United we fall : All-or-none forgetting of complex episodic events

Do complex event representations fragment over time, or are they instead forgotten in an all-or-none manner? For example, if we met a friend in a café and they gave us a present, do we forget the constituent elements of this event (location, person, and object) independently, or would the whole event be forgotten? Research suggests that item-based memories are forgotten in a fragmented manner. However, we do not know how more complex episodic, event-based memories are forgotten. We assessed both retrieval accuracy and dependency-the statistical association between the retrieval successes of different elements from the same event-for complex events. Across 4 experiments, we show that retrieval dependency is found both immediately after learning and following a 12-hr and 1-week delay. Further, the amount of retrieval dependency after a delay is greater than that predicted by a model of independent forgetting. This dependency was only seen for coherent "closed-loops," where all pairwise associations between locations, people, and objects were encoded. When "open-loops" were learned, where only 2 out of the 3 possible associations were encoded, no dependency was seen immediately after learning or after a delay. Finally, we also provide evidence for higher retention rates for closed-loops than for open-loops. Therefore, closed-loops do not fragment as a function of forgetting and are retained for longer than are open-loops. Our findings suggest that coherent episodic events are not only retrieved, but also forgotten, in an all-or-none manner

Hippocampal theta activity during encoding promotes subsequent associative memory in humans

Analyses scripts associated with "Hippocampal theta activity during encoding promotes subsequent associative memory in humans

Tracking the emergence of location-based spatial representations in human scene-selective cortex

Data, analysis scripts, and statical outputs for an fMRI study assessing viewpoint-independent spatial representations in scene selective regions of the cortex

United we fall: All-or-none forgetting of complex episodic events

Do complex event representations fragment over time or are they, instead, forgotten in an all-or-none manner? For example, if we met a friend in a café and they gave us a present, do we forget the constituent elements of this event (location, person and object) independently, or would the whole event be forgotten as one? Research suggests that item-based memories are forgotten in a fragmented manner. However, we do not know how more complex episodic, ‘event-based’ memories are forgotten. We assessed both retrieval accuracy and dependency – the statistical association between the retrieval successes of different elements from the same event – for complex events. Across 4 experiments, we show that retrieval dependency is found both immediately after learning and following a 12-hour and 1-week delay. Further, the amount of retrieval dependency after a delay is greater than that predicted by a model of independent forgetting. This dependency was only seen for coherent ‘closed-loops’, where all pairwise associations between locations, people and objects were encoded. When ‘open-loops’ were learnt, where only two out of the three possible associations were encoded, no dependency was seen immediately after learning nor after a delay. Finally, we also provide evidence for higher retention rates for closed-loops than open-loops. Therefore, closed-loops do not fragment as a function of forgetting, and are retained for longer than open-loops. Our findings suggest that coherent episodic events are not only retrieved, but also forgotten, in an all-or-none manner

An enduring role for hippocampal pattern completion in addition to an emergent non-hippocampal contribution to holistic episodic retrieval after a 24-hour delay

Data and analyses associated with "A continued but non-necessary role for hippocampal pattern completion in holistic episodic retrieval following consolidation