How do the brains of mathematicians and philosophers function when doing what they do?

Posted on 12 January 2009

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Agnostic has an old(er) post showing how a group’s cognitive profile (leaning more on the verbal g-component  than the visuo-spatial) affects a group’s preference for musical composition (leaning more on melodic-style composition than harmonic).

TGGP references Agnostic’s post here in discussing the possible influence of these g-components on political leanings.  Groups that lean more on the verbal g-component tend to be more liberal than conservative; groups that lean more on the visuo-spatial g-component tend to be less liberal, and even more conservative than liberal with some groups.

Here TGGP makes an interesting statement:

Subjects like English, History, Philosophy and even Theology are among the leftiest, and all draw on verbal smarts. Engineering and the hard sciences which draw more on visuo-spatial abilities are to their right, although this only means a little more conservatives and mostly just fewer liberals leading closer to parity.

This statement got me thinking about the brain function of philosophers.  Philosophers naturally draw on the verbal g-component, but is that all they draw on? Furthermore, does drawing on a certain g-component entail the drawing on a certain physical brain component?

Let’s first consider the brain functions involved in doing mathematics well.  There is some interesting research here.  For instance, the Eide Neurolearning Blog posted that precocious children solving mathematical problems actually use both brain hemispheres relatively evenly; but the average child predominately uses the left hemisphere. The blog cites the original article by O’Boyle, which states that:

Over the years, O’Boyle and colleagues have conducted considerable research into the morphological and functional characteristics of the mathematically gifted brain in adolescents and how it differs both qualitatively and quantitatively from those of average-math-ability youths (e.g., O’Boyle, 2000; O’Boyle, Alexander, & Benbow, 1991; O’Boyle & Benbow, 1990; O’Boyle, et al., 1995; O’Boyle, et al., 2005; O’Boyle & Gill, 1998; O’Boyle, Gill, Benbow, & Alexander, 1994; Singh & O’Boyle, 2004). In these studies, a variety of experimental methods have been used to demonstrate that enhanced development of the RH and an unusual reliance upon it when processing information are unique characteristics of the math-gifted brain. Note that in these studies, math-gifted children are operationally defined as 10- to 15-year-olds who have scored at the 99th percentile when taking the SAT-Math exam (Scholastic Aptitude Test, United States) or the SCAT-Numerical Reasoning test (School College Abilities Test, Melbourne, Australia).

So what does this tell us about the connection between active brain areas when doing mathematics and the g-components on which solving mathematical problems loads?  The mathematically gifted adolescents exhibit two very important features: (1) enhanced development of the right cerebral hemisphere, and (2) a special form of brain bilateralism.  Looking at the O’Boyle paper, we find that:

. . . math-gifted children recruit unique brain regions not typically engaged by those of average math ability, particularly the bilateral activation of prefrontal cortex, the parietal lobes, and the anterior cingulate. Note that the latter regions are thought to form a neural circuit known to mediate spatial attention and working memory as well as contributing to the fine-tuning of executive functions (Mesulam, 2000). They may also play an important role in deductive reasoning and, to a lesser extent, the development of cognitive expertise (Knauff, Mulack, Kassubek, Salih, & Greenlee, 2002).

By way of summary, both the behavioral and neuroimaging findings reported here suggest three general characteristics that best describe the operating properties of the mathematically gifted brain: (a) enhanced development of the RH, resulting in a unique form of functional bilateralism, with specialized contributions from both sides of the brain combining to drive cognition and behavior; (b) enhanced interhemispheric communication and cooperation (perhaps via the corpus callosum or increased grey/white matter ratio, or glia/neuron ratio), which assist in coordinating and integrating information between the cerebral hemispheres; and (c) heightened brain activation, approximating (or exceeding) that of an adult brain even though they are still adolescents, which is suggestive of enhanced processing power and may reflect highly developed attentional and executive functions that serve to fine-tune their unique form of cerebral organization.

But the most interesting piece is:

One recent study of this sort, investigating potential differences in the functional brain organization of mathematically gifted children, was conducted by O’Boyle et al. (2005). Functional magnetic imaging (fMRI) was employed to monitor brain activation during performance of a mental rotation task. Note that mental rotation is a visuospatial task that is oftentimes (though not uniformly) reported to correlate with mathematical ability (i.e., the better at mental rotation, the higher the math ability). In this study, 6 math-gifted boys (mean age = 14.3 years) and 6 matched control children performed 3-D mental rotation problems while in the fMRI scanning environment. On each trial, participants were required to press one of four fiber optic buttons to indicate which of the four test objects was identical to the target object when rotated in space (see Figure 2).

. . . for average-math-ability children, predominant activations were found in the right frontal region (relating to spatial working memory) and the right parietal lobe (relating to the maintenance and manipulation of mental, perhaps, visual images); there was only slight evidence of any LH activation. For the math-gifted children, however, the amount of brain activation obtained was several times greater than that of average-math-ability children, and the overall pattern of activity was distributed quite differently. Specifically, there was bilateral activation of the right and left frontal regions, along with significant bilateral activation of the premotor, parietal, and superior occipital regions. Of particular note was the heightened activation of both the right and left anterior cingulate in the math-gifted children as compared to those of average math ability (see Figure 3).

I think the last part is crucial.  It tells me that brain function parity doesn’t translate to favoring one g-component over another.  Average ability students use only the right hemisphere when performing a very g-loaded visuo-spatial task, but the superior students use both hemispheres evenly for the same visuo-spatial task.  Furthermore, it’s stated in the O’Boyle paper that average ability students show a right hemisphere, left ear advantage for recognizing linguistic stimuli, but the superior ability students don’t show that advantage; they, instead, are equally capable with switching ears and thus, hemispheres.  So our superior ability individuals might have a cognitive profile that favors the visuo-spatial g-component, but that doesn’t imply that they have a brain function profile that strictly favors the right hemisphere.  That’s because a cognitive profile isn’t the same as a brain function profile.

[Side Note: The above point needs a further, future post about groups that differ in cognitive profile (e.g. Asians and Ashkenazi Jews) but all excel in mathematics.]

What is said here about mathematical ability can likely be said about ability for physics or any mathematically heavy field.  But most people won’t realize that philosophers use the same types of inductive, deductive, analytical, and analogical reasoning.  They just reason about concepts that aren’t necessarily about mathematics.  I, therefore, believe that those who are the best and brightest at philosophy happen to have similar brains to the mathematically gifted—i.e., the best philosophers utilize the right brain hemisphere and have advanced interhemispheric communication just like the mathematically gifted.  We won’t know for certain unless there are experiments done, but if I’m right, then philosophers might favor the verbal g-component but excel in this area because of their mathematician-like brains (I think this is why both Ashkenazi Jews and Asians can favor different cognitive profiles but still both excel at mathematics—their brains function the same way as described above).