The Impact of Escalating Cognitive Workload on Novice Surgeon's Brain Activation

This study aimed to characterize neural activation in novice surgical residents with increasing cognitive load and its association with performance.

Evaluating the impact of cognitive load on surgical performance is crucial for training and patient safety. Excessive workload can lead to "cognitive overload," impairing performance. Prior work links overload in senior residents to deactivation in the prefrontal cortex, associated with attention and concentration, but neurocognitive responses in novice surgical residents remain unclear.

Twenty novice surgeons performed a suturing task under 3 conditions: self-paced (SP), time-pressured (TP), and time and cognitive stress (CS). Functional near-infrared spectroscopy (fNIRS) recorded activation across the prefrontal and premotor cortices. Suturing performance was assessed with a validated score, subjective cognitive load with the SURG-TLX questionnaire, and physiological stress with heart rate variability (HRV).

Subjective cognitive load increased significantly with task complexity (P<0.00001), while suturing performance declined (P<0.00001). HRV did not differ significantly between tasks (P=0.5905). Neural activation increased in the dorsolateral prefrontal cortex (DLPFC), premotor cortex (PMC), and supplementary motor area (SMA) with escalating load. Left DLFPC activation increased in "maintainers" who preserved performance (HbO2.Ch20= 10.8, P=0.005) but attenuated in "decliners" with performance deterioration (HHbCh21=6.4, P=0.041). Frontal PFC deactivation was greater in decliners (SP: ∆HHbCh57P=0.048; ∆HHbCh57P=0.011).

The DLPFC supports planning and attention, the frontal PFC multitasking, and PMC/SMA motor preparation. These findings contribute to our understanding of cognitive overload resilience in early surgical training and provide a foundation for informing safer surgical training.