Intelligence Measurement

How is intelligence measured? Do those with higher intelligence actually have more synapse? Is there a difference in structure or neural pathways?

Prediction: IQ is well known measure of intelligence. I propose that the entire process of intelligence testing needs to revitalized. I believe that we will not see a structural difference and that there must be another measure of intelligence.

Article 1:

Ramsden S, Richardson FM, Josse G, Thomas MS, Ellis C, Shakeshaft C, Seghier ML, and Price CJ. Verbal and non-verbal intelligence changes in the teenage brain. Nature. 2011 Oct 19. doi: 10.1038/nature10514.

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature10514.html

Validity: My initial attention to this article came from NPR. I was unsatisfied with using a non-scientific journal. I went to the source and went directly to the study conducted by University College London and the University of London. With further research, I was able to see how the Wellcome Trust Centre for Neuroimaging, University College London and the Developmental Neurocognition Laboratory, Department of Psychological Sciences, Birkbeck College, University of London had conducted the study. The study was designed by one individual then a separate team recruited participants. Another team was put together to collect the data. Yet another team was put together to analyze the data. And finally a writing team wrote the paper. All these levels of transparency as well as the availability of supplemental data made me feel very comfortable with validity.

IQ is the standard measure of intelligence. The belief was that this would stay consistent through the life span. Neuroimaging was also used to see if changes occurred whether or not they corresponded with changes in brain development. Teenagers did show fluctuations and that during these years that IQ could change. More specifically:

“By using longitudinal assessments of the same individuals, we obviated the many sources of variation in brain structure that confound cross-sectional studies. This allowed us to dissociate neural markers for the two types of IQ and to show that general verbal and non-verbal abilities are closely linked to the sensorimotor skills involved in learning.”

It makes sense to use this information to my own experiences. As a child, I was seen as intelligent child. I scored relatively well but more so saw results by surrounding myself with other high achievers. By the time, I was 15 years old I was in the gifted and talented crowd. Therefore just like the researchers found intellectual potential did improve. Furthermore the researchers found that changes in grey matter were clearly measures. This completely derailed my hypothesis.

Article 2:

Isabell Wartenburger, Esther Kühn, Uta Sassenberg, Manja Foth, Elizabeth A. Franz, Elke van der Meer, On the relationship between fluid intelligence, gesture production, and brain structure, Intelligence, Volume 38, Issue 1, January-February 2010, Pages 193-201, ISSN 0160-2896, 10.1016/j.intell.2009.11.001.

http://www.sciencedirect.com/science/article/pii/S0160289609001457

Validity: The research was conducted at the Humboldt University Berlin (Department of Psychology, Humboldt University Berlin, Rudower Chausee 18, 12489 Berlin, Germany) and the Berlin NeuroImaging Center (Berlin NeuroImaging Center, Department of Neurology, Charité University Medicine Berlin, Charitéplatz 1, 10117 Berlin, Germany). I could not find more information at this level of article access. I did look into the Intelligence journal itself. I found it promising that it preferred original research and not derivatives. The journal has a standard of ethics in publishing and a conflict of interest clause. The clinical research also must be as follows:

“All randomised controlled trials submitted to Intelligence whose primary purpose is to affect clinical practice (phase 3 trials) must be registered in accordance with the principles outlined by the International Committee of Medical Journal Editors (ICMJE; http://www.icmje.org/).”

The purpose of the study was to see any relationships between fluid intelligence, gesture production, and brain structure. Relationships were clearly seen: “Our results thus indicate that cortical thickness of those brain regions is related to both high fluid intelligence and the production of gestures.”

I found this amusing. I find that those who I see as more intelligent tend to be more purposeful with their physical gestures. More deliberate. I was not surprised after reading the first article that there was a region corresponding with this region. Obviously intelligence can be structurally observed. Although I was surprised that on its own that gesture production was from the same region. I wonder if those who are more innovative and deliver presentations on their revolutionary thoughts are more demonstrative as well in addition to more highly stimulated in the same region.

Article 3:

Aljoscha C. Neubauer, Andreas Fink, Intelligence and neural efficiency, Neuroscience & Biobehavioral Reviews, Volume 33, Issue 7, July 2009, Pages 1004-1023, ISSN 0149-7634, 10.1016/j.neubiorev.2009.04.001.

http://www.sciencedirect.com/science/article/pii/S0149763409000591

Validity: The article again had limited access. It is often cited but this did not actually speak to validity. I was left to only analyze the journal validity. Similar to Intelligence, it had the same clauses in ethics and conflict of interest. It did however also mention that funding must come directly from those doing the research. I do think there was a need to speak to funding.

The basis of the research jumped of a previous study that found that those who are more neurally efficient (use less brain activation energy) in cognitive tasks are brighter as well. This study found that further research was necessary. Results could be varied by amount and quality of learning. Although conclusively: “In very complex tasks more able individuals seem to invest more cortical resources resulting in positive correlations between brain usage and cognitive ability.”

As far as my hypothesis, I found it interesting that intelligence could be studied as far as how brain-energy-efficient one could be. I like the idea that indeed it could be another indicator. I do want to see more research and feel unsatisfied with the results. This is the first time I have really been let down as far as not being able to get more information.

Article 4:

John C Wickett, Philip A Vernon, Donald H Lee, Relationships between factors of intelligence and brain volume, Personality and Individual Differences, Volume 29, Issue 6, December 2000, Pages 1095-1122, ISSN 0191-8869, 10.1016/S0191-8869(99)00258-5.

http://www.sciencedirect.com/science/article/pii/S0191886999002585

Validity: The study only concerns a small population. More specifically, the adult male sibling in London ON Canada. This seems so small scoped. Again access level left me wanting more. The journal had similar requirements as the ones in the previous article.

This study wanted to look more into brain volume and head size in intelligence. The study was consistent with the previous studies. Thusly there was a correlation: “The sum of the data suggested that although brain volume (and to a lesser extent, head size) is predictive of g, fluid ability, and memory, it does not predict crystallized ability.”

After our previous research in male and female brains, I was already aware of studies in volume and brain abilities. I was hoping to find more information about cognitive abilities in relation with specific brain regions and intelligence. I was pleased that the study did find outliers that crystallized ability and spatial image loading.