Study: NCT04036630

Intervention type: DEVICE
Group type: EXPERIMENTAL
Intervention: Transcranial alternating current stimulation (tACS)
Description: The main study intervention is tACS stimulation. TACS is a non-invasive brain stimulation (NIBS) techniques that belong to the class of low current transcranial electric stimulation. In contrast to the better known transcranial direct current stimulation (tDCS), the tACS current is not constant, but alternates with a certain frequency.~The aim of the tACS stimulation is to enhance degraded speech comprehension in healthy individuals.~TACS stimulation will be applied over the left ventral motor cortex, with a current intensity of 2mA (peak-to-peak)~The arm will be compared to the tACS sham stimulation condition.

Intervention type: DEVICE
Group type: EXPERIMENTAL
Intervention: Transcranial alternating current stimulation (tACS)
Description: The main study intervention is tACS stimulation. TACS is a non-invasive brain stimulation (NIBS) techniques that belong to the class of low current transcranial electric stimulation. In contrast to the better known transcranial direct current stimulation (tDCS), the tACS current is not constant, but alternates with a certain frequency.~The aim of the tACS stimulation is to enhance degraded speech comprehension in healthy individuals.~TACS stimulation will be applied over the left ventral motor cortex, with a current intensity of 2mA (peak-to-peak)~The arm will be compared to the tACS sham stimulation condition.

Intervention type: DEVICE
Group type: EXPERIMENTAL
Intervention: Transcranial alternating current stimulation (tACS)
Description: The main study intervention is tACS stimulation. TACS is a non-invasive brain stimulation (NIBS) techniques that belong to the class of low current transcranial electric stimulation. In contrast to the better known transcranial direct current stimulation (tDCS), the tACS current is not constant, but alternates with a certain frequency.~The aim of the tACS stimulation is to enhance degraded speech comprehension in healthy individuals.~TACS stimulation will be applied over the left ventral motor cortex, with a current intensity of 2mA (peak-to-peak)~The arm will be compared to the tACS sham stimulation condition.

Intervention type: DEVICE
Group type: EXPERIMENTAL
Intervention: Transcranial alternating current stimulation (tACS)
Description: The main study intervention is tACS stimulation. TACS is a non-invasive brain stimulation (NIBS) techniques that belong to the class of low current transcranial electric stimulation. In contrast to the better known transcranial direct current stimulation (tDCS), the tACS current is not constant, but alternates with a certain frequency.~The aim of the tACS stimulation is to enhance degraded speech comprehension in healthy individuals.~TACS stimulation will be applied over the left ventral motor cortex, with a current intensity of 2mA (peak-to-peak)~The arm will be compared to the tACS sham stimulation condition.

Intervention type: DEVICE
Group type: SHAM_COMPARATOR
Intervention: Transcranial alternating current stimulation (tACS)
Description: The main study intervention is tACS stimulation. TACS is a non-invasive brain stimulation (NIBS) techniques that belong to the class of low current transcranial electric stimulation. In contrast to the better known transcranial direct current stimulation (tDCS), the tACS current is not constant, but alternates with a certain frequency.~The aim of the tACS stimulation is to enhance degraded speech comprehension in healthy individuals.~TACS stimulation will be applied over the left ventral motor cortex, with a current intensity of 2mA (peak-to-peak)~The arm will be compared to the tACS sham stimulation condition.

Intervention type: DEVICE
Group type: SHAM_COMPARATOR
Intervention: Transcranial alternating current stimulation (tACS)
Description: The main study intervention is tACS stimulation. TACS is a non-invasive brain stimulation (NIBS) techniques that belong to the class of low current transcranial electric stimulation. In contrast to the better known transcranial direct current stimulation (tDCS), the tACS current is not constant, but alternates with a certain frequency.~The aim of the tACS stimulation is to enhance degraded speech comprehension in healthy individuals.~TACS stimulation will be applied over the left ventral motor cortex, with a current intensity of 2mA (peak-to-peak)~The arm will be compared to the tACS sham stimulation condition.

Intervention type: DEVICE
Group type: SHAM_COMPARATOR
Intervention: Transcranial alternating current stimulation (tACS)
Description: The main study intervention is tACS stimulation. TACS is a non-invasive brain stimulation (NIBS) techniques that belong to the class of low current transcranial electric stimulation. In contrast to the better known transcranial direct current stimulation (tDCS), the tACS current is not constant, but alternates with a certain frequency.~The aim of the tACS stimulation is to enhance degraded speech comprehension in healthy individuals.~TACS stimulation will be applied over the left ventral motor cortex, with a current intensity of 2mA (peak-to-peak)~The arm will be compared to the tACS sham stimulation condition.

Intervention type: DEVICE
Group type: SHAM_COMPARATOR
Intervention: Transcranial alternating current stimulation (tACS)
Description: The main study intervention is tACS stimulation. TACS is a non-invasive brain stimulation (NIBS) techniques that belong to the class of low current transcranial electric stimulation. In contrast to the better known transcranial direct current stimulation (tDCS), the tACS current is not constant, but alternates with a certain frequency.~The aim of the tACS stimulation is to enhance degraded speech comprehension in healthy individuals.~TACS stimulation will be applied over the left ventral motor cortex, with a current intensity of 2mA (peak-to-peak)~The arm will be compared to the tACS sham stimulation condition.

Intervention type: DEVICE
Group type: ACTIVE_COMPARATOR
Intervention: Transcranial alternating current stimulation (tACS)
Description: The main study intervention is tACS stimulation. TACS is a non-invasive brain stimulation (NIBS) techniques that belong to the class of low current transcranial electric stimulation. In contrast to the better known transcranial direct current stimulation (tDCS), the tACS current is not constant, but alternates with a certain frequency.~The aim of the tACS stimulation is to enhance degraded speech comprehension in healthy individuals.~TACS stimulation will be applied over the left ventral motor cortex, with a current intensity of 2mA (peak-to-peak)~The arm will be compared to the tACS sham stimulation condition.

Intervention type: DEVICE
Group type: EXPERIMENTAL
Intervention: Transcranial magnetic stimulation (TMS) induced motor-evoked potentials (MEPs)
Description: TMS is a technique where a transient magnetic field (or pulse) is used to cause an electric current to flow in a targeted brain area via electromagnetic induction. The pulse causes the rapid and above-threshold depolarisation of cell membranes affected by the current. Therefore, TMS induces a current that elicits action potentials in neurons.~MEPs are electrical potentials recorded from a target muscle after TMS stimulation. In experiment 1, so-called articulatory MEPs will be recorded from participants' lip muscle (orbicularis oris). Articulatory MEPs will be recorded by placing two recording electrodes on the right part of orbicularis oris and a reference electrode on the right temple.

Intervention type: DEVICE
Group type: SHAM_COMPARATOR
Intervention: Transcranial magnetic stimulation (TMS) induced motor-evoked potentials (MEPs)
Description: TMS is a technique where a transient magnetic field (or pulse) is used to cause an electric current to flow in a targeted brain area via electromagnetic induction. The pulse causes the rapid and above-threshold depolarisation of cell membranes affected by the current. Therefore, TMS induces a current that elicits action potentials in neurons.~MEPs are electrical potentials recorded from a target muscle after TMS stimulation. In experiment 1, so-called articulatory MEPs will be recorded from participants' lip muscle (orbicularis oris). Articulatory MEPs will be recorded by placing two recording electrodes on the right part of orbicularis oris and a reference electrode on the right temple.