Representation of social content in dorsomedial prefrontal cortex underlies individual differences in agreeableness trait

Personality traits reflect key aspects of individual variability in different psychological domains. Understanding the mechanisms that give rise to these differences requires an exhaustive investigation of the behaviors associated with such traits, and their underlying neural sources. Here we investigated the mechanisms underlying agreeableness, one of the five major dimensions of personality, which has been linked mainly to socio-cognitive functions. In particular, we examined whether individual differences in the neural representations of social information are related to differences in agreeableness of individuals. To this end, we adopted a multivariate representational similarity approach that captured within single individuals the activation pattern similarity of social and non-social content, and tested its relation to the agreeableness trait in a hypothesis-driven manner. The main result confirmed our prediction: processing social and non-social content led to similar patterns of activation in individuals with low agreeableness, while in more agreeable individuals these patterns were more dissimilar. Critically, this association between agreeableness and encoding similarity of social and random content was significant only in the dorsomedial prefrontal cortex, a brain region consistently involved during attributions of mental states. The present finding reveals the link between neural mechanisms underlying social information processing and agreeableness, a personality trait highly related to socio-cognitive abilities, thereby providing a step forward in characterizing its neural determinants. Furthermore, it emphasizes the advantage of multivariate pattern analysis approaches in capturing and understanding the neural sources of individual variations

Functional dissociations in temporal preparation: Evidence from dual-task performance

Implicit preparation over time is a complex cognitive capacity important to optimize behavioral responses to a target occurring after a temporal interval, the so-called foreperi- od (FP). If the FP occurs randomly and with the same a priori probability, shorter response times are usually observed with longer FPs than with shorter ones (FP effect). Moreover, responses are slower when the preceding FP was longer than the current one (sequential effects). It is still a matter of debate how different processes influence these temporal prep- aration phenomena. The present study used a dual-task procedure to understand how dif- ferent processes, along the automatic-controlled continuum, may contribute to these temporal preparation phenomena. Dual-task demands were manipulated in two experi- ments using a subtraction task during the FP. This secondary task was administered in blocks (Experiment 1) or was embedded together with a baseline single-task in the same experimental session (Experiment 2). The results consistently showed that the size of the FP effect, but not that of sequential effects, is sensitive to dual-task manipulations. This functional dissociation unveils the multi-faceted nature of implicit temporal preparation: while the FP effect is due to a controlled, resource-consuming preparatory mechanism, a more automatic mechanism underlies sequential effects

Right-lateralized intrinsic brain dynamics predict monitoring abilities

Intrinsic brain dynamics may play an important role in explaining interindividual variability in executive functions. In the present electroencephalography (EEG) study, we focused on the brain lateralization patterns predicting performance on three different monitoring tasks of temporal, verbal, and spatial nature. These tasks were administered to healthy young participants after their EEG was recorded during a resting state session. Behavioral indices of monitoring efficiency were computed for each task and a source-based spectral analysis was performed on participants' resting-state EEG activity. A lateralization index was then computed for each of 75 homologous cortical regions as the right-left difference score for the log-transformed power ratio between beta and alpha frequencies. Finally, skipped Pearson correlations between the lateralization index in each cortical region and behavioral performance of the three monitoring tasks were computed. An intersection among the three tasks showed that right-lateralization in different prefrontal regions, including the middle frontal gyrus, was positively correlated with monitoring abilities across the three tasks. In conclusion, right-lateralized brain mechanisms set the stage for the ability to monitor for targets in the environment, independently of the specific task characteristics. These mechanisms are grounded in hemispheric asymmetry dynamics already observable at rest

Brain oscillatory activity associated with switch and mixing costs during reactive control

