Musical and electrical stimulation as intervention in disorder of consciousness (DOC) patients: A randomised cross-over trial.

BACKGROUND: Disorders of consciousness (DOC), i.e., unresponsive wakefulness syndrome (UWS) or vegetative state (VS) and minimally conscious state (MCS), are conditions that can arise from severe brain injury, inducing widespread functional changes. Given the damaging implications resulting from these conditions, there is an increasing need for rehabilitation treatments aimed at enhancing the level of consciousness, the quality of life, and creating new recovery perspectives for the patients. Music may represent an additional rehabilitative tool in contexts where cognition and language are severely compromised, such as among DOC patients. A further type of rehabilitation strategies for DOC patients consists of Non-Invasive Brain Stimulation techniques (NIBS), including transcranial electrical stimulation (tES), affecting neural excitability and promoting brain plasticity. OBJECTIVE: We here propose a novel rehabilitation protocol for DOC patients that combines music-based intervention and NIBS in neurological patients. The main objectives are (i) to assess the residual neuroplastic processes in DOC patients exposed to music, (ii) to determine the putative neural modulation and the clinical outcome in DOC patients of non-pharmacological strategies, i.e., tES(control condition), and music stimulation, and (iii) to evaluate the putative positive impact of this intervention on caregiver's burden and psychological distress. METHODS: This is a randomised cross-over trial in which a total of 30 participants will be randomly allocated to one of three different combinations of conditions: (i) Music only, (ii) tES only (control condition), (iii) Music + tES. The music intervention will consist of listening to an individually tailored playlist including familiar and self-relevant music together with fixed songs; concerning NIBS, tES will be applied for 20 minutes every day, 5 times a week, for two weeks. After these stimulations two weeks of placebo treatments will follow, with sham stimulation combined with noise for other two weeks. The primary outcomes will be clinical, i.e., based on the differences in the scores obtained on the neuropsychological tests, such as Coma Recovery Scale-Revised, and neurophysiological measures as EEG, collected pre-intervention, post-intervention and post-placebo. DISCUSSION: This study proposes a novel rehabilitation protocol for patients with DOC including a combined intervention of music and NIBS. Considering the need for rigorous longitudinal randomised controlled trials for people with severe brain injury disease, the results of this study will be highly informative for highlighting and implementing the putative beneficial role of music and NIBS in rehabilitation treatments. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05706831, registered on January 30, 2023.

The Pathophysiological Underpinnings of Gamma-Band Alterations in Psychiatric Disorders.

Investigating the biophysiological substrates of psychiatric illnesses is of great interest to our understanding of disorders' etiology, the identification of reliable biomarkers, and potential new therapeutic avenues. Schizophrenia represents a consolidated model of γ alterations arising from the aberrant activity of parvalbumin-positive GABAergic interneurons, whose dysfunction is associated with perineuronal net impairment and neuroinflammation. This model of pathogenesis is supported by molecular, cellular, and functional evidence. Proof for alterations of γ oscillations and their underlying mechanisms has also been reported in bipolar disorder and represents an emerging topic for major depressive disorder. Although evidence from animal models needs to be further elucidated in humans, the pathophysiology of γ-band alteration represents a common denominator for different neuropsychiatric disorders. The purpose of this narrative review is to outline a framework of converging results in psychiatric conditions characterized by γ abnormality, from neurochemical dysfunction to alterations in brain rhythms.

Cognitive and Neuropathophysiological Outcomes of Gamma-tACS in Dementia: A Systematic Review.

Despite the numerous pharmacological interventions targeting dementia, no disease-modifying therapy is available, and the prognosis remains unfavorable. A promising perspective involves tackling high-frequency gamma-band (> 30 Hz) oscillations involved in hippocampal-mediated memory processes, which are impaired from the early stages of typical Alzheimer's Disease (AD). Particularly, the positive effects of gamma-band entrainment on mouse models of AD have prompted researchers to translate such findings into humans using transcranial alternating current stimulation (tACS), a methodology that allows the entrainment of endogenous cortical oscillations in a frequency-specific manner. This systematic review examines the state-of-the-art on the use of gamma-tACS in Mild Cognitive Impairment (MCI) and dementia patients to shed light on its feasibility, therapeutic impact, and clinical effectiveness. A systematic search from two databases yielded 499 records resulting in 10 included studies and a total of 273 patients. The results were arranged in single-session and multi-session protocols. Most of the studies demonstrated cognitive improvement following gamma-tACS, and some studies showed promising effects of gamma-tACS on neuropathological markers, suggesting the feasibility of gamma-tACS in these patients anyhow far from the strong evidence available for mouse models. Nonetheless, the small number of studies and their wide variability in terms of aims, parameters, and measures, make it difficult to draw firm conclusions. We discuss results and methodological limitations of the studies, proposing possible solutions and future avenues to improve research on the effects of gamma-tACS on dementia.

