Vestigial Whisker Muscles in Humans

Japanese anatomists have shown that careful dissection of the upper lip shows vestigial vibrissae (whisker) muscles in a third of humans. You know how your cats whiskers go back if you touch them there or they're just annoyed about something? Those. Apes are strange among mammals for not having vibrissae; in particular rodents are thought to construct their pictures of near-space with their whiskers rather than their eyes, and interestingly vibrissae sensory nerves are afferent trigeminal fibers, many of which pass through the superior colliculus, a midbrain visual structure.

Toward a Physical Measure of Utility

"Electroencephalographic Topography Measurements of Experienced Utility", emphasis on experienced. Pedroni A. et al, The Journal of Neuroscience, 20 July 2011, 31(29): 10474-10480. The response they measured unexpectedly increased disproportionately increasing reward, i.e. it did not demonstrate diminishing returns but rather the opposite.

A measure of the mismatch between decision and reward utility, and understanding its biological basis and how it differs between individuals, would be excellent for psychology as well.

Other Non-G Explanations for the Flynn Effect Besides Re-Testing

Armstrong and Woodley argue that the documented rise in measured IQs is a result of test-takers applying rule-based approaches to tests, resulting in an increase similar to that seen in re-testing. They're arguing that in large part, it is a testing artifact. They make several predictions about what we should observe if their rule-based model is correct. For instance, that measures of crystallized intelligence (i.e. vocabulary) should not rise or not rise as robustly, and they haven't; that most obviously rule-based tests (like Raven's progressive matrices) should show the strongest effect (they do); and that we should expect the gains to appear when countries undergo demographic transition including standardized education, and the rate of increase should correspond to the rate of the transition.

To this last point, it's worth pointing out that there are many other less interesting medical explanations for why intelligence might actually be rising. Specifically, lower parasite load due to public sanitation and better nutrition in early childhood are very good candidates for why the Flynn-type gains are most pronounced in Europe, Japan and Korea in the periods when they were observed. It's hard to make the argument that lower parasite load leads to better cognitive strategies to game tests. It's also not surprising that if bombs are falling around your school and then they stop, the people tested after they stop may perform better - especially since even non-warfare jet and traffic noise has been shown to locally impair reading comprehension in students.

A second, neglected question is whether the abstract rule-based thinking required for the re-testing-type gains actually correlates to some other outcome, like personal or national per capita income, or life satisfaction. If the Flynn effect doesn't represent an increase in g but does correlate with economic growth, do we care that much?


References

Armstrong EL and Woodley MA. The rule-dependence model explains the commonalities between the Flynn effect and IQ gains via retesting. Learning and Individual Differences, Volume 29, January 2014, Pages 41–49.

Eppig C, Fincher CL, Thornhill R. Parasite prevalence and the worldwide distribution of cognitive ability. Intelligence 39 (2011) 155–160.

Haines MM, Stansfeld SA, Job RF, Berglund B, Head J. Chronic aircraft noise exposure, stress responses, mental health and cognitive performance in school children. Psychol Med. 2001 Feb;31(2):265-77.

"Of Course!"

Road Signs for Meditation

The Physical Diversity of Uralic Speakers

The Uralic language family has always intrigued me. Partly it's because some people think that there is a Uralic substrate to proto-Germanic (see Kalevi Wiik); partly it's because Uralic speakers live in the center of a continent that is at once the center of the Old World, and in many ways not thoroughly explored with its interior still largely wild and uninhabited. But it's really intriguing to see how different Uralic speakers look from one another. They range from blonde, Scandinavian-looking, about-as-white-as-you-can-get Finns and Saami, to very Asiatic-appearing Nenets people in north central Siberia. Is this because there really aren't many genes for face shape, eye shape and hair type - that is, if you looked at, say, Germans and Spaniards genetically, are they genetically as distant on average as Finns and Nenets (just a few genes) but the differing German and Spanish genes don't happen to all be represented in easy-to-spot features? Or is there really a greater genetic distance? In which case, are these people whose ancestors adopted the language, or were they such a small group of hunter-gatherers running into big Turkic and Indo-European populations that their genes were swamped by whoever they met?

The interesting thing is that here the Urals form a fairly clear boundary for these genes. The Udmurts to the west (one of the groups above) are famous for being the most red-haired people on the planet, while on the other hand it's not hard to imagine that the Nenets family above is related to Native Americans and Inuit. (The Udmurts are the first one and the Nenets second, but I probably didn't have to tell you which are which!) But of course there is still cross-over between the two, and it's interesting precisely because most of us in the U.S. don't see these traits represented in the same people very often.

Does Mindfulness Act Through Modulation of Serotonergic Circuitry?

Investigating the connections between mindfulness meditation and the brain's serotonergic systems seems like a promising avenue of research. Mindfulness may be a way to directly influence this system based on observations from several domains.


1) A bedrock principle of psychopharmacology is that increasing the amount of serotonin in synapses improves depression and anxiety.

2) Acute doses of HT2A agonists (e.g. psilocybin) can also improve depression. These agents produce brief and intense sensory experiences. At low doses, subjects do not report hallucinations, but do report that sensations seem more intense and more affectively pleasant (e.g., colors are brighter).

3) Mindfulness, which is focused concentration on sensory input, has been shown to be effective in reducing depressive symptoms in RCTs (van Aalderen et al 2011).

4) Therefore, concentrating on sensory input as with mindfulness may produce similar effects to the SSRIs and HT2A agonists, mediated by the same pathway.


In a sense, giving SSRIs (or the more powerful one-time punch of psilocybin) may produce an exogenously-created mindfulness. No research has yet been done on the involvement of serotonergic circuitry with mindfulness meditation's effects.

Many of the measures correlating mindfulness meditation to outcome concern decreased rumination. To that end, the introspective among us should take note of this quote from a 2013 paper by Paul et al in Social Cognitive and Affective Neuroscience: "Our results suggest non-reactivity to inner experience is the key facet of mindfulness that protects individuals from psychological risk for depression."