The reason for the blurriness of memories with age has been revealed

Memory doesn't disappear with age — it "blurs": scientists have uncovered the mechanism that causes the brain to confuse details of the past. It turns out it's not about forgetting — the brain simply stops accurately "replaying" individual events and begins lumping them into general, overlapping categories. The results of the study were published in the journal Cerebral Cortex (CC).

The hippocampus is responsible for storing episodic memories — memories of specific events in our lives. Every time we recall something, it re-activates the same neural connection chains that were formed at the moment of encoding. It is precisely disruptions in this delicate mechanism of "replay," as scientists hypothesized, that make older people's memories fuzzy.

A research team led by Ian McDonough from Binghamton University recruited 61 volunteers from three age groups for the experiment: 17 young participants (18–30 years old), 21 middle-aged individuals (50–60 years old), and 23 older adults (61–74 years old). The subjects memorized pairs of faces while their brain activity was recorded using functional MRI — during the encoding, rest, and recall phases.

The results proved quite revealing. In young people, the overlap of neural patterns during encoding and recall clearly predicted response accuracy. In older adults, the picture was reversed: the brain "recognized" the general type of face but hopelessly confused the details. The numbers speak for themselves — young participants correctly identified pairs in 36% of cases, while older adults managed only 20%. At the same time, differences in brain function accounted for approximately 30% of the age-related memory decline.

As the authors explain, memories don't get "erased" over the years — the brain simply begins storing them in a more generalized form, losing specifics. Understanding this mechanism opens the door to developing methods for maintaining memory precision in old age — for example, specialized training exercises that teach the brain to better distinguish between similar events.

At the same time, the scientists emphasize an important nuance: generalizing experience in itself is not a defect at all. The ability to extract common patterns from numerous events helps us make decisions. The problem arises only when the balance shifts too far toward blurred categories with age, and specific details begin to slip away. The researchers hope that the data obtained will help draw the line between normal age-related memory "generalization" and early warning signs of dementia.