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Background While pharmacological treatments for positive symptoms of schizophrenia are widely used, their beneficial effect on negative symptoms, particularly social impairment, is insufficiently studied. Therefore, there is an increasing interest in preclinical research of potentially beneficial treatments, with mixed results. The current review aims to evaluate the efficacy of available treatments for social deficits in different animal models of schizophrenia. Study Design A systematic literature search generated 145 outcomes for the measures “total time” and “number” of social interactions. Standardized mean differences (SMD) and 95% confidence interval (CI) were calculated, and heterogeneity was tested using Q statistics in a random-effect meta-analytic model. Given the vast heterogeneity in effect sizes, the animal model, treatment group, and sample size were all examined as potential moderators. Study Results The results showed that in almost all models, treatment significantly improved social deficit (total time: SMD = 1.24; number: SMD = 1.1). The moderator analyses discovered significant subgroup differences across models and treatment subgroups. Perinatal and adult pharmacological models showed the most substantial influence of treatments on social deficits, reflecting relative pharmacological validity. Furthermore, atypical antipsychotic drugs had the highest SMD within each model subgroup. Conclusions Our findings indicate that the improvement in social interaction behaviors is dependent on the animal model and treatment family used. Implications for the preclinical and clinical fields are discussed.

The current meta-analysis investigates the efficacy of psychotherapy during psychiatric hospitalization and examines the moderating role of diagnosis and therapeutic approach.We conducted systematic searches in literature databases, including PubMed, PsycInfo, and Google Scholar. In total, 37 samples were included for the meta-analysis with a total of 4,443 patients. The primary outcome was the standardized mean differences in clinical status measured by symptomatic and functional measures.The meta-analysis of 22 samples without a control group resulted in the upper end of the medium effect size for the overall effect of treatment during psychiatric hospitalization that included psychotherapy (k = 22, Cohen's d = 0.70, and 95% Cl 0.36 to 1.04). The meta-analysis of 15 samples with a control group resulted in the upper end of the low effect size for the contribution of psychotherapy to the improvement of patients' clinical status measured by symptomatic and functional measures (k = 15, Cohen's d = 0.43, and 95% CI 0.06 to 0.81). No significant effects were uncovered for psychotherapy orientation. Diagnosis was found to moderate the contribution of psychotherapy in an inpatient setting to the improvement of patients' clinical condition.Psychotherapy during psychiatric hospitalization may be an effective treatment. Across the various samples, psychotherapy has a moderate effect on the reduction of psychiatric symptoms beyond the overall effect of ward treatment.

Idioms entail a competition between bottom-up and top-down activations of literal and figurative meanings. The present study explored the involvement of cognitive control in processing Hebrew ambiguous idioms. Fifty subjects have completed a self-paced reading task and a response inhibition, stop-signal task (SST). Subjects read 26 matched pairs of almost-identical sentences, which included ambiguous idioms (e.g., "break the ice"). The ambiguity was resolved only in the third part of the sentence, which was either literal ("on the parking lot") or figurative ("with funny stories"). Figurative disambiguation parts were read significantly faster than literal ones. The means of the absolute RT difference between the literal and figurative sentences significantly correlated with the SST cognitive control measure. A comparison between three groups of cognitive control levels validated that "Good inhibitors" in the SST were also faster in processing ambiguities. The paper discusses the generality of cognitive control in linguistic processing.

Rivalry, a relational competition, is known to increase motivation and performance. However, a systematic review and meta-analysis that examines the effect sizes is lacking. Further, most research on this topic has not considered the type of rivalry (individual versus collective) and the research field as potential moderators. We conducted a wide-scale search, looking for rivalry and performance studies, which yielded 22 papers (k = 35) with 27,771 observations that were systematically reviewed. Eighteen papers (k = 28) were eligible for a further meta-analysis, including a total of 26,215 observations. The systematic review indicated that rivalry is usually positively related to performance. Results of the meta-analysis revealed that this effect is significant and that the relationship between rivalry and performance is more robust for individual rivalry compared to group rivalry. Further analyses indicated that for group rivalry, correlations are positive and significant only in the domains of sports and donation-raising. Plain Text Abstract Rivalry is a unique and common type of competition in which the competing parties have longstanding relationships. When rivalry is present, the competing actors have an increased desire to win and invest extra effort into the competition, leading to enhanced performance. However, an integration of studies that examine the effects of rivalry, as a relational competition, is lacking. Here, we scanned studies from diverse research fields that claimed to measure rivalry and actor's performance. We considered only research that specifically measured rivalry as a relational competition and its association with performance. We systematically reviewed eligible studies and found that, generally, rivalry is positively related to performance. We then performed a meta-analysis that confirmed that this relationship is statistically significant. We further found that this relationship is more robust for rivalries in the context of individuals compared to groups. The association between rivalry and performance is most prominent in certain domains, such as sports rivalry. These findings can guide scholars in designing research on rivalry. Specifically, considering the various effect sizes found here in different contexts of rivalry will allow researchers to plan for more appropriate sample sizes designed to reveal the relationship between rivalry and performance in a targeted domain. Further, these results can inform managers about the effects of rivalries in or between their organizations, distinguishing among the different contexts of rivalries and their specific outcomes.

