Brainy
The Adult Brain Makes New Neurons, and Effortful Learning Keeps Them Alive
Tracey Shors
Current Directions in Psychological Science, October 2014, Pages 311-318
Abstract:
The brain continues to produce new neurons throughout life. For instance, the hippocampus (a brain region necessary for select learning processes) produces thousands of new neurons each day. However, a significant number of them die and do so within just a few weeks of their birth. Laboratory animals that are trained to learn a new skill between one and two weeks after the new cells are generated retain most cells that would have otherwise died. The types of skills that keep new cells alive are not limited to those that depend on the hippocampus but rather include those that are effortful to learn, requiring more training trials or time spent training. Importantly, training alone is not sufficient to increase cell survival; animals that are trained but do not learn do not retain more cells than animals that are not trained. Therefore, learning increases the survival of newly generated cells in the hippocampus as long as the learning experience is new, effortful, and successful. Once rescued, the vast majority of these cells differentiate into neurons, thereby forming synapses and generating action potentials as they become incorporated into the existing architecture and functional circuitry of the adult brain.
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Spatial cognition, mobility, and reproductive success in northwestern Namibia
Layne Vashro & Elizabeth Cashdan
Evolution and Human Behavior, forthcoming
Abstract:
Males occupy a larger range than females in many mammal populations including humans, and show an advantage in certain spatial-cognitive laboratory tasks. Evolutionary psychologists have explained these patterns by arguing that an increase in spatial ability facilitated navigation, which allowed range expansion in pursuit of additional mating and hunting opportunities. This study evaluates this hypothesis in a population with navigational demands similar to those that faced many of our ancestors, the Twe and Tjimba of northwestern Namibia. Twe and Tjimba men have larger visiting ranges than women and are more accurate in both spatial (mental rotations) and navigational (accuracy pointing to distant locations) tasks. Men who perform better on the spatial task not only travel farther than other men, but also have children with more women. These findings offer strong support for the relationship between sex differences in spatial ability and ranging behavior, and identify male mating competition as a possible selective pressure shaping this pattern.
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Davide Piffer et al.
Intelligence, November–December 2014, Pages 107–112
Abstract:
Individuals with a propensity to wake up early in the morning (“early-morning” types) and those who like to stay up late at night (“night owls”) often exhibit distinctive psychological and physiological profiles. Previous research has shown that night owls score higher than early-morning people on different measures of cognitive ability and academic achievement. Baseline cortisol is one of the physiological variables associated with variation in chronotype and cognitive function. In this study we investigated whether a relationship between chronotype and performance is present also in the high range of intellectual ability and academic achievement, namely, among graduate students in a top-ranked MBA program in the US. In addition, we measured baseline cortisol levels in saliva samples collected in the early afternoon and analyzed them in relation to chronotype and GMAT scores. As predicted, GMAT scores were significantly higher among night owls than among early-morning types, regardless of sex. GMAT scores were also significantly higher among men than women, regardless of chronotype. Morningness/eveningness was not significantly associated with variation in sleep amount or in undergraduate or graduate GPA scores, suggesting that the association between eveningness and high GMAT scores was not due to differences in study effort or skills. Sex, chronotype and baseline cortisol jointly accounted for 14% of the total variance in GMAT scores; baseline cortisol, however, did not mediate the effect of chronotype on GMAT scores. Consistent with the results of previous research, our study shows that the effects of chronotype on cognitive ability and academic performance are relatively small but detectable even among high-achieving individuals. The mechanism linking eveningness and high cognitive function remains unclear but the role of personality traits and neuroendocrine function warrants further investigation.
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Sylvain Moreno et al.
Child Development, forthcoming
Abstract:
Immediate and lasting effects of music or second-language training were examined in early childhood using event-related potentials. Event-related potentials were recorded for French vowels and musical notes in a passive oddball paradigm in thirty-six 4- to 6-year-old children who received either French or music training. Following training, both groups showed enhanced late discriminative negativity (LDN) in their trained condition (music group–musical notes; French group–French vowels) and reduced LDN in the untrained condition. These changes reflect improved processing of relevant (trained) sounds, and an increased capacity to suppress irrelevant (untrained) sounds. After 1 year, training-induced brain changes persisted and new hemispheric changes appeared. Such results provide evidence for the lasting benefit of early intervention in young children.
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Linda Moradzadeh, Galit Blumenthal & Melody Wiseheart
Cognitive Science, forthcoming
Abstract:
This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician) were matched on age and socioeconomic status and administered task switching and dual-task paradigms. Results demonstrated reduced global and local switch costs in musicians compared with non-musicians, suggesting that musical training can contribute to increased efficiency in the ability to shift flexibly between mental sets. On dual-task performance, musicians also outperformed non-musicians. There was neither a cognitive advantage for bilinguals relative to monolinguals, nor an interaction between music and language to suggest additive effects of both types of experience. These findings demonstrate that long-term musical training is associated with improvements in task switching and dual-task performance.
