Locating of the Intelligence Gene ‘myg’
through Functional Neuroimaging Analysis
and Allelic Association
Maxine Helga Pinpin
Locating of
The Intelligence Gene ‘myg’
through Functional Neuroimaging Analysis and Allelic Association
A Research Proposal
By
Maxine Helga Pinpin
INTRODUCTION
Background of Study
Many previous studies () have been finding the genes attributed to intelligence, using
intelligence quotient (IQ) to gauge intelligence, particularly in humans. Through gene deletion
and manipulation tests in animals, some of the studies were successful in finding the correlation
between genes and intelligence (). However, these studies demonstrate different genes to affect
intelligence. This poses the problem of inaccuracy. If, for example, in cognitive testing a deleted
gene causes a desired change in results, the targeted gene could be the gene for brain structure
development and not intelligence.
Statement of the Problem
Intelligence vs. Knowledge
This study believes that intelligence has not been adequately defined, and that
intelligence cannot be sufficiently measured by IQ since a person taking an IQ test has to be
raised, somewhat, in a Western paradigm. Thus, it is of utmost important to define with scientific
precision intelligence and its parameters.
This study will be in line with Gardner’s (2000) theory of “multiple intelligence” which
posits that intelligence is not a single property of the human mind. However, in contrast to the
common belief that intelligence can be improved, this study believes that intelligence is a fixed
value. It has a maximum potential or capacity that can be filled with information or knowledge.
If for instance two people, who have no experience whatsoever in basketball, are asked to dribble
a ball, the person with more intelligence will perform better. Thus, intelligence can be likened to
a sponge and knowledge is what the sponge absorbs. A sponge has a predetermined absorbency
speed and rate. If two different sponges are made to absorb the same amount of liquid, the better
sponge will be able to absorb the liquid faster and retain it more efficiently. Though, through
time, both will be able to absorb the same amount of water. Just like in intelligence, the more
intelligent person will be able to understand and utilize knowledge faster than the less intelligent
person. But given time and training, the less intelligent person can be able to understand and
utilize the same knowledge. Intelligence is applied to different aspects, may it be in
mathematical, spatial, musical, bodily-kinesthetic, intrapersonal, interpersonal, or other
undiscovered aspects. Therefore, each individual is endowed with a unique combination of
intelligence.
This study aims to determine the specific genes attributed to the different types of
intelligence. It also aims to determine the gene responsible for the development of intelligence.
Through the first phase of human testing and statistical analysis of data, this study will provide
more accuracy in determining the different candidate genes ‘myg’ which can then be tested on
animals.
As in Toga and Thompson’s (2005) review, this study will utilize the same brain
mapping and neuroimaging techniques. The functional neuroimaging data of the total number of
humans will be taken. This will be conducted to determine the areas of the brain which are
active during the performance of specific cognitive tasks. The results of the experts as compared
to the average people will show that the area of their brain active during cognitive tasks is more
high functioning than those of the average people. Thus, the allelic association will be compared
to find the different ‘myg’ genes. This approach of allelic association to locate genes is
demonstrated in Denham and Whittaker’s (2003) study. Also, according to Doull et. al. (1996)
“for complex inheritance, allelic associations can be more powerful than linkage for locating a
gene”.
Significance of the Study
This study will provide further information for the genetic attribution of the different
kinds of intelligence. Determining the genes of intelligence will aid in mankind’s endeavour of
finding the gene or genes for genius, and serve as a stepping stone for future studies in the
genetic field, neurological field, and even the medical field.
Review of Related Literature
Intelligence
Gardner (2000) formulated the theory of “Multiple Intelligence”, stating that there are at
least seven distinct intelligences that can be linked to their own neurological substrate: linguistic
intelligence (sensitivity to the spoken and written word and the ability to master languages),
logical-mathematical intelligence (the capacity to analyze problems logically and scientifically),
musical intelligence (skill in the performance, composition, and appreciation of music), bodilykinesthetic intelligence (as exemplified by dancers, surgeons, and artists), spatial intelligence
(characteristic of pilots, graphic artists, and architects), interpersonal intelligence (a talent for
understanding and relating to other people) and intrapersonal intelligence (the capacity for
understanding oneself). Toga and Thompson (2005) cited that “multiple intelligence is
supported by studies of brain lesions that cause specific brain deficits while leaving other
cognitive functions intact (e.g. speech or visuospatial skills).”
