Focus of Attention Impacts Brain Activity and Connectivity Early After Anterior Cruciate Ligament Reconstruction.

CONTEXT: Individuals who undergo anterior cruciate ligament reconstruction (ACLR) have altered sensorimotor brain activity that can persist for years. Directing an individual's focus of attention (FoA) using instructional cues during rehabilitation and motor control training can impact movement performance, but the direct effects on sensorimotor brain activity and network-level relationships in an ACLR population are less understood. This can have important implications for understanding the neural underpinnings of automatic control processes for direct application to motor learning.

OBJECTIVE

Determine differences in brain activity and patterns of activity when ACLR knee movement is cued using an internal FoA (iFoA) compared with an external FoA (eFoA).

DESIGN

Cross-sectional study.

SETTING

Research laboratory.

PATIENTS OR OTHER

PARTICIPANTS

We recruited 12 participants (7 female, 6.9 ± 1.0 weeks post-ACLR) after primary, unilateral ACLR. Participants performed repeated isometric quadriceps contractions under iFoA and eFoA conditions during functional magnetic resonance imaging scans.

MAIN OUTCOME MEASURES: Brain activity (blood oxygen level-dependent response) from anatomic regions of interest were extracted from move-rest contrasts in each FoA condition, and paired t tests determined differences in activity across conditions. Intranetwork and internetwork connectivity analyses were performed using Multivariate Exploratory Linear Optimized Decomposition into Independent Components Independent Component Analysis. Dual regression and fsl randomise were used to determine differences in network connectivity between iFoA and eFoA conditions.

RESULTS

The eFoA condition elicited greater activity in the precuneus compared with the iFoA condition. The default mode network (DMN) demonstrated greater intranetwork connectivity in the eFoA condition compared with the iFoA condition in the precuneus and lateral occipital cortex.

CONCLUSIONS

Increased precuneus activity may be a favorable adaptation for motor performance, and greater within-DMN connectivity could indicate more optimal network organization to improve motor efficiency and support automation. This suggests that automatic control processes may be facilitated neurologically by an eFoA, reducing the attentional demand to perform basic knee movement after ACLR.