Electrophysiological correlates of self-specific prediction errors in the human brain.

Recognising one's self, vs. others, is a key component of self-awareness, crucial for social interactions. Here we investigated whether processing self-face and self-body images can be explained by the brain's prediction of sensory events, based on regularities in the given context. We measured evoked cortical responses while participants observed alternating sequences of self-face or other-face images (experiment 1) and self-body or other-body images (experiment 2), which were embedded in an identity-irrelevant task. In experiment 1, the expected sequences were violated by deviant morphed images, which contained 33%, 66% or 100% of the self-face when the other's face was expected (and vice versa). In experiment 2, the anticipated sequences were violated by deviant images of the self when the other's image was expected (and vice versa), or by two deviant images composed of pictures of the self-face attached to the other's body, or the other's face attached to the self-body. This manipulation allowed control of the prediction error associated with the self or the other's image. Deviant self-images (but not deviant images of the other) elicited a visual mismatch response (vMMR)--a cortical index of violations of regularity. This was source localised to face and body related visual, sensorimotor and limbic areas and had amplitude proportional to the amount of deviance from the self-image. We provide novel evidence that self-processing can be described by the brain's prediction error system, which accounts for self-bias in visual processing. These findings are discussed in the light of recent predictive coding models of self-processing

When empathy leads to aggression: The effects of empathy on punitive attitudes towards aggressors

When witnessing aggression, individuals often empathise more with victims than with aggressors, which may bias their perceptions and interpretations of the transgressions. However, the mechanisms underlying these biases remain poorly understood. Through two experiments, we investigated whether people’s decisions to condemn aggressors are influenced by their predisposition to sympathise with the victim and explored how negative sentiments towards the aggressor may influence these decisions. Further, we tested the moderating role of callous-unemotional traits, hypothesising that moral judgements and decisions to punish may differ among individuals who are less emotionally responsive, as they are less likely to sympathise with victims. Our findings revealed that greater empathy for victims intensified punitive attitudes towards aggressors, primarily mediated by participants’ negative evaluations of the aggressor. Notably, such empathic inclinations were less prevalent among individuals with higher levels of callous-unemotional traits, as reflected by their lower concern for victims and greater inclination towards harsh punishments. These results offer insights into how justice-related attitudes may be shaped and potentially biased by individual differences in emotional responsiveness

Encouraging expressions affect the brain and alter visual attention

Background Very often, encouraging or discouraging expressions are used in competitive contexts, such as sports practice, aiming at provoking an emotional reaction on the listener and, consequently, an effect on subsequent cognition and/or performance. However, the actual efficiency of these expressions has not been tested scientifically. Methodology/Principal Findings To fill this gap, we studied the effects of encouraging, discouraging, and neutral expressions on event-related brain electrical activity during a visual selective attention task in which targets were determined by location, shape, and color. Although the expressions preceded the attentional task, both encouraging and discouraging messages elicited a similar long-lasting brain emotional response present during the visuospatial task. In addition, encouraging expressions were able to alter the customary working pattern of the visual attention system for shape selection in the attended location, increasing the P1 and the SP modulations while simultaneously fading away the SN. Conclusions/Significance This was interpreted as an enhancement of the attentional processes for shape in the attended location after an encouraging expression. It can be stated, therefore, that encouraging expressions, as those used in sport practice, as well as in many other contexts and situations, do seem to be efficient in exerting emotional reactions and measurable effects on cognition

How Is Sentence Processing Affected by External Semantic and Syntactic Information? Evidence from Event-Related Potentials

BACKGROUND: A crucial question for understanding sentence comprehension is the openness of syntactic and semantic processes for other sources of information. Using event-related potentials in a dual task paradigm, we had previously found that sentence processing takes into consideration task relevant sentence-external semantic but not syntactic information. In that study, internal and external information both varied within the same linguistic domain-either semantic or syntactic. Here we investigated whether across-domain sentence-external information would impact within-sentence processing. METHODOLOGY: In one condition, adjectives within visually presented sentences of the structure [Det]-[Noun]-[Adjective]-[Verb] were semantically correct or incorrect. Simultaneously with the noun, auditory adjectives were presented that morphosyntactically matched or mismatched the visual adjectives with respect to gender. FINDINGS: As expected, semantic violations within the sentence elicited N400 and P600 components in the ERP. However, these components were not modulated by syntactic matching of the sentence-external auditory adjective. In a second condition, syntactic within-sentence correctness-variations were combined with semantic matching variations between the auditory and the visual adjective. Here, syntactic within-sentence violations elicited a LAN and a P600 that did not interact with semantic matching of the auditory adjective. However, semantic mismatching of the latter elicited a frontocentral positivity, presumably related to an increase in discourse level complexity. CONCLUSION: The current findings underscore the open versus algorithmic nature of semantic and syntactic processing, respectively, during sentence comprehension

Self-Association and Attentional Processing Regarding Perceptually Salient Items

Earlier work has demonstrated that attention is indirectly cognitively malleable by processes of self-association – processes by which agents explicitly associate an item with the self. We extend this work by considering the manipulation of attention to both salient and non-salient objects. We demonstrate that self-association impacts attentional processing not only of non-salient objects (i.e., shapes), but also regarding salient items known to command attention (i.e., images of food). This result indicates the flexibility and susceptibility of attentional processing to cognitive manipulation

The somatotopy of observed emotions

The ability to experience others’ emotional states is a key component in social interactions. Uniquely among sensorimotor regions, the somatosensory cortex (SCx) plays an especially important role in human emotion understanding. While distinct emotions are experienced in specific parts of the body, it remains unknown whether the SCx exhibits somatotopic activations to different emotional expressions. In the current study, we investigated if the affective response triggered by observing others’ emotional face expressions leads to differential activations in SCx. Participants performed a visual facial emotion discrimination task while we measured changes in SCx topographic EEG activity by tactually stimulating two body-parts representative of the upper and lower limbs, the finger and the toe respectively. The results of the study showed an emotion specific response in the finger SCx when observing angry as opposed to sad emotional expressions, after controlling for carry-over effects of visual evoked activity. This dissociation to observed emotions was not present in toe somatosensory responses. Our results suggest that somatotopic activations of the SCx to discrete emotions might play a crucial role in understanding others’ emotions

Do non-traumatic stressful life events and ageing negatively impact working memory performance and do they interact to further impair working memory performance?

