Context matters: Anterior and posterior cortical midline responses to sad movie scenes

A normative model of brain responses to social scenarios reflects the maturity of children and adolescents' social-emotional abilities

The rapid brain maturation in childhood and adolescence accompanies the development of socio-emotional functioning. However, it is unclear how the maturation of the neural activity drives the development of socio-emotional functioning and individual differences. This study aimed to reflect the age dependence of inter-individual differences in brain responses to socio-emotional scenarios and to develop naturalistic imaging indicators to assess the maturity of socio-emotional ability at the individual level. Using three independent naturalistic imaging datasets containing healthy participants (n = 111, 21 and 122), we found and validated that age-modulated inter-individual concordance of brain responses to socio-emotional movies in specific brain regions. The similarity of an individual's brain response to the average response of older participants was defined as response typicality, which predicted an individual's emotion regulation strategies in adolescence and theory of mind (ToM) in childhood. Its predictive power was not superseded by age, sex, cognitive performance or executive function. We further showed that the movie's valence and arousal ratings grounded the response typicality. The findings highlight that forming typical brain response patterns may be a neural phenotype underlying the maturation of socio-emotional ability. The proposed response typicality represents a neuroimaging approach to measure individuals' maturity of cognitive reappraisal and ToM.

Naturalistic Stimuli in Affective Neuroimaging: A Review

Naturalistic stimuli such as movies, music, and spoken and written stories elicit strong emotions and allow brain imaging of emotions in close-to-real-life conditions. Emotions are multi-component phenomena: relevant stimuli lead to automatic changes in multiple functional components including perception, physiology, behavior, and conscious experiences. Brain activity during naturalistic stimuli reflects all these changes, suggesting that parsing emotion-related processing during such complex stimulation is not a straightforward task. Here, I review affective neuroimaging studies that have employed naturalistic stimuli to study emotional processing, focusing especially on experienced emotions. I argue that to investigate emotions with naturalistic stimuli, we need to define and extract emotion features from both the stimulus and the observer.

Movies and narratives as naturalistic stimuli in neuroimaging

Using movies and narratives as naturalistic stimuli in human neuroimaging studies has yielded significant advances in understanding of cognitive and emotional functions. The relevant literature was reviewed, with emphasis on how the use of naturalistic stimuli has helped advance scientific understanding of human memory, attention, language, emotions, and social cognition in ways that would have been difficult otherwise. These advances include discovering a cortical hierarchy of temporal receptive windows, which supports processing of dynamic information that accumulates over several time scales, such as immediate reactions vs. slowly emerging patterns in social interactions. Naturalistic stimuli have also helped elucidate how the hippocampus supports segmentation and memorization of events in day-to-day life and have afforded insights into attentional brain mechanisms underlying our ability to adopt specific perspectives during natural viewing. Further, neuroimaging studies with naturalistic stimuli have revealed the role of the default-mode network in narrative-processing and in social cognition. Finally, by robustly eliciting genuine emotions, these stimuli have helped elucidate the brain basis of both basic and social emotions apparently manifested as highly overlapping yet distinguishable patterns of brain activity.

Multiscale Integration of Contextual Information During a Naturalistic Task

Everyday experience requires rapid and automatic integration of incoming stimuli with previously stored knowledge. Prior knowledge can help to construct a general "situation model" of the event, as well as aid comprehension of an ongoing narrative. Using fMRI in healthy adult humans, we investigated processing of videos whose locations and characters were always familiar but whose narratives were either a continuation or noncontinuation of an earlier video (high context (HC) or low context (LC), respectively). Responses in parahippocampal gyrus and retrosplenial cortex were composed of an initial transient, locked to the video onsets, followed by a period of lower amplitude activation that was greater in the LC condition. This may reflect rapid processing of core components of situation models such as location and characters and more gradual incorporation of their narrative themes. By contrast, activity increases in left hemisphere middle temporal gyrus (MTG), angular gyrus, and inferior frontal gyrus were maintained throughout the videos and were higher for HC versus LC videos. Further, activity in the left MTG peaked earlier in the HC condition. We suggest that these regions support representations of the specific interlinked concepts necessary to comprehend an ongoing narrative, which are already established for the HC videos.

Dorsal and Ventral Posterior Cingulate Cortex Switch Network Assignment via Changes in Relative Functional Connectivity Strength to Noncanonical Networks

The posterior cingulate cortex (PCC) is often used as a seed region for probing default-mode network (DMN) connectivity. However, there is evidence for a functional segregation between its dorsal (dPCC) and ventral (vPCC) subregions, which suggests differential involvements of d-/vPCC in regulating cognitive demands. Our paradigm included functional magnetic resonance imaging measures for baseline resting state, affective or cognitive tasks, and post-task resting states. We investigated the effect of task demands on intra-PCC coupling and d-/vPCC network assignment to major intrinsic connectivity networks (ICNs), which was estimated via edge weights of a graph network encompassing DMN, dorsal-attention network, and central-executive network (CEN). Although PCC subregions were functionally coupled during both resting-state conditions and cognitive tasks, they decoupled during affective stimulation. For dPCC, functional connectivity strength (FCS) to CEN was higher than to the other two ICNs; whereas for vPCC, FCS to DMN was the highest. We, hence, defined CEN and DMN as the canonical networks at rest for dPCC and vPCC, respectively. Switching from rest to affective stimulation, however, induced the strongest effects to relative network assignments between non-canonical networks of dPCC and vPCC. Although vPCC showed a durable functional connectivity (FC) to DMN, dPCC played a crucial role during switches of between-network FC depending on cognitive versus affective task requirements. Our results underline that it is crucial for future seed-based FC studies to consider these two subregions separately in terms of seed location and discussion of findings. Finally, our findings highlight the functional importance of connectivity changes toward regions outside the canonical networks.

Real-time monitoring prefrontal activities during online video game playing by functional near-infrared spectroscopy

A growing body of literature has suggested that video game playing can induce functional and structural plasticity of the brain. The underlying mechanisms, however, remain poorly understood. In this study, functional near-infrared spectroscopy (fNIRS) was used to record prefrontal activities in 24 experienced game players when they played a massively multiplayer online battle arena video game, League of Legends (LOL), under naturalistic conditions. It was observed that game onset was associated with significant activations in the ventrolateral prefrontal cortex (VLPFC) and concomitant deactivations in the dorsolateral prefrontal cortex (DLPFC) and frontal pole area (FPA). Game events, such as slaying an enemy and being slain by an enemy evoked region-specific time-locked hemodynamic/oxygenation responses in the prefrontal cortex (PFC). It was proposed that the VLPFC activities during LOL playing are likely responses to visuo-motor task load of the game, while the DLPFC/FPA activities may be involved in the constant shifts of attentional states and allocation of cognitive resources required by game playing. The present study demonstrated that it is feasible to use fNIRS to monitor real-time prefrontal activity during online video game playing.