Tag Archives: Cognition

Survival bias

6 Jul

People sometimes remark “my parents let me do x and I turned out OK.” While comments like these often cause heads to nod in agreement, I always think, of course you say that, the ones who didn’t turn out OK aren’t here to tell their stories. Along these lines here is a useful video about survival bias and success advice:

 

Chess: victory to the young

27 Jun

A wonderful piece by Tom Vanderbilt in Nautilus about learning chess with his four year old daughter:

“It wasn’t long before it struck me that chess seemed to be a game for the young. When my daughter began doing scholastic tournaments, I would chat up other parents and ask whether they played—usually the reply was an apologetic shrug and a smile. I would explain that I too was learning to play, and the resulting tone was cheerily patronizing: Good luck with that! Reading about an international tournament, I was struck by a suggestion that a grandmaster had passed his peak. He was in his 30s. We are used to athletes being talked about in this way. But a mind game like chess?”

Read the whole piece, it’s a good reflection on how our brains change with age. I particularly like this sentence:

“As we get older, there is one thing at which we get worse: Being a novice.”

I always found it depressing that my phone, even set to the lowest level, can beat me at chess.

Ravens are just as smart as chimps

8 Jun

A paper in Royal Society Open Science:

“Given birds’ small brain size—in absolute terms—yet flexible behaviour, their motor self-regulation calls for closer study. Corvids exhibit some of the largest relative avian brain sizes—although small in absolute measure—as well as the most flexible cognition in the animal kingdom. We therefore tested ravens, New Caledonian crows and jackdaws in the so-called cylinder task. We found performance indistinguishable from that of great apes despite the much smaller brains. We found both absolute and relative brain volume to be a reliable predictor of performance within Aves. The complex cognition of corvids is often likened to that of great apes; our results show further that they share similar fundamental cognitive mechanisms.”

Here is the press release:

“A study led by researchers at Lund University in Sweden shows that ravens are as clever as chimpanzees, despite having much smaller brains, indicating that rather than the size of the brain, the neuronal density and the structure of the birds’ brains play an important role in terms of their intelligence.”

 

 

Age related cognitive decline is real

7 Mar

While we may be able to do some things to slow cognitive decline, a recent study published in the journal Intelligence reports evidence that age related cognitive decline is real:

“Processing speed is an important human cognitive capability that might underlie differences in other cognitive skills and their aging. We aimed to test aging-related processing speed differences using a novel cross-sectional design that adjusted for cognitive ability tested in youth. We examined aging differences on three different ways of assessing processing speed: psychometric, experimental, and psychophysical. We compared large narrow-age cohorts of 70- and 83-year-old people who were matched for cognitive ability in childhood. There were decrements of substantial effect size in all processing speed assessments in the older group that were not accounted for by prior cognitive ability, health, or fitness differences, though these factors also contributed to processing speed differences. These findings confirm age-related cognitive slowing using an unusual research design, and provide evidence against recent theories characterizing aging-related cognitive decline as a myth.”

Are our brains getting bigger?

17 Feb

A paper in Learning and Individual Differences:

“Secular increases in brain mass over nearly a century have been noted for both males and females in the UK and Germany. It has been argued that such trends may be associated with the Flynn effect. The IQ gain predicted on the basis of these trends is 0.19 and 0.08 points per decade for UK, and 0.2 and 0.15 points per decade for German males and females respectively, indicating a small contribution to the Fullscale IQ trends in these countries (2.95% of the German decadal gain and 12.73% of the UK gain). There is also a sex difference in the rates of brain mass gain in both countries, favoring males. Temporal correlations between the secular trend in UK brain mass and European Flynn effects on Fullscale IQ, Crystallized, Fluid and Spatial abilities reveal correlations ranging from 0.751 in the case of Fluid ability to 0.761 in the case of Crystallized ability. The brain mass increase may be an imperfect proxy for changes in specific neuroanatomical structures important for IQ gains. Its small contribution to these gains is also consistent with the influence of other contributing factors. Increasing brain mass is predicted by the life history model of the Flynn effect as it suggests increased somatic effort allocation into bioenergetically expensive cortical real estate facilitating the development of specialized cognitive abilities.”

 

“A general intelligence factor in dogs”

15 Feb

A paper published in the journal Intelligence: “A general intelligence factor in dogs.

Here is the abstract:

“Hundreds of studies have shown that, in people, cognitive abilities overlap yielding an underlying ‘g’ factor, which explains much of the variance. We assessed individual differences in cognitive abilities in 68 border collies to determine the structure of intelligence in dogs. We administered four configurations of a detour test and repeated trials of two choice tasks (point-following and quantity-discrimination). We used confirmatory factor analysis to test alternative models explaining test performance. The best-fitting model was a hierarchical model with three lower-order factors for the detour time, choice time, and choice score and a higher order factor; these accounted jointly for 68% of the variance in task scores. The higher order factor alone accounted for 17% of the variance. Dogs that quickly completed the detour tasks also tended to score highly on the choice tasks; this could be explained by a general intelligence factor. Learning about g in non human species is an essential component of developing a complete theory of g; this is feasible because testing cognitive abilities in other species does not depend on ecologically relevant tests. Discovering the place of g among fitness-bearing traits in other species will constitute a major advance in understanding the evolution of intelligence.”

 

 

 

Transcranial direct current stimulation decreases performance on intelligence test

7 May

The other day, I linked to a popular account of this story. Here is the abstract for the original paper:

Transcranial direct current stimulation (tDCS) modulates excitability of motor cortex. However, there is conflicting evidence about the efficacy of this non-invasive brain stimulation modality to modulate performance on cognitive tasks. Previous work has tested the effect of tDCS on specific facets of cognition and executive processing. However, no randomized, double-blind, sham-controlled study has looked at the effects of tDCS on a comprehensive battery of cognitive processes. The objective of this study was to test if tDCS had an effect on performance on a comprehensive assay of cognitive processes, a standardized intelligence quotient (IQ) test. The study consisted of two substudies and followed a double-blind, between-subjects, sham-controlled design. In total, 41 healthy adult participants completed the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV) as a baseline measure. At least one week later, participants in substudy 1 received either bilateral tDCS (anodes over both F4 and F3, cathode over Cz, 2 mA at each anode for 20 min) or active sham tDCS (2 mA for 40 s), and participants in substudy 2 received either right or left tDCS (anode over either F4 or F3, cathode over Cz, 2 mA for 20 min). In both studies, the WAIS-IV was immediately administered following stimulation to assess for performance differences induced by bilateral and unilateral tDCS. Compared to sham stimulation, right, left, and bilateral tDCS reduced improvement between sessions on Full Scale IQ and the Perceptual Reasoning Index. This demonstration that frontal tDCS selectively degraded improvement on specific metrics of the WAIS-IV raises important questions about the often proposed role of tDCS in cognitive enhancement.”

The study design seems strong and suggests that one should think twice before running electric currents through the brain.

 

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