neuronavigated-focalized-transcranial-direct-current-stimulation

Neuronavigated Focalized Transcranial Direct Current Stimulation Administered During Functional Magnetic Resonance Imaging

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that allows the modulation of the excitability and plasticity ...

University of Kent

Kent Medway Medical School

A prominent theory claims that the right temporoparietal junction (rTPJ) is especially associated with embodied processes relevant to perspective-taking. In the present study, we use high-definition transcranial direct current stimulation to provide evidence that the rTPJ is causally associated with the embodied processes underpinning perspective-taking. Eighty-eight young human adults were stratified to receive either rTPJ or dorsomedial PFC anodal high-definition transcranial direct current stimulation in a sham-controlled, double-blind, repeated-measures design. Perspective-tracking (line-of-sight) and perspective-taking (embodied rotation) were assessed using a visuo-spatial perspective-taking task that required understanding what another person could see or how they see it, respectively. Embodied processing was manipulated by positioning the participant in a manner congruent or incongruent with the orientation of an avatar on the screen. As perspective-taking, but not perspective-tracking, is influenced by bodily position, this allows the investigation of the specific causal role for the rTPJ in embodied processing. Crucially, anodal stimulation to the rTPJ increased the effect of bodily position during perspective-taking, whereas no such effects were identified during perspective-tracking, thereby providing evidence for a causal role for the rTPJ in the embodied component of perspective-taking. Stimulation to the dorsomedial PFC had no effect on perspective-tracking or taking. Therefore, the present study provides support for theories postulating that the rTPJ is causally involved in embodied cognitive processing relevant to social functioning. The ability to understand another's perspective is a fundamental component of social functioning. Adopting another perspective is thought to involve both embodied and nonembodied processes. The present study used high-definition transcranial direct current stimulation (HD-tDCS) and provided causal evidence that the right temporoparietal junction is involved specifically in the embodied component of perspective-taking. Specifically, HD-tDCS to the right temporoparietal junction, but not another hub of the social brain (dorsomedial PFC), increased the effect of body position during perspective-taking, but not tracking. This is the first causal evidence that HD-tDCS can modulate social embodied processing in a site-specific and task-specific manner.

The Right Temporoparietal Junction Is Causally Associated with Embodied Perspective-taking.

This study investigated effects of multisession transcranial direct-current stimulation on learning and maintenance of novel memory content and scrutinised effects of baseline cognitive status and the role of multi-session tDCS on overnight memory consolidation. In a prospective, randomized, double-blind, parallel-group, sham-tDCS controlled design, 101 healthy young and older adults completed a five-day verbal associative learning paradigm while receiving multisession tDCS to the task-relevant left prefrontal cortex. In older adults, active multisession tDCS enhanced recall performance after each daily training session. Effects were maintained the next morning and during follow-up assessments (one week; three months). In young adults, multisession tDCS significantly increased long-term recall. Unlike previous findings in the motor domain, beneficial effects of multisession tDCS on cognitive learning and memory were notexclusively due to enhanced memory consolidation. Positive stimulation effects were primarily found in participants with lower baseline learning ability, suggesting that multisession tDCS may counteract memory impairment in health and disease.

Multisession transcranial direct current stimulation facilitates verbal learning and memory consolidation in young and older adults.

Low-intensity transcranial electrical stimulation (tES), including alternating or direct current stimulation, applies weak electrical stimulation to modulate the activity of brain circuits. Integration of tES with concurrent functional MRI (fMRI) allows for the mapping of neural activity during neuromodulation, supporting causal studies of both brain function and tES effects. Methodological aspects of tES-fMRI studies underpin the results, and reporting them in appropriate detail is required for reproducibility and interpretability. Despite the growing number of published reports, there are no consensus-based checklists for disclosing methodological details of concurrent tES-fMRI studies. The objective of this work was to develop a consensus-based checklist of reporting standards for concurrent tES-fMRI studies to support methodological rigor, transparency and reproducibility (ContES checklist). A two-phase Delphi consensus process was conducted by a steering committee (SC) of 13 members and 49 expert panelists through the International Network of the tES-fMRI Consortium. The process began with a circulation of a preliminary checklist of essential items and additional recommendations, developed by the SC on the basis of a systematic review of 57 concurrent tES-fMRI studies. Contributors were then invited to suggest revisions or additions to the initial checklist. After the revision phase, contributors rated the importance of the 17 essential items and 42 additional recommendations in the final checklist. The state of methodological transparency within the 57 reviewed concurrent tES-fMRI studies was then assessed by using the checklist. Experts refined the checklist through the revision and rating phases, leading to a checklist with three categories of essential items and additional recommendations: (i) technological factors, (ii) safety and noise tests and (iii) methodological factors. The level of reporting of checklist items varied among the 57 concurrent tES-fMRI papers, ranging from 24% to 76%. On average, 53% of checklist items were reported in a given article. In conclusion, use of the ContES checklist is expected to enhance the methodological reporting quality of future concurrent tES-fMRI studies and increase methodological transparency and reproducibility.

