Kevin Lewis

February 22, 2015

Media and Human Capital Development: Can Video Game Playing Make You Smarter?

Agne Suziedelyte
Economic Inquiry, April 2015, Pages 1140–1155

According to the literature, video game playing can improve such cognitive skills as problem solving, abstract reasoning, and spatial logic. I test this hypothesis using the data from the Child Development Supplement to the Panel Study of Income Dynamics. The endogeneity of video game playing is addressed by using panel data methods and controlling for an extensive list of child and family characteristics. To address the measurement error in video game playing, I instrument children's weekday time use with their weekend time use. After taking into account the endogeneity and measurement error, video game playing is found to positively affect children's problem solving ability. The effect of video game playing on problem solving ability is comparable to the effect of educational activities.


The magical numbers 7 and 4 are resistant to the Flynn effect: No evidence for increases in forward or backward recall across 85 years of data

Gilles Gignac
Intelligence, January–February 2015, Pages 85–95

A substantial amount of empirical research suggests that cognitive ability test scores are increasing by approximately three IQ points per decade. The effect, referred to as the Flynn effect, has been found to be more substantial on measures of fluid intelligence, a construct known to be substantially correlated with memory span. Miller (1956) suggested that the typical short-term memory capacity (STMC) of an adult is seven, plus or minus two objects. Cowan (2005) suggested that the typical working memory capacity (WMC) of an adult is four, plus or minus one object. However, the possibility that both STMC and WMC test scores may be increasing across time, in line with the Flynn effect, does not appear to have been tested comprehensively yet. Based on Digit Span Forward (DSF) and Digit Span Backward (DSB) adult test scores across 85 years of data (respective Ns of 7,077 and 6,841), the mean adult verbal STMC was estimated at 6.56 (± 2.39), and the mean adult verbal WMC was estimated at 4.88 (± 2.58). No increasing trend in the STMC or WMC test scores was observed from 1923 to 2008, suggesting that these two cognitive processes are unaffected by the Flynn effect. Consequently, if the Flynn effect is occurring, it would appear to be a phenomenon that is completely independent of STMC and WMC, which may be surprising, given the close correspondence between WMC and fluid intelligence.


More Symmetrical Children Have Faster and More Consistent Choice Reaction Times

David Hope et al.
Developmental Psychology, forthcoming

Greater cognitive ability in childhood is associated with increased longevity, and speedier reaction time (RT) might account for much of this linkage. Greater bodily symmetry is linked to both higher cognitive test scores and faster RTs. It is possible, then, that differences in bodily system integrity indexed by symmetry may underlie the associations of RT and intelligence with increased longevity. However, RT and symmetry have seldom been examined in the same study, and never in children. Here, in 2 large samples aged 4 to 15 (combined n = 856), we found that more symmetrical children had significantly faster mean choice RT and less variability in RT. These associations of faster and less variable RT with greater symmetry early in life raise the possibility that the determinants of longevity in part originate in processes influencing bodily system integrity early in the life-course.


The influence of video games on executive functions in college students

Melissa Buelow, Bradley Okdie & Ashley Cooper
Computers in Human Behavior, April 2015, Pages 228–234

Video game play can have a negative effect on affect and behavior, but its relationship with cognition has been mixed. Previous research has shown both positive and negative effects of video game play on attention, memory, and other cognitive abilities; however, little research has investigated its effects on executive functions other than working memory. Additionally, most studies have utilized predominantly male samples. The present study sought to examine the effects of active video game play on decision making, problem solving, and risk-taking. Two hundred twenty-eight undergraduate students (114 female) played one of five different video games (n = 91) or were part of a separate, no-game control condition (n = 137). Scores on the Iowa Gambling Task (IGT), Balloon Analogue Risk Task (BART), and Wisconsin Card Sorting Task (WCST) were then compared. Following active video game play, participants decided more advantageously on the IGT, and made fewer errors and completed more categories on the WCST. No group differences emerged on the BART, and gender did not impact any dependent variables. It appears that active video game play may have positive effects on some executive functions with implications for real-world behavior. Implications for future research are discussed.


