The cognitive neuroscience of ageing

Analyzing structural and functional brain changes related to an integrative cognitive remediation program for schizophrenia: A randomized controlled trial.

The perception of emotional cues from voice and face is essential for social interaction. However, this process is altered in various psychiatric conditions along with impaired social functioning. Emotion communication trainings have been demonstrated to improve social interaction in healthy individuals and to reduce emotional communication deficits in psychiatric patients. Here, we investigated the impact of a non-verbal emotion communication training (NECT) on cerebral activation and brain structure in a controlled and combined functional magnetic resonance imaging (fMRI) and voxel-based morphometry study. NECT-specific reductions in brain activity occurred in a distributed set of brain regions including face and voice processing regions as well as emotion processing- and motor-related regions presumably reflecting training-induced familiarization with the evaluation of face/voice stimuli. Training-induced changes in non-verbal emotion sensitivity at the behavioral level and the respective cerebral activation patterns were correlated in the face-selective cortical areas in the posterior superior temporal sulcus and fusiform gyrus for valence ratings and in the temporal pole, lateral prefrontal cortex and midbrain/thalamus for the response times. A NECT-induced increase in gray matter (GM) volume was observed in the fusiform face area. Thus, NECT induces both functional and structural plasticity in the face processing system as well as functional plasticity in the emotion perception and evaluation system. We propose that functional alterations are presumably related to changes in sensory tuning in the decoding of emotional expressions. Taken together, these findings highlight that the present experimental design may serve as a valuable tool to investigate the altered behavioral and neuronal processing of emotional cues in psychiatric disorders as well as the impact of therapeutic interventions on brain function and structure.

Aging is associated with changes in brain structure and function with some brain regions showing more age-related deterioration than others. There is evidence that regional changes in brain structure and function may affect the functioning of other, less- age-sensitive brain regions and lead to more global changes in brain efficiency and cognitive functioning. Fortunately, emerging evidence from health neuroscience suggests that age-related brain changes and associated cognitive declines may not be inevitable. In fact, they may even be reversible. Exercise is a particularly promising health behavior known to induce changes in regional brain structure and function in older adults. However, much less is known about how exercise affects the organization of brain networks in late life. The purpose of this review is to summarize what is known to date regarding the relationships between functional connectivity, exercise, fitness, and physical activity in aging. A critical summary of this literature may reveal novel mechanisms by which physical activity influences brain health, which in turn may be leveraged to improve other aspects of functioning, including physical, cognitive, and mental health in late life.

Genes and early-life adversity (ELA) interactively increase the risk of developing major depressive disorder (MDD). A recent genome-wide association study suggests that the minor T-allele of single-nucleotide polymorphisms in the bicaudal C homolog 1 gene (BICC1) has a protective role against MDD. The aims of the study were to investigate whether the minor T-allele of BICC1 is protective against hippocampal structural brain changes, whether it is associated with increased functional brain activity in the emotion regulation system, and how ELA would modify this association. Forty-four patients with MDD and 44 healthy controls were investigated using structural magnetic resonance imaging (MRI) and functional MRI with an emotion inhibition task. Analysis of a single-nucleotide polymorphism in the BICC1-1 (rs999845) gene was performed. Right hippocampal bodies of patients and controls without a history of ELA and who carry the protective T-allele of BICC1 were significantly larger compared with those participants homozygous for the major C-allele of BICC1. However, MDD patients with ELA, who carry the T-allele, had smaller hippocampal head volumes compared with MDD patients without ELA. FMRI showed that patients and controls carrying the protective T-allele of BICC1 activate the emotion regulation system significantly more compared with those participants homozygous for the major C-allele (p<0.05, family wise error corrected). These results are suggestive that the minor T-allele of BICC1 has a protective role against MDD and its known structural and functional brain changes. However, this protective effect seems to be lost in the case of co-occurrence of ELA.

Age differences in brain activity related to unsuccessful declarative memory retrieval

Despite the fact that physical health and cognitive abilities decline with aging, the ability to regulate emotion remains stable and in some aspects improves across the adult life span. Older adults also show a positivity effect in their attention and memory, with diminished processing of negative stimuli relative to positive stimuli compared with younger adults. The current paper reviews functional magnetic resonance imaging studies investigating age-related differences in emotional processing and discusses how this evidence relates to two opposing theoretical accounts of older adults’ positivity effect. The aging-brain model [Cacioppo et al. in: Social Neuroscience: Toward Understanding the Underpinnings of the Social Mind. New York, Oxford University Press, 2011] proposes that older adults’ positivity effect is a consequence of age-related decline in the amygdala, whereas the cognitive control hypothesis [Kryla-Lighthall and Mather in: Handbook of Theories of Aging, ed 2. New York, Springer, 2009; Mather and Carstensen: Trends Cogn Sci 2005;9:496–502; Mather and Knight: Psychol Aging 2005;20:554–570] argues that the positivity effect is a result of older adults’ greater focus on regulating emotion. Based on evidence for structural and functional preservation of the amygdala in older adults and findings that older adults show greater prefrontal cortex activity than younger adults while engaging in emotion-processing tasks, we argue that the cognitive control hypothesis is a more likely explanation for older adults’ positivity effect than the aging-brain model.

This functional magnetic resonance imaging study presented participants with a face and scene simultaneously on each trial, and assessed the impact of perceptual versus reflective selective attention on activity in parahippocampal place area. Young and older adults showed equivalent activation in parahippocampal place area when cued to attend to the scene when the stimuli were perceptually present and when cued to refresh (briefly think about) the scene after the stimuli were no longer present. The groups also showed equivalent deactivation when cued to attend to the face when the stimuli were perceptually present. However, older adults showed less deactivation than young adults when cued to refresh the face, providing evidence for greater age-related disruption of reflective than perceptual selective attention.

