Clinical trial NCT04681391: tDCS, Moral Decision-Making, fMRI
Official title: The Role of Implicit Attitude in the tDCS Modulation on Moral Decision-Making
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Morality
Keywords: tDCS, Moral Decision-Making, Implicit Attitude, fMRI
Lead sponsor: National Yang Ming Chiao Tung University Hospital
Sponsor class: OTHER
First posted: 2020-12-23
Enrollment: 42
Sex: ALL
Minimum age (years): 20
Maximum age (years): 30
Standard ages: ADULT
Observational model: OTHER
Time perspective: OTHER
Sampling method: PROBABILITY_SAMPLE
Study population: Forty-two healthy volunteers (20 male; 22 female) without any history of psychiatry or neurological disorders (e.g., dementia, seizures), head injury, and alcohol or substance abuse, are all ethnic Chinese, right-handed, and aged between 20 to 30 years old (M = 23.476, SD = 2.211). They were recruited via the online survey sent to the student social group of National Yang-Ming University and National Taiwan University. Additionally, the study was approved by National Yang-Ming University Hospital, Yilan, Taiwan (IRB: 2016B008).

Brief summary: Morality is the social rule about appropriateness of the behavior, containing concepts of justice, fairness, and rights. Previous studies suggested that the activation of right temporoparietal junction (rTPJ) should be involved in mental state reasoning in moral cognition. Implicit moral attitude, which reflects people's fundamental beliefs about right and wrong, could be assessed by implicit association test on moral scenarios (mIAT), as indicated by the D scores. According to our previous findings, we postulate that, during moral decision-making, the high D group would have less rTPJ involvement and the low D group would have more. Here we applied tDCS, a non-invasive neuromodulation technique, to modulate cortical excitability in rTPJ.

Based on our postulation, we divided participants into high D and low D group and hypothesized that tDCS over rTPJ would modulate the behavior depending on the group. The results revealed that, in aspect of mIAT, implicit moral attitude could be modulated differently depending on the group via tDCS over rTPJ. In addition, hemodynamic response within rTPJ showed a main effect of tDCS while carrying out the helping behavior. In conclusion, these findings indicated that tDCS over rTPJ could modulate the implicit moral attitude as well as the rTPJ activity during moral action.


Eligibility criteria: Inclusion Criteria:

* healthy volunteers, are all ethnic Chinese, right-handed, and aged between 20 to 30 years old

Exclusion Criteria:

* any history of psychiatry or neurological disorders (e.g., dementia, seizures), head injury, and alcohol or substance abuse

Primary outcomes:
measure: Justice Sensitivity Inventory
timeFrame: 10 minutes
measure: Morality Implicit Association Test
timeFrame: 15 minutes
measure: Moral Action Task
timeFrame: 10 minutes
Secondary outcomes:
measure: Moral Evaluation: Rating of Moral Action Task
timeFrame: 5 minutes
Other outcomes:
Locations:
Study officials:
References:
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