Anhedonia
Conditions
Brief summary
The aim of this proposal is to demonstrate that stimulation of different brain regions differently affects the electroencephalographic feature known as the Reward Positivity (RewP).
Detailed description
The aim of this proposal is to demonstrate that stimulation of different brain regions differently affects the electroencephalographic feature known as the Reward Positivity (RewP). The RewP is a sensitive and specific biomarker of reward receipt. This proposal will advance a causal test of the hypothesis that there are two major sources of variance that contribute to this brain response: a dorsal midline contribution to information encoding and a ventral midline contribution that is modulated by affect. Together, these findings will reveal how the RewP acts to blend multiple aspects of value together in the service of motivated learning. The objective of this proposal is to gather pilot data to demonstrate the feasibility of using transcranial magnetic stimulation (TMS) to perturb idiosyncratically-defined (fMRI-based) dorsal or ventral targets in order to causally test the hypothesis that these different sources contribute different types of variance to the RewP. TMS double cone deep coil stimulation should diminish +RPE encoding in the RewP when compared to sham. TMS Figure-8 coil stimulation should diminish affective modulation of RewP amplitude when compared to sham.
Interventions
DEVICETranscranial Magnetic Stimulation
Figure 8 coil stimulation
Sponsors
University of New Mexico
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
SINGLE (Subject)
Intervention model description
Two separate arms of study
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
• Men or women aged 18-30
Exclusion criteria
* Participants unwilling or unable to give informed consent * Presence of other known medical or psychiatric comorbidity that in the investigator's opinion would compromise participation in the study * MEG/MRI contraindications * History of psychosis * Not fluent in English
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Reward Positivity | During intervention | EEG Amplitude 200-400 ms following reward receipt |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| dlPFC Stimulation To stimulate fMRI-informed individualized targets in dlPFC to diminish affective modulation of the RewP. Based on our working hypothesis, TMS Figure-8 coil stimulation should diminish affective modulation of RewP amplitude when compared to sham.
Transcranial Magnetic Stimulation: Figure 8 coil stimulation | 4 |
| dmPFC Stimulation To stimulate individualized targets in dmPFC to alter affective modulation of the RewP. Based on our working hypothesis, TMS Deep Cone stimulation should boost learning-related modulation of RewP amplitude when compared to sham.
Transcranial Magnetic Stimulation: Deep Cone stimulation | 4 |
| Total | 8 |
Baseline characteristics
| Characteristic | dlPFC Stimulation | dmPFC Stimulation | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 4 Participants | 4 Participants | 8 Participants |
| Age, Continuous | 25.75 years STANDARD_DEVIATION 5.12 | 29.75 years STANDARD_DEVIATION 3.77 | 27.75 years STANDARD_DEVIATION 4.68 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 1 Participants | 1 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 4 Participants | 3 Participants | 7 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 1 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 2 Participants | 2 Participants |
| Race (NIH/OMB) White | 3 Participants | 2 Participants | 5 Participants |
| Region of Enrollment United States | 4 Participants | 4 Participants | 8 Participants |
| Sex: Female, Male Female | 3 Participants | 0 Participants | 3 Participants |
| Sex: Female, Male Male | 1 Participants | 4 Participants | 5 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 5 | 0 / 4 |
| other Total, other adverse events | 0 / 5 | 0 / 4 |
| serious Total, serious adverse events | 0 / 5 | 0 / 4 |
Outcome results
Primary
Reward Positivity
EEG Amplitude 200-400 ms following reward receipt
Time frame: During intervention
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| dlPFC Stimulation | Reward Positivity | 2.21 femtoteslas | Standard Deviation 1.24 |
| dmPFC Stimulation | Reward Positivity | .29 femtoteslas | Standard Deviation 1.47 |