Eyes don't lie: Eye movements differ during covert and overt autobiographical recall.

In everyday life, autobiographical memories are revisited silently (i.e., covert recall) or shared with others (i.e., overt recall), yet most research regarding eye movements and autobiographical recall has focused on overt recall. With that in mind, the aim of the current study was to evaluate eye movements during the retrieval of autobiographical memories (with a focus on emotion), recollected during covert and overt recall. Forty-three participants recalled personal memories out loud and silently, while wearing eye-tracking glasses, and rated these memories in terms of mental imagery and emotional intensity. Analyses showed fewer and longer fixations, fewer and shorter saccades, and fewer blinks during covert recall compared with overt recall. Participants perceived more mental images and had a more intense emotional experience during covert recall. These results are discussed considering cognitive load theories and the various functions of autobiographical recall. We theorize that fewer and longer fixations during covert recall may be due to more intense mental imagery. This study enriches the field of research on eye movements and autobiographical memory by addressing how we retrieve memories silently, a common activity of everyday life. More broadly, our results contribute to building objective tools to measure autobiographical memory, alongside already existing subjective scales.

"I Remember the Fall": Memory of Falls in Older Adults.

OBJECTIVES: While there is a large body of research on falls and their consequences in older adults, little is known about how older adults remember them. We addressed this gap by inviting older adults to remember falls and control memories. METHODS: We analyzed specificity of memories and invited participants to rate emotional valence, mental time travel, visual imagery, importance, and rehearsal, as experienced during retrieval. RESULTS: Although analysis demonstrated no significant differences between memories of falls and control memories regarding specificity, participants rated memories of falls as more negative than control memories. Furthermore, they rated memories of falls as triggering higher mental time travel, higher visual imagery, higher importance, and higher rehearsal than control memories. CONCLUSIONS: The negative emotional valence of memories of falls, as well as their ability to trigger significant levels of mental time travel, visual imagery, importance, and rehearsal, demonstrate how these memories are different from other memories in older adults. CLINICAL IMPLICATIONS: The findings demonstrate how falls can modulate memory of personal events in older adults.

"Look at the future": Maintained fixation impoverishes future thinking.

We evaluated the relationship between eye movements and future thinking. More specifically, we evaluated whether maintained fixation could influence cognitive characteristics of future thinking. We invited participants to imagine future events in two conditions: while freely exploring a white wall and while fixating a cross on the wall. Results demonstrated fewer and longer fixations, as well as fewer and shorter saccades during maintained fixation condition than in the free gaze condition. Shorter total amplitude of saccades was also observed during the maintained fixation condition than during the free-gaze condition. Regarding the cognitive characteristics of future thinking, fewer spatiotemporal details and less visual imagery, slower retrieval time, and shorter descriptions were observed for future thinking during maintained fixation than during free-gaze condition. These results demonstrate that maintaining fixation results in an effortful construction of future scenarios. We suggest that maintained fixation limits the cognitive resources that are required for future thinking.

The "Sickness" Memory: Can Patients With Alzheimer Disease Remember the Diagnosis Announcement?

BACKGROUND: Diagnosis of Alzheimer disease (AD) can cause substantial psychological distress in patients. We thus assessed how patients with AD remember the announcement of diagnosis. METHODS: We recruited 47 participants with mild AD (26 women; M age=68.89 y, SD=7.37; M years of formal education=9.74, SD=3.00). We invited the participants to remember the moment when their clinicians announced their diagnosis, within 6 months of the event, as well as a control memory, over the same period. We analyzed memory retrieval regarding specificity, as well as the subjective experience of retrieval (ie, regarding mental time travel, visual imagery, emotion and importance). RESULTS: No significant differences were observed between memory of diagnosis and control memory regarding specificity, mental time travel and visual imagery. However, memory of diagnosis triggered a more intense emotional experience and feeling of importance than control memory. DISCUSSION: Retrieval of the diagnosis announcement can activate a strong emotional and personally important experience in patients with AD. When remembering the diagnosis announcement, patients with AD may re-experience some features of that turning point in which they shift from "person" to "patient."

