The Role of the Human Cerebellum for Learning from and Processing of External Feedback in Non-Motor Learning: A Systematic Review.

This review aimed to systematically identify and comprehensively review the role of the cerebellum in performance monitoring, focusing on learning from and on processing of external feedback in non-motor learning. While 1078 articles were screened for eligibility, ultimately 36 studies were included in which external feedback was delivered in cognitive tasks and which referenced the cerebellum. These included studies in patient populations with cerebellar damage and studies in healthy subjects applying neuroimaging. Learning performance in patients with different cerebellar diseases was heterogeneous, with only about half of all patients showing alterations. One patient study using EEG demonstrated that damage to the cerebellum was associated with altered neural processing of external feedback. Studies assessing brain activity with task-based fMRI or PET and one resting-state functional imaging study that investigated connectivity changes following feedback-based learning in healthy participants revealed involvement particularly of lateral and posterior cerebellar regions in processing of and learning from external feedback. Cerebellar involvement was found at different stages, e.g., during feedback anticipation and following the onset of the feedback stimuli, substantiating the cerebellum's relevance for different aspects of performance monitoring such as feedback prediction. Future research will need to further elucidate precisely how, where, and when the cerebellum modulates the prediction and processing of external feedback information, which cerebellar subregions are particularly relevant, and to what extent cerebellar diseases alter these processes.

Idiosyncratic viewing patterns of social scenes reflect individual preferences.

In general, humans preferentially look at conspecifics in naturalistic images. However, such group-based effects might conceal systematic individual differences concerning the preference for social information. Here, we investigated to what degree fixations on social features occur consistently within observers and whether this preference generalizes to other measures of social prioritization in the laboratory as well as the real world. Participants carried out a free viewing task, a relevance taps task that required them to actively select image regions that are crucial for understanding a given scene, and they were asked to freely take photographs outside the laboratory that were later classified regarding their social content. We observed stable individual differences in the fixation and active selection of human heads and faces that were correlated across tasks and partly predicted the social content of self-taken photographs. Such relationship was not observed for human bodies indicating that different social elements need to be dissociated. These findings suggest that idiosyncrasies in the visual exploration and interpretation of social features exist and predict real-world behavior. Future studies should further characterize these preferences and elucidate how they shape perception and interpretation of social contexts in healthy participants and patients with mental disorders that affect social functioning.

Response inhibition to emotional faces is modulated by functional hemispheric asymmetries linked to handedness.

Effective response inhibition requires efficient bottom-up perceptual processing and effective top-down inhibitory control. To investigate the role of hemispheric asymmetries in these processes, 49 right- and 50 left-handers completed a tachistoscopic Go/Nogo task with positive and negative emotional faces while ERPs were recorded. Frontal resting state EEG asymmetry was assessed as a marker of individual differences in prefrontal inhibitory networks. Results supported a dependency of inhibitory processing on early lateralized processes. As expected, right-handers showed a stronger N170 over the right hemisphere, and better response inhibition when faces were projected to the right hemisphere. Left-handers showed a stronger N170 over the left hemisphere, and no behavioural asymmetry. Asymmetries in response inhibition were also valence-dependent, with better inhibition of responses to negative faces when projected to the right, and better inhibition of responses to positive faces when projected to the left hemisphere. Frontal asymmetry was not related to handedness, but did modulate response inhibition depending on valence. Consistent with the asymmetric inhibition model (Grimshaw & Carmel, 2014), greater right frontal activity was associated with better response inhibition to positive than to negative faces; subjects with greater left frontal activity showed an opposite trend. These findings highlight the interplay between bottom-up and top-down processes in explaining hemispheric asymmetries in response inhibition.

Testing the applied potential of the Sheffield Lie Test.

The Sheffield Lie Test (SLT) has been frequently used in laboratory research investigating basic mechanisms of deception. Its applied potential as a lie detection tool has been contested. The current two experiments used a reaction time SLT and investigated whether it can discriminate between participants who committed a mock crime and participants who performed an everyday activity. Results of the first experiment revealed that guilty participants (n = 32) took longer and committed more errors when having to deceptively deny the mock crime and deceptively confirm having performed the everyday activity in contrast to truthfully admitting the mock crime and denying the everyday activity. Innocent participants (n = 29) showed the reversed pattern. Individual Cohen's d's and the area under the ROC curve revealed a high above chance discrimination between both groups. In a second experiment, we repeated this procedure, yet participants were now given a more elaborate explanation of the alibi activity that all should pretend to have done. Although results still revealed the expected pattern in innocent participants (n = 48), the effect was not significant any more for the guilty participants (n = 46). Accordingly, classification accuracies also dropped. These two experiments demonstrate the applied potential of the SLT, yet at the same time its severe limitations. Potential solutions and suggestions for future research will be discussed.