Promoting social plasticity in developmental disorders with non-invasive brain stimulation techniques.

Being socially connected directly impacts our basic needs and survival. People with deficits in social cognition might exhibit abnormal behaviors and face many challenges in our highly social-dependent world. These challenges and limitations are associated with a substantial economical and subjective impact. As many conditions where social cognition is affected are highly prevalent, more treatments have to be developed. Based on recent research, we review studies where non-invasive neuromodulatory techniques have been used to promote Social Plasticity in developmental disorders. We focused on three populations where non-invasive brain stimulation seems to be a promising approach in inducing social plasticity: Schizophrenia, Autism Spectrum Disorder (ASD) and Williams Syndrome (WS). There are still very few studies directly evaluating the effects of transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) in the social cognition of these populations. However, when considering the promising preliminary evidences presented in this review and the limited amount of clinical interventions available for treating social cognition deficits in these populations today, it is clear that the social neuroscientist arsenal may profit from non-invasive brain stimulation techniques for rehabilitation and promotion of social plasticity.

An ethical discussion of the use of transcranial direct current stimulation for cognitive enhancement in healthy individuals: a fictional case study

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique. Because of its low cost, ease of use, safety, and portability, tDCS has been increasingly investigated for therapeutic purposes in neuropsychiatric disorders and in experimental neuropsychological studies with healthy volunteers. These experiments on healthy cognition have shown significant effects on working memory, decision-making, and language. Such promising results have fomented reflections on studying tDCS to enhance or modify normal cognitive function, a concept described by some as "cosmetic" neurology. As the field evolves, discussing whether the use of tDCS in these situations is appropriate is important, including how bioethical principles may help resolve these challenges. In this article, we present some examples of the effects of tDCS on cognition in healthy participants as a starting point for this ethical debate. We envision a futuristic "Brain Boosting" tDCS clinic that specializes in cosmetic neurology and cognitive enhancement. Using the typical cases of a fictitious Dr. Icarus as a discussion starting point, we raise some issues that are both humorous and provocative about the use of tDCS in healthy people. The importance of this work is to ask relatively new questions regarding cosmetic neurology in the field of neuromodulation and discuss the related ethical conflicts...

An ethical discussion of the use of transcranial direct current stimulation for cognitive enhancement in healthy individuals: a fictional case study

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique. Because of its low cost, ease of use, safety, and portability, tDCS has been increasingly investigated for therapeutic purposes in neuropsychiatric disorders and in experimental neuropsychological studies with healthy volunteers. These experiments on healthy cognition have shown significant effects on working memory, decision-making, and language. Such promising results have fomented reflections on studying tDCS to enhance or modify normal cognitive function, a concept described by some as "cosmetic" neurology. As the field evolves, discussing whether the use of tDCS in these situations is appropriate is important, including how bioethical principles may help resolve these challenges. In this article, we present some examples of the effects of tDCS on cognition in healthy participants as a starting point for this ethical debate. We envision a futuristic "Brain Boosting" tDCS clinic that specializes in cosmetic neurology and cognitive enhancement. Using the typical cases of a fictitious Dr. Icarus as a discussion starting point, we raise some issues that are both humorous and provocative about the use of tDCS in healthy people. The importance of this work is to ask relatively new questions regarding cosmetic neurology in the field of neuromodulation and discuss the related ethical conflicts.(AU)

Altered semantic integration in autism beyond language: a cross-modal event-related potentials study.

Autism spectrum disorders (ASDs) are characterized by impaired communication, particularly pragmatic and semantic language, resulting in verbal comprehension deficits. Semantic processing in these conditions has been studied extensively, but mostly limited only to linguistic material. Emerging evidence, however, suggests that semantic integration deficits may extend beyond the verbal domain. Here, we explored cross-modal semantic integration using visual targets preceded by musical and linguistic cues. Particularly, we have recorded the event-related potentials to evaluate whether the N400 and late positive potential (LPP) components, two widely studied electrophysiological markers of semantic processing, are differently sensitive to congruence with respect to typically developing children. Seven ASD patients and seven neurotypical participants matched by age, education and intelligence quotient provided usable data. Neuroelectric activity was recorded in response to visual targets that were related or unrelated to a preceding spoken sentence or musical excerpt. The N400 was sensitive to semantic congruence in the controls but not the patients, whereas the LPP showed a complementary pattern. These results suggest that semantic processing in ASD children is also altered in the context of musical and visual stimuli, and point to a functional decoupling between the generators of the N400 and LPP, which may indicate delayed semantic processing. These novel findings underline the importance of exploring semantic integration across multiple modalities in ASDs and provide motivation for further investigation in large clinical samples.

Modulation of decision-making in a gambling task in older adults with transcranial direct current stimulation.

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.