Science posts

See science posts on page 60 below.

    • 2011
    • Aviva Berkovich-Ohana et al
    • Mindfulness-induced changes in gamma band activity – Implications for the default mode network, self-reference and attention
    • Objective There is a growing scientific interest in mindfulness meditation (MM), yet its underlying neurophysiological mechanism is still uncertain. We investigated whether MM affects self-referential processing, associated with default mode network (DMN), either as short (state) – or long-term (trait) effects. Methods Three levels of MM expertise were compared with controls (n = 12 each) by electroencephalography (EEG). Results DMN deactivation was identified during the transition from resting state to a time production task, as lower gamma (25–45 Hz) power over frontal and midline regions. MM practitioners exhibited a trait lower frontal gamma activity, related to narrative self-reference and DMN activity, as well as producing longer durations, these being negatively correlated with frontal gamma activity. Additionally, we found state increases in posterior gamma power, suggesting increased attention and sensory awareness. MM proficiency did not affect the results. Conc..
    • 2009
    • R. Nathan Spreng et al
    • The Common Neural Basis of Autobiographical Memory, Prospection, Navigation, Theory of Mind, and the Default Mode: A Quantitative Meta-analysis
    • A core brain network has been proposed to underlie a number of different processes, including remembering, prospection, navigation, and theory of mind [Buckner, R. L., & Carroll, D. C. Self-projection and the brain. Trends in Cognitive Sciences, 11, 49–57, 2007]. This purported network—medial prefrontal, medial-temporal, and medial and lateral parietal regions—is similar to that observed during default-mode processing and has been argued to represent self-projection [Buckner, R. L., & Carroll, D. C. Self-projection and the brain. Trends in Cognitive Sciences, 11, 49–57, 2007] or scene-construction [Hassabis, D., & Maguire, E. A. Deconstructing episodic memory with construction. Trends in Cognitive Sciences, 11, 299–306, 2007]. To date, no systematic and quantitative demonstration of evidence for this common network has been presented. Using the activation likelihood estimation (ALE) approach, we conducted four separate quantitative meta-analyses of neuroimaging studies on: (a) autobi..
    • 2014
    • Di Stasi et al
    • Saccadic Eye Movement Metrics Reflect Surgical Residents' Fatigue
    • Objective: Little is known about the effects of surgical residents' fatigue on patient safety. We monitored surgical residents' fatigue levels during their call day using (1) eye movement metrics, (2) objective measures of laparoscopic surgical performance, and (3) subjective reports based on standardized questionnaires. Background: Prior attempts to investigate the effects of fatigue on surgical performance have suffered from methodological limitations, including inconsistent definitions and lack of objective measures of fatigue, and nonstandardized measures of surgical performance. Recent research has shown that fatigue can affect the characteristics of saccadic (fast ballistic) eye movements in nonsurgical scenarios. Here we asked whether fatigue induced by time-on-duty (∼24 hours) might affect saccadic metrics in surgical residents. Because saccadic velocity is not under voluntary control, a fatigue index based on saccadic velocity has the potential to provide an accurate ..
    • 2014
    • Anne Maass et al
    • Laminar activity in the hippocampus and entorhinal cortex related to novelty and episodic encoding
    • The ability to form long-term memories for novel events depends on information processing within the hippocampus (HC) and entorhinal cortex (EC). The HC–EC circuitry shows a quantitative segregation of anatomical directionality into different neuronal layers. Whereas superficial EC layers mainly project to dentate gyrus (DG), CA3 and apical CA1 layers, HC output is primarily sent from pyramidal CA1 layers and subiculum to deep EC layers. Here we utilize this directionality information by measuring encoding activity within HC/EC subregions with 7 T high resolution functional magnetic resonance imaging (fMRI). Multivariate Bayes decoding within HC/EC subregions shows that processing of novel information most strongly engages the input structures (superficial EC and DG/CA2–3), whereas subsequent memory is more dependent on activation of output regions (deep EC and pyramidal CA1). This suggests that while novelty processing is strongly related to HC–EC input pathways, the memory fate of ..
    • 2014
    • Roger E. Beaty et al
    • Creativity and the default network: A functional connectivity analysis of the creative brain at rest
    • The present research used resting-state functional magnetic resonance imaging (fMRI) to examine whether the ability to generate creative ideas corresponds to differences in the intrinsic organization of functional networks in the brain. We examined the functional connectivity between regions commonly implicated in neuroimaging studies of divergent thinking, including the inferior prefrontal cortex and the core hubs of the default network. Participants were prescreened on a battery of divergent thinking tests and assigned to high- and low-creative groups based on task performance. Seed-based functional connectivity analysis revealed greater connectivity between the left inferior frontal gyrus (IFG) and the entire default mode network in the high-creative group. The right IFG also showed greater functional connectivity with bilateral inferior parietal cortex and the left dorsolateral prefrontal cortex in the high-creative group. The results suggest that the ability to generate creative..
