116 research outputs found
Decade of the Mind
In the Fall of 2007, ten neuroscientists published a proposal for an interdisciplinary research initiative, the Decade of the Mind, that would focus on four "broad but intertwined areas": mental health, research on high-level cognitive functions, education, and computational applications (such as intelligent machines). I review the basic ideas behind the proposal and discuss the four proposed areas of research. I argue that for research on higher cognitive functions and in particular, for research and practice in education, the Decade of the Mind is a welcome initiative that may change our lives for the better. Therefore, the proposal, which is scientifically interdisciplinary in nature, has to be politically international
Increased Resting-State Perfusion after Repeated Encoding Is Related to Later Retrieval of Declarative Associative Memories
Electrophysiological studies in animals have shown coordinated reactivation of neuronal ensembles during a restricted time period of behavioral inactivity that immediately followed active encoding. In the present study we directly investigated off-line processing of associative memory formation in the human brain. Subjects' regional cerebral blood flow (rCBF) as a surrogate marker of neural activity during rest was measured by MR-based perfusion imaging in a sample of 14 healthy male subjects prior to (Pre2) and after (Post) extensive learning of 24 face-name associations within a selective reminding task (SR). Results demonstrated significant Post-Pre2 rCBF increases in hippocampal and temporal lobe regions, while in a control comparison of two perfusion scans with no learning task in-between (Pre2-Pre1) no differences in rCBF emerged. Post perfusion scanning was followed by a surprise cued associative recall task from which two types of correctly retrieved names were obtained: older names already correctly retrieved at least once during one of the SR blocks, and recent names acquired during the last SR block immediately prior to the Post scan. In the anterior hippocampus individual perfusion increases were correlated with both correct retrievals of older and recent names. By contrast, older but not recently learned names showed a significant correlation with perfusion increases in the left lateral temporal cortex known to be associated with long-term memory. Recent, but not older names were correlated with dopaminergic midbrain structures reported to contribute to the persistence of memory traces for novel information. Although the direct investigation of off-line memory processing did not permit concomitant experimental control, neither intentional rehearsal, nor substantial variations in subjects' states of alertness appear to contribute to present results. We suggest that the observed rCBF increases might reflect processes that possibly contribute to the long-term persistence of memory traces
Side Effects of Transcranial Magnetic Stimulation Biased Task Performance in a Cognitive Neuroscience Study
Summary:: Transcranial magnetic stimulation (TMS) is increasingly used as a research tool for functional brain mapping in cognitive neuroscience. Despite being mostly tolerable, side effects of TMS could influence task performance in behavioural TMS studies. In order to test this issue, healthy subjects assessed the discomfort caused by the stimulation during a verbal working memory task. We investigated the relation between subjective disturbance and task performance. Subjects were stimulated during the delay period of a delayed-match-to-sample task above cortical areas that had been identified before to be involved in working memory. Task performance and subjective disturbance due to side effects were monitored. The subjects' grade of discomfort correlated with the error rates: the higher the discomfort, the more errors were made. Conclusively, TMS side effects may bias task performance in cognitive neuroscience studies and may thereby lead to misinterpretation of results. We emphasize the importance of controlling side effects of the stimulation as a source of biasing effects in TMS studie
An fMRI Study
Individuals with borderline personality disorder (BPD) are characterized by
emotional instability, impaired emotion regulation and unresolved attachment
patterns associated with abusive childhood experiences. We investigated the
neural response during the activation of the attachment system in BPD patients
compared to healthy controls using functional magnetic resonance imaging
(fMRI). Eleven female patients with BPD without posttraumatic stress disorder
(PTSD) and 17 healthy female controls matched for age and education were
telling stories in the scanner in response to the Adult Attachment Projective
Picture System (AAP), an eight-picture set assessment of adult attachment. The
picture set includes theoretically-derived attachment scenes, such as
separation, death, threat and potential abuse. The picture presentation order
is designed to gradually increase the activation of the attachment system.
