Tal Sela

Transcranial alternating current stimulation increases risk-taking behavior in the balloon analog risk task.

The process of evaluating risks and benefits involves a complex neural network that includes the dorsolateral prefrontal cortex (DLPFC). It has been proposed that in conflict and reward situations, theta-band (4–8 Hz) oscillatory activity in the frontal cortex may reflect an electrophysiological mechanism for coordinating neural networks monitoring behavior, as well as facilitating task-specific adaptive changes. The goal of the present study was to investigate the hypothesis that theta-band oscillatory balance between right and left frontal and prefrontal regions, with a predominance role to the right hemisphere (RH), is crucial for regulatory control during decision-making under risk. In order to explore this hypothesis, we used transcranial alternating current stimulation, a novel technique that provides the opportunity to explore the functional role of neuronal oscillatory activities and to establish a causal link between specific oscillations and functional lateralization in risky decision-making situations. For this aim, healthy participants were randomly allocated to one of three stimulation groups (LH stimulation/RH stimulation/Sham stimulation), with active AC stimulation delivered in a frequency-dependent manner (at 6.5 Hz; 1 mA peak-to-peak). During the AC stimulation, participants performed the Balloon Analog Risk Task. This experiment revealed that participants receiving LH stimulation displayed riskier decision-making style compared to sham and RH stimulation groups. However, there was no difference in decision-making behaviors between sham and RH stimulation groups. The current study extends the notion that DLPFC activity is critical for adaptive decision-making in the context of risk-taking and emphasis the role of theta-band oscillatory activity during risky decision-making situations.

A possible contributory mechanism for impaired idiom perception in schizophrenia.

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.

High-Level Cognitive Functions in Healthy Subjects

This chapter presents and discusses contemporary cutting-edge brain stimulation techniques that have been successful in enhancing high-level cognitive functions in healthy individuals. It focuses primarily on major advances related to language, cognitive control, numerical cognition, planning, learning, and memory research using transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and transcranial random noise stimulation (tRNS). A methodological section then specifies the considerations involved in designing and evaluating a tDCS experiment in the context of cognitive research. The conclusion examines the implications of recent data and suggests avenues for experimental research into future uses of brain stimulation.

Divergent and convergent hemispheric processes in idiom comprehension: The role of idioms predictability

Abstract 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.

Enhancement of Sensory and Cognitive Functions in Healthy Subjects

Cognitive enhancement can be defined as the amplification or extension of core capacities of the mind through augmentation of internal or external information processing systems. Cognitive enhancement could be achieved, among other things, by noninvasive brain stimulation. Noninvasive brain stimulation offers a potential tool for affecting brain functions in the typical and atypical brain and may promote our understanding of brain–behavior relation, and constitute the foundation for rehabilitation efforts. The aim of the present chapter is to introduce up-to-date brain stimulation tools that were successful in enhancing sensory and high-level cognitive functions in healthy individuals. This review mainly focuses on major advances related to language, cognitive control, planning, learning, and memory among healthy individuals and the usage of different methods of brain stimulation such transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and transcranial alternating current stimulation (tACS) to improve these different cognitive functions. Toward the end of this chapter, we provide the reader with a methodological section that specifies the different considerations that one should consider when designing and evaluating a brain stimulation experiment in the context of cognitive research. Finally, we conclude the data that was gathered so far, and offer possible procedures of brain stimulation for future experimental research.

What is the importance and value of research on idiom comprehension in schizophrenia

Australian & New Zealand Journal of Psychiatry, 47(12) Despite eventual resolution, urgent short-term interventions are warranted in view of the distress and possible danger. By blocking dopamine receptors, antipsychotics are recommended as first-line medication (Dewey and Jankovic, 1989). Non-pharmacological interventions include close nursing supervision, skin hygiene, high caloric nutritional support, fluids, an appropriate mattress and padded bed rails. The transient nature of this patient’s symptoms demonstrated that damage to neostriatal tissue was not decisive in itself. With implications on management and prognosis, this warrants further study of the neuropsychiatric findings associated with the different caudate subnuclei.