A checklist for assessing the methodological quality of concurrent tES-fMRI studies (ContES checklist): a consensus study and statement.

Socio-cognitive abilities and challenges change across the healthy lifespan and are essential for successful human interaction. Identifying effective socio-cognitive training approaches for healthy individuals may prevent development of mental or physical disease and reduced quality of life. A systematic search was conducted in MEDLINE Ovid, Web of Science Core Collection, CENTRAL, and PsycInfo databases. Studies that investigated different socio-cognitive trainings for healthy individuals across the human lifespan assessing effects on theory of mind, emotion recognition, perspective taking, and social decision making were included. A random-effects pairwise meta-analysis was conducted. Risk-of-Bias was assessed using the Cochrane Risk-of-Bias-2-Tool. Twenty-three intervention studies with N = 1835 participants were included in the systematic review; twelve randomized controlled trials in the meta-analysis (N = 875). Socio-cognitive trainings differed regarding duration and content in different age groups, with theory of mind being the domain most frequently trained. Results of the meta-analysis showed that trainings were highly effective for improving theory of mind in children aged 3-5 years (SMD = 2.51 (95%CI: 0.48-4.53)), children aged 7-9 years (SMD = 2.71 (95%CI: - 0.28 to 5.71)), and older adults (SMD = 5.90 (95%CI: 2.77-9.02). Theory of mind training was highly effective in all investigated age-groups for improving theory of mind, yet, more research on transfer effects to other socio-cognitive processes and further investigation of training effects in other socio-cognitive domains (e.g., emotion recognition, visual perspective taking, social decision making) is needed. Identified characteristics of successful socio-cognitive trainings in different age groups may help designing future training studies for other populations.Registration: www.crd.york.ac.uk/PROSPERO/ (ID: CRD42020193297).

A systematic review and meta-analysis of social cognition training success across the healthy lifespan.

Trajectories of decline across different socio-cognitive domains in healthy older adults and in pathological aging conditions have not been investigated. This was addressed in the present systematic review and meta-analysis.

Progression of socio-cognitive impairment from healthy aging to Alzheimer's dementia: A systematic review and meta-analysis.

A sense of agency (SoA) over wilful actions is thought to be dependent on the level of choice and the nature of the outcome. In a preregistered study, we manipulated choice and valence of outcome to assess the relationship between SoA across the depression and psychosis continuum. Participants (N = 151) completed a Libet Clock task, in which they had either a free or forced choice to press one of two buttons and received either a rewarding or punishing outcome. Participants also completed questionnaires on depressive and psychosis-like traits. Rewarding outcomes increased intentional binding. The evidence favoured no effect of choice on average, but this was influenced by inter-individual differences. Individuals reporting more depressive traits had less of a difference in intentional binding between free and forced choice conditions. We show that implicit SoA is sensitive to outcome valence and the effect of choice differs across the depression continuum.

Depressive traits are associated with a reduced effect of choice on intentional binding.

Body image concern (BIC) is a prevalent issue thought to be exacerbated by social media. In addition to sociocultural factors, cognitive biases may also contribute to BIC. We explore whether cognitive biases in memory for body image-related words, presented in a mock social-media context, are associated with BIC in young adult women. A sample of 150 university students was presented with a series of body image-related comments aimed at either themselves, a close friend, or a celebrity in a recognisable social media context. Afterwards, a surprise memory task was completed that assessed the participant's memory for body image-related words (item memory), their insight (metamemory), and to whom a specific word was directed (source memory). Self-referential biases were identified for both item memory and source memory. Individuals with greater BIC displayed a greater self-referential bias for correctly and incorrectly sourcing negative words to themselves compared with both friend and celebrity. A greater self-referential effect in metacognitive sensitivity was also associated with higher BIC. We provide novel evidence for a cognitive bias in sourcing negative body image-related information to the self in individuals with higher BIC. The results should inform cognitive remediation programmes aimed at treating individuals with body and eating-related disorders.