Tyrosine promotes cognitive flexibility: Evidence from proactive vs. reactive control during task switching performance

Laura Steenbergen et al.
Neuropsychologia, March 2015, Pages 50–55

Tyrosine (TYR), an amino acid found in various foods, has been shown to increase dopamine (DA) levels in the brain. Recent studies have provided evidence that TYR supplementation can improve facets of cognitive control in situations with high cognitive demands. Here we investigated whether TYR promotes cognitive flexibility, a cognitive-control function that is assumed to be modulated by DA. We tested the effect of TYR on proactive vs. reactive control during task switching performance, which provides a relatively well-established diagnostic of cognitive flexibility. In a double-blind, randomized, placebo-controlled design, 22 healthy adults performed in a task-switching paradigm. Compared to a neutral placebo, TYR promoted cognitive flexibility (i.e. reduced switching costs). This finding supports the idea that TYR can facilitate cognitive flexibility by repleting cognitive resources.


Decision-making conflict and the neural efficiency hypothesis of intelligence: A functional near-infrared spectroscopy investigation

Stefano Di Domenico et al.
NeuroImage, 1 April 2015, Pages 307–317

Research on the neural efficiency hypothesis of intelligence (NEH) has revealed that the brains of more intelligent individuals consume less energy when performing easy cognitive tasks but more energy when engaged in difficult mental operations. However, previous studies testing the NEH have relied on cognitive tasks that closely resemble psychometric tests of intelligence, potentially confounding efficiency during intelligence-test performance with neural efficiency per se. The present study sought to provide a novel test of the NEH by examining patterns of prefrontal activity while participants completed an experimental paradigm that is qualitatively distinct from the contents of psychometric tests of intelligence. Specifically, participants completed a personal decision-making task (e.g., which occupation would you prefer, dancer or chemist?) in which they made a series of forced choices according to their subjective preferences. The degree of decisional conflict (i.e., choice difficulty) between the available response options was manipulated on the basis of participants' unique preference ratings for the target stimuli, which were obtained prior to scanning. Evoked oxygenation of the prefrontal cortex was measured using 16-channel continuous-wave functional near-infrared spectroscopy. Consistent with the NEH, intelligence predicted decreased activation of the right inferior frontal gyrus (IFG) during low-conflict situations and increased activation of the right-IFG during high-conflict situations. This pattern of the right-IFG activity among more intelligent individuals was complemented by faster reaction times in high-conflict situations. These results provide new support for the NEH and suggest that the neural efficiency of more intelligent individuals generalizes to the performance of cognitive tasks that are distinct from intelligence tests.


Do we really become smarter when our fluid-intelligence test scores improve?

Taylor Hayes, Alexander Petrov & Per Sederberg
Intelligence, January–February 2015, Pages 1–14

Recent reports of training-induced gains on fluid intelligence tests have fueled an explosion of interest in cognitive training — now a billion-dollar industry. The interpretation of these results is questionable because score gains can be dominated by factors that play marginal roles in the scores themselves, and because intelligence gain is not the only possible explanation for the observed control-adjusted far transfer across tasks. Here we present novel evidence that the test score gains used to measure the efficacy of cognitive training may reflect strategy refinement instead of intelligence gains. A novel scanpath analysis of eye movement data from 35 participants solving Raven's Advanced Progressive Matrices on two separate sessions indicated that one-third of the variance of score gains could be attributed to test-taking strategy alone, as revealed by characteristic changes in eye-fixation patterns. When the strategic contaminant was partialled out, the residual score gains were no longer significant. These results are compatible with established theories of skill acquisition suggesting that procedural knowledge tacitly acquired during training can later be utilized at posttest. Our novel method and result both underline a reason to be wary of purported intelligence gains, but also provide a way forward for testing for them in the future.


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