Transcranial Direct Current Stimulation (tDCS) is a neuromodulation technique with promising results for enhancing cognitive information processes. So far, however, research has mainly focused on the ...effects of tDCS on cognitive control operations for non-emotional material. Therefore, our aim was to investigate the effects on cognitive control considering negative versus positive material. For this sham-controlled, within-subjects study, we selected a homogeneous sample of twenty-five healthy participants. By using behavioral measures and event related potentials (ERP) as indexes, we aimed to investigate whether a single session of anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) would have specific effects in enhancing cognitive control for positive and negative valenced stimuli. After tDCS over the left DLPFC (and not sham control stimulation), we observed more negative N450 amplitudes along with faster reaction times when inhibiting a habitual response to happy compared to sad facial expressions. Gender did not influence the effects of tDCS on cognitive control for emotional information. In line with the Valence Theory of side-lateralized activity, this stimulation protocol might have led to a left dominant (relative to right) prefrontal cortical activity, resulting in augmented cognitive control specifically for positive relative to negative stimuli. To verify that tDCS induces effects that are in line with all aspects of the well known Valence Theory, future research should investigate the effects of tDCS over the left vs. right DLPFC on cognitive control for emotional information.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
When receiving unfair monetary offers from another person, the most common response is punishment. Existing literature on the Ultimatum Game indicates that individuals frequently refuse unfair offers ...even when this results in a loss for themselves. Here, we present behavioral and neurophysiological evidence demonstrating that friendship substantially modifies this response. When the proposer was a friend rather than an unknown person, unfair offers were less frequently rejected and the medial frontal negativity (MFN) typically associated with unfair offers was reversed to positive polarity. The underlying generators were located in inferior-mesial and right inferior- and medial-lateral frontal regions (BA10 and BA11). These findings highlight the fundamental role of the anterior prefrontal cortex in interpersonal economic interaction and, particularly, present new evidence on the effects of social distance on the MFN.
We aimed to investigate the efficacy of 20 Hz repetitive transcranial magnetic stimulation (rTMS) of either right or left dorsolateral prefrontal cortex (DLPFC) as compared to sham rTMS for the ...relief of posttraumatic stress disorder (PTSD)-associated symptoms.
In this double-blind, placebo-controlled phase II trial conducted between October 2005 and July 2008, 30 patients with DSM-IV-diagnosed PTSD were randomly assigned to receive 1 of the following treatments: active 20 Hz rTMS of the right DLPFC, active 20 Hz rTMS of the left DLPFC, or sham rTMS. Treatments were administered in 10 daily sessions over 2 weeks. A blinded rater assessed severity of core PTSD symptoms, depression, and anxiety before, during, and after completion of the treatment protocol. In addition, a battery of neuropsychological tests was measured before and after treatment.
Results show that both active conditions-20 Hz rTMS of left and right DLPFC-induced a significant decrease in PTSD symptoms as indexed by the PTSD Checklist and Treatment Outcome PTSD Scale; however, right rTMS induced a larger effect as compared to left rTMS. In addition, there was a significant improvement of mood after left rTMS and a significant reduction of anxiety following right rTMS. Improvements in PTSD symptoms were long lasting; effects were still significant at the 3-month follow-up. Finally, neuropsychological evaluation showed that active 20 Hz rTMS is not associated with cognitive worsening and is safe for use in patients with PTSD.
These results support the notion that modulation of prefrontal cortex can alleviate the core symptoms of PTSD and suggest that high-frequency rTMS of right DLPFC might be the optimal treatment strategy.
Given the polarity dependent effects of transcranial direct current stimulation (tDCS) in facilitating or inhibiting neuronal processing, and tDCS effects on pitch perception, we tested the effects ...of tDCS on temporal aspects of auditory processing. We aimed to change baseline activity of the auditory cortex using tDCS as to modulate temporal aspects of auditory processing in healthy subjects without hearing impairment. Eleven subjects received 2mA bilateral anodal, cathodal and sham tDCS over auditory cortex in a randomized and counterbalanced order. Subjects were evaluated by the Random Gap Detection Test (RGDT), a test measuring temporal processing abilities in the auditory domain, before and during the stimulation. Statistical analysis revealed a significant interaction effect of time vs. tDCS condition for 4000 Hz and for clicks. Post-hoc tests showed significant differences according to stimulation polarity on RGDT performance: anodal improved 22.5% and cathodal decreased 54.5% subjects' performance, as compared to baseline. For clicks, anodal also increased performance in 29.4% when compared to baseline. tDCS presented polarity-dependent effects on the activity of the auditory cortex, which results in a positive or negative impact in a temporal resolution task performance. These results encourage further studies exploring tDCS in central auditory processing disorders.