The Neural Correlates of Developmental Prosopagnosia: Twenty-Five Years on.

Faces play a crucial role in social interactions. Developmental prosopagnosia (DP) refers to the lifelong difficulty in recognizing faces despite the absence of obvious signs of brain lesions. In recent decades, the neural substrate of this condition has been extensively investigated. While early neuroimaging studies did not reveal significant functional and structural abnormalities in the brains of individuals with developmental prosopagnosia (DPs), recent evidence identifies abnormalities at multiple levels within DPs' face-processing networks. The current work aims to provide an overview of the convergent and contrasting findings by examining twenty-five years of neuroimaging literature on the anatomo-functional correlates of DP. We included 55 original papers, including 63 studies that compared the brain structure (MRI) and activity (fMRI, EEG, MEG) of healthy control participants and DPs. Despite variations in methods, procedures, outcomes, sample selection, and study design, this scoping review suggests that morphological, functional, and electrophysiological features characterize DPs' brains, primarily within the ventral visual stream. Particularly, the functional and anatomical connectivity between the Fusiform Face Area and the other face-sensitive regions seems strongly impaired. The cognitive and clinical implications as well as the limitations of these findings are discussed in light of the available knowledge and challenges in the context of DP.

Corrigendum to "Self-reported face recognition abilities moderately predict face-learning skills: Evidence from Italian samples" [Heliyon 9 (3) (March 2023) Article e14125].

[This corrects the article DOI: 10.1016/j.heliyon.2023.e14125.].

Deep learning applied to EEG source-data reveals both ventral and dorsal visual stream involvement in holistic processing of social stimuli.

Perception of social stimuli (faces and bodies) relies on "holistic" (i.e., global) mechanisms, as supported by picture-plane inversion: perceiving inverted faces/bodies is harder than perceiving their upright counterpart. Albeit neuroimaging evidence suggested involvement of face-specific brain areas in holistic processing, their spatiotemporal dynamics and selectivity for social stimuli is still debated. Here, we investigate the spatiotemporal dynamics of holistic processing for faces, bodies and houses (adopted as control non-social category), by applying deep learning to high-density electroencephalographic signals (EEG) at source-level. Convolutional neural networks were trained to classify cortical EEG responses to stimulus orientation (upright/inverted), separately for each stimulus type (faces, bodies, houses), resulting to perform well above chance for faces and bodies, and close to chance for houses. By explaining network decision, the 150-200 ms time interval and few visual ventral-stream regions were identified as mostly relevant for discriminating face and body orientation (lateral occipital cortex, and for face only, precuneus cortex, fusiform and lingual gyri), together with two additional dorsal-stream areas (superior and inferior parietal cortices). Overall, the proposed approach is sensitive in detecting cortical activity underlying perceptual phenomena, and by maximally exploiting discriminant information contained in data, may reveal spatiotemporal features previously undisclosed, stimulating novel investigations.

Investigating the impact of disposable surgical face-masks on face identity and emotion recognition in adults with autism spectrum disorder.

With the outburst of the COVID-19 pandemic, disposable surgical face-masks (DSFMs) have been widely adopted as a preventive measure. DSFMs hide the bottom half of the face, thus making identity and emotion recognition very challenging, both in typical and atypical populations. Individuals with autism spectrum disorder (ASD) are often characterized by face processing deficits; thus, DSFMs could pose even a greater challenge for this population compared to typically development (TD) individuals. In this study, 48 ASDs of level 1 and 110 TDs underwent two tasks: (i) the Old-new face memory task, which assesses whether DSFMs affect face learning and recognition, and (ii) the Facial affect task, which explores DSFMs' effect on emotion recognition. Results from the former show that, when faces were learned without DSFMs, identity recognition of masked faces decreased for both ASDs and TDs. In contrast, when faces were first learned with DSFMs, TDs but not ASDs benefited from a "context congruence" effect, that is, faces wearing DSFMs were better recognized if learned wearing DSFMs. In addition, results from the Facial affect task show that DSFMs negatively impacted specific emotion recognition in both TDs and ASDs, although differentially between the two groups. DSFMs negatively affected disgust, happiness and sadness recognition in TDs; in contrast, ASDs performance decreased for every emotion except anger. Overall, our study demonstrates a general, although different, disruptive effect on identity and emotion recognition both in ASD and TD population.