Each picture stimulus was presented for 2 min. Analyses examine group
differences in attachment classifications and neural activation patterns over
the course of the task. Unresolved attachment was associated with increasing
amygdala activation over the course of the attachment task in patients as well
as controls. Unresolved controls, but not patients, showed activation in the
right dorsolateral prefrontal cortex (DLPFC) and the rostral cingulate zone
(RCZ). We interpret this as a neural signature of BPD patients’ inability to
exert top-down control under conditions of attachment distress. These findings
point to possible neural mechanisms for underlying affective dysregulation in
BPD in the context of attachment trauma and fear
From uncertainty to reward: BOLD characteristics differentiate signaling pathways
<p>Abstract</p> <p>Background</p> <p>Reward value and uncertainty are represented by dopamine neurons in monkeys by distinct phasic and tonic firing rates. Knowledge about the underlying differential dopaminergic pathways is crucial for a better understanding of dopamine-related processes. Using functional magnetic resonance blood-oxygen level dependent (BOLD) imaging we analyzed brain activation in 15 healthy, male subjects performing a gambling task, upon expectation of potential monetary rewards at different reward values and levels of uncertainty.</p> <p>Results</p> <p>Consistent with previous studies, ventral striatal activation was related to both reward magnitudes and values. Activation in medial and lateral orbitofrontal brain areas was best predicted by reward uncertainty. Moreover, late BOLD responses relative to trial onset were due to expectation of different reward values and likely to represent phasic dopaminergic signaling. Early BOLD responses were due to different levels of reward uncertainty and likely to represent tonic dopaminergic signals.</p> <p>Conclusions</p> <p>We conclude that differential dopaminergic signaling as revealed in animal studies is not only represented locally by involvement of distinct brain regions but also by distinct BOLD signal characteristics.</p
HDAC1 links early life stress to schizophrenia-like phenotypes.
Significance
Early life stress (ELS) is an important risk factor for schizophrenia. Our study shows that ELS in mice increases the levels of histone-deacetylase (HDAC) 1 in brain and blood. Although altered
Hdac1
expression in response to ELS is widespread, increased
Hdac1
levels in the prefrontal cortex are responsible for the development of schizophrenia-like phenotypes. In turn, administration of an HDAC inhibitor ameliorates ELS-induced schizophrenia-like phenotypes. We also show that
Hdac1
levels are increased in the brains of patients with schizophrenia and in blood from patients who suffered from ELS, suggesting that the analysis of
Hdac1
expression in blood could be used for patient stratification and individualized therapy.
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Psychological therapies for treatment-resistant depression in adults
BACKGROUND: Antidepressants are a first-line treatment for adults with moderate to severe major depression. However, many people prescribed antidepressants for depression don't respond fully to such medication, and little evidence is available to inform the most appropriate 'next step' treatment for such patients, who may be referred to as having treatment-resistant depression (TRD). National Institute for Health and Care Excellence (NICE) guidance suggests that the 'next step' for those who do not respond to antidepressants may include a change in the dose or type of antidepressant medication, the addition of another medication, or the start of psychotherapy. Different types of psychotherapies may be used for TRD; evidence on these treatments is available but has not been collated to date.Along with the sister review of pharmacological therapies for TRD, this review summarises available evidence for the effectiveness of psychotherapies for adults (18 to 74 years) with TRD with the goal of establishing the best 'next step' for this group. OBJECTIVES: To assess the effectiveness of psychotherapies for adults with TRD. SEARCH METHODS: We searched the Cochrane Common Mental Disorders Controlled Trials Register (until May 2016), along with CENTRAL, MEDLINE, Embase, and PsycINFO via OVID (until 16 May 2017). We also searched the World Health Organization (WHO) trials portal (ICTRP) and ClinicalTrials.gov to identify unpublished and ongoing studies. There were no date or language restrictions. SELECTION CRITERIA: We included randomised controlled trials (RCTs) with participants aged 18 to 74 years diagnosed with unipolar depression that had not responded to minimum four weeks of antidepressant treatment at a recommended dose. We excluded studies of drug intolerance. Acceptable diagnoses of unipolar depression were based onthe Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) or earlier versions, International Classification of Diseases (ICD)-10, Feighner criteria, or Research Diagnostic