The use of a wearable camera improves autobiographical memory in patients with Alzheimer's disease

Despite the marked impairment of recent episodic memories in Alzheimer's disease, there have been few attempts to rehabilitate these deficits. We used a novel external memory aid to promote recall of episodic memories in patients with mild to moderate Alzheimer's disease. SenseCam, a small wearable camera, recorded significant events in the lives of six Alzheimer's disease patients. Every two days for two weeks each patient's memory for an event was assessed, followed by a structured review of the SenseCam images. Longer-term recall was tested one and three months later. A written diary control condition followed the same procedure. Across 40 events the SenseCam review method resulted in significantly more details of an event being recalled over two weeks than the written diary method in five out of the six patients. At three months post event, four out of five patients (one had dropped out) recalled significantly more details of events in the SenseCam condition while the other patient showed no significant difference. Viewing SenseCam images of personally experienced events may significantly improve autobiographical memory in patients with even moderate Alzheimer's disease.     

SenseCam improves memory for recent events and quality of life in a patient with memory retrieval difficulties

A wearable camera that takes pictures automatically, SenseCam, was used to generate images for rehearsal, promoting consolidation and retrieval of memories for significant events in a patient with memory retrieval deficits. SenseCam images of recent events were systematically reviewed over a 2-week period. Memory for these events was assessed throughout and longer-term recall was tested up to 6 months later. A written diary control condition followed the same procedure. The SenseCam review procedure resulted in significantly more details of an event being recalled, with twice as many details recalled at 6 months follow up compared to the written diary method. Self-report measures suggested autobiographical recollection was triggered by the SenseCam condition but not by reviewing the written diary. Emotional and social wellbeing questionnaires indicated improved confidence and decreased anxiety as a result of memory rehearsal using SenseCam images. We propose that SenseCam images provide a powerful boost to autobiographical recall, with secondary benefits for quality of life.     

Exploring the basis and boundary conditions of SenseCam-facilitated recollection

SenseCam review has been shown to promote and sustain subsequent access to memories that might otherwise remain inaccessible. While SenseCam review facilitates recollection for personally experienced events, we know little about the boundary conditions under which this operates and about how underlying processing mechanisms can be optimally recruited to offset memory impairments of the sort that occur in dementia. This paper considers some of these issues with a view to targeting future research that not only clarifies our evolving body of theory about how memory works, but also informs about how memory-assistive technologies for patients might be employed to maximal effect. We begin by outlining key factors that are known to influence recollection. We then examine variability in the decline of memory function both in normal ageing and in dementia. Attention is drawn to similarities in the recollection deficits associated with depression and dementia, and we suggest that this may reflect shared underlying mechanisms. We conclude by discussing how one particular theoretical rationale can be intersected with key SenseCam capabilities to define priorities for ongoing and future SenseCam research.     

Supporting older and younger adults’ memory for recent everyday events: A prospective sampling study using SenseCam

This study measured the effect of a wearable camera, SenseCam, on older and younger adults’ memories of recently experienced everyday events. Participants used SenseCam to prospectively sample events from a typical week, which they recalled two weeks later. Recall was cued by a self-generated title only (control condition), by the title and forward-order SenseCam images, or by the title and random-order SenseCam images. In the control condition, older and younger adults’ memories were comparably episodic, but older adults recalled more semantic details. Both forward- and random-order SenseCam images were associated with increased episodic and semantic recall in both groups, and there was a small but significant effect of temporal order favouring the forward-order condition. These findings suggest that SenseCam is effective in supporting retrieval of memory for recent events, and the results of the temporal order manipulation also shed light on the mechanism of SenseCam’s effect.     

SenseCam reminiscence and action recall in memory-unimpaired people

Case studies of memory-impaired individuals consistently show that reminiscing with SenseCam images enhances event recall. This exploratory study examined whether a similar benefit would occur for the consolidation of memories in memory-unimpaired people. We tested delayed recall for atypical actions observed on a lengthy walk. Participants used SenseCam, a diary, or no external memory aid while walking, followed by reminiscence with SenseCam images, diary entries, or no aid, either alone (self-reminiscence) or with the experimenter (social reminiscence). One week later, when tested without SenseCam images or diary entries, prior social reminiscence produced greater recall than self-reminiscence, but there were no differences between memory aid conditions for action free recall or action order recall. When methodological variables were controlled, there was no recall advantage for SenseCam reminiscence with memory-unimpaired participants. The case studies and present study differ in multiple ways, making direct comparisons problematic. SenseCam is a valuable aid to the memory impaired, but its mnemonic value for non-clinical populations remains to be determined.     