Self-reported face recognition abilities moderately predict face-learning skills: Evidence from Italian samples.

Face Recognition Ability (FRA) varies widely throughout the population. Previous research highlights a positive relationship between self-perceived and objectively measured FRA in the healthy population, suggesting that people do have insight into their FRA. Given that this relationship has not been investigated in Italian samples yet, the main aim of the present work was to develop an Italian translation of the Prosopagnosia Index-20 (PI-20), a self-report measure of FRA, to investigate the relationship between PI-20 performances and an objective assessment given by the Cambridge Face Memory Test Long Form (CFMT+) in the Italian population. A sample of 553 participants filled in the PI-20 Italian version 1 or 2 (PI-20_GE or PI-20_BA) and completed the CFMT+. Results showed a negative correlation between both versions of the Italian PI-20 and CFMT+ scores, meaning that the more self-evaluations were negative, the worse they objectively performed. The same results applied to the extreme limits of the distribution (i.e., 10% of the highest and lowest PI-20 scores). Furthermore, both age and administration order of the tests were predictor variables of CFMT+ scores. Overall, our results suggest that people possess insight, although relatively limited, into their FRA.

Face pareidolia is enhanced by 40 Hz transcranial alternating current stimulation (tACS) of the face perception network.

Pareidolia refers to the perception of ambiguous sensory patterns as carrying a specific meaning. In its most common form, pareidolia involves human-like facial features, where random objects or patterns are illusionary recognized as faces. The current study investigated the neurophysiological correlates of face pareidolia via transcranial alternating current stimulation (tACS). tACS was delivered at gamma (40 Hz) frequency over critical nodes of the "face perception" network (i.e., right lateral occipito-temporal and left prefrontal cortex) of 75 healthy participants while completing four face perception tasks ('Mooney test' for faces, 'Toast test', 'Noise pareidolia test', 'Pareidolia task') and an object perception task ('Mooney test' for objects). In this single-blind, sham-controlled between-subjects study, participants received 35 min of either Sham, Online, (40Hz-tACS_ON), or Offline (40Hz-tACS_PRE) stimulation. Results showed that face pareidolia was causally enhanced by 40Hz-tACS_PRE in the Mooney test for faces in which, as compared to sham, participants more often misperceived scrambled stimuli as faces. In addition, as compared to sham, participants receiving 40Hz-tACS_PRE showed similar reaction times (RTs) when perceiving illusory faces and correctly recognizing noise stimuli in the Toast test, thus not exhibiting hesitancy in identifying faces where there were none. Also, 40Hz-tACS_ON induced slower rejections of face pareidolia responses in the Noise pareidolia test. The current study indicates that 40 Hz tACS can enhance pareidolic illusions in healthy individuals and, thus, that high frequency (i.e., gamma band) oscillations are critical in forming coherent and meaningful visual perception.

The effects of transcranial random noise stimulation on motor function: A comprehensive review of the literature.

The present review considers all papers published on the topic up to the end of the year 2022. Transcranial random noise stimulation (tRNS) is a non-invasive neuromodulation technique introduced about 15 years ago whose use is becoming increasingly widespread in neuroscience. It consists of the application over the scalp of a weak, white noise-like current, through electrodes having a surface of several square centimetres, for a duration ranging from seconds to minutes. Despite its relatively low spatial and temporal resolution, tRNS has well defined effects on central motor excitability, which critically depend on stimulation parameters. These effects seem to be chiefly based on an effect on neuronal membrane sodium channels and can last much longer than the stimulation itself. While the effects at the cellular level in the motor cortex are becoming progressively clear, much more studies are needed to understand the effects of tRNS on motor behaviour and performance, where initial research results are nevertheless promising, in both basic and applied research.

Face memory and facial expression recognition are both affected by wearing disposable surgical face masks.

