Clinical trial NCT03148470: Impact of Theta Burst Stimulation Over the Left DLPFC on Language Switching
Official title: Impact of Theta Burst Stimulation Over the Left Dorsolateral Prefrontal Cortex on Language Switching and Cognitive Flexibility
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Languages
Keywords: theta burst stimulation
Language switching
dorsolateral prefrontal cortex
Lead sponsor: University of Fribourg
Sponsor class: OTHER
First posted: 2017-05-11
Enrollment: 41
Sex: ALL
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: FACTORIAL
Primary purpose: BASIC_SCIENCE

Brief summary: The purpose of this study is to investigate whether theta burst stimulation (TBS) over the left dorsolateral prefrontal cortex (DLPFC) influences language switching and cognitive flexibility. The experimental paradigm will assess the impact of inhibitory and excitatory prefrontal stimulation by TBS versus sham-TBS over the DLPFC in healthy bilinguals.

Detailed description: Background:

Clinical observations and neuroimaging studies seem to confirm the role of executive functions and frontal structures in language processing in bilingual subjects.

Repetitive transcranial magnetic stimulation, such as for example theta burst stimulation (TBS), is increasingly being used as a valuable tool for neuroscientists investigating the underlying mechanisms of cognitive functions. Case studies have shown a change in language switching after bilingual patients received repetitive magnetic stimulation to the left DLPFC. However, there is no study investigating the effect of TBS applied to the DLPFC on language switching in healthy participants.

Procedure:

A planned total of 40 unbalanced bilingual participants will be included. Half of the participants will receive inhibitory theta burst stimulation (continuous TBS), the other half excitatory theta burst stimulation (intermittent TBS). After TBS, different language and nonverbal tasks will be performed while an EEG is measured. Before being stimulated, each subject will conduct the same tasks with a sham-TBS as a baseline measure.

Eligibility criteria: Inclusion Criteria:

* L1 (Swiss)German, knowledge of English as a foreign language
* 18-45 years of age
* right-handedness

Exclusion Criteria:

* epilepsy / family history of epilepsy
* brain surgery, traumatic brain injuries
* cardiac pacemaker, metallic objects in the head
* history of neurological diseases or severe psychiatric disorders
* drug use (alcohol, psychoactive medication)
* strong headache
* pregnancy

Primary outcomes:
measure: RTs for Picture Naming With the Factors Language (L1, L2) and Block (Switching, Non-Switching)
timeFrame: Within 30 minutes after intervention
Secondary outcomes:
measure: Nonverbal Switching
timeFrame: Within 30 minutes after intervention
Other outcomes:
Locations:
city: Fribourg
country: Switzerland
facility: Laboratory for Cognitive and Neurological Sciences
Study officials:
affiliation: University of Fribourg
name: Jean-Marie Annoni, Prof. Dr.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Holtzheimer P, Fawaz W, Wilson C, Avery D. Repetitive transcranial magnetic stimulation may induce language switching in bilingual patients. Brain Lang. 2005 Sep;94(3):274-7. doi: 10.1016/j.bandl.2005.01.003.
citation: Lefaucheur JP, Andre-Obadia N, Antal A, Ayache SS, Baeken C, Benninger DH, Cantello RM, Cincotta M, de Carvalho M, De Ridder D, Devanne H, Di Lazzaro V, Filipovic SR, Hummel FC, Jaaskelainen SK, Kimiskidis VK, Koch G, Langguth B, Nyffeler T, Oliviero A, Padberg F, Poulet E, Rossi S, Rossini PM, Rothwell JC, Schonfeldt-Lecuona C, Siebner HR, Slotema CW, Stagg CJ, Valls-Sole J, Ziemann U, Paulus W, Garcia-Larrea L. Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS). Clin Neurophysiol. 2014 Nov;125(11):2150-2206. doi: 10.1016/j.clinph.2014.05.021. Epub 2014 Jun 5.
citation: Nardone R, De Blasi P, Bergmann J, Caleri F, Tezzon F, Ladurner G, Golaszewski S, Trinka E. Theta burst stimulation of dorsolateral prefrontal cortex modulates pathological language switching: A case report. Neurosci Lett. 2011 Jan 10;487(3):378-82. doi: 10.1016/j.neulet.2010.10.060. Epub 2010 Oct 29.