Stress and normal ageing produce allostatic load, which may lead to difficulties with cognition thereby degrading quality of life. The current study’s objective was to assess whether ageing and cumulative stress interact to accelerate cognitive decline. With 60 participants, Marshall et al. found that ageing and cumulative stress interact significantly to impair working memory performance in older adults, suggesting vulnerability to the cumulative effects of life events beyond 60 years old. To replicate and extend this finding, we increased the sample size by conducting 3 independent studies with 156 participants and improved the statistical methods by conducting an iterative Bayesian meta-analysis with Bayes factors. Bayes factors deliver a more comprehensive result because they provide evidence for either the null hypothesis (H0), the alternative hypothesis (H1) or for neither hypothesis due to evidence not being sufficiently sensitive. Young (18-35 yrs) and older (60-85 yrs) healthy adults were categorised as high or low stress based on their life events score derived from the Life Events Scale for Students or Social Readjustment Rating Scale, respectively. We measured accuracy and reaction time on a 2-back working memory task to provide: a) Bayes factors and b) Bayesian meta-analysis, which iteratively added each study’s effect sizes to evaluate the overall strength of evidence that ageing, cumulative stress and/or the combination of the two detrimentally affect working memory performance. Using a larger sample (N=156 vs. N=60) and a more powerful statistical approach, we did not replicate the robust age by cumulative stress interaction effect found by Marshall et al.. The effects of ageing and cumulative stress also fell within the anecdotal range (⅓<BF<3). We therefore conclude that there was inconclusive statistical evidence, as measured with a life events scale, that ageing and cumulative life stress interact to accelerate cognitive decline

Changing connectivity between premotor and motor cortex changes inter-areal communication in the human brain.

The ventral premotor cortex (PMv) is an important component of cortico-cortical pathways mediating prefrontal control over primary motor cortex (M1) function. Paired associative stimulation (ccPAS) is known to change PMv influence over M1 in humans, which manifests differently depending on the behavioural context. Here we show that these changes in influence are functionally linked to PMv-M1 phase synchrony changes induced by repeated paired stimulation of the two areas. PMv-to-M1 ccPAS leads to increased phase synchrony in alpha and beta bands, while reversed order M1-to-PMv ccPAS leads to decreased theta phase synchrony. These changes are visible at rest but are predictive of changes in oscillatory power in the same frequencies during movement execution and inhibition, respectively. The results unveil a link between the physiology of the motor network and the resonant frequencies mediating its interactions and provide a putative mechanism underpinning the relationship between synaptic efficacy and brain oscillations

The Social Readjustment Rating Scale: updated and modernised

The Social Readjustment Rating Scale, originally devised in 1967 by Holmes and Rahe, measures the impact of life events stress. At the time, the SRRS advanced its field of research by standardising the impact of stress with a set of independently derived weights called ‘life change units’ (LCUs) for 43 life events found to predict illness onset. The scale has been criticised for being outdated, e.g. “Mortgage over $10,000” and biased, e.g. “Wife begin or stop work”. The aim of this cross-sectional survey study is to update and improve the SRRS whilst allowing backwards compatibility. We successfully updated the SRRS norms/LCUs using the ratings of 540 predominantly UK adults aged 18 to 84. Moreover, we also updated wording of 12 SRRS items and evaluated the impact of demographics, personal experience and loneliness. Using non-parametric frequentist and Bayesian statistics we found that the updated weights were higher but broadly consistent with those of the original study. Furthermore, changes to item wording did not affect raters’ evaluations relative to the original thereby ensuring cross-comparability with the original SRRS. The raters were not unduly influenced by their personal experiences of events nor loneliness. The target sample was UK rather than US-based and was proportionately representative regarding age, sex and ethnicity. Moreover, the age range was broader than the original SRRS. In addition, we modernised item wording, added one optional extra item to the end of the scale to evaluate the readjustment to living alone and identified 3 potential new items proposed by raters. Backwards-compatibility is maintained

Cortico-cortical paired-associative stimulation to investigate the plasticity of cortico-cortical visual networks in humans

Cortico-cortical paired-associative stimulation (ccPAS) is an advanced dual-site transcranial magnetic stimulation technique that exploits the Hebbian principle to induce plastic changes in functional networks and modulate interactions between cortical brain regions. This review summarizes the growing body of ccPAS research on network dynamics underpinning visual perception. Studies revealed a functional dissociation within cortico-cortical connections in the visual system, where distinct hierarchically organized circuits shape diverse aspects of visual processing, including motion perception, emotion recognition, and metacognitive judgments. Prospective applications integrating ccPAS with neuroimaging techniques such as EEG/MEG hold promise for fine-tuning interventions and gaining deeper insights into visual system network dynamics and functional architecture, with potential clinical applications in neurological and psychiatric conditions