Faces are fundamental stimuli for social interactions since they provide significant information about people's identity and emotional states. With the outburst of the COVID-19 pandemic, global use of preventive measures, such as disposable surgical face masks (DSFMs), has been imposed. The massive use of DSFMs covering a large part of the face could interfere with identity and emotion recognition. Thus, the main aim of the current study was (i) to assess how DSFMs affect identity recognition (Experiment 1), (ii) how DSFMs affect emotion recognition (Experiment 2), and (iii) whether individual empathy levels correlate with emotion recognition with DSFMs. The potential relation between identity and emotion recognition with and without DSFMs was also investigated. Two tasks were administered to 101 healthy participants: (i) the Old-new face memory task aimed to assess whether the learning context (i.e., DSFMs on/off) affects recognition performance, whereas (ii) the Facial affect task explored DSFMs' effect on emotion recognition. Results from the former showed that the stimuli's features in the learning stage affect recognition performances; that is, faces wearing DSFMs were better recognized if wearing DSFMs at first exposure and vice versa. Results from the Facial affect task showed that DSFMs lead to reduced disgust, happiness, and sadness recognition. No significant correlation emerged between identity and emotion recognition. The Interpersonal Reactivity Index (IRI) was administered to assess affective and cognitive empathy; however, IRI scores did not correlate with either face memory recognition or facial affect recognition. Overall, our results demonstrate (a) a "context effect" for face memory with and without DSFMs; (b) a disruptive effect of DSFMs depending on the expressed emotion; and (c) no correlation between empathy and emotion recognition with DSFMs.

Non-invasive neuromodulation can reduce aggressive behaviors in humans: A critical perspective.

Containing aggressive behavior is an ongoing challenge in modern society. Aggressiveness is a multi-level construct that can be driven by emotions (reactive aggression) or can be "cold-blooded" and goal-directed (proactive). Aggressive behavior could arise because of a misjudgment of others' intentions or can follow frontal brain lesions leading to a reduction of impulse control and emotion regulation. In the last few years, interventional and basic research studies adopting Non-Invasive Brain Stimulation (NIBS) have significantly risen. Those techniques have been used both in healthy people, to better understand the role of certain brain regions in psychological processes, and in aggressive subjects to improve their symptoms. From an overview of the literature, focusing on the paper that uses transcranial direct current stimulation (tDCS) to reduce aggressiveness, it emerges that tDCS can (i) enhance facial emotion expression recognition, (ii) improve impulses control, and (iii) affect approach/withdrawal motivation. The current work shows the strengths and weaknesses of tDCS intervention on aggressive individuals, suggesting that this instrument could be adopted on violent people, and paves the way for intervention in some applied settings such as prison.

An update on the use of gamma (multi)sensory stimulation for Alzheimer's disease treatment.

Alzheimer's disease (AD) is characterized by reduced fast brain oscillations in the gamma band (γ, > 30 Hz). Several animal studies show that inducing gamma oscillations through (multi)sensory stimulation at 40 Hz has the potential to impact AD-related cognitive decline and neuropathological processes, including amyloid plaques deposition, neurofibrillary tangles formation, and neuronal and synaptic loss. Therefore Gamma Entrainment Using Sensory stimulation (GENUS) is among the most promising approaches for AD patients' treatment. This review summarizes the evidence on GENUS effectiveness, from animal models to AD patients. Despite the application on human is in its infancy, the available findings suggest its feasibility for the treatment of AD. We discuss such results in light of parameter improvement and possible underlying mechanisms. We finally emphasize the need for further research for its development as a disease-modifying non-pharmacological intervention.

Anodal tDCS effects over the left dorsolateral prefrontal cortex (L-DLPFC) on the rating of facial expression: evidence for a gender-specific effect.

The accurate recognition of others' facial expressions is a core skill for social interactions. The left Dorsolateral Prefrontal Cortex (L-DLPFC) represents a key node in the network for facial emotion recognition. However, its specific role is still under debate. As such, the aim of the current neuromodulation study was to assess the causal role of the L-DLPFC in humans' rating of facial expressions of emotions and implicit attitudes toward other races. In this sham-controlled single-blind between-subject experiment, we offline administered L-DLPFC transcranial direct current stimulation (tDCS) to 69 healthy participants who were divided into three groups of 23 (each receiving anodal 1 mA tDCS, anodal 2 mA tDCS, or Sham), before completing an "Emotion Rating task and two Implicit Association Tests (IATs). The former required the intensity rating of 192 faces (half black and half white) displaying happiness, sadness, anger, or fear. The IATs were designed to assess participants' automatic associations of positive or negative attributes with racial contents. Results on the Emotion Rating task showed participants' gender-specific effect of tDCS. Specifically, a gender bias, with only males showing a tendency to underestimate negative emotions was found in Sham, and absent in the tDCS groups. When considering the race of the stimuli, females but not males in Sham exhibited a racial bias, that is, the tendency to overestimate negative emotions of other-race faces. Again, the bias disappeared in the tDCS groups. Concerning the IATs, no significant effects emerged. We conclude that the L-DLPFC plays a critical role in humans' rating of facial expressions, and for variability in other-race emotional judgements. These results shed light on the neural bases of the human emotional system and its gender-related differences, and have potential implications for interventional settings.

