Tag: Dasa Zeithamova

Memory specificity and generalization: Competing or complementary memory processes?

Presenter(s): Celina Maldonado—Psychology and Linguistics

Faculty Mentor(s): Lea Frank, Dasa Zeithamova

Session: Prerecorded Poster Presentation

Memory serves two important functions: we must remember individual experiences (memory specificity) and we must be able to link across these experiences to form general concepts (generalization) . It is unclear, however, whether generalization and memory specificity are competing or complementary processes . One possibility is that individual memories are stored in detail and then generalized during retrieval . In this case, successful generalization relies on intact memory for the individual memories . Another possibility is that memories are linked to previous experiences during encoding, leading to some of the information of individual experiences being lost to support generalization . In this experiment, two tasks were used to study memory specificity and generalization . To investigate memory specificity, participants studied a series of colored objects . The test phase required participants to select the color of each object from a continuous color wheel, allowing us to measure how precisely they could remember the color-object pair . To measure generalization, participants studied face-scene pairings in which two faces were paired with a given scene (F1-S1, F2-S1), and one of the faces was also paired with a second scene (F2-S2) . Generalization was measured by how often participants linked the second face with the second scene (F2-S2) at test given the faces’ shared preference for the first scene . To understand the relationship between memory specificity and generalization, we correlated performance on the two independent tasks . If generalization relies on intact memory for individual experiences, then I predict performance on generalization and memory specificity will be positively correlated .

Distinct representations of perceived and remembered information in parietal and ventral temporal cortices

Presenter(s): Rennie Kendrick—Biology

Faculty Mentor(s): Dasa Zeithamova, Lea Frank

Session: Prerecorded Poster Presentation

Both the parietal and ventral temporal cortices (VTC) have been implicated in representing externally perceived information and information retrieved from memory . However, while the VTC represents visual features of stimuli, it is believed the parietal cortex represents conceptual features . In this study, a pattern classifier was trained on participants’ neural data from VTC or parietal cortex across two tasks (encoding and recall), and we assessed the classifier’s ability to decode category membership of objects and scenes perceived (encoding) or remembered (recall) . We predicted that the unique roles of VTC and parietal cortex would translate to differences in which task resulted in highest classification accuracy: we predicted that classification accuracy during perception will be higher in VTC, while recall will be higher in parietal cortex . Our results partially confirmed this hypothesis: although the classifier had higher accuracy when considering perception relative to recall data in both parietal cortex and VTC, the difference in accuracy between perception and recall data was significantly larger when considering VTC neural data . The classification accuracy results suggest that losing perceived information of stimuli from perception to recall has a smaller effect on the classifier’s ability to decode category membership in parietal cortex than in VTC . Thus, neural representations in parietal cortex at encoding may reflect non-visual features (e .g . conceptual information) that are later retrieved .

Augemented Reality Effects on Mood, Stress & Cognition

Presenter(s): Ray Jackson—Psychology

Faculty Mentor(s): Dasa Zeithamova-Demircan, Lea Frank

Session 6: Cerebal Matters

Research with Virtual Reality has shown that a brief meditation experience is effective in reducing feelings of stress and anxiety (Keller, Bunnell, Kim & Rothbaum 2017) . When combined with interactive biometric feedback (for example: one’s heart rate) these same interventions have a stronger effect on both subjective feeling states as well as physiological changes associated with a relaxation response (Jester, Rozek, & McKelley 2019) . While it has been previously shown that reductions in stress can facilitate improved performance on cognitive tasks (Wu & Yan 2019), no research to date has specifically examined the ability of a brief Augmented Reality based meditation experience to boost cognitive performance . Our aim was to investigate if an AR-based meditation experience can stimulate a temporary boost in cognition by way of lowering stress, and to examine any additional effects of an addition of biometric feedback .

Effects of Repeated Exposure to Negative Stimuli on Associative Memory

Presenter(s): Takako Iwashita—Psychology

Faculty Mentor(s): Dasa Zeithamova, Caitlin Bowman

Session: Prerecorded Poster Presentation

The ability to remember associations (e .g ., a person’s face with his/her name) is an important
aspect of healthy memory function . Emotional arousal (particularly negative emotion such as fear
or anger) is known to disrupt associative memory more than other types of memory . It is an open question if and how these adverse effects on associative memory can be reduced . In the present study, we hypothesized that repeated exposure to negative images (desensitization) would reduce their negative effects on associative memory . To test this idea, we randomly assigned subjects to either a condition where we evoked negative emotion (negative condition) or did not evoke emotion (neutral condition) during learning of object pairs . To do so, we showed subjects a negative or neutral distractor image followed by paired objects, asking them to only remember the pair of objects for a later test . We administered four study-test blocks to examine changes in memory with repeated exposure . Results revealed that subjects in the negative condition had significantly worse memory accuracy throughout the experiment compared to those in the neutral condition . Further, we found that those in the negative condition were initially numerically slower in making their responses, suggesting difficulty processing even when making a correct response . However, the difference in reaction time between conditions diminished over time . Although our evidence was mixed, these results imply that desensitization to negative stimuli could reduce some effects of negative emotions on associative memory . This suggests a possible role of desensitization in alleviating memory disruption caused by trauma .

The Effect of Emotion on Associative Memory: Anger Versus Fear

Presenter(s): Melissa Adler—Human Physiology

Faculty Mentor(s): Dasa Zeithamova, Caitlin Bowman

Session: Prerecorded Poster Presentation

Studies show that emotion enhances memory for individual items but weakens memory for associations between items . One explanation for this associative memory impairment is that emotional stimuli capture attention, causing enhanced encoding of the emotional item but encoding of the surrounding environment . This hypothesis generates the prediction that emotional information always impairs associative memory . Alternatively, it may be that emotion orients attention towards threats in the environment, thus suggesting anger and fear have different effects on memory for associated information . To adjudicate between these hypotheses, subjects studied sets of three images, consisting of two objects and a face with either a neutral, angry, or fearful expression . Subjects were later tested on their memory for the associations between the three items . Supporting our the first hypothesis, memory for both angry and fearful associations was worse than memory for neutral associations . Contrary to our the second hypothesis, there were no differences in memory for angry versus fearful associations . Thus, emotional information itself seems to capture attention, weakening memory for related information . If we understand the mechanisms of how negative emotion influences associative memory, we may discover methods of counteracting the impairment via various memory-improving techniques . This could lead to increased memory accuracy for emotional events and thus increased accuracy and reliability of eyewitness testimonies .