588 research outputs found
Recommended from our members
Social Mindfulness and Psychosis: Neural response to socially mindful behavior in first-episode psychosis and patients at clinical high-risk
Background: Psychosis is characterized by problems in social functioning and trust, the assumed glue to positive social relations. But what helps building trust? A prime candidate could be social mindfulness: The ability and willingness to see and consider another personâs needs and wishes during social decision making. We investigated whether first-episode psychosis patients (FEP) and patients at clinical high-risk (CHR) show reduced social mindfulness, and examined the underlying neural mechanisms.
Methods: Twenty FEP, 17 CHR and 46 healthy controls, aged 16-31, performed the social mindfulness task (SoMi) during fMRI scanning, spontaneously and after the instruction âto keep the otherâs best interest in mindâ. As first of two people, participants had to choose one out of four products, of which three were identical and one was unique, differing in a single aspect (e.g., color).
Results: FEP tended to choose the unique item (unmindful choice) more often than controls. After instruction, all groups significantly increased the number of mindful choices compared to the spontaneous condition. FEP showed reduced activation of the caudate and medial prefrontal cortex (mPFC) during mindful, and of the anterior cingulate cortex (ACC), mPFC, and left dorso-lateral prefrontal cortex (dlPFC) during unmindful decisions. CHR showed reduced activation of the ACC compared to controls.
Discussion: FEP showed a trend towards more unmindful choices. A similar increase of mindful choices after instruction indicated the ability for social mindfulness when prompted. Results suggested reduced sensitivity to the rewarding aspects of social mindfulness in FEP, and reduced consideration for the other player. FEP (and CHR to a lesser extent) might perceive unmindful choices as less incongruent with the automatic mindful responses than controls. Reduced socially mindful behavior in FEP may hinder the building of trust and cooperative interactions
Episodic memory encoding in middle age: effects of ageing and cognitive fatigue on brain activation
Klaassen, E., Evers, E., De Groot, R. H. M., Veltman, D., & Jolles, J. (2011, September). Episodic memory encoding in middle age: effects of ageing and cognitive fatigue on brain activation. Poster presented at the Annual meeting for the international society for neuroimaging in psychiatry, Heidelberg, Germany.Healthy cognitive aging is thought to impact most heavily on episodic memory [1]. However, changes in episodic memory prior to the age of 60 are more controversial than changes in older adults [2]. Furthermore, cognitive decline already present in middle age may not yet manifest in behavior due to the action of neural compensation processes that preserve performance at the behavioral level. Therefore, fMRI can provide valuable insights into age-related changes present in middle age [3]. It is also important to determine the extent to which middle-aged adults must compensate for the effects of cognitive aging in order to maintain performance not just in the short-term, but following sustained, fatigue inducing task performance likely, for example, to be commonly encountered during the workday. Therefore, in the current study, each participant was tested twice: once following a fatiguing condition involving the sustained performance of cognitively demanding tasks and once following a less demanding baseline condition.At baseline, activation was greater, primarily in PFC regions, in middle-aged compared to young adults. This suggests increased exertion of top-down cognitive control in middle-aged adults during successful encoding.
In the fatigue condition, activation differences between the two age groups were no longer apparent. Activation in both age groups, but particularly the middle-aged group, decreased in comparison to baseline activation. Therefore, in a state of induced fatigue, middle-aged adults no longer showed greater exertion of cognitive control than young adults, and instead showed activation changes suggestive of an exhaustion of cognitive resources
Age differences in brain activation associated with verbal learning and fatigue
Learning abilities have already started to decline in middle age3. However, middle-aged adults are commonly required to continue to maintain performance in fulltime employment. We investigated whether the ability of middle-aged adults to maintain performance despite the effects of cognitive aging comes at the cost of increased cognitive fatigue. Functional MRI studies in patients with disorders characterised by fatigue, such as Multiple Sclerosis3 and Chronic Fatigue Syndrome4, have shown that, although patients could maintain task performance comparable to healthy participants, their performance was associated with increased and more dispersed brain activation. This finding has been attributed to the exertion of greater cognitive effort by patients which, consequentially, has been suggested to underlie their experience of increased cognitive fatigue. Behavioural studies have shown that cognitive fatigue symptoms can be induced in healthy participants by the prolonged performance of cognitively demanding tasks5. In the present study we used fMRI to examine verbal learning related brain activation in young and middle- aged adults following a control intervention and following a fatigue inducing intervention. Conclusions: 1. Middle-aged maintained comparable verbal learning performance to young, and did not indicate greater feelings of subjective fatigue. 2. Middle-aged showed greater activation than young in areas associated with cognitive control and attentional effort following the fatigue intervention during encoding, but not during recognition. 3. Greater subjective fatigue was associated with decreased activation in the left DLPFC in both age groups during encoding, but in young participants only during recognition. 4. It is suggested that middle-aged responded to the increased demands of verbal recognition by switching to more automatic processing
The effect of computer-based cognitive flexibility training on recovery of executive function after stroke: rationale, design and methods of the TAPASS study
Background: Stroke survivors frequently suffer from executive impairments even in the chronic phase after stroke, and there is a need for improved rehabilitation of these functions. One way of improving current rehabilitation treatment may be by online cognitive training. Based on a review of the effectiveness of computer-based cognitive training in healthy elderly, we concluded that cognitive flexibility may be a key element for an effective training, which results in improvements not merely on trained tasks but also in untrained tasks (i.e., far transfer). The aim of the current study was to track the behavioral and neural effects of computer-based cognitive flexibility training after stroke. We expected that executive functioning would improve after the cognitive flexibility training, and that neural activity and connectivity would normalize towards what is seen in healthy elderly. Methods/design: The design was a multicenter, double blind, randomized controlled trial (RCT) with three groups: an experimental intervention group, an active control group who did a mock training, and a waiting list control group. Stroke patients (3 months to 5 years post-stroke) with cognitive complaints were included. Training consisted of 58 half-hour sessions spread over 12 weeks. The primary study outcome was objective executive function. Secondary measures were improvement on training tasks, cognitive flexibility, objective cognitive functioning in other domains than the executive domain, subjective cognitive and everyday life functioning, and neural correlates assessed by both structural and resting-state functional Magnetic Resonance Imaging. The three groups were compared at baseline, after six and twelve weeks of training, and four weeks after the end of the training. Furthermore, they were compared to healthy elderly who received the same training. Discussion: The cognitive flexibility training consisted of several factors deemed important for effects that go beyond improvement on merely the training task themselves. Due to the presence of two control groups, the effects of the training could be compared with spontaneous recovery and with the effects of a mock training. This study provides insight into the potential of online cognitive flexibility training after stroke. We also compared its results with the effectiveness of the same training in healthy elderly
Orbitofrontal gray matter relates to early morning awakening: a neural correlate of insomnia complaints?
Sleep complaints increase profoundly with age; prevalence estimates of insomnia in elderly people reach up to 37%. The three major types of nocturnal complaints are difficulties initiating sleep (DIS), difficulties maintaining sleep (DMS) and early morning awakening (EMA), of which the latter appears most characteristic for aging. The neural correlates associated with these complaints have hardly been investigated, hampering the development of rational treatment and prevention. A recent study on structural brain correlates of insomnia showed that overall severity, but not duration, of insomnia complaints is associated with lower gray matter (GM) density in part of the left orbitofrontal cortex. Following up on this, we investigated, in an independent sample of people not diagnosed with insomnia, whether individual differences in GM density are associated with differences in DIS, DMS and EMA.65 healthy participants filled out questionnaires and underwent structural magnetic resonance imaging. Three compound Z-scores were computed for questionnaire items relating to DIS, DMS and EMA. Whole-brain voxel-based morphometry was used to investigate their association with GM density. Results show that participants with lower GM density in a region where the left inferior orbitofrontal cortex borders the insula report more EMA, but not DIS or DMS.This is the first study to investigate structural brain correlates of specific sleep characteristics that can translate into complaints in insomniacs. The selective association of EMA with orbitofrontal GM density makes our findings particularly relevant to elderly people, where EMA represents the most characteristic complaint. It is hypothesized that low GM density in aforementioned orbitofrontal area affects its role in sensing comfort. An intact ability to evaluate comfort may be crucial to maintain sleep, especially at the end of the night when sleep is vulnerable because homeostatic sleep propensity has dissipated
On the connection between level of education and the neural circuitry of emotion perception
Through education, a social group transmits accumulated knowledge, skills, customs, and values to its members. So far, to the best of our knowledge, the association between educational attainment and neural correlates of emotion processing has been left unexplored. In a retrospective analysis of The Netherlands Study of Depression and Anxiety (NESDA) functional magnetic resonance imaging (fMRI) study, we compared two groups of fourteen healthy volunteers with intermediate and high educational attainment, matched for age and gender. The data concerned event-related fMRI of brain activation during perception of facial emotional expressions. The region of interest (ROI) analysis showed stronger right amygdala activation to facial expressions in participants with lower relative to higher educational attainment (HE). The psychophysiological interaction analysis revealed that participants with HE exhibited stronger right amygdala-right insula connectivity during perception of emotional and neutral facial expressions. This exploratory study suggests the relevance of educational attainment on the neural mechanism of facial expressions processing
The effect of caffeine on working memory load-Ârelated brain activation in middle-Âaged males
