The fact that people usually correctly remember where they were when they learned of the september 11th, 2001, attacks but are less exact about what they were doing or who told them, leads researchers to believe that although not completely reliable, contain "substantial kernels of accuracy."

flashbulb memories

Explanation:

The idea that people typically recall accurately where they were actaully when they heard about September 11, 2001, attacks but are less precise about what they were doing or telling them, leads experts to conclude that flashbulb memories, though not fully reliable, contain "substantial kernels of accuracy."

A flashbulb memory is a finely detailed, extraordinarily detailed ' snapshot ' of the instant and circumstances where a piece of shocking (or emotionally exciting) news has been received.