The image of memory: relationship between autobiographical memory and mental imagery in Korsakoff syndrome.

We evaluated the relationship between autobiographical memory and mental imagery in Korsakoff syndrome (KS). We invited patients with KS and control participants to retrieve personal events and to perform measures of visual imagery (Taller/Wilder task), and spatial imagery (Clock Angles task). On the Taller/Wilder task, participants had to generate a mental image of an object presented as a word and determine whether the object was taller than it was wide. On the Clock Angles task, participants had to imagine the angle created by the hands on a clock set to a certain time and determine whether that angle was <90°. Analyses showed impaired spatial imagery and autobiographical memory but intact visual imagery in KS. Analyses also demonstrated significant correlations between visual imagery, spatial imagery and autobiographical memory in patients with KS and control participants. Our findings demonstrate that autobiographical retrieval in KS is associated with the ability to retrieve (visual imagery) and manipulate mental images (spatial imagery).

The eyes of the past: larger pupil size for autobiographical memories retrieved from field perspective.

BACKGROUND: Visual perspective during memory retrieval has mainly been evaluated with methodologies based on introspection and subjective reports. The current study investigates whether visual perspective can be evaluated with a physiological measurement: pupil dilation. METHODS: While their pupil diameter was measured with an eye-tracker, forty-five participants retrieved one memory from a field perspective (i.e., as viewed through our own eyes) and one memory from an observer perspective (i.e., as viewed from a spectator's standpoint). After retrieval, participants rated the emotional intensity of the memories. RESULTS: Analysis demonstrated larger pupils during the retrieval of memories from a field perspective and higher emotional intensity for memories retrieved from a field perspective. DISCUSSION: The larger pupils for memories recalled from a field perspective could, however, not be attributed to their higher emotional intensity. These findings suggest that pupil dilation could be used as a physiological assessment of visual perspective during memory retrieval.

Awareness for People With Alzheimer's Disease: Profiles and Weekly Trajectories.

Objective: To understand awareness and fluctuations of awareness in Alzheimer's disease (AD), it is fruitful to consider the objects of awareness, e.g., cognitive functioning or recognition of the disease, as well as the mechanisms and modes of expression underlying awareness. With a holistic and discourse-centered approach, we aimed to identify different awareness profiles and test whether these profiles were stable or whether transitions from one profile to another occurred over short time intervals. Methods: Twenty-eight residents of nursing homes with a diagnosis of AD participated in four semistructured interviews at biweekly intervals. These interviews were cluster analyzed to determine profiles of awareness. A Markov chain was applied to model their fluctuation. Results: Five awareness profiles were observed that differed in terms of objects and underlying processes. Awareness proved to be quite stable for four of the five profiles. Interindividual variability in awareness was also observed through numerous different trajectories that were identified. Discussion: Self-awareness and disease awareness are characterized by profiles that vary subtly between individuals. Fluctuations in awareness underscore the need to employ assessment intervals that closely reflect daily life in institutions.

The subjective experience of mind wandering in Alzheimer's disease.

Introduction: Little is known about mind wandering in Alzheimer's disease (AD). In this study, we evaluated the subjective experience of mind wandering in AD.Methods: We invited AD patients and control participants to rate the occurrence, intentionality, emotionality, visual imagery, specificity, self-relatedness and temporal orientation of mind wandering.Results: Analysis showed that AD patients rated their mind wandering as more frequent, negative, and more oriented toward the past, but less vivid and specific than that of control participants. No significant differences were observed between AD patients and control participants regarding the intentionality or self-relatedness of mind wandering.Conclusions: These findings demonstrate the negative content in AD. Regarding the reduction of visual imagery and specificity during mind wandering, this reduction may mirror a diminished subjective experience of mind wandering in AD. Regarding temporality, our results may reflect a tendency of AD patients to reminisce over past experiences. Finally, mind wandering in AD seems to trigger significant self-related content.

The Past as Seen by Women and Men With Alzheimer Disease: Sex Differences in Autobiographical Memory.