The Modified Five-Point Test (MFPT): normative data for a sample of Italian elderly.

INTRODUCTION: Non-verbal figural fluency is related to executive functions and specifically to the ability to create as many unique designs as possible, while minimizing their repetitions. An Italian version of figural fluency is the Modified Five-Point Test (MFPT), which is highly employed in the clinical practice of neuropsychologists. To date, reference data of Italian population are limited to a sample aged between 16 and 60 years old. Thus, the current study aims to provide normative data of the MFPT in the context of a population-based setting, conducted in Southern Italy. MATERIAL AND METHODS: We collected N = 340 Italian healthy subjects, aged over 65 years old (range: 65-91), pooled across subgroups for age, sex, and education. Multiple regression analyses were performed to estimate the effect of age, education, and sex on the participant's performance. Equivalent scores and cut-off scores were also defined for the number of unique designs (UDs) and the number of strategies (CSs). RESULTS: Multiple regression analyses revealed that UDs increase with decreasing age and increasing educational level. CSs are influenced by higher educational levels but neither by age nor sex. A significant inverse correlation between the UDs and percentage of errors occurred, suggesting that a higher number of UDs are associated with a fewer number of errors and higher CSs employed. CONCLUSION: The MFPT provides a measure of cognitive functioning in terms of the ability to initiate and realize designs, affording useful hints for clinical settings. The MFPT may represent a handy and useful tool with a specific focus in the differentiation of healthy versus pathological aging.

Theta- and Gamma-Band Activity Discriminates Face, Body and Object Perception.

Face and body perception is mediated by configural mechanisms, which allow the perception of these stimuli as a whole, rather than the sum of individual parts. Indirect measures of configural processing in visual cognition are the face and body inversion effects (FIE and BIE), which refer to the drop in performance when these stimuli are perceived upside-down. Albeit FIE and BIE have been well characterized at the behavioral level, much still needs to be understood in terms of the neurophysiological correlates of these effects. Thus, in the current study, the brain's electrical activity has been recorded by a 128 channel electroencephalogram (EEG) in 24 healthy participants while perceiving (upright and inverted) faces, bodies and houses. EEG data were analyzed in both the time domain (i.e., event-related potentials-ERPs) and the frequency domain [i.e., induced theta (5-7 Hz) and gamma (28-45 Hz) oscillations]. ERPs amplitude results showed increased N170 amplitude for inverted faces and bodies (compared to the same stimuli presented in canonical position) but not for houses. ERPs latency results showed delayed N170 components for inverted (vs. upright) faces, houses, but not bodies. Spectral analysis of induced oscillations indicated physiological FIE and BIE; that is decreased gamma-band synchronization over right occipito-temporal electrodes for inverted (vs. upright) faces, and increased bilateral frontoparietal theta-band synchronization for inverted (vs. upright) faces. Furthermore, increased left occipito-temporal and right frontal theta-band synchronization for upright (vs. inverted) bodies was found. Our findings, thus, demonstrate clear differences in the neurophysiological correlates of face and body perception. The neurophysiological FIE suggests disruption of feature binding processes (decrease in occipital gamma oscillations for inverted faces), together with enhanced feature-based attention (increase in frontoparietal theta oscillations for inverted faces). In contrast, the BIE may suggest that structural encoding for bodies is mediated by the first stages of configural processing (decrease in occipital theta oscillations for inverted bodies).

Transcranial alternating current stimulation (tACS) at 40 Hz enhances face and object perception.

Neurophysiological evidence suggests that face and object recognition relies on the coordinated activity of neural populations (i.e., neural oscillations) in the gamma-band (>30 Hz) range over the occipito-temporal cortex. To test the causal effect of gamma-band oscillations on face and object perception we applied transcranial Alternating Current Stimulation (tACS) in healthy volunteers (N = 60). In this single-blind, sham-controlled study, we examined whether the administration of offline tACS at gamma-frequency (40 Hz) over the right occipital cortex enhances performance of perception and memory of face and object stimuli. We hypothesized that gamma tACS would enhance the perception of both categories of visual stimuli. Results, in line with our hypothesis, show that 40 Hz tACS enhanced both face and object perception. This effect is process-specific (i.e., it does not affect memory), frequency-specific (i.e., stimulation at 5 Hz did not cause any behavioural change), and site-specific (i.e., stimulation of the sensory-motor cortex did not affect performance). Our findings show that high-frequency tACS modulates human visual perception, and it is in line with neurophysiological studies showing that the perception of visual stimuli (i.e., faces and objects) is mediated by oscillations in the gamma-band range. Furthermore, this study adds insight about the design of effective neuromodulation protocols that might have implications for interventions in clinical settings.

