Shawn is a PhD student working with Anthony Wagner in the Department of Psychology. He leverages neuroimaging (fMRI and scalp EEG) and real-time biofeedback with pupillometry to investigate the neural mechanisms driving the relationship between moment-to-moment fluctuations in preparatory attention and episodic remembering in cognitively healthy young and older adults.

Honors & Awards

  • Mind, Brain, Computation and Technology Student Training Program ($1,500), Wu Tsai Neurosciences Institute (August 2022)
  • Wu Tsai Human Performance Alliance Agility Project Grant ($200,000), Wu Tsai Neurosciences Institute (April 2022)
  • Norman H. Anderson Research Grant ($2,000), Stanford Department of Psychology (April 2022)
  • Horizon Prize for Education, Royal Society of Chemistry (November 2021)
  • Honorable Mention, National Science Foundation Graduate Research Fellowship Program (NSF GRFP) (March 2021)
  • J. Frank Yates Student Conference Diversity & Inclusion Award, Psychonomic Society (November 2020)

Professional Affiliations and Activities

  • Graduate Student Member, Society for Neuroscience (2022 - Present)
  • Member, Sigma Xi Scientific Honor Society (2021 - Present)
  • Graduate Student Member, Psychonomic Society (2019 - Present)

Education & Certifications

  • M.S., University of California, Los Angeles, Biology (2021)
  • B.S., University of California, Los Angeles, Cognitive Science & Biology (2019)

Service, Volunteer and Community Work

  • Diversity Committee Representative, Stanford Department of Psychology (August 2022 - Present)


    Stanford, CA

  • First-Year Graduate Student Representative, Stanford Department of Psychology (September 2021 - June 2022)


    Stanford, CA

Lab Affiliations

Work Experience

  • Graduate Teaching Associate, UCLA Departments of Psychology & Ecology and Evolutionary Biology (6/2020 - 9/2021)


    Los Angeles, CA

  • Graduate Teaching Assistant, UCLA Department of Ecology and Evolutionary Biology (9/2019 - 6/2020)


    Los Angeles, CA

All Publications

  • Serial and strategic memory processes in goal-directed selective remembering. Cognition Murphy, D. H., Schwartz, S. T., Castel, A. D. 2022; 225: 105178


    People often rely on habitual, serial processing when presented with to-be-learned information. We tested how strategic processing can override more bottom-up, serial processes when remembering information by having participants study a list of word triads (e.g., "dollar phone pizza"). Participants' goal was manipulated by maximizing either (i) their recall for each of the studied words or (ii) their total score associated with recalling certain words in each triad that were more valuable (worth more points) to engage either serial or strategic processing and retrieval mechanisms. Results revealed that when learners were told to maximize their total recall, they frequently engaged in serial remembering-remembering guided by an item's location within the study phase (i.e., words were retrieved according to a habitual reading bias). However, when words were paired with point values that counted towards participants' scores if recalled, participants were not only selective for high-value words but also attempted to overcome the tendency to engage in serial remembering; instead, they appeared to engage in strategic remembering whereby retrieval is guided by value. Thus, to maximize memory utility, it may be beneficial to override habitual processes and initiate retrieval with high-value words, and when making recall transitions, to recall high-value words together. Importantly, when certain to-be-remembered words were more valuable than their neighbors, participants still demonstrated some serial processing of the to-be-remembered words, indicating that even when engaging in strategic memory, some habitual processes can persist.

