Brain wave patterns and memory ^{CEFR B1}

The study recorded electrical activity across the brain in patients who were preparing for surgery to treat severe, drug-resistant epilepsy. Doctors implanted electrodes during the presurgical period to help find the brain region that caused seizures while patients stayed in hospital and did memory tests.

One memory task, called a treasure hunt, tested spatial memory in a video-game-like environment where patients learned and later recalled object locations. In a second task, patients memorized sequences of English letters and then tried to recall them.

Each implanted electrode covered about 1 square centimetre of brain surface and could detect activity in up to 1 million brain cells. Anup Das, a postdoctoral fellow in Joshua Jacobs' lab, analysed the electrode signals and identified several clear wave patterns, such as straight lines, spirals, outward sources and inward sinks.

Patterns varied between individuals, but each person showed consistent patterns. The team could decode behaviour from wave shape about 70% of the time, compared with a 50% chance level. G. Bard Ermentrout noted that brain activity is organised into various types of waves, and features like wave direction and strength affected memory performance. Joshua Jacobs said next steps include building models and testing brain stimulation to strengthen helpful waves; the study appears in Nature Communications.