Excitatory repetitive Transcranial Magnetic Stimulation applied to the right inferior frontal gyrus has no effect on motor or cognitive impulsivity in healthy adults

Abstract

Background: Impulsivity is a multi-faceted concept. It is a crucial feature of many neuropsychiatric disorders. Three subtypes of impulsivity have been identified: motor, temporal, and cognitive impulsivity. Existing evidence suggests that the right inferior frontal gyrus (rIFG) plays a crucial role in impulsivity, and such a role has been elucidated using inhibitory repetitive transcranial magnetic stimulation (rTMS). There is a dearth of studies using excitatory rTMS at the rIFG, an important gap in the literature this study aimed to address.
Methods: Twenty healthy male adults completed a single-blind sham-controlled randomised crossover study aimed at assessing the efficacy of rTMS in the neuromodulation of impulsivity. This involved delivering 10-Hz excitatory rTMS to the rIFG at the intensity of 100% motor threshold with 900 pulses per session. Trait impulsivity was measured at baseline using the Barrett Impulsiveness Scale and UPPS-P Impulsiveness Scale. The Stop
Signal Task (SST) and Information Sampling Task (IST), administered before andafter rTMS sessions, were used as behavioural measures of impulsivity.
Results: No significant changes on any measures from either SST or IST after active rTMS at the rIFG compared to the sham-controlled condition were found.
Conclusions: Excitatory rTMS applied to the rIFG did not have a statistically significant effect on response inhibition and reflective/cognitive impulsivity. Further research is required before drawing firm conclusions. This may involve a larger sample of highly impulsive individuals, a different stimulation site or a different TMS modality such as theta burst stimulation.

Citation

Yang, C., Khalifa, N., & Völlm, B. (2018). Excitatory repetitive Transcranial Magnetic Stimulation applied to the right inferior frontal gyrus has no effect on motor or cognitive impulsivity in healthy adults. Behavioural Brain Research, 347, https://doi.org/10.1016/j.bbr.2018.02.047

• Journal Article Type: Article
• Acceptance Date: Feb 27, 2018
• Online Publication Date: Mar 2, 2018
• Publication Date: Jul 16, 2018
• Deposit Date: Mar 1, 2018
• Publicly Available Date: Mar 3, 2019
• Journal: Behavioural Brain Research
• Print ISSN: 0166-4328
• Electronic ISSN: 1872-7549
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 347
• DOI: https://doi.org/10.1016/j.bbr.2018.02.047
• Public URL: https://nottingham-repository.worktribe.com/output/947034
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0166432817318661