RETRACTED: Transcutaneous vagus nerve stimulation (tVNS) enhances response selection during action cascading processes

Supplementation of gamma-aminobutyric acid (GABA) affects temporal, but not spatial visual attention

“…Although evidence of acute effects is limited, GH deficits in patients have been related to impairments in certain cognitive functions (Falleti, Maruff, Burman, & Harris, 2006), suggesting an indirect, alternate route by which orally ingested GABA might act. However, in view of the compatibility with earlier results (Steenbergen et al, 2015a(Steenbergen et al, , 2015b, the present findings do give further credence to the idea that oral ingestion does allow GABA to reach the brain and exert direct effects on cognition, which in the present case were specific to temporal attention. The beneficial nature of these effects furthermore suggests that GABA levels in the brain did not reach a level high enough to become suboptimal through an excess of functional inhibition (Pezze et al, 2014).…”

“…Indeed, it has long been thought that the blood-brain barrier would prevent the uptake of GABA, rendering its consumption ineffective (Van Gelder & Elliott, 1958). Nevertheless, Steenbergen, Sellaro, Stock, Beste, and Colzato (2015b) administered an oral dose of 800 mg GABA to participants, who performed a stop-change paradigm, as in the previously cited study by Steenbergen et al (2015a), and observed enhanced action selection, replicating and extending their previous study.…”

“…Finally, there is also indirect evidence from transcutaneous vagus nerve stimulation that GABA levels modulate the efficiency of response selection (Steenbergen et al, 2015a). Transcutaneous vagus nerve stimulation is a non-invasive experimental technique that triggers the release of the neurotransmitter in the brain (Van Leusden, Sellaro, & Colzato, 2015), and which has been mainly used to treat patients with epilepsy, who suffer from an abnormal reduction in GABA-ergic function (Treiman, 2001).…”

“…However, it is also known to affect a wide range of other physiological mechanisms. Steenbergen et al (2015a) had their participants perform a stop-change action cascading task, in which the speed of changed responses was measured. Stimulation resulted in faster responses than a sham condition, suggesting that response selection was facilitated by increased GABA levels, although it must be noted these were not measured in the study so that the link between performance and GABA levels remains only circumstantially supported.…”

Transcutaneous vagus nerve stimulation (tVNS) modulates flow experience

“…is a short, structured interview of about 15 min that screens for several psychiatric disorders and drug use, and it is often used in clinical and pharmacological research (Colzato et al 2012(Colzato et al , 2013. Following previous published protocols (Colzato et al 2017;Sellaro et al 2015;Steenbergen et al 2015;Beste et al 2016) participants took part in the experiment only if they met the following criteria: (1) age between 18 and 30 years; (2) no history of neurological or psychiatric disorders; (3) no history of substance abuse or dependence; (4) no history of brain surgery, tumors, or intracranial metal implantation; (5) no chronic or acute medications; (6) no pregnancy; (7) no susceptibility to seizures or migraine; (8) no pacemaker or other implanted devices. All participants never experienced tVNS before this study.…”