Gender differences in autobiographical memory for everyday events: retrieval elicited by SenseCam images versus verbal cues

Gender differences are frequently observed in autobiographical memory (AM). However, few studies have investigated the neural basis of potential gender differences in AM. In the present functional MRI (fMRI) study we investigated gender differences in AMs elicited using dynamic visual images vs verbal cues. We used a novel technology called a SenseCam, a wearable device that automatically takes thousands of photographs. SenseCam differs considerably from other prospective methods of generating retrieval cues because it does not disrupt the ongoing experience. This allowed us to control for potential gender differences in emotional processing and elaborative rehearsal, while manipulating how the AMs were elicited. We predicted that males would retrieve more richly experienced AMs elicited by the SenseCam images vs the verbal cues, whereas females would show equal sensitivity to both cues. The behavioural results indicated that there were no gender differences in subjective ratings of reliving, importance, vividness, emotion, and uniqueness, suggesting that gender differences in brain activity were not due to differences in these measures of phenomenological experience. Consistent with our predictions, the fMRI results revealed that males showed a greater difference in functional activity associated with the rich experience of SenseCam vs verbal cues, than did females.     

The neural correlates of everyday recognition memory

We used a novel automatic camera, SenseCam, to create a recognition memory test for real-life events. Adapting a 'Remember/Know' paradigm, we asked healthy undergraduates, who wore SenseCam for 2 days, in their everyday environments, to classify images as strongly or weakly remembered, strongly or weakly familiar or novel, while brain activation was recorded with functional MRI. Overlapping, widely distributed sets of brain regions were activated by recollected and familiar stimuli. Within the medial temporal lobes, 'Remember' responses specifically elicited greater activity in the right anterior and posterior parahippocampal gyrus than 'Know' responses. 'New' responses activated anterior parahippocampal regions. A parametric analysis, across correctly recognised items, revealed increasing activation in the right hippocampus and posterior parahippocampal gyrus (pPHG). This may reflect modulation of these regions by the degree of recollection or, alternatively, by increasing memory strength. Strong recollection elicited greater activity in the left posterior hippocampus/pPHG than weak recollection indicating that this region is specifically modulated by the degree of recollection.     

SenseCam, imagery and bias in memory for wellbeing

Identifying and modifying the negative interpretation bias that characterises depression is central to successful treatment. While accumulating evidence indicates that mental imagery is particularly effective in the modification of emotional bias, this research typically incorporates static and unrelated ambiguous stimuli. SenseCam technology, and the resulting video-like footage, offers an opportunity to produce training stimuli that are dynamic and self-relevant. Here participants experienced several ambiguous tasks and subsequently viewed SenseCam footage of the same tasks, paired with negative or positive captions. Participants were trained to use mental imagery to inter-relate SenseCam footage and captions. Participants reported increased levels of happy mood, reduced levels of sad mood, and increased task enjoyment following SenseCam review with positive versus negative captions. This shift in emotional bias was also evident at 24-hour follow-up, as participants recollected greater task enjoyment for those tasks previously paired with positive captions. Mental imagery appears to play an important role in this process. These preliminary results indicate that in healthy volunteers, SenseCam can be used within a bias modification paradigm to shift mood and memory for wellbeing associated with performing everyday activities. Further refinements are necessary before similar methods can be applied to individuals suffering from subclinical and clinical depression.     

An fMRI study of long-term everyday memory using SenseCam

We used a novel automatic camera, SenseCam, to investigate recognition memory for real-life events at a 5-month retention interval. Using fMRI we assessed recollection and familiarity memory using the remember/know procedure. Recollection evoked no medial temporal lobe (MTL) activation compared to familiarity and new responses. Instead, recollection activated diverse regions in neocortex including medial prefrontal cortex. We observed decreased activation in anterior hippocampus/ anterior parahippocampal gyrus (aPHG) at 5 months compared to a 36-hour retention interval. Familiarity was associated with greater activation in aPHG and posterior parahippocampal gyrus (pPHG) than recollection and new responses. Familiarity activation decreased over time in anterior hippocampus/aPHG and posterior hippocampus/pPHG. The engagement of neocortical regions such as medial prefrontal cortex at a 5-month delay, together with the reduced MTL activation at 5 months relative to at 36 hours is in line with the assumptions of Consolidation theory. SenseCam provides a valuable technique for assessing the processes that underlie remote everyday recognition memory.     

