Serial Position Effect: Buffer Timeline & Recall Curve

This 2D simulator reproduces the classic U-shaped serial position curve from free-recall memory research through a scrolling buffer-occupancy timeline rather than a 3D bar scene. A study list of words enters a limited-capacity rehearsal buffer one item at a time; the timeline draws every tick's buffer contents as colored tiles, so you can watch exactly when each item gets bumped out and see why items that stay resident longest build stronger long-term memory traces — the mechanistic root of the primacy effect. The line chart beneath the timeline reveals the independently computed recall-probability curve, including the textbook finding that a recall delay wipes out recency while leaving primacy intact.