While psychological factors are dominant, some biological theories also explore connections. For example, some researchers have looked at how our brain's metabolism or the speed at which our neurons fire might change with age. One idea suggests that a child's brain processes images and information more quickly, meaning they 'see' more frames per second, so to speak, making a given period of time feel longer. As we age, if this processing slows down, we might perceive fewer 'frames' in the same actual duration. However, these biological explanations are less widely accepted as the primary driver compared to the strong cognitive and memory-based theories, and they are still largely speculative.