Memory updating and the structure of event representations.

People form memories of specific events and use those memories to make predictions about similar new experiences. Living in a dynamic environment presents a challenge: How does one represent valid prior events in memory while encoding new experiences when things change? There is evidence for two seemingly contradictory classes of mechanism: One differentiates outdated event features by making them less similar or less accessible than updated event features. The other integrates updated features of new events with outdated memories, and the relationship between them, into a structured representation.

Modeling human activity comprehension at human scale: prediction, segmentation, and categorization.

Humans form sequences of -representations of the current situation-to predict how activity will unfold. Multiple mechanisms have been proposed for how the cognitive system determines when to segment the stream of behavior and switch from one active event model to another. Here, we constructed a computational model that learns knowledge about event classes (event schemas), by combining recurrent neural networks for short-term dynamics with Bayesian inference over event classes for event-to-event transitions.

Attention to event segmentation improves memory in young adults: A lifespan study.

People spontaneously segment an observed everyday activity into discrete, meaningful events, but segmentation can be modified by task goals. Asking young adults to attend to event segmentation while watching movies of everyday actions improved their memory up to 1 month later (Flores et al., 2017).

No evidence for chunking in spatial memory of route experience.

Spatial memory is important for supporting the successful completion of everyday activities and is a particularly vulnerable domain in late life. Grouping items together in memory, or chunking, can improve spatial memory performance. In memory for desktop scale spaces and well-learned large-scale environments, error patterns suggest that information is chunked in memory.

Bayesian Surprise Predicts Human Event Segmentation in Story Listening.

Event segmentation theory posits that people segment continuous experience into discrete events and that event boundaries occur when there are large transient increases in prediction error. Here, we set out to test this theory in the context of story listening, by using a deep learning language model (GPT-2) to compute the predicted probability distribution of the next word, at each point in the story. For three stories, we used the probability distributions generated by GPT-2 to compute the time series of prediction error.

Impaired prediction of ongoing events in posttraumatic stress disorder.

The ability to make accurate predictions about what is going to happen in the near future is critical for comprehension of everyday activity. However, predictive processing may be disrupted in Posttraumatic Stress Disorder (PTSD). Hypervigilance may lead people with PTSD to make inaccurate predictions about the likelihood of future danger.

Adult age differences in event memory updating: The roles of prior-event retrieval and prediction.

Remembering past events can lead to predictions of what is to come and to experiencing prediction errors when things change. Previous research has shown enhanced memory updating for ongoing events that are inconsistent with predictions based on past experiences. According to the Event Memory Retrieval and Comparison (EMRC) Theory, such memory updating depends on the encoding of configural representations that bind retrieved features of the previous event, changed features, and the relationship between the two.

Cueing natural event boundaries improves memory in people with post-traumatic stress disorder.

People with post-traumatic stress disorder (PTSD) often report difficulty remembering information in their everyday lives. Recent findings suggest that such difficulties may be due to PTSD-related deficits in parsing ongoing activity into discrete events, a process called event segmentation. Here, we investigated the causal relationship between event segmentation and memory by cueing event boundaries and evaluating its effect on subsequent memory in people with PTSD.

The multi-angle extended three-dimensional activities (META) stimulus set: A tool for studying event cognition.

To study complex human activity and how it is perceived and remembered, it is valuable to have large-scale, well-characterized stimuli that are representative of such activity. We present the Multi-angle Extended Three-dimensional Activities (META) stimulus set, a structured and highly instrumented set of extended event sequences performed in naturalistic settings. Performances were captured with two color cameras and a Kinect v2 camera with color and depth sensors, allowing the extraction of three-dimensional skeletal joint positions.

Virtual navigation in healthy aging: Activation during learning and deactivation during retrieval predicts successful memory for spatial locations.

Spatial navigation and spatial memory are two important skills for independent living, and are known to be compromised with age. Here, we investigate the neural correlates of successful spatial memory in healthy older adults in order to learn more about the neural underpinnings of maintenance of navigation skill into old age. Healthy older adults watched a video shot by a person navigating a route and were asked to remember objects along the route and then attempted to remember object locations by virtually pointing to the location of hidden objects from several locations along the route.

PTSD is associated with impaired event processing and memory for everyday events.

