There is an ongoing argument among scientist as to whether it is possible to excel in certain areas of the brain and not in others. If that were true, then the coinciding belief that IQ tests have no real value could be valid. The basis for this would be that if some portions of the brain exhibit higher function than others would an overall IQ test be a valid gauge of a person’s mental function?
A new brain imagery study has just been released that give us the first look at how differences in reasoning and problem solving abilities may be the result of the different firing of neurons in the brain.
In the study, 133 participants performed 11 memory tasks (some geared to reflect working memory and some to reflect short-term memory), two tests of general fluid intelligence, and the Verbal and Quantitative Scholastic Aptitude Tests. The modeling of the results pointed to short-term and working memories reflecting separate but highly related constructs, and that many of the tasks used in the literature as working memory tasks reflect a common construct.
Working memory is the ability to actively hold on to information needed to do complex tasks such as learning, reasoning, and comprehension. It requires manipulation of information or activities despite distractions. Short-term memory is the mind’s capacity to hold on to a small amount of information and have it available for a short period of time — usually a day or two at the most.
From their study they found that working memory indicated a strong connection to “fluid intelligence,” but short-term memory does not. Fluid intelligence involves our current ability to reasons and deal with complex information around us.
They then formed a theory: that working memory capacity and fluid intelligence indicate the ability to keep a person’s memory active, even with distractions. The authors also talked about the correlation between the ability to control attention and the prefrontal cortex functions.
Researchers found subjects who scored high on the Raven’s Advanced Progressive Matrices intelligence test showed more neural activity in specific brain regions while they were working on a complex memory task. This goes along with what experts call “general fluid intelligence,” that studies have found to be hereditary. The results of the Raven’s tests measured closely with scores on IQ tests and other standardized intelligence tests.
”To our knowledge, this is the first large-sample imaging study to probe individual differences in general fluid intelligence, an important cognitive ability and major dimension of human individual difference,” wrote the researchers, led by Dr. Jeremy R. Gray, a research scientist in the department of psychology at Washington University in St. Louis. The paper is in the March issue of the journal Nature Neurosciences.
New York Times — Brain Scans Reflect Problem-Solving Skills, by Erica Goode: http://www.nytimes.com/2003/02/17/us/brain-scans-reflect-problem-solving-skill.html
Wikipedia — Fluid and crystallized intelligence: http://en.wikipedia.org/wiki/Fluid_and_crystallized_intelligence
Ravin’s Progressive Matrix: http://www.psychologyafrica.com/pdf/Products/Ravens/RAVENS%20PROGRESSIVE%20MATRICES%20_RPM_.pdf
Ask.com Psychology — What is Fluid Memory?: http://psychology.about.com/od/findex/g/def_fluidintell.htm
National Academy of Sciences – Increasing fluid intelligence is possible after all, by Robert J. Sternberg: http://www.pnas.org/content/105/19/6791.full
PubMed.gov – Working memory, short-term memory, and general fluid intelligence: a latent-variable approach: http://www.ncbi.nlm.nih.gov/pubmed/10513398