Task-switching paradigms, which involve task repetitions and between-task switches, have long been used as a benchmark of cognitive control processes. When mixed and single-task blocks are presented, two types of costs usually occur: the switch cost, measured by contrasting performance on switch and repeat trials during the mixed-task blocks, and the mixing cost, calculated as the performance difference between the all-repeat trials from the single-task blocks and the repeat trials from the mixed-task blocks. Both costs can be mitigated by informational cues that signal the upcoming task switch beforehand. Recent electroencephalographic studies have started unveiling the brain oscillatory activity underlying the switch cost during the preparatory cue-target interval, thus, targeting proactive control processes. Less attention has instead been paid to the mixing cost and, importantly, to the oscillatory dynamics involved in switch and mixing costs during reactive control. To fill this gap, here, we analyzed the time-frequency data obtained during a task-switching paradigm wherein the simultaneous presentation of task cues and targets increased the need for reactive control. Results showed that while alpha and beta bands were modulated by switch and mixing costs in a similar gradual fashion, with greater suppression going from switch to repeat and all-repeat trials, theta power was sensitive to the switch cost with increased power for switch than repeat trials. Together, our findings join previous studies underlining the importance of theta, alpha and beta oscillations in task-switching and extend them by depicting the oscillations involved in switch and mixing costs during reactive control processes

Left prefrontal tumor and widespread cognitive impairment: multivariate lesion-symptom mapping evidence

Introduction: Despite consistent evidence of hub brain regions with multifaceted functional roles coming from cognitive neuroscience (van den Heuvel & Sporns, 2011), the neuropsychological approach has mainly focused on the functional specialization of individual brain regions. Relatively few neuropsychological studies are focused on studying whether the severity of cognitive impairment across multiple cognitive abilities can be related to focal brain injuries. Methods: Here we approached this issue by applying a latent variable modeling of the severity of cognitive impairment in brain tumor patients, followed by multivariate lesion-symptom mapping (Zhang et al., 2014) identifying brain regions critically involved in multiple cognitive abilities. Results: We observed that lesions in confined left lateral prefrontal areas including the inferior frontal junction produced the most severe cognitive deficits, above and beyond tumor histology. This ef ect remained even when performance on non-verbal tasks only was analyzed. Discussion: Our findings demonstrate that specific brain regions are highly involved across different sub-networks and underpin a vast range of cognitive abilities. Defining such brain regions is relevant not only theoretically but also clinically, since it may facilitate tailored tumor resections and improve cognitive surgical outcomes

Structural hemispheric asymmetries underlie verbal Stroop performance

Performance on tasks involving cognitive control such as the Stroop task is often associated with left lateralized brain activations. Based on this neuro-functional evidence, we tested whether leftward structural grey matter asymmetries would also predict inter-individual differences in combatting Stroop interference. To check for the specificity of the results, both a verbal Stroop task and a spatial one were administered to a total of 111 healthy young individuals, for whom T1-weighted magnetic resonance imaging (MRI) images were also acquired. Surface thickness and area estimations were calculated using FreeSurfer. Participants\u2019 hemispheres were registered to a symmetric template and Laterality Indices (LI) for the surface thickness and for the area at each vertex in each participant were computed. The correlation of these surface LI measures with the verbal and spatial Stroop effects (incongruent\u2013congruent difference in trial performance) was assessed at each vertex by means of general linear models at the whole-brain level. We found a significant correlation between performance and surface area LI in an inferior posterior temporal cluster (overlapping with the so-called visual word form area, VWFA), with a more left-lateralized area in this region associated with a smaller Stroop effect only in the verbal task. These results point to an involvement of the VWFA for higher-level processes based on word reading, including the suppression of this process when required by the task, and could be interpreted in the context of cross-hemispheric rivalry

The case of Air Traffic Control training

Air traffic controllers have to guarantee safe and efficient air traffic by predicting future flight paths based on their perception and interpretation of multiple data on the radar display. The multi-tasking nature of their job makes the cognitive and emotional processes required in Air Traffic Control fundamentally different from those traditionally studied in the lab. Thus, Air Traffic Control represents a unique naturalistic opportunity to investigate how such a demanding job may shape cognition. This chapter reviews work dealing with the cognitive characteristics of air traffic control, as well as the few studies that have investigated how training and experience in this profession change different aspects of cognitive functioning, in particular different facets of cognitive flexibility and planning abilities. Finally, it will also examine the cognitive consequences of the unique challenges represented by man-technology interactions inherent in this job. Despite the promising findings reviewed in this chapter, the research on the cognitive enhancement derived from training and experience on ATC is still limited and not conclusive. Further methodologically well-controlled studies are clearly needed to obtain a more comprehensive picture of the extraordinary potentialities of this profession