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. This disruption in predictive processing may occur not only in response to threatening stimuli, but also during processing of neutral stimuli. Therefore, the current study investigated whether PTSD was associated with difficulty making predictions about near-future neutral activity. Sixty-three participants with PTSD and 63 trauma controls completed two tasks, one testing explicit prediction and the other testing implicit prediction. Higher PTSD severity was associated with greater difficulty with predictive processing on both of these tasks. These results suggest that effective treatments to improve functional outcomes for people with PTSD may work, in part, by improving predictive processing.

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. People with PTSD (n = 38) and trauma-matched controls (n = 36) watched and remembered videos of everyday activities that were either unedited, contained visual and auditory cues at event boundaries, or contained visual and auditory cues at event middles. PTSD symptom severity varied substantial within both the group with a PTSD diagnosis and the control group. Memory performance did not differ significantly between groups, but people with high symptoms of PTSD remembered fewer details from the videos than those with lower symptoms of PTSD. Both those with PTSD and controls remembered more information from the videos in the event boundary cue condition than the middle cue or unedited conditions. This finding has important implications for translational work focusing on addressing everyday memory complaints in people with PTSD.

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. The current study investigated whether PTSD diagnosis and symptom severity predicted event segmentation and memory for everyday activities. To do so, 63 people with PTSD and 64 controls with a trauma history watched, segmented, and recalled videos of everyday activities. Viewers with higher PTSD symptom severity showed lower agreement on locations of event boundaries and recalled fewer fine-grained actions than did those with lower symptom severity. These results suggest that PTSD symptoms alter event segmentation, which may contribute to subsequent memory disturbances.

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 (Ns = 38 and 98), we examined the consequences of mnemonic predictive-looking errors for comprehending and remembering event changes. University students watched movies of everyday activities with actions that were repeated exactly and actions that were repeated with changed features-for example, an actor reached for a paper towel on one occasion and a dish towel on the next. Memory guidance led to predictive-looking errors that were associated with better memory for subsequently changed event features. These results indicate that retrieving recent event features can guide predictions during unfolding events and that error signals derived from mismatches between mnemonic predictions and actual events contribute to new learning.

Development of VM-REACT: Verbal memory RecAll computerized test.

When tracking the progression of neuropsychiatric or neurodegenerative diseases, assessment tools that enable repeated measures of cognition and require little examiner burden are increasingly important to develop. In the current study, we describe the development of the VM-REACT (Verbal Memory REcAll Computerized Test), which assesses verbal memory recall abilities using a computerized, automated version. Four different list versions of the test were applied on a cohort of 798 healthy adults (ages 20-80). Recall and learning scores were computed and compared to existing gender- and age-matched published norms for a similar paper-and-pencil test. Performance was similar to existing age-matched norms for all but the two oldest age groups. These adults (ages 60-80) outperformed their age-matched norms. Processing speed, initiation speed, and number of recall errors are also reported for each age group. Our findings suggest that VM-REACT can be utilized to study verbal memory abilities in a standardized and time efficient manner, and thus holds great promise for assessment in the 21st century.

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. Eye tracking provides a method for noninterruptive measurement of prediction as participants watch a movie of an actor performing a series of actions. In two studies, we used eye tracking to study the time course of prediction around event boundaries. In both studies, viewers looked at objects that were about to be touched by the actor shortly before the objects were contacted, demonstrating predictive looking. However, this behavior was modulated by event boundaries: looks to to-be-contacted objects near event boundaries were less likely to be early and more likely to be late compared to looks to objects contacted within events. This result is consistent with theories proposing that event segmentation results from transient increases in prediction error.

Event segmentation improves event memory up to one month later.

When people observe everyday activity, they spontaneously parse it into discrete meaningful events. Individuals who segment activity in a more normative fashion show better subsequent memory for the events. If segmenting events effectively leads to better memory, does asking people to attend to segmentation improve subsequent memory? To answer this question, participants viewed movies of naturalistic activity with instructions to remember the activity for a later test, and in some conditions additionally pressed a button to segment the movies into meaningful events or performed a control condition that required button-pressing but not attending to segmentation. In 5 experiments, memory for the movies was assessed at intervals ranging from immediately following viewing to 1 month later. Performing the event segmentation task led to superior memory at delays ranging from 10 min to 1 month. Further, individual differences in segmentation ability predicted individual differences in memory performance for up to a month following encoding. This study provides the first evidence that manipulating event segmentation affects memory over long delays and that individual differences in event segmentation are related to differences in memory over long delays. These effects suggest that attending to how an activity breaks down into meaningful events contributes to memory formation. Instructing people to more effectively segment events may serve as a potential intervention to alleviate everyday memory complaints in aging and clinical populations. (PsycINFO Database Record

Ambient and focal visual processing of naturalistic activity.