Klaassen, E. B., De Groot, R. H. M., Evers, E. A. T., Snel, J., Veerman, E. C. I., Ligtenberg, A. J. M., Jolles, J., & Veltman, D. J. (2013). The effect of caffeine on working memory load-related brain activation in middle-aged male. Neuropharmacology, 64, 160-167. doi:10.1016/j.neuropharm.2012.06.026Caffeine is commonly consumed in an effort to enhance cognitive performance. However, little is known about the usefulness of caffeine with regard to memory enhancement, with previous studies showing inconsistent effects on memory performance. We aimed to determine the effect of caffeine on working memory (WM) load-related activation during encoding, maintenance and retrieval phases of a WM maintenance task using functional magnetic resonance imaging (fMRI). 20 healthy, male, habitual caffeine consumers aged 40 to 61 years were administered 100 mg of caffeine in a double-blind placebo-controlled crossover design. Participants were scanned in a non-withdrawn state following a workday during which caffeinated products were consumed according to individual normal use (range = 145 â 595 mg). Acute caffeine administration was associated with increased load-related activation compared to placebo in the left and right dorsolateral prefrontal cortex during WM encoding, but decreased load-related activation in the left thalamus during WM maintenance. These findings are indicative of an effect of caffeine on the fronto-parietal network involved in the top-down cognitive control of WM processes during encoding and an effect on the prefrontal cortico-thalamic loop involved in the interaction between arousal and the top-down control of attention during maintenance. Therefore, the effects of caffeine on WM may be attributed to both a direct effect of caffeine on WM processes, as well as an indirect effect on WM via arousal modulation. Behavioral and fMRI results were more consistent with a detrimental effect of caffeine on WM at higher levels of WM load, than caffeine-related WM enhancement
Associations between depression, lifestyle and brain structure:A longitudinal MRI study
Background: Depression has been associated with decreased regional grey matter volume, which might partly be explained by an unhealthier lifestyle in depressed individuals which has been ignored by most earlier studies. Also, the longitudinal nature of depression, lifestyle and brain structure associations is largely unknown. This study investigates the relationship of depression and lifestyle with brain structure cross-sectionally and longitudinally over up to 9 years. Methods: We used longitudinal structural MRI data of persons with depression and/or anxiety disorders and controls (Nunique participants = 347, Nobservations = 609). Cortical thickness of medial orbitofrontal cortex (mOFC), rostral anterior cingulate cortex (rACC) and hippocampal volume were derived using FreeSurfer. Using Generalized Estimating Equations, we investigated associations of depression and lifestyle (Body mass index (BMI), smoking, alcohol consumption, physical activity and sleep duration) with brain structure and change in brain structure over 2 (n = 179) and 9 years (n = 82). Results: Depression status (B = -.053, p = .002) and severity (B = -.002, p = .002) were negatively associated with rACC thickness. mOFC thickness was negatively associated with BMI (B = -.004, p < .001) and positively with moderate alcohol consumption (B = .030, p = .009). All associations were independent of each other. No associations were observed between (change in) depression, disease burden or lifestyle factors with brain change over time. Conclusions: Depressive symptoms and diagnosis were independently associated with thinner rACC, BMI with thinner mOFC, and moderate alcohol consumption with thicker mOFC. No longitudinal associations were observed, suggesting that regional grey matter alterations are a long-term consequence or vulnerability indicator for depression but not dynamically or progressively related to depression course trajectory
Recommended from our members
Interactions between Affective and Cognitive Processing Systems in Problematic Gamblers: A Functional Connectivity Study
Background: Motivational and cognitive abnormalities are frequently reported in pathological gambling. However, studies simultaneously investigating motivational and cognitive processing in problematic gamblers are lacking, limiting our understanding of the interplay between these systems in problematic gambling. Studies in non-clinical samples indicate that interactions between dorsal âexecutiveâ and ventral âaffectiveâ processing systems are necessary for adequate responses in various emotive situations. Methods: We conducted a generalized Psycho-Physiological Interaction (gPPI) analysis to assess the influence of affective stimuli on changes in functional connectivity associated with response inhibition in 16 treatment seeking problematic gamblers (PRGs) and 15 healthy controls (HCs) using an affective Go-NoGo fMRI paradigm including neutral, gambling-related, positive and negative pictures as neutral and affective conditions. Results: Across groups, task performance accuracy during neutral inhibition trials was positively correlated with functional connectivity between the left caudate and the right middle frontal cortex. During inhibition in the gambling condition, only in PRGs accuracy of task performance was positively correlated with functional connectivity within sub-regions of the dorsal executive system. Group interactions showed that during neutral inhibition, HCs exhibited greater functional connectivity between the left caudate and occipital cortex than PRGs. In contrast, during inhibition in the positive condition, PRGs compared to HCs showed greater functional connectivity between the left caudate and occipital cortex. During inhibition trials in the negative condition, a stronger functional connectivity between the left caudate and the right anterior cingulate cortex in PRGs compared to HCs was present. There were no group interactions during inhibition in the gambling condition. Conclusions: During gamble inhibition PRGs seem to benefit more from functional connectivity within the dorsal executive system than HCs, because task accuracy in this condition in PRGs is positively correlated with functional connectivity, although the groups show similar connectivity patterns during gamble inhibition. Greater functional connectivity between the ventral affective system and the dorsal executive system in PRGs in the affective conditions compared to HCs, suggests facilitation of the dorsal executive system when affective stimuli are present specifically in PRGs
- âŠ