Objective: Although relatively costly and non-scalable, non-invasive neuromodulation interventions are treatment alternatives for neuropsychiatric disorders. The recent developments of highly-deployable transcranial electric stimulation (tES) systems, combined with mobile-Health technologies, could be incorporated in digital trials to overcome methodological barriers and increase equity of access. The study aims are to discuss the implementation of tES digital trials by performing a systematic scoping review and strategic process mapping, evaluate methodological aspects of tES digital trial designs, and provide Delphi-based recommendations for implementing digital trials using tES.Methods: We convened 61 highly-productive specialists and contacted 8 tES companies to assess 71 issues related to tES digitalization readiness, and processes, barriers, advantages, and opportunities for implementing tES digital trials. Delphi-based recommendations (>60% agreement) were provided.Results: The main strengths/opportunities of tES were: (i) non-pharmacological nature (92% of agreement), safety of these techniques (80%), affordability (88%), and potential scalability (78%). As for weaknesses/threats, we listed insufficient supervision (76%) and unclear regulatory status (69%). Many issues related to methodological biases did not reach consensus. Device appraisal showed moderate digitalization readiness, with high safety and potential for trial implementation, but low connectivity.Conclusions: Panelists recognized the potential of tES for scalability, generalizability, and leverage of digital trials processes; with no consensus about aspects regarding methodological biases. Significance: We further propose and discuss a conceptual framework for exploiting shared aspects between mobile-Health tES technologies with digital trials methodology to drive future efforts for digitizing tES trials. (C) 2022 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Although relatively costly and non-scalable, non-invasive neuromodulation interventions are treatment alternatives for neuropsychiatric disorders. The recent developments of highly-deployable transcranial electric stimulation (tES) systems, combined with mobile-Health technologies, could be incorporated in digital trials to overcome methodological barriers and increase equity of access. We convened 61 highly-productive specialists and contacted 8 tES companies to assess 71 issues related to tES digitalization readiness, and processes, barriers, advantages, and opportunities for implementing tES digital trials. Delphi-based recommendations (>60% agreement) were provided. Device appraisal showed moderate digitalization readiness, with high safety and the possibility of trial implementation, but low connectivity. Panelists recognized the potential of tES for scalability, generalizability, and leverage of digital trials processes; although they reached no consensus about aspects regarding methodological biases. We further propose and discuss a conceptual framework for exploiting shared aspects between mobile-Health tES technologies with digital trials methodology to drive future efforts for digitizing tES trials.Graphical Abstract. Consensus Roadmap(A) Recruitment process. The study procedure started with defining the components of the research problem by the core research team. After defining the problems, two different sets of participants (the steering committee (SC) including key leaders of the field identified by the core team and the expert panel (EP) as a more diverse group of experts identified based on the number of publications based on a systematic review) were identified and were invited to participate in a Delphi study. The study facilitators (first and last authors) led the communications with the SC to design the initial questionnaire through an iterative approach. (B) Evidence synthesis: To collect the available evidence, companies producing portable tES (ptES) devices were contacted, based on the companies suggested by the SC and EP to provide details about the available devices. For mapping methodological processes of digitizing tES trials, two distinct strategies were performed and embedded into the questionnaire, namely SIPOC (Suppliers, Inputs, Process, Outputs, and Customer) and SWOT (Strengths, Weaknesses, Opportunities, and Threats) assessment were performed and embedded into the questionnaire. (C) Consensus development: In the next phase, the questionnaire was validated and finalized via collecting and summarizing opinions. Afterward, the SC and EP responded to the final questionnaire, and results were analyzed providing a list of recommendations for running tES digital trials based on a pre-registered consensus threshold.

Previous neuropsychological data have equivocal suggestions concerning hemispheric involvement during idiom comprehension. The possible contribution of idioms transparency to the lateralization of figurative language comprehension has not been investigated using an interference technique. To analyse the cortical lateralization of idiom transparency processing, we employed inhibitory repetitive transcranial magnetic stimulation (rTMS) to the left and right dorsolateral prefrontal cortex (DLPFC) during the processing of opaque idioms, transparent idioms, and non-idiomatic literal phrases. Based on the Coarse Semantic Coding theory, we predicted a greater right hemisphere involvement when processing opaque than transparent idioms. Eighteen young healthy participants underwent rTMS pulses at 1 Hz frequency, 110% of motor threshold intensity for 15 min (900 pulses) in two sessions at one-week intervals. In a semantic decision task, participants judged the relatedness of an idiom and a target word. The target word was figuratively or literally related to the idiom, or unrelated. The study also included non-idiomatic sentences. We found that left DLPFC functions are more critical for comprehension of opaque rather than transparent idioms when referring to the figurative associations of the idioms. Opaque idioms, in the context of their figurative meaning, rely more heavily on left hemisphere resources. This finding suggests that opaque idioms are seemingly processed as one unit. Taken together, we believe that the transparency of idiomatic expressions may play an important role in modulating hemispheric functions involved in figurative language processing.

