Memory justifications remain reliable over time, BGU study finds

BEER-SHEVA, Israel, January 20, 2026 – While memories may fade with time, the explanations people give for why they remember an event remain surprisingly stable and reliable, according to a new study by Ben-Gurion University of the Negev.

The research shows that when a memory is successfully retrieved, the verbal justification supporting it remains rich, detailed, and consistent—even after a delay of 24 hours. The findings were published in Communications Psychology (https://doi.org/10.1038/s44271-025-00378-4).

The study was led by Dr. Talya Sadeh, together with doctoral researchers Avi Gamoran and Zohar Raz Groman, from the Department of Cognitive and Brain Sciences at Ben-Gurion University of the Negev. The team examined memory justifications—the explanations people provide for why a remembered event truly occurred.

Memory justifications play a critical social role. When people share memories, the justifications they offer are used by others to assess credibility, including in contexts such as testimony, investigations, and professional reporting.

To examine how time affects these justifications, the researchers studied 421 participants aged 18–35, who completed memory recall tasks after short (90 seconds) and long (24 hours) delays. More than 4,000 written memory justifications were collected and analyzed using both linguistic and behavioral methods.

As expected, participants remembered significantly fewer items after a one-day delay. However, for items that were successfully remembered, the content of the justifications showed remarkable stability. The level of detail, vocabulary use, and structure of the explanations remained almost identical across both time points.

“When memory was retrieved, its justification stayed rich and well-organized,” said Raz Groman. “Time reduced access to memory, but not the quality of the explanation when recall succeeded.”

The only change observed over time was a slight increase in hedging language—such as words expressing uncertainty—but this shift affected expression rather than the memory content itself. Importantly, linguistic analysis showed that justification content predicted memory credibility better than participants’ self-reported confidence.

The findings support an “all-or-nothing” model of forgetting: either a memory is retrieved along with a stable justification, or it is not retrieved at all.

“Our results suggest that memory justifications provide a temporally stable window into episodic memory,” said Dr. Sadeh. “In legal or forensic contexts, where testimony often relies on delayed recall, encouraging written justifications may offer a more reliable basis for evaluating memory credibility than confidence alone.”

The study was supported by the Israel Science Foundation (ISF) (Grant Nos. 1324/23 and 2055/22).