Looking at remembering: Eye movements, pupil size, and autobiographical memory

The Subjective Experience of Autobiographical Remembering: Conceptual and Methodological Advances and Challenges

The investigation of the phenomenology of autobiographical memories (i.e., how a memory is subjectively experienced and its meaning) has provided an important contribution to our understanding of autobiographical remembering. Over the last two decades, the study of phenomenology has received widespread scientific attention, and the field has undergone quite relevant conceptual and methodological changes. In the present work, we (1) review some basic and well-established research findings and methodological achievements; (2) discuss new theoretical and methodological challenges, with a special focus on the issue of the phenomenological experience of the retrieval process and its relationship with the phenomenology of the products of retrieval; and (3) propose an alternative way of conceptualizing and understanding it in the framework of experimental phenomenology.

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.

Subjective judgments on direct and generative retrieval of autobiographical memory: The role of interoceptive sensibility and emotion

Autobiographical remembering is a subjective experience, and whether retrieval is perceived to occur through involuntary or voluntary, direct or generative cognitive processes is also based on subjective intuition. The present study examined factors that may contribute to the subjective judgment that occurs when we perceive memories as being retrieved directly (i.e., a memory comes to mind directly and immediately) or through generative processes (i.e., recalling a memory with effort or by using additional information). We examined the hypothesis that internal awareness (interoceptive sensibility and mindfulness traits) contributes to the physical reaction and emotional impact of memories at retrieval, which then influence the subjective judgment that memories are retrieved directly. In two online experiments, participants were asked to recall specific memories following verbal cues and to judge the retrieval process (i.e., direct or generative). We demonstrated that emotional awareness, an interoceptive sensibility scale factor, consistently predicted a high probability of direct retrieval judgments independent of other predictors of direct retrieval, such as retrieval latency and cue concreteness. This effect was especially common for concrete cues. In Experiment 2 we demonstrated that emotional awareness predicted direct retrieval judgments through the mediation of retrieval impact (physical reaction and emotional impact). These results indicate the involvement of interoceptive processing in the direct retrieval of autobiographical memories. We discuss the role of interoception in memory retrieval and present interoceptive prediction error as a novel and potentially integrative account of our findings.

Increased Pupil Size during Future Thinking in a Subject with Retrograde Amnesia

Recent research has assessed pupil size during past thinking in patients with retrograde amnesia. Building on this research, we assessed pupil size during future thinking in a retrograde amnesia patient. To this end, we measured pupil size during past and future thinking in L, a 19-year-old, right-handed man free of neurological/psychiatric disorders except for retrograde amnesia that occurred after an episode of fugue. During a past thinking condition, we invited L to retrieve retrograde events (i.e., events that occurred before amnesia) and anterograde events (i.e., events that occurred after amnesia). During a future thinking condition, we invited him to imagine events that might occur the following week, the following month, and in the new year. Past and future thinking occurred while L's pupil size was monitored with eye-tracking glasses. L demonstrated higher specificity during future than during past thinking. Critically, the results demonstrated a larger pupil size during future than during past thinking. The larger pupil size during future thinking observed in L can be attributed to the high cognitive load involved in future thinking. Our study not only demonstrates preserved future thinking in a patient with dissociative retrograde amnesia, but also shows that pupillometry can be used for the physiological assessment of future thinking in retrograde amnesia patients.

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.

Amnesia in your pupils: decreased pupil size during autobiographical retrieval in a case of retrograde amnesia

We investigate whether retrograde-amnesia can be indexed with pupil activity. We present the case of L, 19-year-old, without neurological or psychiatric disorders except for retrograde-amnesia. We invited L to retrieve retrograde and anterograde memories while his pupil size was monitering with eye-tracking glasses. Results demonstrated impaired retrograde retrieval but successful anterograde retrieval in L. He also attributed lower emotional value and visual imagery to his retrograde compared to his anterograde memories. Critically, smaller pupils were observed during retrograde than during anterograde retrieval. Our study provides the first evidence on the value of pupillometry as a potential physiological marker of amnesia.