依恋差异对自传记忆加工的影响

自传记忆是个体对过去生活事件的记忆, 是自我系统形成、发展和变化的基础, 对维持自我同一性和连续性具有重要意义。自传记忆的形成是一个建构过程, 依恋可能通过概念性自我系统和工作自我目标系统两种途径影响自传记忆的加工。依恋与自传记忆加工的已有研究主要集中于个体依恋特征及亲代依恋特征分别与自传记忆客观性特征、现象学特征、叙事特征及重构特征之间的关系。未来研究应聚焦依恋影响自传记忆加工的心理和神经机制, 增加不同社会文化情境、不同发展阶段亲代依恋特征和子代自传记忆加工的相关研究, 并使用启动范式、静息态成像技术、感知相机等变量控制更加严格、更具生态效度的研究方法。     

Passive imaging technology in aphasia therapy

We describe a brief pilot study undertaken to investigate the potential benefit(s) of using a SenseCam in aphasia therapy. Five post-stroke persons with aphasia and their caregivers agreed to participate. Each person with aphasia wore the SenseCam for 1 day during the daytime. Slide shows and printed images were created from the images obtained and presented at a (videotaped) weekly group conversation session. Therapists' observations, reflections, and opinions were subsequently elicited in a group interview and online survey. Wearable, sensor-triggered automatic imaging devices offer potential advantages over both conventional cameras and generic pictures when used in aphasia therapy. We identified three advantages of a SenseCam over conventional imaging methods: Images can be acquired without the presence of the researcher, no action is required by the wearer for image acquisition and the continuous point of view is that of the wearer. Acquired images are of personal relevance to the wearer and may have greater efficacy for the person with aphasia in aiding conversation, and for the speech language therapist in setting functional language goals.     

Using SenseCam with an amnesic patient: accessing inaccessible everyday memories

Forgetting is a normal and everyday occurrence that may sometimes reflect a complete loss of the mnemonic record or a failure to encode it in the first place. However, on many occasions with the help of cues we can eventually or suddenly recall a memory that seemed to be lost, thus highlighting the probability that many instances of "forgetting" may in fact reflect inaccessibility rather than true loss. We report here on our amnesic patient CR who presents an extreme example of this normal everyday forgetting. For 4 weeks, CR recorded regular personal autobiographical events both on a SenseCam (henceforth SC) and in a written diary form. Subjective and objective aspects of recall were measured each weekend both without any cues and then with either a SC or diary cue. We show that the SC enabled CR to recall significantly more detailed episodic memories than reading the diary and importantly we observed that the qualitative nature of these memories was different. We comment on the considerable potential of SC for therapeutic purposes.     

Disturbed memory and amnesia related to intensive care

Patients, when admitted to an intensive care unit (ICU), have one thing in common: their illness is life-threatening. Patients may remain on ICU in a critical condition, needing support with their breathing, circulation, and/or kidneys for varying lengths of time, from days to weeks. During that time the patients will receive sedative and analgesic drugs to ensure compliance with artificial ventilation. Patients recovering from critical illness frequently have little or no recall of their period in ICU, or remember nightmare, hallucinations, or paranoid delusions. The nature, extent and reason for these difficulties, have been under-reported and consequently our purpose was to conduct a review of memory problems experienced by ICU patients. A systematic literature review of computer databases (Medline, PsycLit, and CINAHL) identified 25 relevant papers. In addition, other relevant articles were obtained, citation lists and associated articles retrieved. Due to lack of research on processes underlying memory problems in ICU patients all articles that introduced an insight into possible mechanisms were included in the review. There seem to be two possible processes contributing to memory problems in ICU patients. First the illness and treatment may have a general dampening effect on memory. Delirium and sleep disturbance are both common in ICU patients. Delirium can result in a profound amnesia for the period of confusion. Sleep deprivation exacerbates the confusional state. Slow wave sleep is important for the consolidation of episodic memories. Treatment administered to patients in ICU can have effects on memory. Opiates, benzodiazepines, sedative drugs such as propofol, adrenaline, and corticosteroids can all influence memory. In addition, the withdrawal of drugs, such as benzodiazepines, can cause profound withdrawal reactions, which may contribute to delirium. Second, we hypothesise that there is a process that affects memory negatively for external events but enhances memory for internal events. The physical constraints and social isolation experienced by ICU patients and the life-threatening nature of the illness may increase the experience of hypnagogic hallucinations. Attentional shift during hypnagogic images from external stimuli to internally generated images would explain why ICU patients have such poor recall of external ICU events, but can clearly remember hallucinations and nightmares. Patients describe these memories as being very vivid and this is explored in terms of flashbulb memory formation. The absence of memories for real events on ICU can result in ICU patients remembering paranoid delusions of staff trying to kill them, with little information to reject these vivid memories as unreal. This has implications for patients' future psychological health.     

