Effects of transcranial direct current stimulation on risky decision making are mediated by ‘hot’ and ‘cold’ decisions, personality, and hemisphere

Abstract

Previous results point towards a lateralization of dorsolateral prefrontal cortex (DLPFC) function in risky decision making. While the right hemisphere seems involved in inhibitory cognitive control of affective impulses, the left DLPFC is crucial in the deliberative processing of information relevant for the decision. However, a lack of empirical evidence precludes definitive conclusions. The aim of our study was to determine whether anodal transcranial direct current stimulation (tDCS) over the right DLPFC with cathodal tDCS over the lDLPFC (anodal right/cathodal left) or vice versa (anodal left/cathodal right) differentially modulates risk-taking in a task [the Columbia Card Task (CCT)] specifically engaging affect-charged (Hot CCT) vs. deliberative (Cold CCT) decision making. The facilitating effect of the anodal stimulation on neuronal activity was emphasized by the use of a small anode and a big cathode. To investigate the role of individual differences in risk-taking, participants were either smokers or non-smokers. Anodal left/cathodal right stimulation decreased risk-taking in the 'cold' cognition version of the task, in both groups, probably by modulating deliberative processing. In the 'hot' version, anodal right/cathodal left stimulation led to opposite effects in smokers and non-smokers, which might be explained by the engagement of the same inhibitory control mechanism: in smokers, improved controllability of risk-seeking impulsivity led to more conservative decisions, while inhibition of risk-aversion in non-smokers resulted in riskier choices. These results provide evidence for a hemispheric asymmetry and personality-dependent tDCS effects in risky decision making, and may be important for clinical research on addiction and depression.

Pilot study of feasibility of the effect of treatment with tDCS in patients suffering from treatment-resistant depression treated with escitalopram

“…Previous works reported an acute cognitive effects following the first tDCS session on attentional performance and information processing suggesting that multiple tDCS sessions do not have cumulative cognitive enhancing effects independent of mood effects (Boggio et al, 2007;Loo et al, 2012). In healthy volunteers, prior studies addressing the potential lingering cognitive effects of online tDCS observed enhancement of cortical activity and improvements in cognitive functions but the interaction of stimulation polarity, cognitive domain and other intra-and interindividual variables such as genetic factors (Plewnia et al, 2013), personality (Peña-Gómez et al, 2011;Pripfl et al, 2013) or cognitive strategy (Berryhill and Jones, 2012) is still largely unexplored and need translational exploration in neuropsychiatric populations.…”

Exploring prefrontal cortex functions in healthy humans by transcranial electrical stimulation

“…The results of a related study conducted by Pripfl and coworkers [55] show different effects of tDCS in risky decisionmaking dependent on the inclusion of emotional content and smoking state, which hints at the impact of task characteristics and personality factors on informationprocessing in the prefrontal cortex. In another risk-taking task, however, the same electrode arrangement did not modulate risky behavior, but enhanced confidence in the decision, which shows that evaluative aspects of a decision are also under prefrontal control [56] .…”

Enhancing decision-making and cognitive impulse control with transcranial direct current stimulation (tDCS) applied over the orbitofrontal cortex (OFC): A randomized and sham-controlled exploratory study

“…Because of its neural effects, tDCS has been increasingly used to gauge the functional relationship between cognitive/behavioural dimensions and putatively relevant neurocircuitry (Coffman et al, 2014;Jacobson et al, 2012). For example, anodal tDCS applied to the dorsolateral prefrontal cortex (DLPFC) of healthy volunteers has been reported to not only enhance planning abilities (Dockery et al, 2009), working memory (Zaehle et al, 2011) and attention (Stone and Tesche, 2009), but to also decrease correlates of impulsivity and risk-taking behaviour (Fecteau et al, 2007;Pripfl et al, 2013). However, despite the extensive evidence relating the activity of the OFC to decisionmaking and cognitive impulse control, no study to date has assessed whether non-invasive brain stimulation techniques applied over this brain region are able to modulate these two key neurocognitive dimensions.…”