Brain connectivity
Gazzaniga (2008) compiled several researches that demonstrated the areas of brain active
when performing different cognitive tasks; some of the studies have found possible genes that
could be attributed to the different intelligences.
Brain mapping and statistical analysis
Toga and Thompson (2005) developed a model-driven algorithm to create a 3D
representation of the brain that shows the structural and functional analysis of the brain. They
tested identical twins, fraternal twins, and normal individuals. They used a tissue classification
algorithm to segment the data into regions representing gray matter, white matter, cerebrospinal
fliud (CSF) and nonbrain tissues, and used statistical analysis to find the parts of the brain which
are hereditable. These brain mapping techniques, according to Toga and Thompson, may be used
to visualize the correlations between genes and morphology, cognitive scores and other effects.
Quantitive Trait Loci (QTL), DNA Markers and Linkage Maps
According to Farnoosh (2004), multiple-gene systems result in dimensions (quantative
traits) as opposed to disorders (qualitative dichotomies). These genes in multiple-gene systems
are called quantative trait loci (QTLs), and are used to discover multiple genes, with different
effect sizes, contributing to the variation of the trait (Farnoosh), 2005). As cited by Farnoosh, the
IQ QTL Project (Plomin, et. Al., 1994) “focuses on ability rather than disability”, and states that
being very high functioning requires positive alleles rather than negative alleles. As opposed to
the IQ QTL Project, this study will focus on the brain activity during cognitive tasks instead of
the intelligence quotient or IQ of the human subjects.
Linkage maps are constructed to show the position of genetic markers in the DNA. These
are used to find the hereditability of the trait of interest (Collard, Jahufer, Brouwer & Pang,
2005).
MATERIALS AND METHODS
Process Flowchart
IDENTIFICATION OF CANDIDATE GENES IN HUMANS
Cognitive testing
of human
subjects
Neuroimaging of
human subjects
Brain mapping
Statistical Analysis of
active brain regions
Comparison with Thompson
and Toga’s degree of
heritability
Construction of Linkage
Map
to
Allelic Association of Polymorphisms
to
Pinpointing of different intelligence
genes ‘myg’
to
Cognitive Testing and Neuroimaging
Two groups of 700 human individuals will be gathered: the expert group (Group E) and
the average group (Group A). Group E will comprise of 100 experts of the following kinds of
intelligence Mathematical, Spatial, Musical, Bodily-kinesthetic, Intrapersonal, Interpersonal and
Linguistic will be labelled E1, E2, E3, E4, E5, E6, and E7 respectively. Group A will comprise
of individuals with minimal experience or knowledge in the five fields of study. They will be
divided into 7 groups of 100 individuals as well, and will be labelled A1, A2, A3, A4, A5, A6
and A7. Refer to the Figure 1.
Figure 1: Classification of test subjects
Group A and Group B will be given cognitive tasks according to their assigned
intelligence type. Functional magnetic resonance imaging (fMRI) will be used to determine the
active brain areas during their cognitive tasks.
Brain Mapping and Statistical Analysis
Using Toga and Thompson’s (2005) algorithms and programs, brain map models
showing the active brain areas will be constructed. Through statistical analysis of the brain map
models of all test subjects, the average areas of the brain which are active during specific
cognitive tasks will be established. These will be called the brain activity map model.
Comparison with degree of heritability and Linkage Map
For reliability, accuracy and validity, the brain activity map model will be compared to
the brain map of heritability of Toga and Thompson (2005). This will demonstrate the heritable
parts of the brain which are candidate phenotypes for the intelligence genes. After which, the
linkage maps of the humans will be constructed to narrow down the candidate genes. The genetic
loci which are close to each other will be picked since they are heritable.
Allelic Association of Polymorphisms
Since the Group E have more high functioning in their type of intelligence, then the
variation of their gene must be somewhat similar. For example, Group E1, the experts of
mathematics, have higher mathematical intelligence than Group A1. Thus, the variation of their
mathematical intelligence gene or the allele of their mathematical ‘myg’ is similar to each other
while the alleles of individuals in Group A1 is similar to each other. On the other hand, the
alleles of Group E1 vary from those of Group A1. Therefore, the alleles of Group E can be
compared to those of Group A.
Pinpointing of Intelligence Genes ‘myg’
Since alleles are variations of genes, it will be possible to use allelic information to locate
the gene of interest. After the allelic association has been established, the gene for each type of
intelligence can then be pinpointed in the DNA sequence or DNA map.
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