Use Your Noggin

Kevin Lewis

October 24, 2009

Does having a drink help you think? 6-7 year old children show improvements in cognitive performance from baseline to test after having a drink of water

Caroline Edmonds & Ben Jeffes
Appetite, forthcoming

Little research has examined the effect of water consumption on cognition in children. We examined whether drinking water improves performance from baseline to test in 23 6-7 year old children. There were significant interactions between time of test and water group (water/no water), with improvements in the water group on thirst and happiness ratings, visual attention and visual search, but not visual memory or visuomotor performance. These results indicate that even under conditions of mild dehydration, not as a result of exercise, intentional water deprivation or heat exposure, children's cognitive performance can be improved by having a drink of water.


School sport - a neurophysiological approach

Stefan Schneider, Tobias Vogt, Johanna Frysch, Petra Guardiera & Heiko Strüder
Neuroscience Letters, forthcoming

The aim of this study was to identify neurophysiological correlates for previously reported positive effects of exercise on academic achievement in school children by using a distributed source localization algorithm. Electro cortical activity of eleven school children (9-10y) was recorded before and after a moderate fifteen-minute bike exercise. Data were analyzed using standardized low resolution brain electromagnetic tomography (sLORETA) in the alpha (7.5-12.5 Hz) and beta (12.5-35 Hz) frequency range. We were able to show a significant increase in alpha activity post-exercise, which could be localized in the precuneus. Moreover a distinct decrease of beta activity could be noticed post-exercise in left temporal areas including Wernicke's area. We propose that apart from health promoting aspects school sport serves a second even more important challenge. On a central level a well observed overall state of physical relaxation after exercise is reflected by a more synchronized state in the precuneus. We speculate this to be responsible for an increase in concentrativeness and cognitive function post exercise. Moreover a previously reported increase in academic achievement post exercise could be directly linked to exercise induced neuroplasticity in regions that are relevant for language processing.


Dramatic Increase in Heritability of Cognitive Development From Early to Middle Childhood: An 8-Year Longitudinal Study of 8,700 Pairs of Twins

Oliver Davis, Claire Haworth & Robert Plomin
Psychological Science, October 2009, Pages 1301-1308

The generalist genes hypothesis implies that general cognitive ability (g) is an essential target for understanding how genetic polymorphisms influence the development of the human brain. Using 8,791 twin pairs from the Twins Early Development Study, we examine genetic stability and change in the etiology of g assessed by diverse measures during the critical transition from early to middle childhood. The heritability of a latent g factor in early childhood is 23%, whereas shared environment accounts for 74% of the variance. In contrast, in middle childhood, heritability of a latent g factor is 62%, and shared environment accounts for 33%. Despite increasing importance of genetic influences and declining influence of shared environment, similar genetic and shared environmental factors affect g from early to middle childhood, as indicated by a cross-age genetic correlation of .57 and a shared environmental correlation of .65. These findings set constraints on how genetic and environmental variation affects the developing brain.


Is Homo Economicus a Five Year Old?

Shelly Fisk & Yoella Bereby-Meyer
Ben-Gurion University Working Paper, August 2009

Standard economic models assume that people exclusively pursue material self-interests in social interactions. However, fairness considerations and factors such as trust and reciprocity affect behavior. This study examined whether negative reciprocity (punishment for unfair divisions) develops during childhood. Kindergarteners (five-years old), second graders and sixth graders played a mini-Ultimatum Game with a human proposer or a random machine and a Dictator Game. Kindergarteners proposed and accepted very little, thus behaving according to the standard economic model and show no fairness considerations. Evidence for negative reciprocity and strategic thinking emerged by age seven.


Turning the knots in your stomach into bows: Reappraising arousal improves performance on the GRE

Jeremy Jamieson, Wendy Berry Mendes, Erin Blackstock & Toni Schmader Journal of Experimental
Social Psychology, forthcoming

This research examined the benefits of interpreting physiological arousal as a challenge response on practice and actual Graduate Record Examination (GRE) scores. Participants who were preparing to take the GRE reported to the laboratory for a practice GRE study. Participants assigned to a reappraisal condition were told arousal improves performance, whereas control participants were not given this information. We collected saliva samples at baseline and after the appraisal manipulation, which were then assayed for salivary alpha amylase (sAA), a measure of sympathetic nervous system activation. Reappraisal participants exhibited a significant increase in sAA and outperformed controls on the GRE-math section. One to three months later, participants returned to the lab and provided their score reports from their actual GRE. Again, reappraisal participants scored higher than controls on the GRE-math section. These findings illuminate the powerful influence appraisal has on physiology and performance both in and out of the laboratory.


