Handbook of Frontal Lobe Assessment (DRAFT)

Bilingualism, social cognition and executive functions: A tale of chickens and eggs

“…Thus, the putative specificity of a bilingual advantage in studies that report significant differences fits intuitively with the theoretical cognitive requirements of bilingualism. It also fits with our understanding of executive functions as heterogeneous and potentially dissociable higher-order control processes (including executive components e.g., Collette et al, 2006, Shallice and Burgess, 1996, Baddeley, 1996 and the regulation of social behavior e.g., Brazzelli et al, 1994, Eslinger and Damasio, 1985 see MacPherson et al (2015)). …”

“…In terms of moral dilemmas (the degree to which participants would endorse a series of hypothetical scenarios which variably pit their personal moral boundaries against the benefit for the greater good), there is some recent literature suggesting an influence of bilingualism (Costa et al, 2014), but in this case the difference is not found between mono- and bilinguals, but between bilinguals’ first and second language. The Reversal Learning test requires participants to identify when a previously-rewarding stimulus ceases to become beneficial by switching to an alternative response schema, so may plausibly be sensitive to the superior mental flexibility putatively exhibited in bilingualism (though it reportedly involves distinct frontal regions to the Simon Task; MacPherson et al, 2015). We are unaware of any bilingualism research using Reversal Learning; thus analyses using this test are purely exploratory.…”

Getting Spearman off the Skyhook: One More in a Century (Since Thomson, 1916) of Attempts to Vanquishg

“…First, executive processes show different ageing patterns. One plausible reason for reports of heterochronicity in the ageing of executive functions may be because not all executive processes are equally supported by the frontal cortex (Andr es, Guerrini, Phillips, & Perfect, 2008), nor do all such functions necessarily receive equal support from precisely the same frontal subregions (Kievit et al, 2014;MacPherson, Della Sala, Cox, Girardi, & Iveson, 2015). Comparative differences in executive test reliabilities and/or the psychometric treatment of memory and fluid variables may also partly drive their observed differential age effects (Johnson, Logie, & Brockmole, 2010;Kievit et al, 2014).…”

Genetic contributions to Trail Making Test performance in UK Biobank

“…[4][5][6][7][8] TMT performance has been ascribed to a number of cognitive processes, 'including attention, visual search and scanning, sequencing and shifting, psychomotor speed, abstraction, flexibility, ability to execute and modify a plan of action, and ability to maintain two trains of thought simultaneously'. 9 It is considered a useful tool in research and clinical practice due to the sensitivity of the task (particularly TMT B and B − A) to frontal lobe damage (in some, but not other studies 10 ) and dementia. [11][12][13] There are declines in both TMT A and B performance in ageing.…”

“…[11][12][13] There are declines in both TMT A and B performance in ageing. 10,[14][15][16][17][18][19][20] There is also evidence for performance deficits on TMT B in mood disorders 21 and in patients with schizophrenia and their relatives 18,[22][23][24][25][26][27] Family-based and twin-based studies have provided evidence for a genetic contribution to individual differences in trail making, estimating the heritability for trail making part A between 0.23 and 0.38, and between 0.39 and 0.65 for trail making part B. [28][29][30] A recent genome-wide association study (GWAS) of trail making part A and part B in a sample of around 6000 individuals did not find any genome-wide significant hits; 31 however, GWAS of other cognitive phenotypes have demonstrated that much larger sample sizes are required to reliably identify significant genetic loci.…”