.021). Similar patterns were observed among younger subjects. Improved insulin sensitivity over the trial was the parameter most strongly associated with brain atrophy attenuation (P < 0.05). Greater Mankai, green tea, and walnut intake and less red and processed meat were significantly and independently associated with reduced HOC decline (P < 0.05). Elevated urinary concentrations of the polyphenols urolithin-A (r = 0.24; P = 0.013) and tyrosol (r = 0.26; P = 0.007) were significantly associated with lower HOC decline. CONCLUSIONS: A Green-MED (high-polyphenol) diet, rich in Mankai, green tea, and walnuts and low in red/processed meat, is potentially neuroprotective for age-related brain atrophy.This trial was registered at clinicaltrials.gov as NCT03020186.

Retest Reliability of Integrated Speed-Accuracy Measures.

Cognitive tasks borrowed from experimental psychology are often used to assess individual differences. A cardinal issue of this transition from experimental to correlational designs is reduced retest reliability of some well-established cognitive effects as well as speed-accuracy trade-off. The present study aimed to address these issues by examining the retest reliability of various methods for speed-accuracy integration and by comparing between two types of task modeling: difference scores and residual scores. Results from three studies on executive functions show that (a) integrated speed-accuracy scoring is generally more reliable as compared with nonintegrated methods: mean response time and accuracy; and (b) task modeling, especially residual scores, reduced reliability. We thus recommend integrating speed and accuracy, at least for measuring executive functions.

Automatic effects of instructions: a tale of two paradigms.

When examining rapid instructed task learning behaviorally, one out of two paradigms is usually used, the Inducer-Diagnostic (I-D) and the NEXT paradigm. Even though both paradigms are supposed to examine the same phenomenon of Automatic Effect of Instructions (AEI), there are some meaningful differences between them, notably in the size of the AEI. In the current work, we examined, in two pre-registered studies, the potential reasons for these differences in AEI size. Study 1 examined the influence of the data-analytic approach by comparing two existing relatively large data-sets, one from each paradigm (Braem et al., in Mem Cogn 47:1582-1591, 2019; Meiran et al., in Neuropsychologia 90:180-189, 2016). Study 2 focused on the influence of instruction type (concrete, as in NEXT, and abstract, as in I-D) and choice complexity of the task in which AEI-interference is assessed. We did that while using variants of the NEXT paradigm, some with modifications that approximated it to the I-D paradigm. Results from Study 1 indicate that the data-analytic approach partially explains the differences between the paradigms in terms of AEI size. Still, the paradigms remained different with respect to individual differences and with respect to AEI size in the first step following the instructions. Results from Study 2 indicate that Instruction type and the choice complexity in the phase in which AEI is assessed do not influence AEI size, or at least not in the expected direction. Theoretical and study-design implications are discussed.

Perspectives, they might be a-changin': A proactive-control take on the cognitive cost of maintaining one's own perspective.

The world abounds with different perspectives, which necessitates balancing between maintaining the currently relevant perspective and flexibly switching between perspectives, if needed. Employing the distinction between reactive and proactive control (Braver, 2012), we argue that previous research on perspective-taking has mainly looked at the cost of activating reactive control to deal with what is happening now. Here we examine the cost of activating proactive control in order to be prepared for what might happen in the future. In three experiments, we embed a perspective-taking task (Samson et al., 2010) into a task-switching design and calculate perspective-mixing costs to capture proactive control. We show that a context in which perspective shifts might occur unpredictably (compared to a context in which such shifts are not expected) results in a poorer ability to maintain any perspective, but especially one's own. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Cognitive appraisal contributes to feeling generation through emotional evidence accumulation rate: Evidence from instructed fictional reappraisal.

How do (reportable) emotional feelings come to be? Following William James and many others, Givon et al. (2020) described the generation of feelings as evidence accumulation toward a boundary. In this work, we began clarifying the nature of "evidence". In two preregistered experiments, participants were presented with normed emotion-evoking negative/positive pictures that were described as reflecting either authentic or fictitious happenings ("fictional reappraisal"). In negative pictures (but contrary to our predictions, not in positive pictures), fictional reappraisal slowed feeling reports and reduced the rate of unpleasant feeling reports. An evidence accumulation model, the Hierarchical Linear Ballistic Accumulator model, was fit to the results from negative stimuli. This analysis indicated that fictional reappraisal selectively slowed the rate of evidence accumulation favoring (the normatively "correct") unpleasant feeling reports and speeded evidence accumulation favoring (the normatively "wrong") pleasant feeling reports. Fictional reappraisal did not change the response criterion, specifying the required amount of evidence for report. These results suggest that cognitive appraisals contribute to (and are a part of) emotional evidence, as operationalized in evidence accumulation models, and provide additional support for the usefulness of these models for the study of feeling reports. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Learning the Abstract General Task Structure in a Rapidly Changing Task Content.