Test Length and Cognitive Fatigue: An Empirical Examination of Effects on Performance and Test-Taker Reactions

Phillip Ackerman & Ruth Kanfer
Journal of Experimental Psychology: Applied, June 2009, Pages 163-181

Person and situational determinants of cognitive ability test performance and subjective reactions were examined in the context of tests with different time-on-task requirements. Two hundred thirty-nine first-year university students participated in a within-participant experiment, with completely counterbalanced treatment conditions and test forms. Participants completed three test sessions of different length: (a) a standard-length SAT test battery (total time 4½ hr), (b) a shorter SAT test battery (total time 3½ hr), and (c) a longer SAT test battery (total time 5½ hr). Consistent with expectations, subjective fatigue increased with increasing time-on-task. However, mean performance increased in the longer test length conditions, compared with the shorter test length condition. Individual differences in personality/interest/motivation trait complexes were found to have greater power than the test-length situations for predicting subjective cognitive fatigue before, during, and at the end of each test session. The relative contributions of traits and time-on-task for cognitive fatigue are discussed, along with implications for research and practice.


Increasing Cognitive Load to Facilitate Lie Detection: The Benefit of Recalling an Event in Reverse Order

Aldert Vrij, Samantha Mann, Ronald Fisher, Sharon Leal, Rebecca Milne & Ray Bull
Law and Human Behavior, June 2008, Pages 253-265

In two experiments, we tested the hypotheses that (a) the difference between liars and truth tellers will be greater when interviewees report their stories in reverse order than in chronological order, and (b) instructing interviewees to recall their stories in reverse order will facilitate detecting deception. In Experiment 1, 80 mock suspects told the truth or lied about a staged event and did or did not report their stories in reverse order. The reverse order interviews contained many more cues to deceit than the control interviews. In Experiment 2, 55 police officers watched a selection of the videotaped interviews of Experiment 1 and made veracity judgements. Requesting suspects to convey their stories in reverse order improved police observers' ability to detect deception and did not result in a response bias.


Genetic variation in dopaminergic neuromodulation influences the ability to rapidly and flexibly adapt decisions

Lea Krugel, Guido Biele, Peter Mohr, Shu-Chen Li & Hauke Heekeren
Proceedings of the National Academy of Sciences, 20 October 2009, Pages 17951-17956

The ability to rapidly and flexibly adapt decisions to available rewards is crucial for survival in dynamic environments. Reward-based decisions are guided by reward expectations that are updated based on prediction errors, and processing of these errors involves dopaminergic neuromodulation in the striatum. To test the hypothesis that the COMT gene Val158Met polymorphism leads to interindividual differences in reward-based learning, we used the neuromodulatory role of dopamine in signaling prediction errors. We show a behavioral advantage for the phylogenetically ancestral Val/Val genotype in an instrumental reversal learning task that requires rapid and flexible adaptation of decisions to changing reward contingencies in a dynamic environment. Implementing a reinforcement learning model with a dynamic learning rate to estimate prediction error and learning rate for each trial, we discovered that a higher and more flexible learning rate underlies the advantage of the Val/Val genotype. Model-based fMRI analysis revealed that greater and more differentiated striatal fMRI responses to prediction errors reflect this advantage on the neurobiological level. Learning rate-dependent changes in effective connectivity between the striatum and prefrontal cortex were greater in the Val/Val than Met/Met genotype, suggesting that the advantage results from a downstream effect of the prefrontal cortex that is presumably mediated by differences in dopamine metabolism. These results show a critical role of dopamine in processing the weight a particular prediction error has on the expectation updating for the next decision, thereby providing important insights into neurobiological mechanisms underlying the ability to rapidly and flexibly adapt decisions to changing reward contingencies.


A negative association between video game experience and proactive cognitive control

Kira Bailey, Robert West & Craig Anderson
Psychophysiology, forthcoming

Some evidence demonstrates that video game experience has a beneficial effect on visuospatial cognition. In contrast, other evidence indicates that video game experience may be negatively related to cognitive control. In this study we examined the specificity of the influence of video game experience on cognitive control. Participants with high and low video game experience performed the Stroop task while event-related brain potentials were recorded. The behavioral data revealed no difference between high and low gamers for the Stroop interference effect and a reduction in the conflict adaptation effect in high gamers. The amplitude of the medial frontal negativity and a frontal slow wave was attenuated in high gamers, and there was no effect of gaming status on the conflict slow potential. These data lead to the suggestion that video game experience has a negative influence on proactive, but not reactive, cognitive control.