Interpersonal physiological synchrony is the spontaneous temporal coordination of physiological processes between several individuals. This type of synchrony is critical for human relationships, as it promotes two important outcomes: the quality of the relationships between synchronized individuals, and how well synchronized individuals perform together. Nonetheless a clear estimation of the size of the correlations between interpersonal physiological synchrony and relationship or performance outcomes is missing. To address this gap in knowledge was the main goal of the current meta-analysis. We focused on interpersonal physiological synchrony in measures of autonomic nervous system activity, and specifically we examined the distinct branches of the autonomic nervous system. We conducted two meta-analyses: (1) Estimating the association between interpersonal physiological synchrony and relationship outcomes (2) Estimating the association between interpersonal physiological synchrony and performance outcomes. In the first meta-analysis (i.e., relationships), the overall estimated correlation was small with a marginal significance (ES=0.09, p>.10) and high heterogeneity (I2=76.0%). In further sub-group analysis, we discovered a positive relationship for measures of sympathetic synchrony (ES=0.19, p=.02), a negative relationship for measures of parasympathetic synchrony(ES=-0.21, p=.03), and a positive relationship for measures of combined sympathetic and parasympathetic synchrony (ES =0.16, p=.02). As for the second meta-analysis (i.e., performance), the overall effect size of correlation was small (ES=0.26, p

Background: Clients and therapists often have different perspectives on their therapeutic alliance (TA), affecting the process and outcome of therapy. The aim of the present meta-analysis was to assess the mean differences between clients’ and therapists’ estimations of TA among clients with severe disturbances, while focusing on two potential moderators: client diagnosis and alliance instrument. Method: We conducted a systematic literature search of studies examining both client perspective and therapist perspective on TA in psychotherapy among people with schizophrenia spectrum disorders, personality disorders, and substance misuse disorders. We then analyzed the data using a random-effects meta-analytic model with Cohen’s d standardized mean effect size. Results: Heterogeneity analyses (k = 22, Cohen’s d = −.46, 95% confidence interval = .31–1.1) produced a significant Q-statistic (Q = 94.96) and indicated high heterogeneity, suggesting that moderator analyses were appropriate. Conclusions: Our findings show that the type of TA instrument moderates the agreement on TA between client and therapist, but there was no indication of the client’s diagnosis moderating the effect. The agreement between client and therapist estimations seems to be dependent on the instrument that is used to assess TA. Specific setting-related instruments seem to result in higher agreement between clients’ and therapists’ estimations than do more general instruments that are applied to assess TA.

Tourette syndrome (TS) is a childhood-onset disorder characterized by motor and vocal tics. Recent findings point to a possible role of executive functions system development in the tic reduction observed with age. The goal of the present work was to track the development of executive functions system measured by well-established cognitive tasks and its correlation with diminished tic severity over time in order to understand the role of executive functions in the remission process observed in most adults. The first study followed 25 young TS patients, measuring their executive functions and clinical condition at three time- points. In the second study we compared executive functions performance of 19 adult TS patients with 19 healthy controls and 12 remitted TS patients. The first study showed that tic reduction is related to the development of the executive functions components associated with response inhibition. The second study similarly showed impaired inhibition ability in TS patients but not in controls or the remitted TS patients. The remitted group performed at normal or even higher levels on certain measures. We conclude that inhibition, an important executive function, is impaired in subjects suffering from TS and that intact executive function development is related to remission processes.

Schizophrenia (Sz) is a mental health disorder characterized by severe cognitive, emotional, social, and perceptual deficits. Visual deficits are found in tasks relying on the magnocellular/dorsal stream. In our first experiment we established deficits in global motion processing in Sz patients compared to healthy controls. We used a novel task in which background optic flow produces a distortion of the apparent trajectory of a moving stimulus, leading control participants to provide biased estimates of the true motion trajectory under conditions of global stimulation. Sz patients were significantly less affected by the global background motion, and reported trajectories that were more veridically accurate than those of controls. In order to study the mechanism of this effect, we performed a second experiment where we applied transcranial electrical stimulation over area MT+ to selectively modify global motion processing of optic flow displays in healthy participants. Cathodal and high frequency random noise stimulation had opposite effects on trajectory perception in optic flow. The brain stimulation over a control site and in a control task revealed that the effect of stimulation was specific for global motion processing in area MT+. These findings both support prior studies of impaired early visual processing in Sz and provide novel approaches for measurement and manipulation of the underlying circuits. Electronic supplementary material The online version of this article (10.1007/s10548-018-0639-6) contains supplementary material, which is available to authorized users.

Previous research has demonstrated that the Action-Observation Network (AON) is involved in both emotional-embodiment (empathy) and action-embodiment mechanisms. In this study, we hypothesized that interfering with the AON will impair action recognition and that this impairment will be modulated by empathy levels. In Experiment 1 (n = 90), participants were asked to recognize facial expressions while their facial motion was restricted. In Experiment 2 (n = 50), we interfered with the AON by applying transcranial Direct Current Stimulation to the motor cortex. In both experiments, we found that interfering with the AON impaired the performance of participants with high empathy levels; however, for the first time, we demonstrated that the interference enhanced the performance of participants with low empathy. This novel finding suggests that the embodiment module may be flexible, and that it can be enhanced in individuals with low empathy by simple manipulation of motor activation.

While most cognitive control enhancement studies have focused on reactive inhibition paradigms, enhancement of proactive control of urge-driven behaviors has been relatively neglected. With the aim of focusing on the proactive components of cognitive control over motor output, we designed a simple, ecologically valid eye blinking suppression task and applied transcranial direct current stimulation (tDCS) over the right inferior frontal gyrus (rIFG). Fifty-three subjects randomly allocated to three different stimulation groups underwent active or sham stimulation, subsequently performing eye blinking and stop signal tasks. Results showed that anodal stimulation over the rIFG increased the ability to suppress blinks compared to sham and active control stimulation. In addition, the rIFG group demonstrated a general slowdown of the stop signal reaction time, implying proactive control enhancement. Herein, we discuss our results with regard to previous findings as well as possible interventions in clinical populations.

