Atypical brain lateralization for speech processing at the sublexical level in autistic children revealed by fNIRS.

Autistic children often exhibit atypical brain lateralization of language processing, but it is unclear what aspects of language contribute to this phenomenon. This study employed functional near-infrared spectroscopy to measure hemispheric lateralization by estimating hemodynamic responses associated with processing linguistic and non-linguistic auditory stimuli. The study involved a group of autistic children (N = 20, mean age = 5.8 years) and a comparison group of nonautistic peers (N = 20, mean age = 6.5 years). The children were presented with stimuli with systematically decreasing linguistic relevance: naturalistic native speech, meaningless native speech with scrambled word order, nonnative speech, and music. The results revealed that both groups showed left lateralization in the temporal lobe when listening to naturalistic native speech. However, the distinction emerged between autism and nonautistic in terms of processing the linguistic hierarchy. Specifically, the nonautistic comparison group demonstrated a systematic reduction in left lateralization as linguistic relevance decreased. In contrast, the autism group displayed no such pattern and showed no lateralization when listening to scrambled native speech accompanied by enhanced response in the right hemisphere. These results provide evidence of atypical neural specialization for spoken language in preschool- and school-age autistic children and shed new light on the underlying linguistic correlates contributing to such atypicality at the sublexical level.

Delay discounting decisions are linked to temporal distance representations of world events across cultures.

Delay discounting describes the phenomenon whereby the subjective value of a reward declines as the time until its receipt increases. Individuals differ in the subjective value that they assign to future rewards, yet, the components feeding into this appraisal of value remain unclear. We examined whether temporal psychological distance, i.e. the closeness one feels to the past and future, is one such component. English speakers in the USA and Mandarin speakers in China completed a delay discounting task and organized past and future world events on a canvas according to their representation of the event's temporal position relative to themselves. Previous work has identified linguistic and cultural differences in time conception between these populations, thus, we hypothesized that this sample would display the variability necessary to probe whether temporal psychological distance plays a role in reward valuation. We found that English speakers employed horizontal, linear representations of world events, while Mandarin speakers used more two-dimensional, circular representations. Across cultures, individuals who represented the future as more distant discounted future rewards more strongly. Distance representations of past events, however, were associated with discounting behaviors selectively in Mandarin speakers. This suggests that temporal psychological distance plays a fundamental role in farsighted decision-making.

[The effect of oxytocin on fear responses: bidirectional regulation or methodological issues?]

One of the core symptoms in anxiety disorders is dysregulated fear response. It is crucial for psychologists and neuroscientists to understand how fear responses are enhanced and inhibited. Although oxytocin (OXT) was initially conceived as a prosocial molecule and mammalian neuropeptide that enhances cooperation and trust, later studies showed that it produces modulatory influence on fear responses. Therefore, OXT is now regarded as a promising pharmacological agent to boost treatment response in anxiety disorders. However, the effect of OXT on fear responses have been somewhat complex, and there are some contradictions among animal experiments and human studies. In this article, we summarize recent studies that employed animal models, brain region-specific manipulations and preclinical studies to explore the role of OXT in the acquisition and processing of fear response. We also discuss the methodological differences among these studies and review the potential factors that may contribute to the complicated effect of OXT on fear response. This review will help to promote the potential clinical application of OXT.