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Cognitive performance usually declines in older adults as a result of neurodegenerative processes. One of the cognitive domains usually affected is decision‐making. Based on our recent findings ...suggesting that non‐invasive brain stimulation can improve decision‐making in young participants, we studied whether bifrontal transcranial direct current stimulation (tDCS) applied over the right and left prefrontal cortex of older adult subjects can change balance of risky and safe responses as it can in younger individuals. Twenty‐eight subjects (age range from 50 to 85 years) performed a gambling risk task while receiving either anodal tDCS over the right and cathodal tDCS over the left dorsolateral prefrontal cortex (DLPFC), anodal tDCS over the left with cathodal tDCS over the right DLPFC, or sham stimulation. Our main finding was a significant group effect showing that participants receiving left anodal/right cathodal stimulation chose more often high‐risk prospects as compared with participants receiving sham or those receiving right anodal/left cathodal stimulation. This result is contrary to previous findings in young subjects, suggesting that modulation of cortical activity in young and elderly results in opposite behavioral effects; thus supporting fundamental changes in cognitive processing in the elderly.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Alzheimer's disease (AD) is a neurodegenerative and progressive disease related to a gradual decline in cognitive functions such as memory, attention, perceptual-spatial abilities, language, and ...executive functions. Recent evidence has suggested that interventions promoting neural plasticity can induce significant cognitive gains especially in subjects at risk of or with mild AD. Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are non-invasive techniques that can induce significant and long-lasting changes in focal and non-focal neuroplasticity. In this review, we present initial preliminary evidence that TMS and tDCS can enhance performance in cognitive functions typically impaired in AD. Also, we reviewed the initial six studies on AD that presented early findings showing cognitive gains such as in recognition memory and language associated with TMS and tDCS treatment. In addition, we showed that TMS has also been used to assess neuroplasticity changes in AD supporting the notion that cortical excitability is changed in AD due to the neurodegenerative process. Due to the safe profile, cost of these tools, and initial clinical trials results, further studies are warranted in order to replicate and extend the initial findings of rTMS and tDCS as cognitive enhancers in AD. Further trials should explore different targets of stimulation along with different paradigms of stimulation including combination with behavioural interventions.
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BFBNIB, DOBA, FSPLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The ultimatum game (UG) is an endowment sharing game in which a proposer suggests a division of an asset to a recipient, who must accept or reject it. Economic studies showed that despite recipients ...usually rejecting unfair offers, perception and reaction to unfairness are highly dependent on who is the proposer. Event-related potentials (ERPs) commonly detected in UG games are the medial frontal negativity (MFN), a component detected in recipients facing unfair offers, and the P300, a component related to attentional and memory processes. Given this, we aimed to investigate the behavioral and ERP responses of healthy people playing the UG game with Down syndrome (DS) and typical development (TD) proposers. Nineteen subjects participated in this study. The UG behavioral data were similar to previous studies. ERP analysis showed no MFN in participants facing unfair offers. A higher P300 amplitude was detected when participants faced fair offers from TD compared to DS fair offers. We also found a positive correlation between P300 amplitude for TD offers and self-esteem scale score. Together these findings indicate that insertion of an atypical player in the UG led to changes in participants' perception and expectancy of the game.
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People react aversely when faced with unfair situations, a phenomenon that has been related to an electroencephalographic (EEG) potential known as medial frontal negativity (MFN). To our knowledge, ...the existence of the MFN in children has not yet been demonstrated. Here, we recorded EEG activity from 15 children playing the ultimatum game (UG) and who afterward performed a recognition task, in order to assess whether they could recognize the unfair and fair (familiar) proposers among unfamiliar faces. During the recognition task, we also acquired pupil dilation data to investigate subconscious recognition processes. A typical (adult-like) MFN component was detected in reaction to unfair proposals. We found a positive correlation between reaction time and empathy, as well as a negative correlation between reaction time and systematic reasoning scores. Finally, we detected a significant difference in pupil dilation in response to unfamiliar faces versus UG proposers. Our data provide the first evidence of MFN in children, which appears to index similar neurophysiological phenomena as in adults. Also, reaction time to fair proposals seems to be related to individual traits, as represented by empathy and systematizing. Our pupil dilation data provide evidence that automatic responses to faces did not index fairness, but familiarity. These findings have implications for our understanding of social development in typically developing children.
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BFBNIB, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Previous studies have led to hypothesizing that right DLPFC activity is related to risk propensity, but the generality of this relationship remains unclear. Here, we experimentally modulated DLPFC ...activity in 47 healthy, female volunteers during a risky decision-making task, where monetary gambles defined by potential win, loss, and outcome probability were evaluated in the absence of feedback and uncertainty. Three participant groups, receiving left anodal/right cathodal, right anodal/left cathodal, and sham tDCS, were compared. Overall, participants performed the task well above chance level and were significantly risk averse, but tDCS did not affect task performance or risk propensity. However, right anodal/left cathodal tDCS significantly elevated response confidence, independently of accept/reject response. Our results suggest that the relationship between DLPFC activity and risk propensity may not be universally valid for all task types and requires further characterization. Enhancing right and attenuating left DLPFC activity boosts subjective confidence, with potential implications for understanding pathological gambling.
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10.
Propriedades psicométricas da Escala de Conexão Social Silva Soares, Ana Karla; Ferreira Goedert, Maria Celina; Campanhã, Camila ...
Revista interamericana de psicología,
10/2023, Volume:
57, Issue:
2
Journal Article
Peer reviewed
A conexão social (CS) percebida é um construto unidimensional conceituado como a avaliação cognitiva de que existe uma relação próxima com os outros, com os quais o contato pode ser feito. Este ...estudo objetivou adaptar a Escala de Conexão Social (ECS) para o contexto brasileiro, reunindo evidências de adequação psicométrica. Procederam-se dois estudos, o primeiro (N = 285; idade média 24 anos; DP = 4,92; 62% masculino) para obter a estrutura fatorial exploratória e o segundo (N = 300; idade média 23 anos; DP = 5,43; 51% masculino) direcionado a análise confirmatória da unidimensionalidade e dos parâmetros da teoria de resposta ao item. A consistência interna foi satisfatória, assim como as evidências de validade convergente obtidas a partir das correlações negativas com a escala de depressão, ansiedade e estresse. Os resultados revelam que a versão em português da ECS reuniu evidências psicométricas adequadas apoiando seu uso na mensuração da CS.
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