The AB refers to the performance impairment that occurs when visual selective attention is overloaded through the very rapid succession of two targets (T1 and T2) among distractors by using the rapid serial visual presentation task (RSVP). Under these conditions, performance is typically impaired when T2 is presented within 200–500 ms from T1 (AB). Based on neuroimaging studies suggesting a role of top-down attention and working memory brain hubs in the AB, here we potentiated via anodal or sham tDCS the activity of the right DLPFC (F4) and of the right PPC (P4) during an AB task. The findings showed that anodal tDCS over the F4 and over P4 had similar effects on the AB. Importantly, potentiating the activity of the right frontoparietal network via anodal tDCS only benefitted poor performers, reducing the AB, whereas in good performers it accentuated the AB. The contribution of the present findings is twofold: it shows both top-down and bottom-up contributions of the right frontoparietal network in the AB, and it indicates that there is an optimal level of excitability of this network, resulting from the individual level of activation and the intensity of current stimulation.

Idioms are a form of figurative language expressions in which their intended meaning is not derived from the meaning of constituent words. Previous studies examining hemispheric asymmetries in idiom comprehension argue about the relative contributions of the hemispheres to the figurative and literal processing. However, it is not clear what psycholinguistic factors may direct hemispheric asymmetries and the way in which figurative vs. literal interpretations are processed. In the current studs we report a behavioral study that examined whether idiom-irrelevant meanings are suppressed or retained as a function of visual field and the degree of predictability of the idioms. Native Hebrew speakers were presented with idioms in a semantic judgment task, where we manipulated visual field and predictability. The results seem to support the notion that a bi-hemispheric network is involved in idiom comprehension with prevalence for the left hemisphere. Overall, the results confirm the role of idioms predictability as the main factor that directs idiom comprehension and modulates hemispheric asymmetry in semantic processing.

Persons with Mild Cognitive Impairment (MCI) are at high Alzheimer's Disease (AD) risk but the development of sensitive measures to assess subtle cognitive decline in this population poses a major challenge for clinicians and researchers. Eye movement monitoring is a non-invasive, sensitive way to assess subtle cognitive processes in clinical populations. We conducted a critical review and a meta-analysis of the literature on pro and antisaccade paradigm in AD/MCI. The meta-analysis included 20 studies, all of which used the prosaccade paradigm and 13 of which studied the antisaccade paradigm as well. Our meta-analysis showed that AD but not MCI patients showed longer prosaccade latencies when compared to controls. While antisaccade latencies did not differentiate between patients from controls, antisaccade error rate were significantly increased among patients in comparison to controls in over 87% of the studies. These findings highlight antisaccade error rate as a reliable tool to distinguish inhibition abilities between AD/MCI and healthy older persons.

Background:Deficits in metacognition are one of the major causes of the difficulties experienced by individuals with schizophrenia. Studies have linked these deficits to symptom exacerbation and deterioration in psychosocial functioning. The aim of the present meta-analysis was to examine the extensive existing literature regarding metacognitive deficits among persons with schizophrenia; a further aim was to assess the extent to which metacognitive abilities are linked to outcome measures of symptoms and psychosocial functioning.Method:We conducted a systematic literature search of studies examining the relationship between metacognitive abilities and outcome measures among people with schizophrenia. We then analyzed the data using a random-effects meta-analytic model with Cohen's d standardized mean effect size.Results:Heterogeneity analyses (k = 32, Cohen's d = −.12, 95% CI.−1.92 to 1.7) produced a significant Q-statistic (Q = 456.89) and a high amount of heterogeneity, as indicated by the I2 statistic (93.04%), suggesting that moderator analyses were appropriate. As hypothesized, measure type moderated the metacognitive deficit with homogenous effect for psychosocial functioning measures (Q = 9.81, I2 = 19.47%, d = .94. 95% CI .58 to 1.2) and symptoms (Q = 19.87, I2 = 0%, d = −1.07, 95% CI −1.18 to −.75). Further analysis found homogenous effects for MAS-A subscales as well as PANSS factors of symptoms.Conclusion:Our meta-analysis results illustrated a significant association between metacognitive deficits and both symptomatic and psychosocial functioning measures. These links suggest that the associations between metacognitive abilities and symptomatic outcomes are different from those between metacognitive abilities and psychosocial functioning measures. Intriguing hypotheses are raised regarding the role that metacognitive abilities play in both symptoms and psychosocial functioning measures of people diagnosed with schizophrenia spectrum disorders.

Background Tourette syndrome (TS) is a childhood-onset disorder characterized by motor and vocal tics. While cognitive features of common comorbid conditions such as attention deficit hyperactive disorder and obsessive compulsive disorder have been widely investigated, the cognitive profile of TS patients remains to be precisely defined. In this regard, the executive functions system (EF) is of especial interest. Aims The aim of the study was to delineate the various components of executive processes in adult TS patients. Methods A sample of 19 adults diagnosed with TS and 19 age-matched control subjects underwent computerized battery of executive tasks, as well as block design and memory tests. All patients received a thorough clinical assessment with an emphasis on illness severity. Results There was a marked impairment in response inhibition ability regardless of comorbid conditions, In addition, there was decreased accuracy in set shifting, but not in response time. These results imply that impaired response inhibition in the EF system is the primary cognitive impairment in TS and that many of the previously reported impaired executive functions in TS are secondary to this impairment. Conclusions This finding of impaired response inhibition in TS may imply that rehabilitation of this inhibition component could prove to be an important therapeutic strategy in adults with TS.

