Reshaping the Motor Engram - An Online Crowdsourcing Study.

Not Applicable

Completed

• Conditions: Healthy Volunteers
• Interventions: Behavioral: No interference; Behavioral: Interference through learning of a competing motor skill.

• Registration Number: NCT05511480
• Lead Sponsor: Medical University of South Carolina

Brief Summary

A critical point in learning and memory research is whether memories, once consolidated, remain unchanged or whether they continue to undergo plastic changes and remodeling. While previous research has focused on experimental destabilization during early stages of the memory life cycle, i.e., during encoding or early consolidation, experimental data that provides information about the effect of destabilization interventions on well-consolidated memories is still missing. This is particularly true for the procedural memory domain, such as learning a sensorimotor skill. This project is designed to characterize the effect of a single behavioral interference intervention on a previously consolidated sensorimotor skill in a large sample of healthy volunteers recruited through an online crowdsourcing platform. In a longitudinal design, participants will perform an implicit sequence learning task over five consecutive sessions, followed by an interference intervention in session six and a follow-up evaluation of the stability of the learned skill in session seven. The experimental design includes two levels of sequential information (spatial and temporal), which allows the testing of the specificity of the interference intervention. Behavioral performance throughout the experimental sessions is acquired via the manual input on the participants' computer keyboards and used to extract the learning rate and the interference effect (primary outcome).

Detailed Description

Not available

Study Timeline

• Study Start: 2022-08-01
• Study First Submitted: 2022-08-11
• Study First Submitted QC: 2022-08-22
• Study First Posted: 2022-08-23
• Primary Completion: 2023-06-30
• Study Completion: 2023-06-30
• Status Verified: 2023-08
• Last Update Submitted: 2023-08-14
• Last Update Posted: 2023-08-16

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 404

Inclusion Criteria

• registered Amazon Mechanical Turk users (called 'workers')
• with >95% approval rate on all previous Amazon Mechanical Turk assignments
• location in North America or Europe
• ≥18 years of age
• not having participated in this experiment before

Exclusion Criteria

• prior participation in this experiment

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
No interference	No interference	The interference intervention (session six) will be applied.
Interference on sequences 1 and 2	Interference through learning of a competing motor skill.	The interference intervention (session six) will be applied to both of the two previously learned sequences (temporal and spatial).
Interference on sequence 1	Interference through learning of a competing motor skill.	The interference intervention (session six) will be applied to one of the two previously learned sequences (temporal).
Interference on sequence 2	Interference through learning of a competing motor skill.	The interference intervention (session six) will be applied to one of the two previously learned sequences (spatial).

Primary Outcome Measures

Name	Time	Method
Delayed interference rate (change in performance precision)	seven days	The delayed interference rate is calculated in analogy to the immediate interference effects with a 24-hours latency of the post-interference measure. Delayed interference is analyzed based on the change in performance from before the interference intervention (pre-interference in session six) to 24 hours after the interference intervention in session seven (24hours post-interference). This change is normalized to the performance at baseline (pre-interference session six) and computed as \[(24 hours post-interference - pre-interference)/pre-interference\*100\].
Immediate interference rate (change in performance precision)	six days	Performance in the learning task is derived from the precision of timing of key presses relative to the occurrence and duration of visual cues presented on the computer screen. The interference rate is operationalized as the change in performance precision over time.; The immediate interference effect is analyzed based on the change in performance from before (pre-interference) the interference intervention to directly after the interference intervention in session six (post-interference). This change is normalized to the performance at baseline (pre-interference session six) and computed as \[(post-interference - pre-interference)/pre-interference\*100\].

Secondary Outcome Measures

Name	Time	Method
Learning rate (change in performance precision)	five days	Skill learning is defined based on the precision of timing of key presses relative to the occurrence and duration of visual cues presented on the computer screen. Skill learning is indexed by increased precision over time, operationalized as declining deviation of key on- and offsets from the timing of cue on- and offsets. Learning rate is the absolute change of precision over the learning phase of five days, which is expected to follow an asymptotic exponential function.

Trial Locations

Locations (1)

Medical University of South Carolina; 🇺🇸 Charleston, South Carolina, United States