Obesity is a major health issue. Obesity started from teenagers has become a major health concern in recent years. Intermittent fasting increases the life span. However, it is not known whether obesity and intermittent fasting affect brain functions and structures before brain aging. Here, we subjected 7-week old CD-1 wild type male mice to intermittent (alternate-day) fasting or high fat diet (45% caloric supplied by fat) for 11 months. Mice on intermittent fasting had better learning and memory assessed by the Barnes maze and fear conditioning, thicker CA1 pyramidal cell layer, higher expression of drebrin, a dendritic protein, and lower oxidative stress than mice that had free access to regular diet (control mice). Mice fed with high fat diet was obese and with hyperlipidemia. They also had poorer exercise tolerance. However, these obese mice did not present significant learning and memory impairment or changes in brain structures or oxidative stress compared with control mice. These results suggest that intermittent fasting improves brain functions and structures and that high fat diet feeding started early in life does not cause significant changes in brain functions and structures in obese middle-aged animals.

The cognitive neuroscience of aging is a large and diverse field seeking to understand cross-sectional differences and longitudinal changes in brain structure and function. Research in this field also investigates how brain differences or changes influence behavior in later life. There is consistent evidence indicating that cross-sectionally the brain is smaller in older adults (OA) relative to younger adults (YA), and this is due to longitudinal change over time. Furthermore, there are differences in functional activation patterns and the functional network architecture in the aging brain, both of which may contribute to the behavioral differences experienced by OA. Most notably, the differences in functional activation patterns suggest that perhaps the aging brain may compensate for the impacts of aging in an attempt to preserve performance. As such, several frameworks for understanding the processes of aging have taken hold resulting in testable hypotheses that link brain function and structure to behavior. Finally, in Alzheimer’s Disease, cognitive neuroscience methodologies have provided additional insights into the impacts of the disease on brain structure, function, and behavior.

MR imaging of the effects of methylphenidate on brain structure and function in Attention-Deficit/Hyperactivity Disorder

This review describes our current understanding of the changes in brain function and structure that occur in response to an intensive form of motor rehabilitation, constraint-induced movement therapy (CIMT), that has been shown to be efficacious in promoting motor function of the paretic upper limb of stroke patients. Studies using transcranial magnetic stimulation have demonstrated consistently an increase in the size of the representation of paretic hand muscles in the ipsilesional motor cortex after CIMT. This motor map expansion occurs in response to CIMT delivered at all time periods after stroke, from within days to after several years. Functional neuroimaging studies have shown varying patterns of change in activation within the sensorimotor network after CIMT. This variability may depend on the extent of stroke-induced damage to the corticospinal tract, the major descending motor pathway in the brain. This variability may also stem from interacting plastic changes in brain structure occurring in response to CIMT. CIMT is the first well defined poststroke motor rehabilitation to have identified changes in brain function and structure that accompany gains in motor function of the paretic upper limb. However, a causal link between observed changes in brain function/structure and motor gains due to CIMT has not yet been established. There is still much work to be done to understand the relationship between changes in brain function/structure and gains in motor function. Such studies should employ rigorous experimental controls to enable strong conclusions to be drawn regarding the neural effects of CIMT and how those effects confer behavioral efficacy of the therapy.

P 44. Structural and functional brain alterations in patients with myasthenia gravis

Sex differences in brain aging

In recent years, changes in brain structure and function have been studied extensively in patients with complex regional pain syndrome (CRPS) following clinical observations of altered central processing of sensory stimuli and motor control. However, concerning MRI data, the evidence is complex to interpret due to heterogeneity in statistical methods and results. The aim of this study was to determine if CRPS patients exhibit specific, clinically relevant changes in brain structure and function in rest. We do this by presenting MRI data on brain structure and function in 19 chronic, female CRPS patients and age- and sex-matched healthy controls (HCs). In addition, we analyse and report the data in multiple ways to make comparison with previous studies possible and to demonstrate the effect of different statistical methods, in particular, concerning the correction for multiple testing. Using family-wise error (FWE) correction for multiple testing, in our group of CRPS patients, we find no specific difference in brain structure or function in rest in comparison to HCs. In addition, we argue that previously found MRI results in the literature are inconsistent in terms of localization, quantity and directionality of the reported changes in brain structure and function. Previously published MRI-based evidence for altered brain structure and function in rest in CRPS patients is not consistent and our data suggests that no such phenomenon exists. WHAT DOES THIS STUDY ADD?: This article does not replicate the previous found results. The reported evidence in MRI literature of aberrant neuroplasticity in CRPS patients is inconsistent in terms of localization, quantity and directionality of changes in brain structure and function.

During the past decades brain structure and function have been studied intensively in schizophrenic patients. Schizophrenic patients have been reported to have smaller total brain volume and sulcal and ventricular enlargement compared with healthy controls. Functionally, lower metabolism or rCBF in prefrontal cortex, especially during frontal activation tests, has been the most reproducible finding. These structural and functional brain changes have been studied relative to specific schizophrenic symptoms. There seems to be a tendency that structural brain changes are related to more negative or less positive symptoms. The findings concerning functional brain changes are more complex, pointing to a lower total metabolism in autistic patients, while patients with many positive symptoms and/or thought disorder may have a relatively higher rCBF/metabolism in some cortical brain areas.