Abstract. Research suggests that the action-observation network is involved in both emotional-embodiment (empathy) and action-embodiment (imitation) mechanisms. Here we tested whether empathy modulates action-embodiment, hypothesizing that restricting imitation abilities will impair performance in a hand gesture comprehension task. Moreover, we hypothesized that empathy levels will modulate the imitation restriction effect. One hundred twenty participants with a range of empathy scores performed gesture comprehension under restricted and unrestricted hand conditions. Empathetic participants performed better under the unrestricted compared to the restricted condition, and compared to the low empathy participants. Remarkably however, the latter showed the exactly opposite pattern and performed better under the restricted condition. This pattern was not found in a facial expression recognition task. The selective interaction of embodiment restriction and empathy suggests that empathy modulates the way people employ embodiment in gesture comprehension. We discuss the potential of embodiment-induced therapy to improve empathetic abilities in individuals with low empathy.

Previous research has demonstrated that the Action-Observation Network (AON) is involved in both emotional-embodiment (empathy) and action-embodiment mechanisms. In the current study, we hypothesized that interfering with the AON will impair action recognition and that this impairment will be modulated by empathy levels. Fifty-two participants conducted a semantic decision task of hand gesture recognition, while we interfered with the AON by applying active (n = 26) or sham (n = 26) transcranial Direct Current Stimulation (tDCS) to the hand area of the primary motor cortex. We found that interfering with the AON impaired the performance of participants with high empathy levels and enhanced the performance of participants with low empathy. This finding suggests that the embodiment module may be flexible, and that it can be enhanced in individuals with low empathy by simple manipulation of motor activation.

Objective Various brain regions have been identified as involved in addictions, yet inconsistencies remain regarding the primary regions that may underlie addictive behaviors. To address this, we conducted a meta-analysis investigating cue-reactivity functional MRI studies for different addictions. Method We explored 8 different addiction-related brain regions in 27 studies (29 samples) using homogeneity tests of effect sizes. Results An initial qualitative review failed to identify consistent activations in any brain region. We subsequently explored possible moderators related to either the addiction, participants, or study design, and found addiction type to be a relevant moderator, suggesting that different addictions may not necessarily involve the same brain regions. Successive quantitative analyses found that internet gaming addiction and heroin dependence modulated neural activation in the right dorsolateral prefrontal cortex and heroin dependence further in the right orbitofrontal cortex. Our analyses also demonstrated the expected mean effect sizes in each region when conducting cue-reactivity experiments on addictions. Conclusions It appears that distinct addiction types may manifest differently in the brain and may moderate cue reactivity to a greater extent than previously suggested factors. This study underscores the need for additional research comparing the neural mechanisms underlying different addiction types. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Creative thinking comprises two main components: divergent and convergent thinking. The Remote Associates Test (RAT) was designed to examine the ability to form associative elements into new combinations, however it is widely used as a general creativity measure, without sub-dividing it to its components. Our goal here was to explore the sub-components of the RAT, aiming to link them to the angular gyrus (AG) activation. The AG seems as a good candidate to host both aspects of the RAT, as neuroimaging studies observed deactivation in the AG while participants were engaged in creative tasks, however it also seems to play a role in arithmetic solution retrieval and automatic knowledge retrieval. Our objective was therefore to test whether transcranial direct current stimulation (tDCS) of the AG will influence creative and automatic performance in the RAT. In Experiment 1, in the creative group we administrated cathodal right AG stimulation in order to deactivate the AG aiming to improve divergent features of the RAT. In the automatic group, we administrated double anodal AG stimulation in order to improve convergent features of the RAT and included a control SHAM condition in each group. Experiment 2 activated the AG by stimulation and arithmetic training. We hypothesized that anodal stimulation of the AG will improve automatic convergent features as in Experiment 1. In addition, we expected the arithmetic training to improve the automatic score in the RAT. In Experiment 1, activation of the AG interrupted creative abilities and enhanced automatic abilities. Additionally, deactivation of the AG enhanced creative abilities reflecting divergent thinking. While in Experiment 2 both stimulation and arithmetic training resulted in higher automatic performance. We argue that the RAT measures automatic rather than creative abilities.

Abstract. This paper is aimed at providing an introduction to up-to-date noninvasive brain stimulation tools that have been successful in modulating higher-level cognitive functions in healthy individuals. The current review focuses on transcranial electrical stimulation (tES) studies aiming to explore cognitive models from an experimental rather than clinical viewpoint. It focuses primarily on major advances in language, working memory, learning, response inhibition, and other executive functions in healthy individuals, and the use of different methods of electrical brain stimulation such as transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and transcranial random noise stimulation (tRNS). The final section summarizes the scientific novelty of the reviewed papers and discusses the possible roles of brain stimulation in future experimental research and clinical applications.

Transcranial direct current stimulation (tDCS) of 1 mA for 13 min was reported to create a linear inter-dependency between the intensity and duration of the current and the effects of the stimulation. tDCS on the primary motor cortex (M1) has been shown to have an effect on both motor-evoked potential (MEP) and motor learning. However, recent findings have shown that the known linear effect is invalid in a 2 mA stimulation for 20 min, where cathodal stimulation led to excitability, rather than inhibition, as measured by MEP changes. Here we aim to replicate the non-linear effect of cathodal stimulation over the M1, using a cognitive task. Twenty-two healthy subjects participated in three sessions, where they were administered with a 2 mA anodal and cathodal stimulation for 20 min over the left M1, and a sham stimulation, while performing the serial reaction time task (SRTT). The overall analysis failed to show any effects of either polarity of tDCS on SRTT performance and hence did not replicate previous findings. However, given our goal to replicate the previously reported reversed polarity effects on MEP, we conducted an exploratory analysis to see whether there were any more subtle signs of a change in sign of the cathodal effect compared with anodal. Anodal stimulation led to faster performance than cathodal stimulation before 13 min of stimulation have passed, however, after 13 min, the pattern had switched, and performance under cathodal stimulation was faster. We conclude that cathodal tDCS has a non-linear effect, and the known polarity-dependent effects of tDCS shift after 13 min of stimulation, leading to an increased, rather than decreased, excitability.

