To investigate the causal involvement of the ralPFC in the offset of fear (study 1) and SSRT (study 2) by temporally inhibiting this area using transcranial magnetic stimulation (TMS).
ID
Source
Brief title
Condition
- Anxiety disorders and symptoms
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The main study parameter for study 1 is the effect of TMS stimulation on the
reduction in FPS at offset of a threat cue, for study 2 the increase in SSRT
(behaviourally) and concomitant decrease of N1 (derived from the EEG).
Secondary outcome
N/A.
Background summary
Previous research has indicated that offset of a threat cue is associated with
rapid decrement of fear as indexed by fear-potentiated startle (FPS). With
functional magnetic resonance imaging (fMRI), corresponding activation of an
area of the right anterolateral prefrontal cortex (ralPFC) was demonstrated.
This protocol investigates whether activity in this area is necessary for the
fast inhibition of an ongoing fear reaction (study 1; N = 28). If findings from
study 1 support the involvement of the ralPFC in inhibition of fear, a
subsequent study will be performed to investigate whether activity in the
ralPFC is also necessary for inhibition of behaviour as observed in the stop
signal reaction time task (SSRT, study 2; N = 28). This allows to investigate
the extent to which inhibition of fear may be related to inhibition of
behaviour. However, if study 1 does not provide support for involvement of the
ralPFC in inhibition of fear, this rationale for study 2 would not hold. In
that case, study 2 will be reconsidered and the METC will be consulted again.
Study objective
To investigate the causal involvement of the ralPFC in the offset of fear
(study 1) and SSRT (study 2) by temporally inhibiting this area using
transcranial magnetic stimulation (TMS).
Study design
Single-blind cross-over intervention with active and control sites.
Intervention
Participants visit the laboratory on two separate days, and receive 40 sec.
slow-repetitive TMS stimulation at 70% of the motor threshold to the right side
of their forehead on one of the days, and control stimulation on the other day.
Study burden and risks
The burden consists of participating in two test days that take approximately 2
hours each, undergoing TMS stimulation and the fear-potentiated startle test
(study 1) and SSRT with EEG measurements (study 2). All research procedures are
well-validated and with careful screening of subjects for TMS exclusion
criteria represents a very minimal risk. The stimulation combined with the
tasks and measurements consists of a moderate burden for research participants.
Participants are adult, mentally able healthy volunteers who give informed
consent and are compensated for their time investment.
Heidelberglaan 1
Utrecht 3584 CS
NL
Heidelberglaan 1
Utrecht 3584 CS
NL
Listed location countries
Age
Inclusion criteria
- Age between 18 and 45.
- Right-handedness.
- Written informed consent.
Exclusion criteria
Violation of standard TMS safety criteria (Rossi, Hallett, Rossini, & Pascual-Leone, 2009; see also Appendix F1.1: TMS screenings questionnaire):
- Incapability of giving an informed consent
- Ferrous objects in or around the head (e.g. braces, pacemaker, metal fragments)
- History of closed- or open-head injury
- History of epilepsy
- History of epilepsy in first-degree relatives
- History of neurological or psychiatric illness
- Major medical history
- Drug or alcohol abuse over a period of six months prior to the experiment
- Pregnancy
Design
Recruitment
Medical products/devices used
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL60815.041.17 |