Suffix Effect
A cognitive bias where when trying to hear a list of items to be remembered, which is then followed by an irrelevant item or list (the suffix), the initial list is more challenging to recall.
Origin
The effect was first reported by R. Conrad and A.J. Hull in a 1968 paper, and elaborated in landmark 1969 and 1971 studies by Robert Crowder and John Morton, who proposed the "precategorical acoustic storage" (PAS) model to explain it. They argued that auditory information is held briefly in a pre-linguistic echoic trace — and that the suffix displaces the final list items from that trace. The work challenged prevailing models of working memory by showing that presentation modality — heard versus read — fundamentally shapes how ordered sequences are recalled.