In this review, we focus on the ability of people with schizophrenia to correctly perceive the meaning of idioms; figurative language expressions in which intended meaning is not derived from the meaning of constituent words. We collate evidence on how idiom perception is impaired, ascertain the clinical relevance of this impairment, and consider possible psychological and neural mechanisms behind the impairment. In reviewing extant literature, we searched the PubMed database, from 1975–2014, focussing on articles that directly concerned schizophrenia and idioms, with follow up searches to explore the viability of possible underlying mechanisms. We learn that there is clear evidence of impairment, with a tendency to err towards literal interpretations unless the figurative meaning is salient, and despite contextual cues to figurative interpretations. Given the importance of idioms in everyday language, the potential impact is significant. Clinically, impaired idiom perception primarily relates to positive symptoms of schizophrenia, but also to negative symptoms. The origins of the impairment remain speculation, with impaired executive function, impaired semantic functions, and impaired context processing all proposed to explain the phenomenon. We conclude that a possible contributory mechanism at the neural level is an impaired dorsolateral prefrontal cortex system for cognitive control over semantic processing.

The current study is an interdisciplinary examination of the interplay among music, language, and emotions. It consisted of two experiments designed to investigate the relationship between musical abilities and vocal emotional recognition. In experiment 1 ( N = 24), we compared the influence of two short-term intervention programs – music and art – on vocal emotion recognition. In experiment 2 ( N = 47), we compared musicians, who had undergone long-term music training, to non-musicians regarding their vocal emotion recognition. The results from experiment 1 revealed that short-term music intervention, which focused on ways music conveys emotions, significantly improved the vocal emotion recognition of the participants., In experiment 2, which examined the long-term effects of music training, there were no significant differences between musicians and non-musicians in vocal emotion recognition. The uniqueness of the short-term intervention and the inconsistency between the two experiments’ findings are discussed, and possible directions for future studies are proposed.

Background Understanding actions based on either language or observation of gestures is presumed to involve the motor system, and reflect the engagement of an embodied conceptual network. The role of the left inferior frontal gyrus (IFG) in language tasks is well established, but the role of the right hemisphere is unclear with some imaging evidence suggesting right IFG activation when gestures mismatch speech. Objective Using transcranial direct current stimulation (tDCS), we explored the hemispheric asymmetries in the assumed cognitive embodiment required for gestural-verbal integration. Methods Symbolic gestures served as primes for verbal targets. Primes were clips of symbolic gestures taken from a rich set of emblems and pantomimes. Participants responded by performing a semantic relatedness-judgment under 3 stimulation conditions – anodal tDCS (atDCS) over the left IFG, atDCS over the right IFG, and sham. There was also a non-semantic control task of attentional load. Results AtDCS of the right IFG generated faster responses to symbolic gestures than atDCS over the left IFG or sham stimulation. For the attentional load task, no differences were observed across the three stimulation conditions. These results support a right-lateralization bias of the human mirror neuron system in processing gestural-verbal stimuli. Conclusion Gesture comprehension may be enhanced by improved gesture and language integration.

To better understand the contribution of the dorsal system to word reading, we explored transcranial direct current stimulation (tDCS) effects when adults with developmental dyslexia received active stimulation over the visual extrastriate area MT/V5, which is dominated by magnocellular input. Stimulation was administered in 5 sessions spread over two weeks, and reading speed and accuracy as well as reading fluency were assessed before, immediately after, and a week after the end of the treatment. A control group of adults with developmental dyslexia matched for age, gender, reading level, vocabulary and block-design WAIS-III sub-tests and reading level was exposed to the same protocol but with sham stimulation. The results revealed that active, but not sham stimulation, significantly improved reading speed and fluency. This finding suggests that the dorsal stream may play a role in efficient retrieval from the orthographic input lexicon in the lexical route. It also underscores the potential of tDCS as an intervention tool for improving reading speed, at least in adults with developmental dyslexia.

Selective attention relies on working memory to maintain an attention set of task priorities. Consequently, selective attention is more efficient when working memory resources are not depleted. However, there is some evidence that distractors are processed even when working memory load is low. We used tDCS to assess whether boosting the activity of the Dorsolateral Prefrontal Cortex (DLPFC), involved in selective attention and working memory, would reduce interference from emotional distractors. Findings showed that anodal tDCS over the DLPFC was not sufficient to reduce interference from angry distractors. In contrast, cathodal tDCS over the DLPFC reduced interference from happy distractors. These findings show that altering the DLPFC activity is not sufficient to establish top-down control and increase selective attention efficiency. Although, when the neural signal in the DLPFC is altered by cathodal tDCS, interference from emotional distractors is reduced, leading to an improved performance.