Negative comments and social media: How cognitive biases relate to body image concerns.

Loneliness describes a negative experience associated with perceived social disconnection. Despite the clear links between loneliness and mental and physical health, relatively little is known about how loneliness affects cognition. In this study, we tested the effect of loneliness on cognitive distance between the self and others, using a task in which participants completed a surprise memory task for adjectives implicitly encoded in relation to the self, a close friend or a celebrity. We assessed item memory sensitivity, metacognitive sensitivity, metacognitive efficiency and source memory for positive and negative words. In addition, participants reported their trait loneliness and depression. Results revealed an overall self-referential advantage compared with both friend and celebrity encoded items. Likewise, a friend-referential advantage was identified compared to celebrity-encoded items. Individuals who experienced more loneliness showed a greater self-referential bias in comparison to words encoded in relation to a close friend, and a smaller friend-referential bias in comparison to words encoded in relation to celebrity. These findings suggest that loneliness is reflected in a greater cognitive distance between the self and close friends in relation to memory biases. The results have important implications for understanding the social contextual effects on memory and the cognitive ramifications of loneliness.

Loneliness is associated with a greater self-reference effect in episodic memory when compared against a close friend.

Older adults have difficulties to detect the intentions, thoughts, and feelings of others, indicating an age-associated decline of socio-cognitive abilities that are known as "mentalizing". These deficits in mental state recognition are driven by neurofunctional alterations in brain regions that are implicated in mentalizing, such as the right temporo-parietal junction (rTPJ) and the dorso-medial prefrontal cortex (dmPFC). We tested whether focal transcranial current stimulation (tDCS) of the rTPJ and dmPFC has the potential to eliminate mentalizing deficits in older adults. Mentalizing deficits were assessed with a novel mindreading task that required the recognition of mental states in child faces. Older adults (n = 60) performed worse than younger adults (n = 30) on the mindreading task, indicating age-dependent deficits in mental state recognition. These mentalizing deficits were ameliorated in older adults who received sham-controlled andodal tDCS over the rTPJ (n = 30) but remained unchanged in older adults who received sham-controlled andodal tDCS over the dmPFC (n = 30). We, thus, showed for the first time that anodal tDCS over the rTPJ has the potential to remediate age-dependent mentalizing deficits in a region-specific way. This provides a rationale for exploring stimulation-based interventions targeting mentalizing deficits in older age.

Article	Year
The Right Temporoparietal Junction Is Causally Associated with Embodied Perspective-taking. The Journal of neuroscience : the official journal of the Society for Neuroscience\| PubMed ID: 32132264	2020
Multisession transcranial direct current stimulation facilitates verbal learning and memory consolidation in young and older adults. Brain and language\| PubMed ID: 32199339	2020
A checklist for assessing the methodological quality of concurrent tES-fMRI studies (ContES checklist): a consensus study and statement. Nature protocols\| PubMed ID: 35121855	2022
A systematic review and meta-analysis of social cognition training success across the healthy lifespan. Scientific reports\| PubMed ID: 35241715	2022
Progression of socio-cognitive impairment from healthy aging to Alzheimer's dementia: A systematic review and meta-analysis. Neuroscience and biobehavioral reviews\| PubMed ID: 35905800	2022
Depressive traits are associated with a reduced effect of choice on intentional binding. Consciousness and cognition\| PubMed ID: 36087487	2022
Negative comments and social media: How cognitive biases relate to body image concerns. Body image\| PubMed ID: 36812802	2023
Loneliness is associated with a greater self-reference effect in episodic memory when compared against a close friend. British journal of psychology (London, England : 1953)\| PubMed ID: 37022204	2023
Improving mentalizing deficits in older age with region-specific transcranial direct current stimulation. GeroScience\| PubMed ID: 38878152	2024

Andrew K. Martin

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