title: Behavioral effects of transcranial pulsed current stimulation (tPCS): Speed-accuracy tradeoff in attention switching task.
abstract: Transcranial pulsed current stimulation (tPCS) has been shown to increase inter-hemispheric coherence of brain oscillatory activity, mainly in fronto-temporal regions, leading to enhancement of functional connectivity across neural networks. The question is whether tPCS can modulate behavior significantly. Our aim was to identify the effects of tPCS on paired associative learning task (PALT) and attention switching task (AST), and to further categorize physiological autonomic responses by heart rate variability and electrodermal activity measurements before and after task performance. Thirty healthy volunteers were randomized to receive a single session of sham or active 2mA tPCS stimulation with a random frequency between 1 and 5Hz. We show that active tPCS significantly improved response time in the AST compared to sham stimulation, so that subjects who received active tPCS significantly exhibit decreased switching cost between repeat and switch trials. No differences were found in response accuracy on AST and PALT. No significant changes were observed in physiological parameters. Based on our results, we suggest that tPCS has a more pronounced effect on tasks that require the increase of functional connectivity across pre-existent neural circuitry, rather than on tasks that require the development of new learning circuits or the creation of new connections.
authors: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA; School of Health Sciences, De Montfort University, Leicester, UK.
authors: Leon
authors: L
authors: Morales-Quezada
authors: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA; Neuropsychophysiology Laboratory, CIPsi, School of Psychology, University of Minho, Campus de Gualtar, Braga, Portugal.
authors: Jorge
authors: J
authors: Leite
authors: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA; Neuropsychophysiology Laboratory, CIPsi, School of Psychology, University of Minho, Campus de Gualtar, Braga, Portugal.
authors: Sandra
authors: S
authors: Carvalho
authors: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA.
authors: Laura
authors: L
authors: Castillo-Saavedra
authors: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA; Post Graduate Program, Interactive Process of Organs and Systems, Federal University of Bahia, Salvador, Brazil.
authors: Camila
authors: C
authors: Cosmo
authors: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA. Electronic address: felipe.fregni@ppcr.hms.harvard.edu.
authors: Felipe
authors: F
authors: Fregni
mesh_terms: D000328:Adult; D001288:Attention; D005260:Female; D005712:Galvanic Skin Response; D006339:Heart Rate; D006801:Humans; D007858:Learning; D008297:Male; D011939:Mental Recall; D011897:Random Allocation; D013569:Synapses / Q000502:physiology; D065908:Transcranial Direct Current Stimulation; D055815:Young Adult
keywords: Autonomic responses; Cognitive flexibility, Speed-accuracy tradeoff; tPCS