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Effects of the FITKids Randomized Controlled Trial on Executive Control and Brain Function
Charles Hillman et al.
Pediatrics, October 2014, Pages e1063-e1071
Objective: To assess the effect of a physical activity (PA) intervention on brain and behavioral indices of executive control in preadolescent children.
Methods: Two hundred twenty-one children (7–9 years) were randomly assigned to a 9-month afterschool PA program or a wait-list control. In addition to changes in fitness (maximal oxygen consumption), electrical activity in the brain (P3-ERP) and behavioral measures (accuracy, reaction time) of executive control were collected by using tasks that modulated attentional inhibition and cognitive flexibility.
Results: Fitness improved more among intervention participants from pretest to posttest compared with the wait-list control (1.3 mL/kg per minute, 95% confidence interval [CI]: 0.3 to 2.4; d = 0.34 for group difference in pre-to-post change score). Intervention participants exhibited greater improvements from pretest to posttest in inhibition (3.2%, 95% CI: 0.0 to 6.5; d = 0.27) and cognitive flexibility (4.8%, 95% CI: 1.1 to 8.4; d = 0.35 for group difference in pre-to-post change score) compared with control. Only the intervention group increased attentional resources from pretest to posttest during tasks requiring increased inhibition (1.4 µV, 95% CI: 0.3 to 2.6; d = 0.34) and cognitive flexibility (1.5 µV, 95% CI: 0.6 to 2.5; d = 0.43). Finally, improvements in brain function on the inhibition task (r = 0.22) and performance on the flexibility task correlated with intervention attendance (r = 0.24).
Conclusions: The intervention enhanced cognitive performance and brain function during tasks requiring greater executive control. These findings demonstrate a causal effect of a PA program on executive control, and provide support for PA for improving childhood cognition and brain health.
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Enhancing dentate gyrus function with dietary flavanols improves cognition in older adults
Adam Brickman et al.
Nature Neuroscience, forthcoming
Abstract:
The dentate gyrus (DG) is a region in the hippocampal formation whose function declines in association with human aging and is therefore considered to be a possible source of age-related memory decline. Causal evidence is needed, however, to show that DG-associated memory decline in otherwise healthy elders can be improved by interventions that enhance DG function. We addressed this issue by first using a high-resolution variant of functional magnetic resonance imaging (fMRI) to map the precise site of age-related DG dysfunction and to develop a cognitive task whose function localized to this anatomical site. Then, in a controlled randomized trial, we applied these tools to study healthy 50–69-year-old subjects who consumed either a high or low cocoa–containing diet for 3 months. A high-flavanol intervention was found to enhance DG function, as measured by fMRI and by cognitive testing. Our findings establish that DG dysfunction is a driver of age-related cognitive decline and suggest non-pharmacological means for its amelioration.
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Assal Habibi et al.
Frontiers in Human Neuroscience, September 2014
Abstract:
Several studies comparing adult musicians and non-musicians have provided compelling evidence for functional and anatomical differences in the brain systems engaged by musical training. It is not known, however, whether those differences result from long-term musical training or from pre-existing traits favoring musicality. In an attempt to begin addressing this question, we have launched a longitudinal investigation of the effects of childhood music training on cognitive, social and neural development. We compared a group of 6- to 7-year old children at the start of intense after-school musical training, with two groups of children: one involved in high intensity sports training but not musical training, another not involved in any systematic training. All children were tested with a comprehensive battery of cognitive, motor, musical, emotional, and social assessments and underwent magnetic resonance imaging and electroencephalography. Our first objective was to determine whether children who participate in musical training were different, prior to training, from children in the control groups in terms of cognitive, motor, musical, emotional, and social behavior measures as well as in structural and functional brain measures. Our second objective was to determine whether musical skills, as measured by a music perception assessment prior to training, correlates with emotional and social outcome measures that have been shown to be associated with musical training. We found no neural, cognitive, motor, emotional, or social differences among the three groups. In addition, there was no correlation between music perception skills and any of the social or emotional measures. These results provide a baseline for an ongoing longitudinal investigation of the effects of music training.
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High intelligence prevents the negative impact of anxiety on working memory
Adam Chuderski
Cognition and Emotion, forthcoming
Abstract:
Using a large sample and the confirmatory factor analysis, the study investigated the relationships between anxiety, working memory (WM) and (fluid) intelligence. The study showed that the negative impact of anxiety on WM functioning diminishes with increasing intelligence, and that anxiety can significantly affect WM only in people below average intelligence. This effect could not be fully explained by the sheer differences in WM capacity (WMC), suggesting the importance of higher-level cognition in coping with anxiety. Although intelligence moderated the impact of anxiety on WM, it was only weakly related to anxiety. In contrast to previous studies, anxiety explained the substantial amount of WMC variance (17.8%) in less intelligent participants, but none of the variance in more intelligent ones. These results can be explained in terms of either increased motivation of intelligent but anxious people to cope with a WM task, or their ability to compensate decrements in WM.