Medial prefrontal cortex and self-referential mental activity: Relation to a default mode of brain function

Medial prefrontal cortex (MPFC) is among those brain regions having the highest baseline metabolic activity at rest and one that exhibits decreases from this baseline across a wide variety of goal-directed behaviors in functional imaging studies. This high metabolic rate and this behavior suggest the existence of an organized mode of default brain function, elements of which may be either attenuated or enhanced. Extant data suggest that these MPFC regions may contribute to the neural instantiation of aspects of the multifaceted “self.” We explore this important concept by targeting and manipulating elements of MPFC default state activity. In this functional magnetic resonance imaging (fMRI) study, subjects made two judgments, one self-referential, the other not, in response to affectively normed pictures: pleasant vs. unpleasant (an internally cued condition, ICC) and indoors vs. outdoors (an externally cued condition, ECC). The ICC was preferentially associated with activity increases along the dorsal MPFC. These increases were accompanied by decreases in both active task conditions in ventral MPFC. These results support the view that dorsal and ventral MPFC are differentially influenced by attentiondemanding tasks and explicitly self-referential tasks. The presence of self-referential mental activity appears to be associated with increases from the baseline in dorsal MPFC. Reductions in ventral MPFC occurred consistent with the fact that attention-demanding tasks attenuate emotional processing. We posit that both self-referential mental activity and emotional processing represent elements of the default state as represented by activity in MPFC. We suggest that a useful way to explore the neurobiology of the self is to explore the nature of default state activity.

Evidence that replication fork components catalyze establishment of cohesion between sister chromatids

Accurate chromosome segregation requires that replicated sister chromatids are held together until anaphase, when their “cohesion” is dissolved, and they are pulled to opposite spindle poles by microtubules. Establishment of new cohesion between sister chromatids in the next cell cycle is coincident with replication fork passage. Emerging evidence suggests that this temporal coupling is not just a coincident timing of independent events, but rather that the establishment of cohesion is likely to involve the active participation of replication-related activities. These include PCNA, a processivity clamp for some DNA polymerases, Trf4/Pol σ (formerly Trf4/Polκ), a novel and essential DNA polymerase, and a modified Replication Factor C clamp–loader complex. Here we describe recent advances in how cohesion establishment is linked to replication, highlight important unanswered questions in this new field, and describe a “polymerase switch” model for how cohesion establishment is coupled to replication fork progression. Building the bridges between newly synthesized sister chromatids appears to be a fundamental but previously unrecognized function of the eukaryotic replication machinery.

Examining the Relationship Between Passion and Perceptions of Cohesion in Athletes

The purpose of the present study was to examine the relationship of harmonious and obsessive passion to perceptions of task and social cohesion in team sport athletes. Participants were 370 competitive (N=252) and recreational (N=118) athletes ranging from 18- to 28-years-old (Mage=20.20, SD=1.52) from a wide variety of team sports. Participants completed the Passion Scale (Vallerand et al., 2003) and the Group Environment Questionnaire (Carron et al., 1985). A MANOVA revealed that competitive athletes were more passionate and had higher perceptions of cohesion than did recreational athletes. Multiple regression analyses revealed a positive relationship between both harmonious and obsessive passion and both task (ATG-T, GI-T) and social (ATG-S, GI-S) cohesion. Theoretical and practical implications are discussed pertaining to the importance of harmonious and obsessive passion in athletes and perceptions of cohesion in competitive and recreational sport.

Children’s Perceptions of Cohesion

The general purpose of the two studies reported here was to examine perceptions of team cohesiveness in children aged 9 to 12 years. In Study 1, focus groups were used to examine individual perceptions of cohesion from the perspective of group integration – the group as a totality. In Study 2, open-ended questionnaires were used to examine individual perceptions of cohesion from the perspective of individual attractions to the group. The results showed that children as young as nine years understand the phenomenon known as cohesion. They can discuss the group as a totality, the characteristics of cohesive and non-cohesive teams, and identify the major factors attracting them to and maintaining their involvement in the group. Also, the ability to clearly distinguish between task and social cohesion is present. The results provide insight into the world of child sport and emphasise the importance of group cohesion, affiliation, and other social constructs in children’s involvement and adherence to sport groups

The Social Environment in Children’s Sport: Cohesion, Social Acceptance, Commitment, and Enjoyment

The primary purpose of the current study was to determine whether perceptions of cohesion mediated the relationship between social acceptance and individual commitment and enjoyment in children’s sport. A secondary purpose involved the assessment of the temporal nature of cohesion over the course of an athletic season. A total of 209 (Mage = 9.87 years; SD = 1.34) recreational soccer players completed questionnaires at three time points (T1 – social acceptance, cohesion; T2 – cohesion; T3 – commitment, enjoyment, cohesion) during an athletic season. Using structural equation modeling, the results indicated that task cohesion mediated the relationship between social acceptance and commitment and enjoyment, whereas social cohesion did not. In addition, individual perceptions of cohesion did not vary significantly over the course of the season. These results will be discussed in terms of their theoretical and practical implications. As one example, the relative stability in terms of perceptions of cohesion in this population could inform future intervention work aimed at enriching the social environment

1 + 1 = 3? EU-US voting cohesion in the United Nations General Assembly. EU Diplomacy Paper 07/2012, September 2012

This paper investigates the factors that explain the voting cohesion of the United States (US) and the European Union (EU) on foreign policy issues in the United Nations General Assembly (UNGA). It is often argued that the EU and the US are simply too different to cooperate within international organizations and thus to vote the same way, for example, in the UNGA. However, there is still a lack of research on this point and, more importantly, previous studies have not analyzed which factors explain EU-US voting cohesion. In this paper, I try to fill this gap by studying voting cohesion from 1980 until 2011 on issues of both ‘high’ politics (security) and ‘low’ politics (human rights) not only as regards EU-US voting cohesion, but also concerning voting cohesion among EU member states. I test six hypotheses derived from International Relations theories, and I argue that EU-US voting cohesion is best explained by the topic of the issue voted upon, whether an issue is marked as ‘important’ by the US government, and by the type of resolution. On the EU level, the length of Union membership and transaction costs matter most.