    View details for DOI 10.1016/j.cognition.2022.105178

    View details for PubMedID 35644091

  • SARS-CoV-2: Cross-scale Insights from Ecology and Evolution TRENDS IN MICROBIOLOGY Snedden, C. E., Makanani, S. K., Schwartz, S. T., Gamble, A., Blakey, R., Borremans, B., Helman, S. K., Espericueta, L., Valencia, A., Endo, A., Alfaro, M. E., Lloyd-Smith, J. O. 2021; 29 (7): 593-605


    Ecological and evolutionary processes govern the fitness, propagation, and interactions of organisms through space and time, and viruses are no exception. While coronavirus disease 2019 (COVID-19) research has primarily emphasized virological, clinical, and epidemiological perspectives, crucial aspects of the pandemic are fundamentally ecological or evolutionary. Here, we highlight five conceptual domains of ecology and evolution - invasion, consumer-resource interactions, spatial ecology, diversity, and adaptation - that illuminate (sometimes unexpectedly) the emergence and spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We describe the applications of these concepts across levels of biological organization and spatial scales, including within individual hosts, host populations, and multispecies communities. Together, these perspectives illustrate the integrative power of ecological and evolutionary ideas and highlight the benefits of interdisciplinary thinking for understanding emerging viruses.

    View details for DOI 10.1016/j.tim.2021.03.013

    View details for Web of Science ID 000659031800005

    View details for PubMedID 33893024

    View details for PubMedCentralID PMC7997387

  • Selective memory disrupted in intra-modal dual-task encoding conditions MEMORY & COGNITION Siegel, A. M., Schwartz, S. T., Castel, A. D. 2021


    Given natural memory limitations, people can generally attend to and remember high-value over low-value information even when cognitive resources are depleted in older age and under divided attention during encoding, representing an important form of cognitive control. In the current study, we examined whether tasks requiring overlapping processing resources may impair the ability to selectively encode information in dual-task conditions. Participants in the divided-attention conditions of Experiment 1 completed auditory tone-distractor tasks that required them to discriminate between tones of different pitches (audio-nonspatial) or auditory channels (audio-spatial), while studying items in different locations in a grid (visual-spatial) differing in reward value. Results indicated that, while reducing overall memory accuracy, neither cross-modal auditory distractor task influenced participants' ability to selectively encode high-value items relative to a full attention condition, suggesting maintained cognitive control. Participants in Experiment 2 studied the same important visual-spatial information while completing demanding color (visual-nonspatial) or pattern (visual-spatial) discrimination tasks during study. While the cross-modal visual-nonspatial task did not influence memory selectivity, the intra-modal visual-spatial secondary task eliminated participants' sensitivity to item value. These results add novel evidence of conditions of impaired cognitive control, suggesting that the effectiveness of top-down, selective encoding processes is attenuated when concurrent tasks rely on overlapping processing resources.

    View details for DOI 10.3758/s13421-021-01166-1

    View details for Web of Science ID 000632361500001

    View details for PubMedID 33763815

  • Test Anxiety and Metacognitive Performance in the Classroom EDUCATIONAL PSYCHOLOGY REVIEW Silaj, K. M., Schwartz, S. T., Siegel, A. M., Castel, A. D. 2021
  • Sashimi: A toolkit for facilitating high-throughput organismal image segmentation using deep learning METHODS IN ECOLOGY AND EVOLUTION Schwartz, S. T., Alfaro, M. E. 2021: 1-14

    View details for DOI 10.1111/2041-210X.13712

  • An own-race bias in the categorisation and recall of associative information MEMORY Murphy, D. H., Silaj, K. M., Schwartz, S. T., Rhodes, M. G., Castel, A. D. 2021: 1-16


    Serial position effects involve the differential recall of information based on its temporal order at encoding. Previous research indicates that learners may be aware of these effects under certain encoding conditions, but it is unclear whether metacognitive control is sensitive to serial position effects. The current study examined whether there are serial position effects in participants' study time and whether they can learn about serial position effects under fixed encoding conditions and then transfer what they have learned to self-paced study conditions. Specifically, participants were given lists of to-be-remembered words and studied each word for a fixed duration on initial lists, but self-paced their study time on later lists. Results revealed that self-paced study times oppositely mirrored serial position effects (i.e., briefer study times in the beginning and end of each list), and serial position effects were reduced in self-paced study conditions, particularly in participants initially studying under fixed conditions before self-pacing their study time. Specifically, participants may have monitored their output and, based on observations of forgetting middle items, transferred their learning of serial position effects from prior lists. Thus, participants may use forgetting and serial position information to guide encoding, indicating that fundamental properties of the memory system can be incorporated into the processes that guide metacognitive control.

