Improving Cross-cultural "Mind-reading" with Electrical Brain Stimulation

The Effects of Transcranial Direct Current Stimulation (tDCS) on the Cognitive Functions: A Systematic Review and Meta-analysis

Previous studies have investigated the effect of transcranial direct current stimulation (tDCS) on cognitive functions. However, these studies reported inconsistent results due to differences in experiment design, measurements, and stimulation parameters. Nonetheless, there is a lack of meta-analyses and review studies on tDCS and its impact on cognitive functions, including working memory, inhibition, flexibility, and theory of mind. We performed a systematic review and meta-analysis of tDCS studies published from the earliest available data up to October 2021, including studies reporting the effects of tDCS on cognitive functions in human populations. Therefore, these systematic review and meta-analysis aim to comprehensively analyze the effects of anodal and cathodal tDCS on cognitive functions by investigating 69 articles with a total of 5545 participants. Our study reveals significant anodal tDCS effects on various cognitive functions. Specifically, we observed improvements in working memory reaction time (RT), inhibition RT, flexibility RT, theory of mind RT, working memory accuracy, theory of mind accuracy and flexibility accuracy. Furthermore, our findings demonstrate noteworthy cathodal tDCS effects, enhancing working memory accuracy, inhibition accuracy, flexibility RT, flexibility accuracy, theory of mind RT, and theory of mind accuracy. Notably, regarding the influence of stimulation parameters of tDCS on cognitive functions, the results indicated significant differences across various aspects, including the timing of stimulation (online vs. offline studies), population type (clinical vs. healthy studies), stimulation duration (< 15 min vs. > 15 min), electrical current intensities (1-1.5 m.A vs. > 1.5 m.A), stimulation sites (right frontal vs. left frontal studies), age groups (young vs. older studies), and different cognitive tasks in each cognitive functioning aspect. In conclusion, our results demonstrate that tDCS can effectively enhance cognitive task performance, offering valuable insights into the potential benefits of this method for cognitive improvement.

Reading language of the eyes

The need for assessment of social skills in clinical and neurotypical populations has led to the widespread, and still increasing use of the 'Reading the Mind in the Eyes Test' (RMET) developed more than two decades ago by Simon Baron-Cohen and colleagues for evaluation of social cognition in autism. By analyzing most recent clinical and brain imaging data, we illuminate a set of factors decisive for using the RMET. Converging evidence indicates: (i) In neurotypical individuals, RMET scores are tightly correlated with other social skills (empathy, emotional intelligence, and body language reading); (ii) The RMET assesses recognition of facial affect, but also heavily relies on receptive language skills, semantic knowledge, and memory; (iii) RMET performance is underwritten by the large-scale ensembles of neural networks well-outside the social brain; (iv) The RMET is limited in its capacity to differentiate between neuropsychiatric conditions as well as between stages and severity of a single disorder, though it reliably distinguishes individuals with altered social cognition or elevated pathological traits from neurotypical persons; (v) Merely gender (as a social construct) rather than neurobiological sex influences performance on the RMET; (vi) RMET scores do not substantially decline in healthy aging, and they are higher with higher education level, cognitive abilities, literacy, and mental well-being; (vii) Accuracy on the RMET, and engagement of the social brain, are greater when emotions are expressed and recognized by individuals with similar cultural/ethnic background. Further research is required to better inform usage of the RMET as a tool for swift and reliable examination of social cognition. In light of comparable visual input from the RMET images and faces covered by masks due to COVID-19 regulations, the analysis is of value for keeping efficient social interaction during the current pandemic, in particular, in professional settings related to social communication.

A cross-modal component of alexithymia and its relationship with performance in a social cognition task battery

BACKGROUND

The personality trait alexithymia describes an altered emotional awareness that is associated with a range of social impairments and constitutes a transdiagnostic risk factor for various psychopathologies. Despite the characteristic interoceptive deficits in alexithymia, it is predominantly assessed via self-reports. This can result in unreliable measurements and arguably contributes to the prevailing uncertainty regarding its components, including constricted imaginal processes and emotional reactivity.