BACKGROUND: Although there is a large body of research demonstrating the negative effects of Alzheimer disease (AD) on autobiographical memory (ie, memory of personal information), little is known about sex differences in autobiographical retrieval in AD. METHODS: We addressed this issue by inviting patients with AD and healthy control participants to retrieve autobiographical memories and analyzed them with regard to specificity, subjective experience (ie, time travel, emotion, and visual imagery), and retrieval time. RESULTS: Analyses demonstrated no significant differences between women and men with AD with regard to autobiographical specificity, time travel, visual imagery, or retrieval time. However, the higher emotional value was attributed to memories by women with AD than by men with AD. DISCUSSION: AD seems to equally affect the ability of women and men with AD to construct specific autobiographical memories, to mentally travel in time to relive these memories, to construct mental visual images during memory retrieval, and to organize and monitor search processes, as the latter are mirrored by retrieval time. However, women with AD seem to attribute greater emotional value to autobiographical memories than men with AD.

A look into hallucinations: the relationship between visual imagery and hallucinations in Alzheimer's disease.

Introduction: We investigated the relationship between visual hallucinations and vividness of visual imagery in patients with Alzheimer's disease (AD). Method: We recruited 28 patients with AD and 30 healthy control participants, matched for age and education. We evaluated proneness towards hallucinations with the Launay-Slade Hallucinations Scale, which includes items assessing visual and auditory hallucinations. We also evaluated vividness of visual imagery with the Vividness of Visual Imagery Questionnaire on which participants had to imagine four images (i.e., imagining the face of a friend, the rising sun, a familiar shop-front, and a country scene) and report the vividness of the images they generated. Results: Analysis demonstrated significant positive correlations between visual hallucinations and vividness of visual imagery in AD patients, however, no significant correlations were observed between auditory hallucinations and vividness of visual imagery in these participants. No significant correlations were observed between hallucinations and vividness of visual imagery in healthy control participants, probably due to the lack of hallucinations in these participants. Discussion: These results demonstrate a selective relationship between the occurrence of visual (but not auditory) hallucinations and the ability to generate vivid visual images in AD.

Future Thinking in Korsakoff Syndrome.

AIMS: Prior research has been mainly concerned with the ability of patients with Korsakoff syndrome (KS) to project themselves into the past. Little is known about the patients' ability to project themselves into the future. We therefore compared past and future thinking in patients with KS. METHODS: We invited patients with KS and control participants to retrieve past events and reconstruct future events. Participants were also invited to rate subjective characteristics (i.e. time travel, emotional feeling, and visual imagery) of the past and future events. RESULTS: Patients with KS demonstrated low specificity, time travel, and emotional experience during past and future thinking. However, while lower emotional experience was observed in patients with KS than in the control participants during future thinking, no significant differences were observed between the two populations during past thinking. Regarding within-group comparisons, patients with KS demonstrated no significant differences between past and future thinking in terms of specificity, time travel, and visual imagery; however, they demonstrated higher emotional experience during past than during future thinking. Regarding control participants, they demonstrated no significant differences between past and future thinking in terms of specificity, time travel, emotional experience, and visual imagery. CONCLUSION: Our findings demonstrate a diminished ability to construct specific future scenarios as well as a diminished subjective experience during future thinking in KS.

Mental imagery and autobiographical memory in Alzheimer's disease.

OBJECTIVE: A body of experimental, neuropsychological, and neuroanatomical evidence suggests a relationship between autobiographical memory and the ability to generate mental images. This study investigated this relationship in Alzheimer's disease (AD). METHOD: Twenty six AD participants and 28 control participants were asked to retrieve 2 autobiographical events. They were also administered measures of visual imagery (i.e., the taller/wider task), and spatial imagery (i.e., the clock angles task). RESULTS: Analysis showed preserved autobiographical memory and visual imagery but compromised spatial imagery in AD. Significant correlations were observed between autobiographical memory and visual and spatial imagery in AD and control participants. However, autobiographical memory was predicted by visual but not by spatial imagery. CONCLUSIONS: The ability to retrieve (i.e., visual imagery) and manipulate mental images (i.e., spatial imagery) seems to be related with autobiographical recall in AD. In particular, visual imagery may contribute to autobiographical retrieval in AD participants by providing them with visual cues that increase the ease and speed of search through the hierarchical structure of autobiographical memory. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Off-track thoughts: Intentional and unintentional mind wandering in Alzheimer's disease.