Anodal tDCS and High-Frequency tRNS Targeting the Occipitotemporal Cortex Do Not Always Enhance Face Perception.

There has been increasing interest in the utility of transcranial electrical stimulation as a tool to enhance cognitive abilities. In the domain of face perception, enhancements have been reported for both transcranial direct current stimulation (tDCS) and high-frequency transcranial random noise stimulation (tRNS) targeting the occipitotemporal cortex. In a series of two experiments, we attempted to replicate these findings for face identity perception, and extend on previous studies, to determine if similar enhancements are also observed for object and facial expression perception. In Experiment 1, using a single blind, between-subjects design in healthy volunteers (N = 53), we examined whether anodal tDCS over the occipitotemporal cortex enhanced performance on tasks involving perception of face identity, facial expression, and object stimuli, when compared to sham stimulation. We failed to replicate previous findings of enhanced performance on face and object perception, nor extend findings to facial expression perception. In Experiment 2, using a single blind, between-subjects design (N = 39), we examined the effect of high-frequency tRNS over the occipitotemporal cortex using the same three tasks employed in Experiment 1. We failed to replicate previous findings of enhanced face perception following high-frequency tRNS over the occipitotemporal cortex, relative to sham stimulation (although we used different stimulation parameters to that employed in a previous study). We also found no evidence of enhanced facial expression and object perception following high-frequency tRNS. The findings align with a growing body of studies that have failed to replicate previously reported enhancements following administration of tDCS and hint for different efficacy of, on first sight, related stimulation protocols. Future studies should explore the foundation of these differential effects in greater detail.

Atypical holistic processing of facial identity and expression in a case of acquired prosopagnosia.

Typical face perception is mediated by holistic processing (i.e., the simultaneous integration of face parts into a whole representation). People with Acquired Prosopagnosia (AP), who have lost the ability to recognise faces after a brain lesion, should thus show atypical holistic coding. Our aim is to use the composite-face effect (CFE) as a measure of holistic processing in ST, a 48-year-old woman with AP but normal recognition of facial expressions of emotions, and matched healthy control participants. Two experiments examining the CFE for identity (Experiment 1) and for expression of emotions (Experiment 2) were conducted. Contrary to controls, in both experiments, ST showed an atypical (i.e., reversed) CFE, thus suggesting altered holistic mechanisms affecting both components of perceptual judgement. Results also suggest that normal facial expression recognition is achievable even with holistic processing difficulties, possibly through compensatory, part-based, mechanisms.

Anodal transcranial direct current stimulation over the right dorsolateral prefrontal cortex enhances reflective judgment and decision-making.

BACKGROUND: Accounts of cognitive processes in judgment and decision-making are frequently based on a dual-process framework, which reflects two qualitatively different types of processing: intuitive (Type 1) and analytical (Type 2) processes. OBJECTIVE: The present study investigated the effects of bilateral transcranial direct current stimulation (tDCS) to the dorsolateral prefrontal cortex (DLPFC) on judgment and decision-making performance. METHODS: Participants received anodal tDCS stimulation to the right DLPFC, left DLPFC or sham. There were 3 tasks: vignettes measuring heuristic thinking, belief bias syllogisms, and the cognitive reflection test (CRT), a measure of the ability to inhibit automatic responses to reach a correct solution. Fifty-four participants (mean age = 24.63 ±â€¯4.46 years; 29 females) were recruited. RESULTS: Results showed that anodal tDCS to the right DLPFC was associated with an increase in cognitive reflection performance (Type 2 processing) as compared to left DLPFC and to sham. Logic thinking was reduced following anodal tDCS to the left DLPFC. CONCLUSION: These findings are broadly consistent with a dual process framework, and cannot be explained by differences in cognitive ability and thinking style. The results demonstrate the involvement of the right DLPFC in cognitive reflection, and suggest the possibility of improving cognitive performance through tDCS.