Criteria. We included the following comparisons.1. Any psychological therapy versus antidepressant treatment alone, or another psychological therapy.2. Any psychological therapy given in addition to antidepressant medication versus antidepressant treatment alone, or a psychological therapy alone.Primary outcomes required were change in depressive symptoms and number of dropouts from study or treatment (as a measure of acceptability). DATA COLLECTION AND ANALYSIS: We extracted data, assessed risk of bias in duplicate, and resolved disagreements through discussion or consultation with a third person. We conducted random-effects meta-analyses when appropriate. We summarised continuous outcomes using mean differences (MDs) or standardised mean differences (SMDs), and dichotomous outcomes using risk ratios (RRs). MAIN RESULTS: We included six trials (n = 698; most participants were women approximately 40 years of age). All studies evaluated psychotherapy plus usual care (with antidepressants) versus usual care (with antidepressants). Three studies addressed the addition of cognitive-behavioural therapy (CBT) to usual care (n = 522), and one each evaluated intensive short-term dynamic psychotherapy (ISTDP) (n = 60), interpersonal therapy (IPT) (n = 34), or group dialectical behavioural therapy (DBT) (n = 19) as the intervention. Most studies were small (except one trial of CBT was large), and all studies were at high risk of detection bias for the main outcome of self-reported depressive symptoms.A random-effects meta-analysis of five trials (n = 575) showed that psychotherapy given in addition to usual care (vs usual care alone) produced improvement in self-reported depressive symptoms (MD -4.07 points, 95% confidence interval (CI) -7.07 to -1.07 on the Beck Depression Inventory (BDI) scale) over the short term (up to six months). Effects were similar when data from all six studies were combined for self-reported depressive symptoms (SMD -0.40, 95% CI -0.65 to -0.14; n = 635). The quality of this evidence was moderate. Similar moderate-quality evidence of benefit was seen on the Patient Health Questionnaire-9 Scale (PHQ-9) from two studies (MD -4.66, 95% CI 8.72 to -0.59; n = 482) and on the Hamilton Depression Rating Scale (HAMD) from four studies (MD -3.28, 95% CI -5.71 to -0.85; n = 193).High-quality evidence shows no differential dropout (a measure of acceptability) between intervention and comparator groups over the short term (RR 0.85, 95% CI 0.58 to 1.24; six studies; n = 698).Moderate-quality evidence for remission from six studies (RR 1.92, 95% CI 1.46 to 2.52; n = 635) and low-quality evidence for response from four studies (RR 1.80, 95% CI 1.2 to 2.7; n = 556) indicate that psychotherapy was beneficial as an adjunct to usual care over the short term.With the addition of CBT, low-quality evidence suggests lower depression scores on the BDI scale over the medium term (12 months) (RR -3.40, 95% CI -7.21 to 0.40; two studies; n = 475) and over the long term (46 months) (RR -1.90, 95% CI -3.22 to -0.58; one study; n = 248). Moderate-quality evidence for adjunctive CBT suggests no difference in acceptability (dropout) over the medium term (RR 0.98, 95% CI 0.66 to 1.47; two studies; n = 549) and lower dropout over long term (RR 0.80, 95% CI 0.66 to 0.97; one study; n = 248).Two studies reported serious adverse events (one suicide, two hospitalisations, and two exacerbations of depression) in 4.2% of the total sample, which occurred only in the usual care group (no events in the intervention group).An economic analysis (conducted as part of an included study) from the UK healthcare perspective (National Health Service (NHS)) revealed that adjunctive CBT was cost-effective over nearly four years. AUTHORS' CONCLUSIONS: Moderate-quality evidence shows that psychotherapy added to usual care (with antidepressants) is beneficial for depressive symptoms and for response and remission rates over the short term for patients with TRD. Medium- and long-term effects seem similarly beneficial, although most evidence was derived from a single large trial. Psychotherapy added to usual care seems as acceptable as usual care alone.Further evidence is needed on the effectiveness of different types of psychotherapies for patients with TRD. No evidence currently shows whether switching to a psychotherapy is more beneficial for this patient group than continuing an antidepressant medication regimen. Addressing this evidence gap is an important goal for researchers
Wissen und Können
Die Wissenschaft von den Nervenzellen und dem Gehirn, die Neurobiologie, hat in den letzten Jahren einen beispiellosen Aufschwung durchgemacht und zu noch vor wenigen Jahren ungeahnten Ergebnissen geführt. In diesem Buch geht es darum, mit Hilfe der Gehirnforschung das Lernen besser zu verstehen. Das daraus folgende vertiefte Verständnis des Lernens bleibt nicht im Elfenbeinturm der Wissenschaft, sondern geht uns alle an, denn wir alle lernen dauernd, ob wir wollen oder nicht. (DIPF/Orig.
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