Disturbed memory and amnesia related to intensive care

Patients, when admitted to an intensive care unit (ICU), have one thing in common: their illness is life-threatening. Patients may remain on ICU in a critical condition, needing support with their breathing, circulation, and/or kidneys for varying lengths of time, from days to weeks. During that time the patients will receive sedative and analgesic drugs to ensure compliance with artificial ventilation. Patients recovering from critical illness frequently have little or no recall of their period in ICU, or remember nightmare, hallucinations, or paranoid delusions. The nature, extent and reason for these difficulties, have been under-reported and consequently our purpose was to conduct a review of memory problems experienced by ICU patients. A systematic literature review of computer databases (Medline, PsycLit, and CINAHL) identified 25 relevant papers. In addition, other relevant articles were obtained, citation lists and associated articles retrieved. Due to lack of research on processes underlying memory problems in ICU patients all articles that introduced an insight into possible mechanisms were included in the review. There seem to be two possible processes contributing to memory problems in ICU patients. First the illness and treatment may have a general dampening effect on memory. Delirium and sleep disturbance are both common in ICU patients. Delirium can result in a profound amnesia for the period of confusion. Sleep deprivation exacerbates the confusional state. Slow wave sleep is important for the consolidation of episodic memories. Treatment administered to patients in ICU can have effects on memory. Opiates, benzodiazepines, sedative drugs such as propofol, adrenaline, and corticosteroids can all influence memory. In addition, the withdrawal of drugs, such as benzodiazepines, can cause profound withdrawal reactions, which may contribute to delirium. Second, we hypothesise that there is a process that affects memory negatively for external events but enhances memory for internal events. The physical constraints and social isolation experienced by ICU patients and the life-threatening nature of the illness may increase the experience of hypnagogic hallucinations. Attentional shift during hypnagogic images from external stimuli to internally generated images would explain why ICU patients have such poor recall of external ICU events, but can clearly remember hallucinations and nightmares. Patients describe these memories as being very vivid and this is explored in terms of flashbulb memory formation. The absence of memories for real events on ICU can result in ICU patients remembering paranoid delusions of staff trying to kill them, with little information to reject these vivid memories as unreal. This has implications for patients' future psychological health.     

The effects of end-of-day picture review and a sensor-based picture capture procedure on autobiographical memory using SenseCam

Emerging "life-logging" technologies have tremendous potential to augment human autobiographical memory by recording and processing vast amounts of information from an individual's experiences. In this experiment undergraduate participants wore a SenseCam, a small, sensor-equipped digital camera, as they went about their normal daily activities for five consecutive days. Pictures were captured either at fixed intervals or as triggered by SenseCam's sensors. On two of five nights, participants watched an end-of-day review of a random subset of pictures captured that day. Participants were tested with a variety of memory measures at intervals of 1, 3, and 8 weeks. The most fruitful of six measures were recognition rating (on a 1-7 scale) and picture-cued recall length. On these tests, end-of-day review enhanced performance relative to no review, while pictures triggered by SenseCam's sensors showed little difference in performance compared to those taken at fixed time intervals. We discuss the promise of SenseCam as a tool for research and for improving autobiographical memory.     