Current theories of posttraumatic stress disorder (PTSD) propose that memory abnormalities are central to the development and persistence of symptoms. While the most notable memory disturbances in PTSD involve memory for the trauma itself, individuals often have trouble remembering aspects of everyday life. Further, people with PTSD may have difficulty segmenting ongoing activity into discrete units, which is important for our perception and later memory of the activity.

Understanding Everyday Events: Predictive-Looking Errors Drive Memory Updating.

Memory-guided predictions can improve event comprehension by guiding attention and the eyes to the location where an actor is about to perform an action. But when events change, viewers may experience predictive-looking errors and need to update their memories. In two experiments (s = 38 and 98), we examined the consequences of mnemonic predictive-looking errors for comprehending and remembering event changes.

The hippocampus constructs narrative memories across distant events.

Life's events are scattered throughout time, yet we often recall different events in the context of an integrated narrative. Prior research suggests that the hippocampus, which supports memory for past events, can support the integration of overlapping associations or separate events in memory. However, the conditions that lead to hippocampus-dependent memory integration are unclear.

Priming of movie content is modulated by event boundaries.

Perceivers spontaneously segment ongoing activity into discrete events. This segmentation is important for the moment-by-moment understanding of events, but may also be critical for how events are encoded into episodic memory. In 3 experiments, we used priming to test the possibility that perceptual event boundaries organize memory for everyday activity into episodic units.

Narratives bridge the divide between distant events in episodic memory.

Many studies suggest that information about past experience, or episodic memory, is divided into discrete units called "events." Yet we can often remember experiences that span multiple events. Events that occur in close succession might simply be linked because of their proximity to one another, but we can also build links between events that occur farther apart in time.

The role of prior-event retrieval in encoding changed event features.

When people experience everyday activities, their comprehension can be shaped by expectations that derive from similar recent experiences, which can affect the encoding of a new experience into memory. When a new experience includes changes-such as a driving route being blocked by construction-this can lead to interference in subsequent memory. One potential mechanism of effective encoding of event changes is the retrieval of related features from previous events.

Knowledge and the reliability of constructive memory.

Memory is constructive, but that does not mean it is unreliable. When people remember the events of their lives they depend on knowledge, some of which is in the form of scripts or schemata. Schematic information encodes typical patterns in events, and for this reason schemata often contribute veridical features to memory reconstruction.

Aging and the encoding of changes in events: The role of neural activity pattern reinstatement.

When encountering unexpected event changes, memories of relevant past experiences must be updated to form new representations. Current models of memory updating propose that people must first generate memory-based predictions to detect and register that features of the environment have changed, then encode the new event features and integrate them with relevant memories of past experiences to form configural memory representations. Each of these steps may be impaired in older adults.

Structured Event Memory: A neuro-symbolic model of event cognition.

Humans spontaneously organize a continuous experience into discrete events and use the learned structure of these events to generalize and organize memory. We introduce the (SEM) model of event cognition, which accounts for human abilities in event segmentation, memory, and generalization. SEM is derived from a probabilistic generative model of event dynamics defined over structured symbolic scenes.

Event Perception and Memory.

Events make up much of our lived experience, and the perceptual mechanisms that represent events in experience have pervasive effects on action control, language use, and remembering. Event representations in both perception and memory have rich internal structure and connections one to another, and both are heavily informed by knowledge accumulated from previous experiences. Event perception and memory have been identified with specific computational and neural mechanisms, which show protracted development in childhood and are affected by language use, expertise, and brain disorders and injuries.

Event Representations and Predictive Processing: The Role of the Midline Default Network Core.

The human brain is tightly coupled to the world through its sensory-motor systems-but it also spends a lot of its metabolism talking to itself. One important function of this intrinsic activity is the establishment and updating of event models-representations of the current situation that can predictively guide perception, learning, and action control. Here, we propose that event models largely depend on the default network (DN) midline core that includes the posterior cingulate and anterior medial prefrontal cortex.

Dynamic prediction during perception of everyday events.

The ability to predict what is going to happen in the near future is integral for daily functioning. Previous research suggests that predictability varies over time, with increases in prediction error at those moments that people perceive as boundaries between meaningful events. These moments also tend to be points of rapid change in the environment.

Age differences in the perception of goal structure in everyday activity.

Human activity is structured by goals and subgoals. To understand an everyday activity, a viewer must perceive its goal structure, and viewers may segment activity into units that correspond to perceived goals. In this study, we examined age differences in the ability to perceive hierarchical goal structure in ongoing activity.