Coherence and recurrency: maintenance,control and integration in working memory

Working memory (WM), including a ‘central executive’, is used to guide behavior by internal goals or intentions. We suggest that WM is best described as a set of three interdependent functions which are implemented in the prefrontal cortex (PFC). These functions are maintenance, control of attention and integration. A model for the maintenance function is presented, and we will argue that this model can be extended to incorporate the other functions as well. Maintenance is the capacity to briefly maintain information in the absence of corresponding input, and even in the face of distracting information. We will argue that maintenance is based on recurrent loops between PFC and posterior parts of the brain, and probably within PFC as well. In these loops information can be held temporarily in an active form. We show that a model based on these structural ideas is capable of maintaining a limited number of neural patterns. Not the size, but the coherence of patterns (i.e., a chunking principle based on synchronous firing of interconnected cell assemblies) determines the maintenance capacity. A mechanism that optimizes coherent pattern segregation, also poses a limit to the number of assemblies (about four) that can concurrently reverberate. Top-down attentional control (in perception, action and memory retrieval) can be modelled by the modulation and re-entry of top-down information to posterior parts of the brain. Hierarchically organized modules in PFC create the possibility for information integration. We argue that large-scale multimodal integration of information creates an ‘episodic buffer’, and may even suffice for implementing a central executive.     

Parental Influences on Young Women’s Certainty about Their Career Aspirations

Identity control theory (Kerpelman, Pittman, & Lamke, Journal of Adolescent Research, 12: 325–346, 1997) and the literature on possible selves (Markus & Nurius, American Psychologist, 41: 954–969, 1986) and family influences on adolescents’ vocational choices (e.g., Otto, Journal of Career Development, 27: 111–117, 2000; Whiston & Keller, The Counseling Psychologist, 32: 493–568, 2004) were used to guide this study of young women’s career aspirations. How mother–daughter and father–daughter relationships were associated with young women’s certainty about their anticipated future careers was addressed with data from 304 female undergraduates. Findings indicated that parent–daughter connectedness predicted the young women’s anticipated distress, as well as their willingness to change to fit parental views should their parents disagree with their career aspirations. In addition, anticipated distress mediated associations between willingness to change and connectedness with parents, and between willingness to change and father–daughter career discussions. Discussing career goals with mother increased mother’s influence, but decreased father’s influence, on daughter’s career certainty under conditions of father–daughter disagreement about career choice. The ability to separate her own feelings from those of her father was particularly important in reducing the daughter’s willingness to change her career goals to fit maternal or paternal expectations. Collectively, these findings offer additional insights about the role of parent–adolescent relationships in understanding young women’s career aspirations and note the importance of considering the distinct influences of mothers and fathers on their daughters’ career goals and plans.     

Work–family conflict and facilitation: The combined influence of the job demand–control model and achievement striving

This study investigated the moderating effect of achievement striving (AS) on the relationship between situational variables, defined by the Job Demand–Control model (JDC), and both work–family conflict and work–family facilitation. In a sample of 224 employees in the welfare sector, the results of two hierarchical regression analyses showed that job demands were significantly positively related and job control was significantly negatively related to work–family conflict but not to work–family facilitation. For AS, a significant positive relationship was found with both work–family conflict and work–family facilitation. Interactions between situational variables and AS were insignificant although the interaction between AS and job control on work–family facilitation was close to significance in line with the expectations. Specifically, a lower level of job control did not lower the level of WFF experienced by individuals high on AS. Theoretical and practical implications are discussed.     

The Demand–Control model and target's reports of bullying at work: A test within Spanish and Belgian blue-collar workers

The present study explores whether Karasek's Job Demand–Control (JDC) model's strain hypothesis can be applied to target's reports of bullying at work in matched samples of Spanish and Belgian blue-collar workers. In the Spanish sample, results reveal a positive main effect of workload and a negative main effect of autonomy. The relationship between workload and bullying is particularly strong under the condition of low autonomy (i.e., interaction), in line with Karasek's strain hypothesis. In the Belgian sample, results show a positive main effect of workload and a significant workload–autonomy interaction effect in accordance with the strain hypothesis. In sum, high strain jobs associate with target's reports of bullying in both the Spanish and Belgian sample. Karasek's JDC model may accordingly be extended to target's reports of bullying as a form of social behavioural strain. These findings furthermore enhance research in the realm of bullying at work by introducing a well-established theoretical framework to account for the relationship between workload, autonomy, and target's reports of bullying.     

The role of functional variability in a whole body co-ordinated movement – Application to high bar giant circles

When performing a giant circle on high bar a gymnast flexes at the hips in the lower part of the circle, increasing the kinetic energy, and extends in the upper part of the circle, decreasing the kinetic energy. In order to perform a sequence of giant circles at even tempo, any variation in angular velocity at the end of the flexion phase needs to be reduced by the end of the extension phase. The aim of this study was to determine the nature and contribution of such adjustments. A computer simulation model of a gymnast performing giant circles on high bar was used to investigate strategies of (a) fixed timing of the extension phase (feedforward control) and (b) stretched timing in order to extend at the same point of the giant circle (feedforward with additional feedback control). For three elite gymnasts fixed timing reduced the angular velocity variation on average by 36% whereas stretched timing reduced the variation by 63%. The mean reduction for the actual gymnast techniques was 61%. It was concluded that both feedforward and feedback control strategies are used by gymnasts for controlling such movements.