METHODS

The current study employed an interview and two validated questionnaires to derive a shared component of multi-modally assessed alexithymia in a German non-clinical sample (n = 78) via prinicipal component analysis. This component was used as a predictor for performance in four behavioural social cognition tasks. The relative importance of this predictor against related variables was assessed via dominance analysis.

RESULTS

The identified component reflected cognitive alexithymia. Higher cognitive alexithymia scores were associated with less affective distress in an ostracizing task. Dominance analysis revealed the dominance of competing autism traits relative to cognitive alexithymia and competing predictors empathy, depression, and anxiety, in predicting affective distress.

LIMITATIONS

Emotional reactivity was only assessed via self-report and no implicit measures of alexithymia were employed. Due to the low reliability of the self-report measure, no measure of emotional reactivity could be included in the principal component analysis.

CONCLUSIONS

Our results provide compelling evidence that cognitive interoceptive deficits are at the core of alexithymia across assessment modalities. Behavioural data suggest that these deficits result in diminished emotional sensitivity to high-pressure social situations, which may cause a lack of behavioural adaptation.

Perspectives on Rehabilitation Using Non-invasive Brain Stimulation Based on Second-Person Neuroscience of Teaching-Learning Interactions

Recent advances in second-person neuroscience have allowed the underlying neural mechanisms involved in teaching-learning interactions to be better understood. Teaching is not merely a one-way transfer of information from teacher to student; it is a complex interaction that requires metacognitive and mentalizing skills to understand others’ intentions and integrate information regarding oneself and others. Physiotherapy involving therapists instructing patients on how to improve their motor skills is a clinical field in which teaching-learning interactions play a central role. Accumulating evidence suggests that non-invasive brain stimulation (NIBS) modulates cognitive functions; however, NIBS approaches to teaching-learning interactions are yet to be utilized in rehabilitation. In this review, I evaluate the present research into NIBS and its role in enhancing metacognitive and mentalizing abilities; I then review hyperscanning studies of teaching-learning interactions and explore the potential clinical applications of NIBS in rehabilitation. Dual-brain stimulation using NIBS has been developed based on findings of brain-to-brain synchrony in hyperscanning studies, and it is delivered simultaneously to two individuals to increase inter-brain synchronized oscillations at the stimulated frequency. Artificial induction of brain-to-brain synchrony has the potential to promote instruction-based learning. The brain-to-brain interface, which induces inter-brain synchronization by adjusting the patient’s brain activity, using NIBS, to the therapist’s brain activity, could have a positive effect on both therapist-patient interactions and rehabilitation outcomes. NIBS based on second-person neuroscience has the potential to serve as a useful addition to the current neuroscientific methods used in complementary interventions for rehabilitation.

Reading Covered Faces

Covering faces with masks, due to mandatory pandemic safety regulations, we can no longer rely on the habitual daily-life information. This may be thought-provoking for healthy people, but particularly challenging for individuals with neuropsychiatric and neurodevelopmental conditions. Au fait research on reading covered faces reveals that: 1) wearing masks hampers facial affect recognition, though it leaves reliable inferring basic emotional expressions; 2) by buffering facial affect, masks lead to narrowing of emotional spectrum and dampen veridical evaluation of counterparts; 3) masks may affect perceived face attractiveness; 4) covered (either by masks or other veils) faces have a certain signal function introducing perceptual biases and prejudices; 5) reading covered faces is gender- and age-specific, being more challenging for males and more variable even in healthy aging; 6) the hampering effects of masks on social cognition occur over the globe; and 7) reading covered faces is likely to be supported by the large-scale assemblies of the neural circuits far beyond the social brain. Challenges and limitations of ongoing research and parallels to the Reading the Mind in the Eyes Test are assessed. Clarification of how masks affect face reading in the real world, where we deal with dynamic faces and have entrée to additional valuable social signals such as body language, as well as the specificity of neural networks underlying reading covered faces calls for further tailored research.