AIM: Despite the recent upsurge of interest in mind wandering (i.e. the occurrence of task-unrelated and stimulus-independent thoughts), little research has attempted to evaluate mind wandering in Alzheimer's disease (AD). We addressed this issue by evaluating intentional and unintentional mind wandering, as well as the relationship between both mind-wandering domains. We also investigated the relationship between mind wandering and depression and working memory. METHODS: A total of 30 participants with AD and 33 control participants participated in the study. RESULTS: The results showed higher intentional and unintentional mind wandering in AD participants than in controls. In AD participants and controls, both mind wandering domains were significantly correlated with depression, but not with working memory. CONCLUSIONS: The present findings show a tendency of AD patients to shift from external stimuli to task-unrelated thoughts and concerns, a tendency that seems to be related with depression. Geriatr Gerontol Int 2019; 19: 342-346.

Don't stare, unless you don't want to remember: Maintaining fixation compromises autobiographical memory retrieval.

This study has developed an original approach to the relationship between eye movements and autobiographical memory, by investigating how maintained fixation could influence the characteristics of retrieved memories. We invited participants to retrieve autobiographical memories in two conditions: while fixating a cross at the centre of a screen and while freely exploring the screen. Memories retrieved during the maintained fixation condition were less detailed and contained less visual imagery than those retrieved during the free-gaze condition. Memories retrieved during the maintained fixation condition were retrieved slower and took less time to describe than those retrieved during the free-gaze condition. As for the characteristics of eye movements, analysis showed fewer and longer fixations as well as fewer saccades in the maintained fixation than in the free-gaze condition. Maintaining fixation is likely to tax cognitive resources that are necessary for the reconstruction of autobiographical memory. Our findings demonstrate how maintained fixation may result in a more effortful construction of autobiographical memory and memories with lower spatiotemporal specificity and poorer mental images.

Visual imagery: The past and future as seen by patients with Alzheimer's disease.

We investigated visual imagery for past and future thinking in Alzheimer's Disease (AD). We invited AD patients and controls to retrieve past events and to imagine future events. Participants also provided a "Field" response if they see the event through their own eyes, or an "Observer" response if they see themselves in the scene as a spectator would. Less "Field" and more "Observer" responses were observed in AD participants than in controls during past and future thinking, suggesting a diminished ability to mentally visualize past and future events in AD. Results also demonstrated significant positive correlations between the production of "Field" responses and specificity during past and future thinking, suggesting a relationship between the ability to mentally visualize past and future events and autobiographical overgenerality in AD.

Phenomenological Characteristics of Future Thinking in Alzheimer's Disease.

This study investigates phenomenological reliving of future thinking in Alzheimer's disease (AD) patients and matched controls. All participants were asked to imagine in detail a future event, and afterward, were asked to rate phenomenological characteristics of their future thinking. As compared to controls, AD participants showed poor rating for reliving, travel in time, visual imagery, auditory imagery, language, and spatiotemporal specificity. However, no significant differences were observed between both groups in emotion and importance of future thinking. Results also showed lower rating for visual imagery relative to remaining phenomenological features in AD participants compared to controls; conversely, these participants showed higher ratings for emotion and importance of future thinking. AD seems to compromise some phenomenological characteristics of future thinking, especially, visual imagery; however, other phenomenological characteristics, such as emotion, seem to be relatively preserved in these populations. By highlighting the phenomenological experience of future thinking in AD, our paper opens a unique window into the conscious experience of the future in AD patients.

Mindfulness and meditation: treating cognitive impairment and reducing stress in dementia.