When people inspect a picture, they progress through two distinct phases of visual processing: an ambient, or exploratory, phase that emphasizes input from peripheral vision and rapid acquisition of low-frequency information, followed by a focal phase that emphasizes central vision, salient objects, and high-frequency information. Does this qualitative shift occur during dynamic scene viewing? If so, when? One possibility is that shifts to exploratory processing are triggered at subjective event boundaries. This shift would be adaptive, because event boundaries typically occur when activity features change and when activity becomes unpredictable. Here, we used a perceptual event segmentation task, in which people identified boundaries between meaningful units of activity, to test this hypothesis. In two studies, an eye tracker recorded eye movements and pupil size while participants first watched movies of actors engaged in everyday activities and then segmented them into meaningful events. Saccade amplitudes and fixation durations during the initial viewings suggest that event boundaries function much like the onset of a new picture during static picture presentation: Viewers initiate an ambient processing phase and then progress to focal viewing as the event progresses. These studies suggest that this shift in processing mode could play a role in the formation of mental representations of the current environment.

Posttraumatic Stress and the Comprehension of Everyday Activity.

People with Posttraumatic Stress Disorder (PTSD) often report difficulties with attention and memory on tasks that are unrelated to their trauma. One important component of everyday event comprehension is the segmentation of ongoing activity into meaningful events. The present study asked whether PTSD symptom severity was associated with impaired segmentation and memory for neutral, ongoing activity. A sample of 137 participants, ages 21-79, completed event segmentation and memory tasks, general cognitive functioning tasks, and questionnaires assessing PTSD symptom severity. People with higher levels of PTSD symptoms had poorer event segmentation and event memory performance. Hierarchical multiple regression analyses demonstrated that PTSD symptom severity explained unique variance in event segmentation performance, even after controlling for general cognitive function. These results suggest that interventions aimed at improving event comprehension may help compensate for memory disruptions in PTSD.

Event segmentation ability uniquely predicts event memory.

Memory for everyday events plays a central role in tasks of daily living, autobiographical memory, and planning. Event memory depends in part on segmenting ongoing activity into meaningful units. This study examined the relationship between event segmentation and memory in a lifespan sample to answer the following question: Is the ability to segment activity into meaningful events a unique predictor of subsequent memory, or is the relationship between event perception and memory accounted for by general cognitive abilities? Two hundred and eight adults ranging from 20 to 79years old segmented movies of everyday events and attempted to remember the events afterwards. They also completed psychometric ability tests and tests measuring script knowledge for everyday events. Event segmentation and script knowledge both explained unique variance in event memory above and beyond the psychometric measures, and did so as strongly in older as in younger adults. These results suggest that event segmentation is a basic cognitive mechanism, important for memory across the lifespan.

Prediction error associated with the perceptual segmentation of naturalistic events.

Predicting the near future is important for survival and plays a central role in theories of perception, language processing, and learning. Prediction failures may be particularly important for initiating the updating of perceptual and memory systems and, thus, for the subjective experience of events. Here, we asked observers to make predictions about what would happen 5 sec later in a movie of an everyday activity. Those points where prediction was more difficult corresponded with subjective boundaries in the stream of experience. At points of unpredictability, midbrain and striatal regions associated with the phasic release of the neurotransmitter dopamine transiently increased in activity. This activity could provide a global updating signal, cuing other brain systems that a significant new event has begun.

Computer animations stimulate contagious yawning in chimpanzees.

People empathize with fictional displays of behaviour, including those of cartoons and computer animations, even though the stimuli are obviously artificial. However, the extent to which other animals also may respond empathetically to animations has yet to be determined. Animations provide a potentially useful tool for exploring non-human behaviour, cognition and empathy because computer-generated stimuli offer complete control over variables and the ability to program stimuli that could not be captured on video. Establishing computer animations as a viable tool requires that non-human subjects identify with and respond to animations in a way similar to the way they do to images of actual conspecifics. Contagious yawning has been linked to empathy and poses a good test of involuntary identification and motor mimicry. We presented 24 chimpanzees with three-dimensional computer-animated chimpanzees yawning or displaying control mouth movements. The apes yawned significantly more in response to the yawn animations than to the controls, implying identification with the animations. These results support the phenomenon of contagious yawning in chimpanzees and suggest an empathic response to animations. Understanding how chimpanzees connect with animations, to both empathize and imitate, may help us to understand how humans do the same.