    View details for DOI 10.1080/09658211.2021.1999982

  • Is the Future Bright or Bleak? Assessing Past and Future Outlooks Across the Adult Lifespan GERONTOLOGY AND GERIATRIC MEDICINE Silaj, K. M., Schwartz, S. T., Castel, A. D., McDonough, I. M. 2021
  • Younger and Older Adults' Mood and Expectations Regarding Aging During COVID-19 GERONTOLOGY AND GERIATRIC MEDICINE Whatley, M. C., Siegel, A. M., Schwartz, S. T., Silaj, K. M., Castel, A. D. 2020; 6: 2333721420960259


    The 2019 novel coronavirus disease (COVID-19) has broadly impacted our daily lives. Here, we used a longitudinal approach to investigate older adults' mood and expectations regarding aging before and during the global pandemic (Study 1). We also examined age differences in mood, expectations regarding aging, COVID-19 attitudes, and loneliness using a cross-sectional approach (Study 2). In Study 1, older adults completed a mood and expectations regarding aging survey up to 2 years prior to the pandemic and again in April, 2020 (during the pandemic). Participants also completed surveys regarding COVID-19 attitudes and loneliness. In Study 2, a United States sample of younger and older adults completed these surveys during the pandemic. Older adults' mood and expectations regarding aging remained fairly constant, and younger adults showed lower mood and expectations regarding aging than did older adults, despite older adults showing greater concern about COVID-19. Overall, we find that some older adults seem to be resilient with respect to their mood and expectations regarding aging. These findings reveal important preliminary implications for how older adults may be impacted as a result of lifestyle changes necessary for well-being and the well-being of society.

    View details for DOI 10.1177/2333721420960259

    View details for Web of Science ID 000573125700001

    View details for PubMedID 32984443

    View details for PubMedCentralID PMC7498965

  • Strategic encoding and enhanced memory for positive value-location associations MEMORY & COGNITION Schwartz, S. T., Siegel, A. M., Castel, A. D. 2020; 48 (6): 1015-1031


    People often need to remember the location of important objects or events, and also to remember locations that are associated with negative objects. In the current study, we examined how both positive and negative items might be selectively remembered in the visuospatial domain. Participants studied number-items ranging from -25 to +25 indicating point values in a grid display and were instructed to maximize their score (a summation of correctly remembered positive and negative information; incorrectly placed negative items resulted in a subtraction from the overall score). Items were presented in a sequential, simultaneous (Experiment 1), or self-regulated format (Experiment 2) where participants controlled which items to study and the length of study time per item. In Experiment 1, participants selectively recalled high-magnitude over low-magnitude items, but also displayed a positivity preference in memory. In Experiment 2, we were able to determine whether this positivity preference was a result of bottom-up, automatic, or top-down strategic processes. Results indicated that participants explicitly chose to study positive items more frequently and for more total time relative to negative items, suggesting a deliberate strategy to focus on positive information. This bias for highly positive information suggests an overt points-gained approach, as opposed to a loss-aversion approach, to remembering value in the visuospatial domain.

    View details for DOI 10.3758/s13421-020-01034-4

    View details for Web of Science ID 000526998900001

    View details for PubMedID 32291586

    View details for PubMedCentralID PMC7387219

  • The Evolution of Color Pattern in Butterflyfishes (Chaetodontidae) INTEGRATIVE AND COMPARATIVE BIOLOGY Alfaro, M. E., Karan, E. A., Schwartz, S. T., Shultz, A. J. 2019; 59 (3): 604-615

    View details for DOI 10.1093/icb/icz119

  • Smart access to 3D structures NATURE REVIEWS CHEMISTRY Dang, J., Lin, B., Yuan, J., Schwartz, S. T., Shah, R. M., Garg, N. K. 2018; 2 (7): 95-96