The combined effects of neurostimulation and priming on creative thinking. A preliminary tDCS study on dorsolateral prefrontal cortex

Abstract

The role of prefrontal cortex (PFC) in influencing creative thinking has been investigated by many researchers who, while succeeding in proving an effective involvement of PFC, reported suggestive but sometimes conflicting results. In order to better understand the relationships between creative thinking and brain activation in a more specific area of the PFC, we explored the role of dorsolateral PFC (DLPFC). We devised an experimental protocol using transcranial direct-current stimulation (tDCS). The study was based on a 3 (kind of stimulation: anodal vs. cathodal vs. sham) × 2 (priming: divergent vs. convergent) design. Forty-five healthy adults were randomly assigned to one stimulation condition. Participants’ creativity skills were assessed using the Product Improvement subtest from the Torrance Tests of Creative Thinking (TTCT). After 20 min of tDCS stimulation, participants were presented with visual images of common objects. Half of the participants were instructed to visualize themselves using the object in an unusual way (divergent priming), whereas the other half were asked to visualize themselves while using the object in a common way (convergent priming). Priming was aimed at inducing participants to adopt different attitudes toward the creative task. Afterwards, participants were asked to describe all of the possible uses of the objects that were presented. Participants’ physiological activation was recorded using a biofeedback equipment. Results showed a significant effect of anodal stimulation that enhanced creative performance, but only after divergent priming. Participants showed lower skin temperature values after cathodal stimulation, a finding which is coherent with studies reporting that, when a task is not creative or creative thinking is not prompted, people show lower levels of arousal. Differences in individual levels of creativity as assessed by the Product Improvement test were not influential. The involvement of DLPFC in creativity has been supported, presumably in association to shift of attention modulated by priming.

Inhibitory Control as a Core Process of Creative Problem Solving and Idea Generation from Childhood to Adulthood

“…For example, using noninvasive brain stimulation, Mayseless and Shamay‐Tsoory () reported that decreasing the activity in the left frontal parts of the brain and increasing activity in the right frontal parts of the brain—a brain modulation supposed to reduce cognitive control—have a positive effect on creative ideas production. In sharp contrast with this finding, another noninvasive brain stimulation study reported that a hyperactivation of the prefrontal cortex was beneficial for creative production, suggesting that better cognitive control led to better creative ideas generation (Colombo, Bartesaghi, Simonelli, & Antonietti, ). In a similar vein, numerous studies on clinical disorders associated with inhibitory control deficits suggest that impaired cognitive control might facilitate original associations and stimulate creative ideas generation (see de Souza et al., ).…”

Using Transcranial Direct Current Stimulation to Enhance Creative Cognition: Interactions between Task, Polarity, and Stimulation Site

“…However, pairing the same stimulation design with explicit instructions to visualize using an object in an unusual, relative to its typical, way significantly elevated AUT total creativity scores (Colombo et al, 2015). In line with the findings of Green et al (2017), these results demonstrate that when participants deliberately search for more creative or unusual responses the need for selectivity is amplified.…”

Improvement in creativity after transcranial random noise stimulation (tRNS) over the left dorsolateral prefrontal cortex

“…Additional evidence of verbal convergent thinking improvement after anodal stimulation over the left DLPFC came from the study carried out by Zmigrod et al 15 , who reported significantly better performance in a similar version of the RAT (Compound Remote Associates Task) 16 . Colombo et al 17 additionally found a significant improvement in verbal divergent thinking (alternate uses task), but only after priming on creative thinking. This last finding suggests that stimulation of the left DLPFC may also induce higher divergent thinking scores by asking participants to deliberately search for more unusual answers.…”