Snakes on a Brain

In October, 2013 ScienceNews put out a press release describing an article published by researchers from UC Davis and U Toyama (Japan) advancing the “Snake Detection Theory.” They measured the responses of pulvinar neurons to visual stimuli, including a hand, face, geometric shape, and a snake. They report that they found a specific response to the snake as a visual stimulus, and that it supports the notion that the primate brain evolved under evolutionary pressure from living alongside snakes as competitors and predators.

The pulvinar neurons are located in the thalamus (in humans, the pulvinar nucleus, or cluster or neurons, is the largest in this structure). The thalamus is a structure that is deep in the vertebrate brain and it relays sensory and motor signals to the cerebral cortex, it regulates consciousness, sleep, alertness. This group of neurons receives input from crossed optic fibers (that is, the right part receives input from the left eye), which then relays information to the cortex of the occipital lobe. They also communicate with other regions, but that is the path of visual stimuli. Continue reading

Undergraduate Biology Should Teach More Evolution

I have been researching the literature in science education, specifically neuroscience, genetics, and microbiology, and I’m surprised to find that not much import is given to the theory of evolution (or natural selection). Given that “Nothing in biology makes sense except in the light of evolution” (a 1973 essay), I really expected to find a unit on evolution or at least this theme within the curricula of these disciplines.


Kerchner, Hardwick, and Thornton surveyed faculty of undergraduate neuroscience programs to determine which “Core Competencies” were most important for undergraduate neuroscience majors (for the record, when I was an undergrad, very few colleges offered this field of study as a major, it was regarded to be a specialty reserved for graduate study — for example, you could major in biology, molecular genetics, biochemistry,  evolution-ecology-organismal biology, and microbiology, but not neuroscience at Ohio State).  The three most important core competencies for a neuroscience program:  1. Ability to engage in critical & integrative thinking, 2. Basic neuroscience knowledge, and 3. Scientific Inquiry / Research Skills (in that order). Interestingly, quantitative ability was ranked the least essential by the greatest proportion of faculty.

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