    • Creative cognition; Default mode network; Divergent thinking; Resting-state functional connectivity; Inferior frontal gyrus
    • 2012
    • Anna Abraham et al
    • Creativity and the brain: Uncovering the neural signature of conceptual expansion
    • Neurophysiological studies of creativity thus far have not allowed for clear conclusions to be made regarding the specific neural underpinnings of such complex cognition due to overgeneralizations concerning the creativity construct, heterogeneity in the type of creativity tasks used, and the questionable efficacy of the employed comparison tasks. A novel experimental design was developed in the present fMRI study which rendered it possible to investigate a critical facet of creative cognition – that of conceptual expansion – as distinct from general divergent thinking, working memory, or cognitive load. Brain regions involved in the retention, retrieval and integration of conceptual knowledge such as the anterior inferior frontal gyrus, the temporal poles and the lateral frontopolar cortex were found to be selectively involved during conceptual expansion. The findings go against generic ideas that argue for the dominance of the right hemisphere during creative thinking and indicate ..
    • Creative cognition; fMRI; Semantic cognition; Working memory; Higher-order cognition; Divergent thinking
    • 2008
    • Nicola Canessa et al
    • The Different Neural Correlates of Action and Functional Knowledge in Semantic Memory: An fMRI Study
    • Previous reports suggest that the internal organization of semantic memory is in terms of different “types of knowledge,” including “sensory” (information about perceptual features), “action” (motor-based knowledge of object utilization), and “functional” (abstract properties, as function and context of use). Consistent with this view, a specific loss of action knowledge, with preserved functional knowledge, has been recently observed in patients with left frontoparietal lesions. The opposite pattern (impaired functional knowledge with preserved action knowledge) was reported in association with anterior inferotemporal lesions. In the present study, the cerebral representation of action and functional knowledge was investigated using event-related analysis of functional magnetic resonance imaging data. Fifteen subjects were presented with pictures showing pairs of manipulable objects and asked whether the objects within each pair were used with the same manipulation pattern (“action ..
    • anterior inferotemporal cortex, conceptual knowledge, functional semantic features, inferior parietal lobule, manipulative semantic features
    • 2007
    • A.M. Clare Kelly et al
    • Competition between functional brain networks mediates behavioral variability
    • Increased intraindividual variability (IIV) is a hallmark of disorders of attention. Recent work has linked these disorders to abnormalities in a “default mode” network, comprising brain regions routinely deactivated during goal-directed cognitive tasks. Findings from a study of the neural basis of attentional lapses suggest that a competitive relationship between the “task-negative” default mode network and regions of a “task-positive” attentional network is a potential locus of dysfunction in individuals with increased IIV. Resting state studies have shown that this competitive relationship is intrinsically represented in the brain, in the form of a negative correlation or antiphase relationship between spontaneous activity occurring in the two networks. We quantified the negative correlation between these two networks in 26 subjects, during active (Eriksen flanker task) and resting state scans. We hypothesized that the strength of the negative correlation is an index of the degree..
    • 2014
    • Sebastian Schindler et al
    • It’s all in your head – how anticipating evaluation affects the processing of emotional trait adjectives
    • Language has an intrinsically evaluative and communicative function. Words can serve to describe emotional traits and states in others and communicate evaluations. Using electroencephalography (EEG), we investigate how the cerebral processing of emotional trait adjectives is modulated by their perceived communicative sender in anticipation of an evaluation. 16 students were videotaped while they described themselves. They were told that a stranger would evaluate their personality based on this recording by endorsing trait adjectives. In a control condition a computer program supposedly randomly selected the adjectives. Actually, both conditions were random. A larger parietal N1 was found for adjectives in the supposedly human-generated condition. This indicates that more visual attention is allocated to the presented adjectives when putatively interacting with a human. Between 400 and 700 ms a fronto-central main effect of emotion was found. Positive, and in tendency also negative ad..
    • 2014
    • Donald J. Bolger et al
    • The Role and Sources of Individual Differences in Critical-Analytic Thinking: a Capsule Overview
    • Critical-analytic thinking is typically conceived as a meta-construct that arises at the junction of a problem state (i.e., a situation that requires analysis that challenges previous assumptions) and an individual (i.e., an entity with the capacity to exercise critical-analytic thinking). With regard to the latter, there is a substantial body of research focusing on developmental and educational prerequisites for critical-analytic thinking. A less studied aspect of critical-analytic thinking pertains to individual differences, particularly in the set of foundational or componential cognitive skills that embody this construct. The bottom line here is whether, all else being equal (i.e., the same situation and the same developmental/educational stage), there is variation in whether, when, and how people think critically/analytically. We argue that there is unequivocal evidence for both the existence and importance of individual differences in critical-analytic thinking. This review fo..