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“Why Don’t Woodpeckers Get Concussions?”

5 Feb

Good question:

Hat tip to Dear Kitty. Some blog.

Is Alzheimer’s caused by brain atherosclerosis?

3 Jan

Please  understand that this explanation if one of a number of competing hypotheses. Dr. Greger makes his case here:

The great debate resolved

6 Dec

[Hat tip to BoingBoing]

By the way, Suzana Herculano-Houzel’s is the inventor of the most accurate method for counting neurons in a brain. 

The case of Tatiana And Krista Hogan

17 Nov

Tatiana And Krista Hogan are co-joined twins who share brain tissue. According to Wikipedia they are joined at the thalamus, brain structure that projects sensory information onto the cerebral cortex. According to a post on the CBC website:

Neurological studies have stunned the doctors. Tatiana can see out of both of Krista’s eyes, while Krista can only see out of one of Tatiana’s. They also share the senses of touch and taste and the connection even extends to motor control. Tatiana controls 3 arms and a leg, while Krista controls 3 legs and an arm.
Amazingly, the girls say they also know one another’s thoughts without needing to speak. “We talk in our heads” is how they describe it.

The CBC has produced a documentary about the twins, unfortunately not yet available in the U.S.

Psychiatric Disorders and Brain pH

27 Oct

From Scientific American:

There were earlier hints of the acid-disorder link: studies that directly measured pH—a metric of how acidic or basic something is—in dozens of postmortem human brains revealed lower pH (higher acidity) in patients with schizophrenia and bipolar disorder. Multiple studies in the past few decades have found that when people with panic disorder are exposed to air with a higher than normal concentration of carbon dioxide—which can combine with water in the body to form carbonic acid—they are more likely to experience panic attacks than healthy individuals are. Other research has revealed that the brains of people with panic disorder produce elevated levels of lactate, an acidic source of fuel that is constantly generated and consumed in the energy-hungry brain.

If these findings hold up, there may be new avenues for treatment.

 

“Tympanic Membrane Temperature and Hemispheric Cognitive Style”

4 Oct

I am a co-author on this paper, just published in The Journal of Genetic Psychology:

The authors tested the hypothesis that there is a correlation between hemispheric cognitive style and ear temperature. A sample of 100 participants completed a measure of hemispheric cognitive style, the Hemispheric Consensus Prediction Profile. Ear temperatures were taken in 2 sessions, 2 times for each ear at each session. Average left ear temperature was subtracted from average right ear temperature as an index of dominant temperature. Only 56 of the participants showed a stable dominant ear temperature. For these 56 participants, there was a statistically significant positive correlation between scores on the Hemispheric Consensus Prediction Profile and tympanic member temperature (Spearman’s ρ =.29, 95% CI [.04,.51]). Individuals with a left hemispheric cognitive style tended to have a warmer left tympanic membrane temperature while those with a right hemispheric cognitive style tended to have a warmer right tympanic membrane temperature. Tympanic membrane temperatures are easily obtained using inexpensive and noninvasive technology. The relationship suggested by these findings may open new opportunities for the study of cerebral asymmetry.

The Higher Efficiency of the Bilingual Brain

2 Jun

A paper in The Journal of Neurolinguistics: “Interference Control at the Response Level: Functional Networks Reveal Higher Efficiency in the Bilingual Brain.” Here is the abstract:

The bilingual advantage in interference control tasks has been studied with the Simon task, among others. The mixed evidence from the existing studies has led to contradictions in the literature regarding the bilingual advantage. Moreover, fMRI evidence on the neural basis of interference control mechanisms with the Simon task is limited. Previous work by our team showed that equivalent performance on the Simon task was associated with different activation maps in elderly bilinguals and monolinguals. This study aims to provide a more in-depth perspective on the neural bases of performance on the Simon task in elderly bilinguals and monolinguals, by adopting a network perspective for the functional connectivity analysis. A node-by-node analysis led to the identification of the specific topology that characterized the bilingual and monolingual functional networks and the degree of connectivity between each node across groups. Results showed greater connectivity in bilinguals in the inferior temporal sulcus, which plays a role in visuospatial processing. On the other hand, in monolinguals, brain areas involved in visual, motor, executive functions and interference control were more connected to resolve the same task. In other words, in comparison to the monolingual brain, the bilingual brain resolves visuospatial interference economically, by allocating fewer and more clustered regions. These results demonstrate a larger global efficiency in task performance in bilinguals as compared to monolinguals. Also, the provided evidence filters out the task-specific so-called bilingual advantage discussed in the literature and posits that bilinguals are strategically more efficient in a given performance than monolinguals, thus enhancing our understanding of successful aging.

You can read about the Simon Task here.

 

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