This isn’t anything new (probably), so I’m just making the connection for myself. If bioavailable glucose is what we colloquially refer to as “mental energy” then this can explain a lot.
-Why smarter people have more PET activity while watching TV (bigger supply leading to higher baseline expenditure, like with money)
-Why the neural efficiency hypothesis fails to predict the very high mental activity in males who ace the math SAT, but not in females (high engagement in males)
-Why caffeine cures ADHD (temporarily raises average engagement level, where ADHD is analogous to financial conservatism)
If we take all of these anecdotal results as representative of factors, then we should predict that mental energy expenditure on a novel task will have five dependent variables: total bioavailable glucose remaining, conservatism (personality tending to conserve energy), interest level (strength of desire to complete the task), fluid intelligence (novel problems solved per energy spent or just “efficiency”), and difficulty of the task. Here’s a naive math statement of this,
Change in Energy (negative) ~= Interest * Thrift(Total energy, conservatism) * (g-loading/fluid IQ)
A couple of further thoughts on this.
-I expect that Interest is a function dependent on people-focus versus object-focus. For example, females (who tend to prefer people-oriented jobs) would be expected to have more interest in a math lecture than a math book, and vice versa for males (and particularly those on the autism spectrum). This appears to be largely related to testosterone and introversion.
–This may also explain Paul Cooijmans’ observation that high-ability male spergs often suffer from impaired visuospatial abilities, whereas high-ability female spergs don’t. Speaking anecdotally (from introspection), visuospatial tasks require relaxation and unfocus, rather than high focus and effort.
-The thrift function likely takes the same form as personal expenditures. If anyone knows an empirically based microeconomic formula for that, please let me know.
-The typical skill curve in an activity appears (to me) to be an exponential decay curve approaching a person’s highest possible skill level. This probably means that “mastery” is just the absence of novel problems, which is to say crystallized intelligence. This could be measured objectively in units of candela (photons emitted in PET), so that crystallized intelligence would be inversely proportional to energy spent while playing Tetris at a mastery level of skill with diminishing returns in improvement.
The important thing about the latter point is that it’s a ratio scale with physical units and a true zero, with zero indicating the highest possible crystallized intelligence.
Also anecdotally, I’ve noticed that increasing oxygen availability (with cardio exercise) increases readily available mental energy (because of the ease of burning glucose) and that increasing blood flow to the brain (during cardio or hot showers) causes mental energy to be spent more indiscriminately.