Neural pattern change during encoding of a narrative predicts retrospective duration estimates

Life’s episodes unfold against a context that changes with time. Recent neuroimaging studies have revealed significant findings about how specific areas of the human brain may support the representation of temporal information in memory. A consistent theme in these studies is that the hippocampus appears to play a central role in representing temporal context, as operationalized in neuroimaging studies of arbitrary lists of items, sequences of items, or meaningful, lifelike events. Additionally, activity in a posterior medial cortical network may reflect the representation of generalized temporal information for meaningful events. The hippocampus, posterior medial network, and other regions—particularly in prefrontal cortex—appear to play complementary roles in memory for temporal context.

Section: Consistent Themes and Questions For Future Researchmentioning

confidence: 88%

Section: Consistent Themes and Questions For Future Researchmentioning

confidence: 99%

Time regained: how the human brain constructs memory for time

Cohn‐Sheehy

Ranganath

2017

“…Like sequential integration [5], these apparent time distortions in memory were linked to greater hippocampal pattern stability during encoding, with more stability relating to judgments of closer temporal proximity [27]. More recent neuroimaging evidence showed that retrospective judgments of time duration were associated with reduced entorhinal cortex pattern similarity between two clips during encoding [51]. …”

Section: Temporal Drift As a Mode Of Event Separationmentioning

confidence: 99%

The ebb and flow of experience determines the temporal structure of memory

Clewett

Davachi

2017

Everyday life consists of a continuous stream of information, yet somehow we remember the past as distinct episodic events. Prominent models posit that event segmentation is driven by erroneous predictions about how current experiences are unfolding. Yet this perspective fails to explain how memories become integrated or separated in the absence of prior knowledge. Here, we propose that contextual stability dictates the temporal organization of events in episodic memory. To support this view, we summarize new findings showing that neural measures of event organization index how ongoing changes in external contextual cues and internal representations of time influence different forms of episodic memory.

“…Furthermore, the degree to which neural activity patterns change across events has been associated with memory for temporal order and distance [16–19]. Critically, this relationship has been observed in the same regions that show slow drift [20*,21]. A link between slow drift and spontaneous organization of memory was recently established in an fMRI study that tracked lingering activation of recently-experienced items [22].…”

Section: Evidence For Slow Passive Contextual Driftmentioning

confidence: 99%

Does mental context drift or shift?

DuBrow

Rouhani

Niv

et al. 2017

Self Cite

Theories of episodic memory have generally proposed that individual memory traces are linked together by a representation of context that drifts slowly over time. Recent data challenge the notion that contextual drift is always slow and passive. In particular, changes in one’s external environment or internal model induce discontinuities in memory that are reflected in sudden changes in neural activity, suggesting that context can shift abruptly. Furthermore, context change effects are sensitive to top-down goals, suggesting that contextual drift may be an active process. These findings call for revising models of the role of context in memory, in order to account for abrupt contextual shifts and the controllable nature of context change.