The speed of free will

Todd Horowitz, Jeremy Wolfe, George Alvarez, Michael Cohen & Yoana Kuzmova
Quarterly Journal of Experimental Psychology, November 2009, Pages 2262-2288

Do voluntary and task-driven shifts of attention have the same time course? In order to measure the time needed to voluntarily shift attention, we devised several novel visual search tasks that elicited multiple sequential attentional shifts. Participants could only respond correctly if they attended to the right place at the right time. In control conditions, search tasks were similar but participants were not required to shift attention in any order. Across five experiments, voluntary shifts of attention required 200-300 ms. Control conditions yielded estimates of 35-100 ms for task-driven shifts. We suggest that the slower speed of voluntary shifts reflects the "clock speed of free will". Wishing to attend to something takes more time than shifting attention in response to sensory input.


Cognitive learning is associated with gray matter changes in healthy human individuals: A tensor-based morphometry study

Antonia Ceccarelli, Maria Assunta Rocca, Elisabetta Pagani, Andrea Falini, Giancarlo Comi & Massimo Filippi
NeuroImage, 15 November 2009, Pages 585-589

Longitudinal voxel-based morphometry studies have demonstrated morphological changes in cortical structures following motor and cognitive learning. In this study, we applied, for the first time, tensor-based morphometry (TBM) to assess the short-term structural brain gray matter (GM) changes associated with cognitive learning in healthy subjects. Using a 3 T scanner, a 3D T1-weighted sequence was acquired from 32 students at baseline and after two weeks. Students were separated into two groups: 13 defined as "students in cognitive training", who underwent a two-week cognitive learning period, and 19 "students not in cognitive training", who were not involved in any teaching activity. GM changes were assessed using TBM and statistical parametric mapping. Baseline regional GM volume did not differ between the two groups. At follow up, compared to "students not in cognitive training", the "students in cognitive training" had a significant GM volume increase in the dorsomedial frontal cortex, the orbitofrontal cortex, and the precuneus (p<0.001). These results suggest that cognitive learning results in short-term structural GM changes of neuronal networks of the human brain, which are known to be involved in cognition. This may have important implications for the development of rehabilitation strategies in patients with neurological diseases.


Training induces changes in white-matter architecture

Jan Scholz, Miriam Klein, Timothy Behrens & Heidi Johansen-Berg
Nature Neuroscience, forthcoming

Although experience-dependent structural changes have been found in adult gray matter, there is little evidence for such changes in white matter. Using diffusion imaging, we detected a localized increase in fractional anisotropy, a measure of microstructure, in white matter underlying the intraparietal sulcus following training of a complex visuo-motor skill. This provides, to the best of our knowledge, the first evidence for training-related changes in white-matter structure in the healthy human adult brain.


Belief inhibition during thinking: Not always winning but at least taking part

Wim De Neys & Samuel Franssens
Cognition, October 2009, Pages 45-61

Human thinking is often biased by intuitive beliefs. Inhibition of these tempting beliefs is considered a key component of human thinking, but the process is poorly understood. In the present study we clarify the nature of an inhibition failure and the resulting belief bias by probing the accessibility of cued beliefs after people reasoned. Results indicated that even the poorest reasoners showed an impaired memory access to words that were associated with cued beliefs after solving reasoning problems in which the beliefs conflicted with normative considerations (Experiment 1 and 2). The study further established that the impairment was only temporary in nature (Experiment 3) and did not occur when people were explicitly instructed to give mere intuitive judgments (Experiment 4). Findings present solid evidence for the postulation of an inhibition process and imply that belief bias does not result from a failure to recognize the need to inhibit inappropriate beliefs, but from a failure to complete the inhibition process. This indicates that people are far more logical than hitherto believed.


Unsuccessful Retrieval Attempts Enhance Subsequent Learning

Nate Kornell, Matthew Jensen Hays & Robert Bjork
Journal of Experimental Psychology: Learning, Memory, and Cognition, July 2009, Pages 989-998

Taking tests enhances learning. But what happens when one cannot answer a test question-does an unsuccessful retrieval attempt impede future learning or enhance it? The authors examined this question using materials that ensured that retrieval attempts would be unsuccessful. In Experiments 1 and 2, participants were asked fictional general-knowledge questions (e.g., "What peace treaty ended the Calumet War?"). In Experiments 3-6, participants were shown a cue word (e.g., whale) and were asked to guess a weak associate (e.g., mammal); the rare trials on which participants guessed the correct response were excluded from the analyses. In the test condition, participants attempted to answer the question before being shown the answer; in the read-only condition, the question and answer were presented together. Unsuccessful retrieval attempts enhanced learning with both types of materials. These results demonstrate that retrieval attempts enhance future learning; they also suggest that taking challenging tests-instead of avoiding errors-may be one key to effective learning.

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