Clinical trial NCT03197181: Frontopolar Cortex and Motivation in Healthy Older Adults
Official title: Causal Role of Frontopolar Cortex for Motivation in Healthy Older Adults: a Transcranial Direct Current Stimulation Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Motivation in Healthy Older Adults
Lead sponsor: University of Zurich
Sponsor class: OTHER
First posted: 2017-06-23
Enrollment: 26
Sex: ALL
Minimum age (years): 65
Maximum age (years): 80
Standard ages: OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: In two separate sessions, participants receive either anodal or sham transcranial direct current stimulation while the participants are performing a decision-making task on the computer.
Primary purpose: BASIC_SCIENCE

Brief summary: Motivation represents a core aspect of goal-directed behavior as it determines how much effort individuals are willing to invest to reach their goals. While research on effort-based decision-making focuses mainly on effort preferences in younger adults, loss of motivation might be a key component of the apathetic tendencies frequently seen in older adults. However, an open question refers to which brain mechanisms underlie motivational processes in older adults. The investigators have recently shown that the frontopolar cortex plays a crucial in motivating the exertion of rewarded effort in younger adults. The goal of the current study is to determine whether frontopolar cortex plays a crucial role for motivation also in older adults and may thus be a promising target for improving the motivation deficits in healthy aging. Participants perform computer-based experimental tasks measuring the propensity to exert cognitive or physical effort for monetary rewards. During task performance, participants receive anodal or sham transcranial direct current stimulation (tDCS) over their frontopolar cortex. The study tests whether tDCS over frontopolar cortex allows modulating participants' motivation to engage in rewarded effort.

Detailed description: Motivation represents a core aspect of goal-directed behavior as it determines how much effort individuals are willing to invest to reach their goals. While research on effort-based decision-making focuses mainly on effort preferences in younger adults, loss of motivation might be a key component of the apathetic tendencies frequently seen in older adults. However, an open question refers to which brain mechanisms underlie motivational processes in older adults. The investigators have recently shown that the frontopolar cortex plays a crucial in motivating the exertion of rewarded effort in younger adults (Soutschek et al., 2018, Biological Psychiatry). The goal of the current study is to determine whether frontopolar cortex plays a crucial role for motivation also in older adults and may thus be a promising target for improving the motivation deficits in healthy aging. 30 older participants (65-80 years) perform computer-based experimental tasks measuring the propensity to exert cognitive or physical effort for monetary rewards. During task performance, participants receive 1 mA anodal or sham transcranial direct current stimulation (tDCS) over their frontopolar cortex. The study tests whether tDCS over frontopolar cortex allows modulating participants' motivation to engage in rewarded effort.

Eligibility criteria: Inclusion Criteria:

* Age 65-80 years
* Informed consent as documented by signature
* Normal or corrected-to-normal vision
* Cognitive and language ability to understand study content and procedure
* Normal cognitive functioning (assessed by MMST)
* BDI-II score \< 20

Exclusion Criteria:

* Negative response to TMS/tDCS in past
* History of seizure
* History of stroke or heart attack
* History of head injury
* Psychiatric or neurological disorder
* Metal in body/head
* Implanted medical products like pacemaker, medical pumps, heart catheter
* Headache
* Tinnitus
* Currently taking medication affecting the central nervous system
* Insufficient sleep in preceding night
* Excessive consumption of alcohol within last 24 hours

Primary outcomes:
measure: participants' decisions to exert cognitive or physical effort for monetary rewards
timeFrame: All participants perform this decision-making task in both experimental sessions (i.e., both the anodal and the sham stimulation session) for 20 min while receiving anodal or sham stimulation.
Secondary outcomes:
Other outcomes:
Locations:
city: Zürich
country: Switzerland
facility: University of Zurich
Study officials:
affiliation: University of Zurich
name: Philippe N Tobler, Prof.
role: PRINCIPAL_INVESTIGATOR
References: