ABSTRACT
Creativity pervades many areas of everyday life and is considered highly relevant in several human living domains. Previous literature suggests that the posterior parietal cortex (PPC) is related to creativity. However, none of previous studies have compared the effect of transcranial random noise stimulation (tRNS) over bilateral PPC on both verbal and visual divergent thinking (DT) and Remote Associates Test (RAT) in the same experimental design. Forty healthy participants were randomly assigned to tRNS (100-500 Hz) over bilateral PPC or sham group, for 15 min and current was set at 1.5 mA. Participants' creativity skills were assessed before and after brain stimulation with the Unusual Uses and the Picture Completion subtests from the Torrance Test of Creative Thinking and the RAT. ANCOVA (baseline scores as covariate) results indicated that tRNS group had significantly higher scores at post-test in RAT and visual originality compared to sham group. Unusual Uses, on the other hand, was not significant. Improvement in RAT suggests the involvement of PPC during via insight solution which may reflect internally directed attention that helps the recombination of remotely associated information. The improvement in visual originality dimension from DT may be due to a higher internally directed attention while reducing externally oriented attention.
Subject(s)
Cognition/physiology , Parietal Lobe/physiology , Thinking/radiation effects , Transcranial Direct Current Stimulation/adverse effects , Adult , Attention/physiology , Attention/radiation effects , Cognition/radiation effects , Creativity , Female , Healthy Volunteers , Humans , Male , Neuropsychological Tests , Parietal Lobe/radiation effects , Young AdultABSTRACT
The present studies evaluated to what extent duration (all-night or 4-hour exposures) and timing of nocturnal bright light (BL) (beginning or end of the night) modulate effects on vigilance. The results showed that all-night BL exposure is able to alleviate the nocturnal decrements in alertness and performance. However, under certain circumstances, this continuous BL exposure may induce adverse effects on mood and finally reveal to be counterproductive. Shorter BL exposure (4 h) during nighttime helps improve mood and performance, although the effects of short BL pulses were less efficacious than all-night BL exposure. The latter part of the night appears the best time for using the alerting effect of BL. The immediate alerting effect of BL seems to be mediated by a global activation of the central nervous system.