This study explored the effect of a novel theory-based intervention intended to enhance semantic skills. A cognitive training program was developed based on theories and empirical findings which describe the role of the right hemisphere (RH) in semantic processing. The importance of RH linguistic processes to daily communication has been emphasized in recent neurolinguistic research, allowing to create a selective intervention to stimulate and enhance these processes in a way that will affect real-life performance. In order to evaluate the effectiveness of the training and its selective effect on semantic performance (as opposed to general verbal and non-verbal skills), we conducted an experiment with an active control group. Fifteen participants used the computerized training program for five weeks and 15 participants trained on a non-semantic control program using the same game-like platform, stimuli and feedback. In a semantic-relatedness judgment task, administrated before and after the training, significant post-training enhancement was observed among the training participants, compared to the control group. This enhancement was predicted by shifts in laterality indices along the training, so that participants with increasing RH bias showed more improvement on the semantic task. Moreover, the training group did not show any significant enhancement in any of the verbal and non-verbal control tasks – implying that the training effect was selective to semantic processing. These findings provide preliminary evidence for transfer of the coarse semantic training. They are discussed from an applied perspective, with the conclusion that applying current knowledge on semantic processes successfully resulted in a non-invasive enhancement of semantic abilities, which may be used to affect semantic processing in daily life; and from a theoretical perspective, describing the contribution of this study to the body of knowledge on RH involvement in semantic processing.

Background Recent studies revealed that anodal transcranial direct current stimulation (tDCS) to the left dorsolateral prefrontal cortex (DLPFC) may improve verbal working memory (WM) performance in humans. In the present study, we evaluated executive attention, which is the core of WM capacity, considered to be significantly involved in tasks that require active maintenance of memory representations in interference-rich conditions, and is highly dependent on DLPFC function. Objectives We investigated verbal WM accuracy using a WM task that is highly sensitive to executive attention function. We were interested in how verbal WM accuracy may be affected by WM load, unilateral DLPFC stimulation, and gender, as previous studies showed gender-dependent brain activation during verbal WM tasks. Methods We utilized a modified verbal n -Back task hypothesized to increase demands on executive attention. We examined "online" WM performance while participants received transcranial direct current stimulation (tDCS), and implicit learning performance in a post-stimulation WM task. Results Significant lateralized "online" stimulation effects were found only in the highest WM load condition revealing that males benefit from left DLPFC stimulation, while females benefit from right DLPFC stimulation. High WM load performance in the left DLPFC stimulation was significantly related to post-stimulation recall performance. Conclusions Our findings support the idea that lateralized stimulation effects in high verbal WM load may be gender-dependent. Further, our post-stimulation results support the idea that increased left hemisphere activity may be important for encoding verbal information into episodic memory as well as for facilitating retrieval of context-specific targets from semantic memory.

Previous studies have reported a hemispheric asymmetry in processing dominant (e.g., paper) and subordinate (e.g., farmer) associations of ambiguous words (pen). Here we applied sham and anodal Transcranial Direct Current Stimulation (tDCS) over Wernicke's area and its right homologue to test whether we can modulate the selective hemispheric expertise in processing lexical ambiguity. Ambiguous prime words were presented followed by target words that could be associated to the dominant or subordinate meaning of the prime in a semantic relatedness task. Anodal stimulation of the right Wernicke's area significantly decreased response time (RTs) to subordinate but not dominant associations compared to sham stimulation. There was also a complementary trend of faster responses to dominant associations following anodal stimulation of Wernicke's area. The results support brain asymmetry in processing lexical ambiguity and show that tDCS can enhance complex language processing even in a sample of highly literate individuals.

In delay discounting tasks, participants decide between receiving a certain amount of money now or a larger sum sometime in the future. This study investigated the effects of transcranial direct current stimulation on delay discounting. Participants made delay discounting choices while receiving a bi-frontal stimulation of right-hemisphere anodal/left-hemisphere cathodal, left-hemisphere anodal/right-hemisphere cathodal, and sham stimulation, in three separate sessions. When the difference between the alternatives was 10% or more, participants generally preferred to wait for the larger sum. Nevertheless, there were more choices of smaller "immediate" gains, instead of the larger delayed options, when the left dorsolateral prefrontal cortex (DLPFC) was facilitated and the right DLPFC inhibited, compared to the sham stimulation. These observations indicate the significant role of the prefrontal cortex in delay discounting choices, and demonstrate that increased left frontal activation combined with decreased right frontal activation can alter decision-making by intensifying a tendency to choose immediate gains.

Solving insight problems is a complex task found to involve coarse semantic processing in the right hemisphere when tested in English. In Hebrew, the left hemisphere (LH) may be more active in this task, due to the inter-hemispheric interaction between semantic, phonological and orthographic processing. In two Hebrew insight problems experiments, we revealed a performance advantage in the LH, in contrast to the patterns previously observed in English. A third experiment, conducted in English with early Hebrew–English bilinguals, confirmed that the LH advantage found with Hebrew speakers does not depend on specific task requirements in Hebrew. We suggest that Hebrew speakers show redundancy between the hemispheres in coarse semantic processing in handling frequent lexical ambiguities stemming from the orthographic structure in Hebrew. We further suggest that inter-hemispheric interactions between linguistic and non-linguistic processes may determine the hemisphere in which coarse coding will take place. These findings highlight the possible effect of exposure to a specific mother tongue on the lateralization of processes in the brain, and carries possible theoretical and methodological implications for cross-language studies.

