Myths of Neuropsychology: Intelligence, Neurometabolism, and Cognitive Ability

Abstract

Recently, Dodrill (1999) revised a previously described "Myth of neuropsychology" (1997) to state: "Just as below average performances on neuropsychological tests are found when intelligence is below average, to that same degree above average performances on neuropsychological tests are expected when intellectual abilities are above average." This study addresses the relationship between intellectual and neuropsychological performance in the context of Magnetic Resonance Spectroscopy (MRS) measurements of the neurometabolite N-acetylaspartate (NAA). When subjects were stratified by Full Scale IQ (Average, High Average, Superior) they differed significantly in terms of total neuropsychological performance [F(2,47) = 17.63; p <.001] and the neuronal marker NAA [F(2,47) = 3.25; p <.05]. Regression analysis across groups demonstrated that FSIQ and NAA were independently related to Total z-score [F(1,47) = 29.43; p <.0001] and accounted for over half the variance (r(2) of model =.56). The concurrent relationship of FSIQ and NAA to total neuropsychological performance suggests that the relationship between measures sensitive to intellectual ability and neuropsychological performance is real, and does not reflect arbitrary psychometric or scaling properties of the WAIS-III.

The association of gender, age, and intelligence with neuropsychological functioning in young typically developing children: The Generation R study

“…Previous studies (mainly in adults or adolescents) have shown various neuropsychological functions to be substantially related to general intelligence (DiazAsper, Schretlen, & Pearlson, 2004;Jung, Yeo, Chiulli, Sibbitt, & Brooks, 2000;Seidenberg, Giordani, Berent, & Boll, 1983). However, results are mixed with regard to the strength of the association for different neuropsychological domains, and multiple studies have pointed out that not all different neuropsychological functions can be explained equally well by intelligence.…”

Effects of IQ on Executive Function Measures in Children with ADHD

“…The issue of neuropsychological test performance among individuals with above average IQ has been the topic of some controversy (Jung, Yeo, Chiulli, Sibbitt, & Brooks, 2000;Russell, 2001;Tremont, Hoffman, Scott, & Adams, 1998). Dodrill (1997Dodrill ( , 1999 observed that while IQ scores below the average range are often correlated with a variety of neuropsychological measures, the same relationship does not hold true for individuals with average to above average IQ.…”

A possible correlation between performance IQ, visuomotor adaptation ability and mu suppression

“…Previously it has been used to correlate low-level sensory discriminations with intelligence (Melnick and Harrison et al, 2013), developmental cognitive abilities with task performance (Pangelinan and Zhang et al, 2011;Smits-Engelsman and Hill, 2012), and neural correlates of specific cognitive abilities (Margolis and Bansal et al, 2013). It is also suggested that the cognitive motor abilities and intelligence may share the same neural substrates (Jung and Yeo et al, 2000;Duncan, 2005;Stevens, 2009). Similarly, functional studies support the idea of distributed networks in the brain and suggest that intelligent brains process information more efficiently during a cognitive task (Achard and Salvador et al, 2006;Jung and Haier, 2007;van den Heuvel and Stam et al, 2009).…”

“…Many studies on the neuroscience of intelligence or on differential psychology have tried to identify the fundamental parameters of cognitive processing or the functional and biological variables that account for inter-individual intelligence differences. Psychometric tests of intelligence evaluate cognitive domains such as reasoning, processing speed, executive function, memory, and spatial ability (Wechsler, 1981;Jung and Yeo et al, 2000;Colom and Abad et al, 2002;Raven and Raven, 2003;MacDonald and Nyberg et al, 2006). The intelligence quotient (IQ) tends to remain relatively stable across development (Deary and Whalley et al, 2000;McArdle and Ferrer-Caja et al, 2002) and the estimation of IQ by means of psychometric tests is an index of relative intelligence that measures how well an individual performs in a cognitive domain with respect to a reference group of the same age.…”