| williams_et_al_spr_2018.pdf |
ABSTRACT:
Without a doubt, we have all experienced times in which our minds operate automatically, and other instances in which we must put forth considerable effort in order to prosper within our environment. These two modes of thinking are broadly classified as System 1 and System 2, respectively. Seminal work by Kahneman and colleagues (1968) manipulated these by having participants retain four digits in one condition (add-zero condition, System 1) and add one to each of the four digits in another condition (add-one condition, System 2). They concluded that increased pupil size in the difficult condition was analogous to increased processing load. Although at the time pupillometry was the leading technology, advances in neuroimaging have opened the way to more direct measures of brain activity and underlying cognitive mechanisms. Here, we sought to replicate these findings and incorporate electroencephalographic measures to explore the underlying mechanisms that drive System 1 and System 2 thinking. Indeed, we confirmed the results of Kahneman and colleagues (1968) in that pupil dilation was larger for the add-one condition in comparison to the add-zero condition. Furthermore, we found frontal theta – a frequency component theorized to reflect cognitive control – to be enlarged and parietal alpha – a frequency component inversely associated with attentional mechanisms – to be reduced in the add-one condition relative to the add-zero condition. These findings indicate that cognitive control and attention are two core neurocognitive mechanisms underlying System 1 and System 2.