Here we aim to evaluate the ability of transcranial direct current stimulation (tDCS), which is applied over Wernicke's area and its right homologue, to influence lexical decisions and semantic priming and establish an involvement for temporo-parietal areas in lexical and semantic processing. Thirty-two subjects (17 women) completed a lexical decision task and a semantic priming task while receiving 20 min of bilateral tDCS stimulation (right anodal/left cathodal or left anodal/right cathodal stimulation) or sham stimulation. We hypothesized that right anodal/left cathodal stimulation over temporo-parietal areas would selectively interrupt the typical lexical processing dominance of the left hemisphere and facilitate mediated priming, while left anodal/right cathodal stimulation would selectively facilitate lexical processing and direct priming. Results showed impaired lexical processing under right anodal/left cathodal stimulation in comparison with sham and left anodal/right cathodal stimulation. Results are discussed in light of previous findings and hemispheric lateralization models.

Both cerebral hemispheres contain phonological, orthographic and semantic representations of words, however there are between-hemisphere differences in the relative engagement and specialization of the different representations. Taking orthographic processing for example, previous studies suggest that orthographic neighbourhood size (N) has facilitatory effects in the right but not the left hemispheres. To pursue the nature of this asymmetric N effect, in particular whether there are individual differences in such specialisation, we examined N in a case of developmental dyslexia, FM. We first describe the nature of his difficulties, which are mainly severe phonological deficits. Employing the divided visual field paradigm with FM revealed a greater sensitivity in the right than in the left hemisphere to orthographic variables, with a significant inhibitory N effect in the left, but not right hemisphere. Such inhibition, to a lesser degree, was found among a group of adults with dyslexia but not among age-matched normal readers. We argue that enhanced sensitivity to orthographic cues is developed in some cases of dyslexia when a normal, phonology-based left hemisphere word recognition processing is not achieved. The interpretation presented here is cast in terms of differences between people with dyslexia and typical readers that originate in the atypical way in which orthographic representations are initially set up.

For complex linguistic strings such as idioms, making a decision as to the correct meaning may require complex top-down cognitive control such as the suppression of incorrect alternative meanings. In the study presented here, we used transcranial direct current stimulation to test the hypothesis that a domain general dorsolateral prefrontal cognitive control network is involved in constraining the complex processing involved. Specifically, we sought to test prominent theoretical stances on the division of labour across dorsolateral prefrontal cortex in the left- and right-hemispheres of the brain, including the role of salience and fine vs. coarse semantic coding. 32 healthy young adult participants were randomly allocated to one of two stimulation montage groups (LH anodal/RH cathodal or RH anodal/LH cathodal). Participants were tested twice, completing a semantic decision task after either receiving active or sham stimulation. The semantic decision task required participants to judge the relatedness of an idiom and a target word. The target word was figuratively related, literally related, or unrelated to the idiom. Control non-literal non-idiomatic sentences were also included that only had a literal meaning. The results showed that left-hemisphere dorsolateral prefrontal cortex is highly involved in processing figurative language, whereas both left- and right- dorsolateral prefrontal cortex contributed to literal language processing. In comparison, semantic processing for the non-idiomatic control sentences did not require domain general cognitive control as it relates to suppression of the rejected alternative meaning. The results are discussed in terms of the interplay between need for domain general cognitive control in understanding the meaning of complex sentences, hemispheric differences in semantic processing, and salience detection.

Recently, transcranial alternating current stimulation (tACS) has emerged as a tool to enhance human cognitive processes. Here, we provide a brief summary of the rationale behind tACS-induced effects on task-relevant brain oscillations and associated cognitive functions and review previous studies in young subjects that have applied tACS in cognitive paradigms. Additionally, we present pilot data where we administered theta-tACS (6 Hz) over the temporoparietal cortex and a supraorbital reference for 20 min during implicit language learning in healthy young (mean/SD age: 22/2) and older (mean/SD age: 66/4) adults, in a sham-controlled crossover design. Linear mixed models revealed significantly increased retrieval accuracy following tACS-accompanied associative learning, after controlling for session order and learning success. These data provide the first implementation of tACS during cognitive performance in older adults and support recent studies suggesting that tACS in the theta frequency range may serve as a tool to enhance cognition, possibly through direct modulation of task-relevant brain oscillations. So far, studies have been heterogeneous in their designs, leaving a number of issues to be addressed in future research, including the setup of electrodes and optimal stimulation frequencies to be employed, as well as the interaction with age and underlying brain pathologies in specific patient populations.

Many previous studies reported that the hyperpolarization of cortical neurons following cathodal stimulation (in transcranial direct current stimulation) has resulted in cognitive performance degradation. Here, we challenge this assumption by showing that cathodal stimulation will not always degrade cognitive performance. We used an attentional load paradigm in which irrelevant stimuli are processed only under low but not under high attentional load. Thirty healthy participants were randomly allocated into three interventional groups with different brain stimulation parameters (active anodal posterior parietal cortex [PPC], active cathodal PPC, and sham). Cathodal but not anodal stimulation enabled flanker processing even in high-loaded scenes. A second experiment was carried out to assert whether the improved flanker processing under cathodal stimulation is because of altered attention allocation between center and surround or, alternatively, enhanced attentional resources. In this experiment, the flanker was presented centrally. The results of Experiment 2 replicated Experiment 1's finding of improved flanker processing. We interpret the results from these two experiments as evidence for the ability of cathodal stimulation to enhance attentional resources rather than simply change attention allocation between center and periphery. Cathodal stimulation in high-loaded scenes can act like a noise filter and may in fact enhance cognitive performance. This study contributes to understanding the way the PPC is engaged with attentional functions and explains the cathodal effects, which thus might lead to more efficient brain stimulation protocols.