Wearable Cameras Are Useful Tools to Investigate and Remediate Autobiographical Memory Impairment: A Systematic PRISMA Review

Autobiographical memory, central in human cognition and every day functioning, enables past experienced events to be remembered. A variety of disorders affecting autobiographical memory are characterized by the difficulty of retrieving specific detailed memories of past personal events. Owing to the impact of autobiographical memory impairment on patients’ daily life, it is necessary to better understand these deficits and develop relevant methods to improve autobiographical memory. The primary objective of the present systematic PRISMA review was to give an overview of the first empirical evidence of the potential of wearable cameras in autobiographical memory investigation in remediating autobiographical memory impairments. The peer-reviewed literature published since 2004 on the usefulness of wearable cameras in research protocols was explored in 3 databases (PUBMED, PsycINFO, and Google Scholar). Twenty-eight published studies that used a protocol involving wearable camera, either to explore wearable camera functioning and impact on daily life, or to investigate autobiographical memory processing or remediate autobiographical memory impairment, were included. This review analyzed the potential of wearable cameras for 1) investigating autobiographical memory processes in healthy volunteers without memory impairment and in clinical populations, and 2) remediating autobiographical memory in patients with various kinds of memory disorder. Mechanisms to account for the efficacy of wearable cameras are also discussed. The review concludes by discussing certain limitations inherent to using cameras, and new research perspectives. Finally, ethical issues raised by this new technology are considered.     

Enhancement from targets and suppression from cues in fast task-irrelevant perceptual learning

Task-irrelevant perceptual learning (TIPL) refers to the phenomenon where the stimulus features of a subject's task are learned when they are consistently presented at times when behaviorally relevant events occur. In this article, we addressed two points concerning TIPL. First, we address the question, are all behaviorally relevant events equal in their impact on encoding processes? Second, we address the hypothesis that TIPL involves mechanisms of the alerting attentional system. Two experiments of fast-TIPL were conducted in which the attentional state of participants was manipulated by using an alerting cue (visual or auditory) that informed participants of the arrival of an upcoming target. Images were presented with task-related stimuli (cues, targets and distractors) and subjects were tested on their memory of those images. Results indicate that memory for target-paired images was enhanced and cue-paired images were suppressed relative to that of distractor-paired images. The alerting cue increased the ability to recall target-paired images presented after this cue, although this result depended on the proportion of cued trials in a session. These results demonstrate a complex interplay between task-elements and the encoding of stimuli paired with them where both enhancement and suppression of task-paired stimuli can be found depending whether those stimuli are paired with task-targets or cues.     

Memory reactivation and consolidation during sleep

Do our memories remain static during sleep, or do they change? We argue here that memory change is not only a natural result of sleep cognition, but further, that such change constitutes a fundamental characteristic of declarative memories. In general, declarative memories change due to retrieval events at various times after initial learning and due to the formation and elaboration of associations with other memories, including memories formed after the initial learning episode. We propose that declarative memories change both during waking and during sleep, and that such change contributes to enhancing binding of the distinct representational components of some memories, and thus to a gradual process of cross-cortical consolidation. As a result of this special form of consolidation, declarative memories can become more cohesive and also more thoroughly integrated with other stored information. Further benefits of this memory reprocessing can include developing complex networks of interrelated memories, aligning memories with long-term strategies and goals, and generating insights based on novel combinations of memory fragments. A variety of research findings are consistent with the hypothesis that cross-cortical consolidation can progress during sleep, although further support is needed, and we suggest some potentially fruitful research directions. Determining how processing during sleep can facilitate memory storage will be an exciting focus of research in the coming years.The idea that memory storage is supported by events that take place in the brain while a person is sleeping is an idea that is only rarely acknowledged in the neuroscience community. At present, most memory research proceeds with no mention of any influence of sleep on memory. Nonetheless, this hypothesis is gaining empirical support. Research into connections between memory and sleep represents a burgeoning enterprise at the crossroads of traditional memory research and sleep research, an enterprise poised to provide novel insights into the human experience.This article presents some speculations about connections between memory and sleep. We entertain the notion that declarative memories are subject to modification during sleep, and that enduring storage of such memories is systematically influenced by neural events taking place during sleep. Although other types of memory may also be subject to change during sleep (see Maquet et al. 2003), we emphasize declarative memory here.This article also functions as an introduction to the set of papers selected for this special issue of Learning & Memory. These papers together outline portions of the current empirical basis for memory-sleep connections, including research in humans and in nonhuman animals. The findings are tantalizing, and yet there are undoubtedly major gaps in our knowledge about the functions of sleep and about how sleep may be related to memory storage. Future research on this topic is bound to grow in exciting and unpredictable ways. Here, we explore questions about declarative memory and sleep that may serve as a useful guide for such research.