Afternoon session

Memory experiments conducted in naturalistic settings offer greater ecological validity, but what is the value of this ecological validity? Allen Newell (1991) once remarked that psychology is still in a “pre-paradigm state,” unlike fields such as chemistry and biology, where important discoveries all “get converted to things that help you to actually do things, like find solutions to diseases, build new devices, or build calculations that you can make”. Despite over a century of memory research, it remains a challenge to develop a theory-driven way to improve human memory. I argue that this disconnect between theoretical work and practical applications arises, in part, from the tradition of developing memory theories under highly controlled laboratory environments. Attempts to apply these theories to naturalistic settings can reveal important gaps in the theories themselves. In this talk, I will describe our lab's current efforts to extend computational models of memory to more realistic stimuli and scenarios. I will also discuss the unique challenges we face in finding and utilizing real-world datasets for memory research, particularly in comparison to other subfields such as decision making, planning, and linguistics.

This is an in-person presentation on November 21, 2024 (14:10 ~ 14:40 EST).

Motivated by observations that memory was affected by the pandemic lifestyle which contained very little change in our experiences, we hypothesized that variation in daily experience and novelty are broadly important for cognition and perhaps overall mood. Using an intensive longitudinal “daily diary” study, we examined the relationships between experiential novelty, emotions and real-world autobiographical event memory. Participants provided descriptions of three events per day for two weeks as well as additional information about their overall daily mood and specific details (social, spatial, emotional) about each event. After a delay of two weeks, memory for these events was tested. First, we found that novel events were remembered more vividly and with greater episodic detail than familiar events. Furthermore, we found that non-novel events that occurred on the same day as a novel event were also better remembered. This shows that novelty can exert a penumbra effect on other more typical experiences of each day, improving their retention. Novel events were also associated with more emotion (both positive and negative). Other factors that improved autobiographical memory were steps taken and spending time with others. This real-world data collection allowed us to test specific targeted hypotheses about experiential novelty and autobiographical memory while also collecting a rich, multidimensional dataset allowing us to place these effects in their daily context of behaviors, emotions and social experiences.

This is an in-person presentation on November 21, 2024 (14:40 ~ 15:10 EST).

We investigated memory encoding and retrieval during a quasi-naturalistic spatial-episodic memory task in which subjects delivered items to landmarks in a desktop virtual environment and later recalled the delivered items. Transition probabilities and latencies revealed the spatial and temporal organization of memory. As subjects gained experience with the town, their improved spatial knowledge led to more efficient navigation and increased spatial organization during recall. Subjects who exhibited stronger spatial organization exhibited weaker temporal organization. Scalp-recorded electroencephalographic (EEG) signals revealed spectral corre- lates of successful encoding and retrieval. Increased theta power (T+) and decreased alpha/beta power (A−) accompanied successful encoding, with the addition of increased gamma (G+) ac- companying successful retrieval. Logistic-regression classifiers trained on spectral features reliably predicted mnemonic success in held-out sessions. Univariate and multivariate EEG analyses revealed a similar spectral T+A−G+ of successful memory. These findings extend behavioral and neural signatures of successful encoding and retrieval to a naturalistic task in which learning occurs within a spatiotemporal context.

This is an in-person presentation on November 21, 2024 (15:30 ~ 16:00 EST).

The act of remembering an everyday experience influences how we interpret the world, how we think about the future, and how we perceive ourselves. It also enhances long-term retention of the recalled content, increasing the likelihood that it will be recalled again. Unfortunately, the ability to recollect event-specific details tends to decline with age, resulting in an impoverished ability to mentally re-experience the past. This shift has been linked to a corresponding decline in the distinctiveness of hippocampal memory representations. Despite these well-established changes, there are few effective cognitive behavioral interventions that target real-world episodic memory. We addressed this gap by developing a smartphone-based application called HippoCamera that allows participants to record labelled videos of everyday events and subsequently replay standardized, high-fidelity autobiographical memory cues. In two experiments with older adults, we found that using HippoCamera to repeatedly reactivate memories for real-world events improved episodic recollection and it evoked more positive autobiographical sentiment at the time of retrieval. Moreover, more detailed recollection was associated with more differentiated memory signals in the hippocampus. In a third experiment, conducted during the COVID lockdowns of 2020, we used HippoCamera to characterize the relationship between impoverished experiential diversity with memory, mood, and the perception of time. We found that unique events were not only recalled in richer episodic detail, but that increased uniqueness was associated with greater positive affect, decreased boredom, and the perception of time passing faster for the entire day. These findings highlight the intimate connection between memory for the events of our lives and our well-being overall.

This is an in-person presentation on November 21, 2024 (16:00 ~ 16:30 EST).