Neural mechanisms of error correction during manual interception of moving targets

Project Summary Sensorimotor impairment is common after stroke. Sensorimotor impairment can degrade quality of life by limiting simple acts like reaching to catch a child's hand.

This project is based on the premise that the individualization of therapeutic intervention needed to optimize motor function after neuromotor injury is predicated on an understanding how healthy brains integrate sensory, motor, and cognitive functioning to control movement.

Our project focuses on reaching to moving objects using a cued manual interception task because interception underlies many activities of daily life in an unpredictable environment. People and objects do not always move as expected, making mid-movement error corrections critical for success.

Our project will advance a fundamental understanding of how the brain adjusts ongoing actions to correct performance errors that arise mid-movement.

We focus on neurologically intact people as a foundational step toward our long-term goal, which is to develop and test intervention strategies to address the impact of each patient's neural injury on spatiotemporal and dynamic aspects of error correction in everyday activities.

Cued manual interception affords ideal experimental control over the timing of events giving rise to movement and error.

Our innovative project exploits the precision motion and measurement abilities of a rehabilitation robot, the fine temporal resolution of electroencephalography (EEG), and a highly multidisciplinary team to advance understanding of the behavioral and neural basis of mid-movement error correction during manual interception.

We will characterize behavioral and neural responses to three different sources of error: inherent errors in the selection and execution of action, unpredictable target motion, and unpredictable environmental dynamics resisting hand motion.

Error correction is significant to study because it enables success in everyday tasks, particularly when things do not go as initially planned. We will conduct human subjects experiments that will address two specific aims. Neurologically-intact people will hold the handle of a planar robot while trying to catch a moving visual target.

Infrequently, at reach onset target speed will increase or the robot will render an unexpected change to the hand's load.

Analysis of behavioral data (Aim 1) will determine the dynamics of behavioral corrections in response to target interception errors.

We hypothesize that response latencies reflect differences in information processing required to correct errors arising from the three different error sources.

Analysis of EEG data (Aim 2) will identify patterns of neural activity and functional connectivity leading to error corrections in response to target interception errors.

We hypothesize that neural correlates of error correction reflect differences in the type and timing of information processing required to compensate for the three sources of error.

If successful, this R21 project will lead to new knowledge about the spatiotemporal patterns of neural activity in response to errors that arise when reaching toward moving targets.

This project will also identify neural circuits contributing to the initiation of movement, to the on-line detection of performance errors, and to the generation of corrective actions in response to those errors.

Advancing understanding of mid-movement error correction will facilitate the development of therapeutic interventions designed to enhance functional movement and quality of life in patients with neuromotor injury.