The ability to learn abstract generalized structures of tasks is crucial for humans to adapt to changing environments and novel tasks. In a series of five experiments, we investigated this ability using a Rapid Instructed Task Learning paradigm (RITL) comprising short miniblocks, each involving two novel stimulus-response rules. Each miniblock included (a) instructions for the novel stimulus-response rules, (b) a NEXT phase involving a constant (familiar) intervening task (0-5 trials), (c) execution of the newly instructed rules (2 trials). The results show that including a NEXT phase (and hence, a prospective memory demand) led to relatively more robust abstract learning as indicated by increasingly faster responses with experiment progress. Multilevel modeling suggests that the prospective memory demand was just another aspect of the abstract task structure which has been learned.

Neural correlates of future weight loss reveal a possible role for brain-gastric interactions.

Lifestyle dietary interventions are an essential practice in treating obesity, hence neural factors that may assist in predicting individual treatment success are of great significance. Here, in a prospective, open-label, three arms study, we examined the correlation between brain resting-state functional connectivity measured at baseline and weight loss following 6 months of lifestyle intervention in 92 overweight participants. We report a robust subnetwork composed mainly of sensory and motor cortical regions, whose edges correlated with future weight loss. This effect was found regardless of intervention group. Importantly, this main finding was further corroborated using a stringent connectivity-based prediction model assessed with cross-validation thus attesting to its robustness. The engagement of senso-motor regions in this subnetwork is consistent with the over-sensitivity to food cues theory of weight regulation. Finally, we tested an additional hypothesis regarding the role of brain-gastric interaction in this subnetwork, considering recent findings of a cortical network synchronized with gastric activity. Accordingly, we found a significant spatial overlap with the subnetwork reported in the present study. Moreover, power in the gastric basal electric frequency within our reported subnetwork negatively correlated with future weight loss. This finding was specific to the weight loss related subnetwork and to the gastric basal frequency. These findings should be further corroborated by combining direct recordings of gastric activity in future studies. Taken together, these intriguing results may have important implications for our understanding of the etiology of obesity and the mechanism of response to dietary intervention.

Power of instructions for task implementation: superiority of explicitly instructed over inferred rules.

"Power of instructions" originally referred to automatic response activation associated with instructed rules, but previous examination of the power of instructed rules in actual task implementation has been limited. Typical tasks involve both explicit aspects (e.g., instructed stimulus-response mapping rules) and implied, yet easily inferred aspects (e.g., be ready, attend to error beeps) and it is unknown if inferred aspects also become readily executable like their explicitly instructed counterparts. In each mini-block of our paradigm we introduced a novel two-choice task. In the instructions phase, one stimulus was explicitly mapped to a response; whereas the other stimulus' response mapping had to be inferred. Results show that, in most cases, explicitly instructed rules were implemented more efficiently than inferred rules, but this advantage was observed only in the first trial following instructions (though not in the first implementation of the rules), which suggests that the entire task set was implemented in the first trial. Theoretical implications are discussed.

Enhancing task-demands disrupts learning but enhances transfer gains in short-term task-switching training.

Content variability was previously suggested to promote stronger learning effects in cognitive training whereas less variability incurred transfer costs (Sabah et al. Psychological Research, https://doi.org/10.1007/s00426-018-1006-7 , 2018). Here, we expanded these findings by additionally examining the role of learners' control in short-term task-switching training by comparing voluntary task-switching to a yoked control forced task-switching condition. To this end, four training conditions were compared: (1) forced fixed content, (2) voluntary fixed content, (3) forced varied content, and (3) voluntary varied content. To further enhance task demands, bivalent stimuli were used during training. Participants completed baseline assessment commencing with task-switching and verbal fluency blocks, followed by seven training blocks and last by task-switching (near transfer) and verbal fluency (far transfer) blocks, respectively. For the baseline and transfer task-switching blocks, we used the exact same baseline and first transfer block from Sabah et al. (Psychological Research, https://doi.org/10.1007/s00426-018-1006-7 , 2018), employing univalent stimuli and alternating-runs task sequence. Our results pointed again to the contribution of content variability to task-switching performance. No indications for far transfer were observed. Allowing for learners' control was not found to produce additional transfer gains beyond content variability. A between-study comparison suggests that enhanced task demands, by means of bivalency, promoted higher transfer gains in the current study when compared to Sabah et al. (Psychological Research, https://doi.org/10.1007/s00426-018-1006-7 , 2018). Taken together, the current results provide further evidence to the beneficial impact of variability on training outcomes. The lack of modulatory effect for learners' control is discussed in relation to possible methodological limitations.

