Events are thought to be stored in episodic memory as coherent representations, in which the constituent
elements are bound together so that a cue can trigger reexperience of all elements via pattern completion.
Negative emotional content can strongly influence memory, but opposing theories predict strengthening
or weakening of memory coherence. Across a series of experiments, participants imagined a number of
person-location-object events with half of the events including a negative element (e.g., an injured
person), and memory was tested across all within event associations. We show that the presence of a
negative element reduces memory for associations between event elements, including between neutral
elements encoded after a negative element. The presence of a negative element reduces the coherence
with which a multimodal event is remembered. Our results, supported by a computational model, suggest
that coherent retrieval from neutral events is supported by pattern completion, but that negative content
weakens associative encoding which impairs this process. Our findings have important implications for
understanding the way traumatic events are encoded and support therapeutic strategies aimed at restoring
associations between negative content and its surrounding context