A new study challenged the assumption that deep-brain stimulation (DBS) benefits movement symptoms but has limited impact on cognition in Parkinson’s disease. Researchers reported that tuning DBS to the brain’s theta rhythm improved cognitive performance in Parkinson’s patients with cognitive impairments. The work adds an electrophysiology-specific angle, focusing on the timing and frequency of stimulation rather than DBS as a general platform. For clinical research teams, the study suggests that cognitive endpoints may be sensitive to stimulation parameter selection, including oscillatory targets tied to attention and memory networks. The results may influence how future trials design comparator arms and whether they stratify patients by baseline cognitive profiles.