Effects of neurofeedback and working memory-combined training on executive functions in healthy young adults.

Given the interest in improving executive functions, the present study examines a promising combination of two training techniques: neurofeedback training (NFT) and working memory training (WMT). NFT targeted increasing the amplitude of individual's upper Alpha frequency band at the parietal midline scalp location (Pz), and WMT consisted of an established computerized protocol with working memory updating and set-shifting components. Healthy participants (n = 140) were randomly allocated to five combinations of training, including visual search training used as an active control training for the WMT; all five groups were compared to a sixth silent control group receiving no training. All groups were evaluated before and after training for resting-state electroencephalogram (EEG) and behavioral executive function measures. The participants in the silent control group were unaware of this procedure, and received one of the training protocols only after study has ended. Results demonstrated significant improvement in the practice tasks in all training groups including non-specific influence of NFT on resting-state EEG spectral topography. There was only a near transfer effect (improvement in working memory task) for WMT, which remained significant in the delayed post-test (after 1 month), in comparison to silent control group but not in comparison to active control training group. The NFT + WMT combined group showed improved mental rotation ability both in the post-training and in the follow-up evaluations. This improvement, however, did not differ significantly from that in the silent control group. We conclude that the current training protocols, including their combination, have very limited influence on the executive functions that were assessed in this study.

Stimulus- and response-based interference contributes to the costs of switching between cognitive tasks.

Little is known about how stimulus- and response-based interference might interact to contribute to the costs of switching between cognitive tasks. We analyzed switch costs in a novel cued task-switching/card-matching paradigm in a large study (N = 95). We reasoned that interference from previously active task sets may be contingent upon the retrieval of these task sets via stimulus processing, or alternatively, via response processing. We examined the efficacy of these two factors through eligibility manipulations. That is, stimulus/response features that were capable of retrieving task sets from the previous trial remained eligible (or not) on the current trial. We report three main findings: first, no switch costs were found when neither stimulus features, nor response features, were adequate for the retrieval of the previously executed task sets. Second, we found substantial switch costs when, on switch trials, stimulus features kept the previously executed task eligible, and we found roughly equivalent switch costs when the previously executed response remained eligible. Third, evidence for stimulus-induced switch costs was exclusively observed when previously executed responses remained ineligible. These data indicate that stimulus-based interference, and of importance, response-based interference, contribute comparably to switch costs. Possible interpretations of non-additive switch costs are discussed.

How does the emotional experience evolve? Feeling generation as evidence accumulation.

How do people answer the question "How do you feel?" In the present work, participants were given 2 tasks in each trial. They first indicated whether a picture made them feel pleasant (or was supposed to be felt as pleasant, in another group), and then made gender decisions regarding faces. Evidence accumulation modeling showed that (a) reporting genuine feeling is qualitatively different from reporting the supposed feeling; (b) reporting one's feeling is remarkably similar to gender decisions; and (c) evidence regarding negative feelings accumulates more quickly than in positive feelings. These results support the assumption that when asked, participants report genuine as opposed to supposed feelings and strengthen the analogy between feeling reports and perceptual decisions. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Rapid instructed task learning (but not automatic effects of instructions) is influenced by working memory load.

The ability to efficiently perform actions immediately following instructions and without prior practice has previously been termed Rapid Instructed Task Learning (RITL). In addition, it was found that instructions are so powerful that they can produce automatic effects, reflected in activation of the instructions in an inappropriate task context. RITL is hypothesized to rely on limited working memory (WM) resources for holding not-yet implemented task rules. Similarly, automatic effects of instructions presumably reflect the operation of task rules kept in WM. Therefore, both were predicted to be influenced by WM load. However, while the involvement of WM in RITL is implicated from prior studies, evidence regarding WM involvement in instructions-based automaticity is mixed. In the current study, we manipulated WM load by increasing the number of novel task rules to be held in WM towards performance in the NEXT paradigm. In this task, participants performed a series of novel tasks presented in mini-blocks, each comprising a) instructions of novel task rules; b) a NEXT phase measuring the automatic activation of these instructed rules, in which participants advance the screen using a key-press; and c) a GO phase in which the new rules are first implemented and RITL is measured. In three experiments, we show a dissociation: While RITL (rule implementation) was impaired by increased WM load, the automatic effects of instructions were not robustly influenced by WM load. Theoretical implications are discussed.