Evidence for working memory storage operations in perceptual cortex

Isolating the short-term storage component of working memory (WM) from the myriad of associated executive processes has been an enduring challenge. Recent efforts have identified patterns of activity in visual regions that contain information about items being held in WM. However, it remains unclear (1) whether these representations withstand intervening sensory input and (2) how communication between multimodal association cortex and the unimodal perceptual regions supporting WM representations is involved in WM storage. We present evidence that the features of a face held in WM are stored within face-processing regions, that these representations persist across subsequent sensory input, and that information about the match between sensory input and a memory representation is relayed forward from perceptual to prefrontal regions. Participants were presented with a series of probe faces and indicated whether each probe matched a target face held in WM. We parametrically varied the feature similarity between the probe and target faces. Activity within face-processing regions scaled linearly with the degree of feature similarity between the probe face and the features of the target face, suggesting that the features of the target face were stored in these regions. Furthermore, directed connectivity measures revealed that the direction of information flow that was optimal for performance was from sensory regions that stored the features of the target face to dorsal prefrontal regions, supporting the notion that sensory input is compared to representations stored within perceptual regions and is subsequently relayed forward. Together, these findings indicate that WM storage operations are carried out within perceptual cortex.     

Job demands,job resources and innovative work behaviour: a European Union study

This study aims to investigate the relationship between several job design variables and innovative work behaviour (IWB). Guided by the Job Demands Resources model, the aim was to evaluate the relationship between work demands (time constraints), resources (autonomy and social support), and other work factors (task monotony, complexity, and dealing with unforeseen circumstances) with idea generation and idea implementation behaviours in a sample of 12,924 participants from the 27 European Union member states in 2010. We also wished to investigate if individual IWB, at the country level, is associated with country innovative performance (an aggregate of process/product and marketing/organizational innovation). We employed a multilevel generalized structural equation model to test our hypotheses. In our final model autonomy, manager encouragement and dealing with unforeseen problems showed the highest positive relationship with idea generation and idea implementation. Conversely, monotonous tasks and working at high speed were negatively related to IWB. Furthermore, we have found strong indications that country-level IWB positively relates to the odds of a country scoring higher on the aforementioned innovation indicators. Between-country unexplained variance in IWB was reduced from 17.1% in our initial model, to 1.9% in our final iteration. Limitations, implications and suggestions for future research are discussed.     

Intellectual and adaptive functioning in Sturge-Weber Syndrome

The present study examined the intellectual and adaptive functioning in a sample of children and young adults with Sturge-Weber Syndrome (SWS). A total of 80 research participants from a SWS study database underwent full neurological evaluation as part of their participation or concurrent medical care. Twenty-nine of the participants received neuropsychological evaluations. Analyses indicated no significant demographic or neurological differences between those who did and did not receive neuropsychological evaluations. Overall, the neuropsychological evaluation sample displayed significantly lower functioning relative to published normative data across domains of intellectual and adaptive functioning. Thirty-two percent of the sample displayed impaired performance (standard score ≤ 75) in intellectual functioning and 58% displayed impaired performance in adaptive functioning. Hemiparesis status independently predicted overall adaptive functioning while seizure frequency independently predicted overall intellectual functioning. Younger participants displayed significantly higher (more intact) ratings in adaptive functioning compared to older participants, specifically in overall adaptive functioning, motor skills, and community living skills. A composite measure of neurological status (SWS-NRS) incorporating seizure and hemiparesis status effectively distinguished between individuals with impaired or nonimpaired adaptive and intellectual functioning and showed promise as a screening method for identifying individuals with more involved intellectual and/or adaptive needs.     

Iterated Belief Change and the Recovery Axiom

The axiom of recovery, while capturing a central intuition regarding belief change, has been the source of much controversy. We argue briefly against putative counterexamples to the axiom—while agreeing that some of their insight deserves to be preserved—and present additional recovery-like axioms in a framework that uses epistemic states, which encode preferences, as the object of revisions. This makes iterated revision possible and renders explicit the connection between iterated belief change and the axiom of recovery. We provide a representation theorem that connects the semantic conditions we impose on iterated revision and our additional syntactical properties. We show interesting similarities between our framework and that of Darwiche–Pearl (Artificial Intelligence 89:1–29 1997). In particular, we show that intuitions underlying the controversial (C2) postulate are captured by the recovery axiom and our recovery-like postulates (the latter can be seen as weakenings of (C2)). We present postulates for contraction, in the same spirit as the Darwiche–Pearl postulates for revision, and provide a theorem that connects our syntactic postulates with a set of semantic conditions. Lastly, we show a connection between the contraction postulates and a generalisation of the recovery axiom. Portions of this paper were originally presented at ECAI 2002.     

V for Volunteer(ing)��The Journeys of Undergraduate Volunteers

This article studies undergraduate students journeys in volunteering, and details the motivations of and challenges that these volunteers face during the journey. We conducted five focus groups on a total of 38 undergraduate volunteers, and obtained seven themes as we undertook an investigation of our three research questions. Our findings revolved around these seven themes, which ranged from motivations to experiences to challenges. Our findings have helped us understand the motivations and challenges that undergraduate volunteers have and face during the journey of volunteering. Some of these challenges are particular to a university setting, but some others can certainly be generalized to other settings. Recommendations for future research are also included.     

The temporal context model in spatial navigation and relational learning: toward a common explanation of medial temporal lobe function across domains

The medial temporal lobe (MTL) has been studied extensively at all levels of analysis, yet its function remains unclear. Theory regarding the cognitive function of the MTL has centered along 3 themes. Different authors have emphasized the role of the MTL in episodic recall, spatial navigation, or relational memory. Starting with the temporal context model (M. W. Howard & M. J. Kahana, 2002a), a distributed memory model that has been applied to benchmark data from episodic recall tasks, the authors propose that the entorhinal cortex supports a gradually changing representation of temporal context and the hippocampus proper enables retrieval of these contextual states. Simulation studies show this hypothesis explains the firing of place cells in the entorhinal cortex and the behavioral effects of hippocampal lesion in relational memory tasks. These results constitute a first step toward a unified computational theory of MTL function that integrates neurophysiological, neuropsychological, and cognitive findings.     

Functional overlap of top-down emotion regulation and generation: An fMRI study identifying common neural substrates between cognitive reappraisal and cognitively generated emotions

One factor that influences the success of emotion regulation is the manner in which the regulated emotion was generated. Recent research has suggested that reappraisal, a top-down emotion regulation strategy, is more effective in decreasing self-reported negative affect when emotions were generated from the top-down, versus the bottom-up. On the basis of a process overlap framework, we hypothesized that the neural regions active during reappraisal would overlap more with emotions that were generated from the top-down, rather than from the bottom-up. In addition, we hypothesized that increased neural overlap between reappraisal and the history effects of top-down emotion generation would be associated with increased reappraisal success. The results of several analyses suggested that reappraisal and emotions that were generated from the top-down share a core network of prefrontal, temporal, and cingulate regions. This overlap is specific; no such overlap was observed between reappraisal and emotions that were generated in a bottom-up fashion. This network consists of regions previously implicated in linguistic processing, cognitive control, and self-relevant appraisals, which are processes thought to be crucial to both reappraisal and top-down emotion generation. Furthermore, individuals with high reappraisal success demonstrated greater neural overlap between reappraisal and the history of top-down emotion generation than did those with low reappraisal success. The overlap of these key regions, reflecting overlapping processes, provides an initial insight into the mechanism by which generation history may facilitate emotion regulation.