Clinical trial NCT06257433: InformationSeekingMesolimbicEngagementStudy2
Official title: The Influence of Mesolimbic-hippocampal Interactions on Episodic Memory During Active Information Seeking
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Motivation
Lead sponsor: Temple University
Sponsor class: OTHER
First posted: 2024-02-14
Enrollment: 80
Sex: ALL
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: BASIC_SCIENCE

Brief summary: Participants will complete a treasure task during neuroimaging where they have to learn which keys open a treasure chest, and then they are tested on the contents of the treasure chest.

Detailed description: Study 2 will use a treasure task (employed in C.2.1.1), in which participants select amongst 3 keys to learn which feature of keys unlocks the treasure chest, revealing a trial unique object image (Fig. 8b). On each encoding trial participants view three multi-featural keys and a treasure chest. Each key varies on three dimensions: color (red, blue, yellow), shape of the handle (square, circle, triangle), and number of ridges (one, two, three). On each trial, all 9 dimensions of the keys are represented, but the dimensions represented on each key are randomized across trials. During hypothesis testing runs, participants are instructed to find the feature of a key that opens the treasure chest to reveal a trial-unique image. Critically, there is one target feature of a key that deterministically opens the treasure chest. The target feature of the key randomly changes after participants successfully open the chest 4 consecutive times. This design manipulates goal-oriented exploration by allowing participants to resolve uncertainty until they identify the target feature of the key. Uncertainty resolution is the greatest after the target features switches and incrementally reduces via individuals' active hypothesis testing. During control runs, participants will be instructed to select specific keys, and key selection and outcomes will be yolked to prior hypothesis testing runs. Participants will complete 3 runs of hypothesis testing runs and 3 control runs. Trial number for each run is determined by participant behavior, in that hypothesis testing runs end when participants complete 4 rule switches (\~30 trials). Encoding is incidental in this task. Following encoding, participants will complete an immediate and delayed item memory test. On each trial, participants will view objects from the hypothesis testing and control conditions as well as new foil objects. Memory will be tested for half the stimuli immediately and at a 24-hour delay. These memory measures will be related to uncertainty resolution estimated by reinforcement learning, to determine how prior knowledge during information seeking has subsequent effects on memory.

Eligibility criteria: Inclusion Criteria:

* 20/40 far acuity (either corrected or uncorrected)
* In good medical health

Exclusion Criteria:

* History of head injury
* History of illness with Central Nervous Systems implications
* On Medications that Affect blood flow response and alertness
* Consumption of smoking and/or coffee 30 minutes prior to laboratory testing
* Placement of a device contraindicated for magnetic resonance imaging including cardia pacemaker, aneurysm clip, cochlear implants, pregnancy, intra-uterine device, shrapnel, metal fragments in the eyes, neurostimulators
* Weight \> 250lbs
* Claustrophobia

Primary outcomes:
measure: Mesolimbic Hippocampal Interactions
timeFrame: During Procedure
measure: Episodic Memory
timeFrame: 24-hours After Procedure
Secondary outcomes:
Other outcomes:
Locations:
city: Philadelphia
country: United States
facility: Temple University
state: Pennsylvania
Study officials:
References: