Summary Episodic memory retrieval is thought to involve reinstatement of the neurocognitive processes engaged when an episode was encoded. Prior fMRI studies and computational models have suggested that reinstatement is limited to instances in which specific episodic details are recollected. We used multi-voxel pattern-classification analyses of fMRI data to investigate how reinstatement is associated with different memory judgments, particularly those accompanied by recollection versus a feeling of familiarity (when recollection is absent). Classifiers were trained to distinguish between brain activity patterns associated with different encoding tasks, and were subsequently applied to recognition-related fMRI data to determine the degree to which patterns were reinstated. Reinstatement was evident during both recollection- and familiarity-based judgments, providing clear evidence that reinstatement is not sufficient for eliciting a recollective experience. The findings are interpreted as support for a continuous, recollection-related neural signal that has been central to recent debate over the nature of recognition memory processes.

It has been proposed that a core network of brain regions, including the hippocampus, supports both past remembering and future imagining. We investigated the importance of the hippocampus for these functions. Five patients with bilateral hippocampal damage and one patient with large medial temporal lobe lesions were tested for their ability to recount autobiographical episodes from the remote past, the recent past, and to imagine plausible episodes in the near future. The patients with hippocampal damage had intact remote autobiographical memory, modestly impaired recent memory, and an intact ability to imagine the future. The patient with large medial temporal lobe lesions had intact remote memory, markedly impaired recent memory, and also had an intact ability to imagine the future. The findings suggest that the capacity for imagining the future, like the capacity for remembering the remote past, is independent of the hippocampus.episodic memory | semantic memory | medial temporal lobe | remote memory | amnesia B ilateral damage to medial temporal lobe structures impairs the formation of new memories and also impairs recall of facts, events, and autobiographical experiences that were acquired during the years before the damage occurred (1, 2). This finding suggests that common mechanisms may underlie the ability to form new memories and the ability to recollect recent memories. There has also been interest in the possible link between remembering past experiences and imagining plausible episodes in the future (3). It was noted, for example, that the memory-impaired patient KC was impaired at generating autobiographical details about his past and also could not imagine future autobiographical episodes (4, 5). A link between past remembering and future imagining has received additional support from other patient studies. Thus, the densely amnesic patient DB had difficulty imagining future episodes (6). Similarly, four of five memory-impaired patients with lesions involving the hippocampus were reported to have difficulty constructing future autobiographical scenarios (7). Moreover, elderly individuals who provided fewer specific details about the recent past also provided fewer specific details about the future (8). Last, patients with mild Alzheimer's disease were impaired at providing autobiographical details about both past and future events (9).Consistent with these observations, neuroimaging studies have described substantial overlap between the brain regions activated when volunteers retrieve past memories and when they imagine future experiences (e.g., refs. 10-14). Schacter et al. (14) suggested that a core network of brain regions supports past remembering and future imagining. The key components of this network are proposed to be the medial prefrontal cortex, posterior regions in medial and lateral parietal cortex, lateral temporal cortex, and the medial temporal lobe including hippocampus (14,15).Within this network, the importance of the hippocampus and related medial temporal lobe structures for f...

We used multivoxel pattern analysis (MVPA) of functional MRI (fMRI) data to gain insight into how subjects' retrieval agendas influence source memory judgments (was item X studied using source Y?). In Experiment 1, we used a single-agenda test where subjects judged whether items were studied with the targeted source or not. In Experiment 2, we used a multiagenda test where subjects judged whether items were studied using the targeted source, studied using a different source, or nonstudied. To evaluate the differences between singleand multiagenda source monitoring, we trained a classifier to detect source-specific fMRI activity at study, and then we applied the classifier to data from the test phase. We focused on trials where the targeted source and the actual source differed, so we could use MVPA to track neural activity associated with both the targeted source and the actual source. Our results indicate that single-agenda monitoring was associated with increased focus on the targeted source (as evidenced by increased targeted-source activity, relative to baseline) and reduced use of information relating to the actual, nontarget source. In the multiagenda experiment, high levels of actual-source activity were associated with increased correct rejections, suggesting that subjects were using recollection of actual-source information to avoid source memory errors. In the single-agenda experiment, there were comparable levels of actual-source activity (suggesting that recollection was taking place), but the relationship between actual-source activity and behavior was absent (suggesting that subjects were failing to make proper use of this information).

The time-course for lymphedema development depends on breast cancer treatment received. ALND is associated with early-onset lymphedema, and RLNR is associated with late-onset lymphedema. These results can influence clinical practice to guide lymphedema surveillance strategies and patient education.