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Space and time are both essential aspects of human episodic memory. Yet, behavioral studies into the dynamics of recall have focused more on time than space. For instance, it is now well known that temporally contiguous events are more likely to be subsequently recalled than temporally remote events, as measured by the lag-conditional response probability (lag-CRP), which represents the probability of recalling item i + lag after recalling item i. The present study administered both verbal and spatial delayed free recall (DFR) tasks to a sample of 168 participants in order to measure lag-CRPs along both spatial and temporal associative dimensions. Whereas only the temporal lag-CRP could be measured in the verbal DFR task, both temporal and spatial lag-CRPs could be measured in the spatial DFR task. As expected, the results obtained in the verbal DFR task indicated the typical temporal contiguity effect. More importantly, the results obtained in the spatial DFR task indicated significant contiguity effects along both associative dimensions, and the spatial contiguity effect was found to be significantly larger than the temporal contiguity effect. In addition, the relatively small temporal contiguity effect observed in the spatial DFR task was also found to be significantly smaller than the temporal contiguity effect observed in the verbal DFR task. Altogether, the present findings provided novel evidence that spatial and temporal proximity can both cue sequential dependencies between successive recalls. As such, retrieved context models of episodic memory should be expanded to include spatial context as well as temporal context.

Time is usually conceived of in terms of space: many natural languages refer to time according to a back-to-front axis. Indeed, whereas the past is usually conceived to be “behind us”, the future is considered to be “in front of us.” Despite temporal coding is pivotal for the development of autonoetic consciousness, little is known about the organization of autobiographical memories along this axis. Here we developed a spatial compatibility task (SCT) to test the organization of autobiographical memories along the sagittal plane, using spatiotemporal interference. Twenty-one participants were asked to recall both episodic and semantic autobiographical memories (EAM and SAM, respectively) to be used in the SCT. Then, during the SCT, they were asked to decide whether each event occurred before or after the event presented right before, using a response code that could be compatible with the back-to-front axis (future in front) or not (future at back). We found that performance was significantly worse during the non-compatible condition, especially for EAM. The results are discussed in light of the evidence for spatiotemporal encoding of episodic autobiographical memories, taking into account possible mechanisms explaining compatibility effects. Supplementary Information The online version contains supplementary material available at 10.3758/s13423-021-01906-z.

Increasing evidence indicates that the subjective experience of recollection is diminished in autism spectrum disorder (ASD) compared to neurotypical individuals. The neurocognitive basis of this difference in how past events are re-experienced has been debated and various theoretical accounts have been proposed to date. Although each existing theory may capture particular features of memory in ASD, recent research questions whether any of these explanations are alone sufficient or indeed fully supported. This review first briefly considers the cognitive neuroscience of how episodic recollection operates in the neurotypical population, informing predictions about the encoding and retrieval mechanisms that might function atypically in ASD. We then review existing research on recollection in ASD, which has often not distinguished between different theoretical explanations. Recent evidence suggests a distinct difficulty engaging recollective retrieval processes, specifically the ability to consciously reconstruct and monitor a past experience, which is likely underpinned by altered functional interactions between neurocognitive systems rather than brain region-specific or process-specific dysfunction. This integrative approach serves to highlight how memory research in ASD may enhance our understanding of memory processes and networks in the typical brain. We make suggestions for future research that are important for further specifying the neurocognitive basis of episodic recollection in ASD and linking such difficulties to social developmental and educational outcomes.

The mental context in which we experience an event plays a fundamental role in how we organize our memories of an event (e.g. in relation to other events) and, in turn, how we retrieve those memories later. Because we use contextual representations to retrieve information pertaining to our past, processes that alter our representations of context can enhance or diminish our capacity to retrieve particular memories. We designed a functional magnetic resonance imaging (fMRI) experiment to test the hypothesis that people can intentionally forget previously experienced events by changing their mental representations of contextual information associated with those events. We had human participants study two lists of words, manipulating whether they were told to forget (or remember) the first list prior to studying the second list. We used pattern classifiers to track neural patterns that reflected contextual information associated with the first list and found that, consistent with the notion of contextual change, the activation of the first-list contextual representation was lower following a forget instruction than a remember instruction. Further, the magnitude of this neural signature of contextual change was negatively correlated with participants’ abilities to later recall items from the first list.