The primary objective is to influence amygdala and ventral striatum neuronal activity, thereby changing their influence on consequent approach/avoidance decisions, as indicated with left or right button presses.
ID
Source
Brief title
Condition
- Anxiety disorders and symptoms
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Approach/avoidance choice behaviour as indicated by index-finger button-press
will be used to assess the neuromodulatory effects of TUS.
Secondary outcome
Pupil size; Heart rate.
These secondary study parameters fall under the blanket approval for standard
research (CMO2014/288, version 3; titled: *Imaging Human Cognition*).
Background summary
Avoidance behaviour is one of the key predictive factors in maintaining
pervasive emotional disorders such as anxiety. Previous studies have shown that
the Amygdalae are important regions involved in threat-assessment and
consequent avoidance when people make approach or avoid decisions based on
predicted reward or punishment. Disruption or ablation of the amygdala in
animal models results in reduced avoidance and increased approach behaviour,
allowing animals to gain rewards even in the presence of threat.
Theoretically,being able to disrupt amygdala activity might provide a way to
reduce avoidance biases in patients with anxiety-related disorders,allowing
them to benefit from exposure treatment. Until recently, the only way to
influence deep neural structures such as the amygdala was to open the skull and
insert a deep-brain electrode. However, newly developed Transcranial focused
Ultrasound Stimulation (TUS) can target and modulate neural activity in deep
structures such as the amygdala non invasively, potentially providing a safe
way to efficiently reduce threat avoidance. The current study is aimed at
manipulating approach/avoidance behaviour through modulation of amygdala and
ventral striatum, a neural region associated with reward processing, whilst
participants make approach/avoid decisions based on threat (electrical shocks)
and reward information (monetary bonusses).
Transcranial Ultrasonic Stimulation (TUS) is a non-invasive neuromodulation
technique that can achieve focal modulation of deep brain structures such as
the amygdala. Here, we will combine TUS with a well-validated decision making
paradigm allowing us to test whether amygdala/striatal balance is causally
related to approach/avoidance decision making. The outcomes of this study can
provide a first stepping-stone for the development of TUS based interventions
aimed at reducing anxiety disorders.
Study objective
The primary objective is to influence amygdala and ventral striatum neuronal
activity, thereby changing their influence on consequent approach/avoidance
decisions, as indicated with left or right button presses.
Study design
This study consists of three experimental sessions in a single-blind,
randomized, sham-controlled trial. In the first session, a structural MRI scan
will be obtained, followed by a behavioural approach/avoidance (AA) task. The
second and third sessions are intervention sessions where TUS will be applied,
aimed at bilateral ventral striatum or amygdalae in a counterbalanced fashion,
whilst participants perform the same AA task.
Intervention
Transcranial Ultrasound Stimulation aimed at bilateral amygdalae and ventral
striatum (in separate sessions).
Study burden and risks
Participants will receive no direct benefit from participating, though they
often report enjoying their participation and the opportunity to experience MRI
and TUS. Participants will receive a standard financial compensation where
applicable (¤10/hour). Before participation, all subjects will be screened for
contraindications with respect to non-invasive brain stimulation and MRI. The
estimated risk for participating in MRI measurements and TUS-based
interventions is minimal. The noise and the relative confined space of the MRI
scanner, and the requirement to remain seated during the TUS experiment, may
cause discomfort to some subjects. TUS for human neuromodulation has never
resulted in serious adverse events (Blackmore et al., 2019; Pasquinelli et al.,
2019). Similar to applications of well-established biomedical ultrasound (ter
Haar, 2010), safety of study participants is ensured by adherence to
internationally recognized practices and guidelines (e.g., from the Food and
Drug Administration). Minor side effects of TUS may include light transient
headache and fatigue (Legon et al., 2020). To conclude, the risk and burden
associated with participation is considered minimal, and we do not expect any
(serious) adverse events during the project.
kapittelweg 29
Nijmegen 6525EN
NL
kapittelweg 29
Nijmegen 6525EN
NL
Listed location countries
Age
Inclusion criteria
- Healthy participants between 18-40 years of age;
- The ability and agreement to provide informed consent, and the ability to
fulfil the study's requirements.
Exclusion criteria
•Under 18 years of age
•Current or planned pregnancy
•Claustrophobia
•A history or brain surgery or serious head trauma
•A history of or any close relatives (parents, siblings, children) with
epilepsy, convulsion, or seizure
•Predisposition for fainting spells (syncope)
•A cardiac pacemaker or intra-cardiac lines
•An implanted neurostimulator
•Implanted medication infusion device
•Implanted metal devices or large ferromagnetic fragments in the head or upper
body (excluding dental wire),or jewellery/piercing that cannot be removed
•Use of a medical plaster that cannot or may not be taken off (e.g., nicotine
plaster)
•Cochlear implants
•Metal in the brain, skull, or elsewhere in your body (fragments, clips, etc.)
•Diagnosed neurological or psychiatric disorders
•Use of psychoactive (prescription) medication (excluding anti-conception)
•Skin disease at intended stimulation sites
•The consumption of more than four alcoholic units within 24 hours before
participation or any recreational drugs within 48 hours before participation
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 | NL81177.091.22 |