This study investigates the relationship between mindfulness, meditation, cognition and stress in people with Alzheimer's disease (AD), dementia, mild cognitive impairment and subjective cognitive decline. Accordingly, we explore how the use of meditation as a behavioural intervention can reduce stress and enhance cognition, which in turn ameliorates some dementia symptoms. A narrative review of the literature was conducted with any studies using meditation as an intervention for dementia or dementia-related memory conditions meeting inclusion criteria. Studies where moving meditation was the main intervention were excluded due to the possible confounding of exercise. Ten papers were identified and reviewed. There was a broad use of measures across all studies, with cognitive assessment, quality of life and perceived stress being the most common. Three studies used functional magnetic resonance imaging to measure functional changes to brain regions during meditation. The interventions fell into the following three categories: mindfulness, most commonly mindfulness-based stress reduction (six studies); Kirtan Kriya meditation (three studies); and mindfulness-based Alzheimer's stimulation (one study). Three of these studies were randomised controlled trials. All studies reported significant findings or trends towards significance in a broad range of measures, including a reduction of cognitive decline, reduction in perceived stress, increase in quality of life, as well as increases in functional connectivity, percent volume brain change and cerebral blood flow in areas of the cortex. Limitations and directions for future studies on meditation-based treatment for AD and stress management are suggested.

Eying the future: Eye movement in past and future thinking.

We investigated eye movement during past and future thinking. Participants were invited to retrieve past events and to imagine future events while their scan path was recorded by an eye-tracker. Past thinking triggered more fixation (p < .05), and saccade counts (p < .05) than future thinking. Past and future thinking triggered a similar duration of fixations and saccades, as well as a similar amplitude of saccades. Interestingly, participants rated past thinking as more vivid than future thinking (p < .01). Therefore, the vividness of past thinking seems to be accompanied by an increased number of fixations and saccades. Fixations and saccades in past thinking can be interpreted as an attempt by the visual system to find (through saccades) and activate (through fixations) stored memory representations. The same interpretation can be applied to future thinking as this ability requires activation of past experiences. However, future thinking triggers fewer fixations and saccades than past thinking: this may be due to its decreased demand on visual imagery, but could also be related to a potentially deleterious effect of eye movements on spatial imagery required for future thinking.

Phenomenological characteristics of autobiographical memory in Korsakoff's syndrome.

A body of research suggests compromise of autobiographical memory in Korsakoff's syndrome (KS). The present paper extends this literature by investigating the subjective experience of autobiographical recall in the syndrome. Patients with KS and controls were asked to retrieve autobiographical memories. After memory retrieval, participants were asked to rate phenomenological characteristics of their memories (i.e., reliving, back in time, remembering, realness, visual imagery, auditory imagery, language, emotion, rehearsal, importance, spatial recall and temporal recall). Analysis showed lower "Mean Phenomenological Experience" in the Korsakoff patients than in controls. However, the Korsakoff patients attributed relatively high emotional value and importance to their memories. Although our findings suggest compromised phenomenological reliving of autobiographical memory in patients with KS, affective characteristics such as emotion and importance are likely to play a main role in the subjective experience of the past in these patients.

Eye movement during retrieval of emotional autobiographical memories.

This study assessed whether specific eye movement patterns are observed during emotional autobiographical retrieval. Participants were asked to retrieve positive, negative and neutral memories while their scan path was recorded by an eye-tracker. Results showed that positive and negative emotional memories triggered more fixations and saccades but shorter fixation duration than neutral memories. No significant differences were observed between emotional and neutral memories for duration and amplitude of saccades. Positive and negative retrieval triggered similar eye movement (i.e., similar number of fixations and saccades, fixation duration, duration of saccades, and amplitude of saccades). Interestingly, the participants reported higher visual imagery for emotional memories than for neutral memories. The findings demonstrate similarities and differences in eye movement during retrieval of neutral and emotional memories. Eye movement during autobiographical retrieval seems to be triggered by the creation of visual mental images as the latter are indexed by autobiographical reconstruction.