Research

Our team investigates the neural and cognitive processes that govern the transformation of experiences into memory. Current research themes include the following:

Information Sampling and Memory

As a general rule, learning and memory work best when learners have some element of control over the flow of information, such as choosing when and in what order items are studied. At the same time, there are also cognitive costs associated with need to manage one’s own learning behaviors, and not everyone does so effectively. Moreover, many learning behaviors consist of “micro-choices”—such as eye movements, covert shifts of attention, or other forms of information sampling—which tend to be deployed rapidly and with minimal awareness, and which are not easily amenable to verbal report. In this line of work, we use high-temporal resolution techniques such as eye tracking and EEG to: 1) connect moment-to-moment information sampling behaviors to learning and memory outcomes, and 2) determine the neural and cognitive resources that promote the optimal use of these sampling behaviors.

Representative publications:

  • Lucas, H.D., Daugherty, A.M., McAuley, E., Kramer, A.F., & Cohen, N.J. (2023). Dynamic interactions between memory and viewing behaviors: Insights from dyadic modeling of eye movements. Journal of Experimental Psychology: Human Perception and Performance, 49(6), 786. 
  • Lucas, H.D., Duff, M.C., & Cohen, N.J. (2019). The hippocampus promotes effective saccadic information gathering in humans. Journal of Cognitive Neuroscience, 31(2), 186-201.

 

Language and Memory

An effective technique for forming new memories is to relate new information to what you already know. For instance, in order to remember that the golden trout is native to California, you might imagine a trout swimming near the Golden Gate Bridge in San Francisco. Current research suggests that there are important individual and age differences in how concepts are stored, structured, and accessed in real-time. In this line of work, we investigate how this variability in so-called “semantic cognition” impacts the ability to call upon pre-existing knowledge to facilitate new learning. For example, we are examining how age-related changes in processing noun-noun modification relationships (e.g., interpreting the word pair “elephant” and “ferry” as “an elephant ferry”) impacts the effectiveness of certain memorization strategies.

Another, related line of work investigates the role of co-speech hand gesture in facilitating memory for spoken language. Hand gestures are ubiquitous in social communication, and can serve multiple purposes, including directing attention to salient parts discourse and/or reinforcing the meaning of what is being said. Our research examines the impacts of co-speech gesture on multiple stages of language processing so as to provide insight into when and for whom gestures are most likely to benefit language comprehension and memory.

Representative publications:

  • Cairney, B.E., West, S.H., Haebig, E., Lucas, H.D. (under review). Iconic gestures form conceptual pegs: Evidence from electrophysiology and associative memory.
  • Cairney, B.E., West, S.H., Haebig, E., Cox, C.R., & Lucas, H.D. (2023). Interpretations of meaningful and ambiguous hand gestures in autistic and non-autistic adults: A norming study. Behavior Research Methods, 1-14. 
  • Lucas, H.D., Gupta, R.S., Hubbard, R.J., & Federmeier, K.D. (2019). Adult age differences in the use of conceptual combination as an associative encoding strategy. Frontiers in Human Neuroscience, 13, 339.
  • Lucas, H.D., Hubbard, R.J., & Federmeier, K.D. (2017). Flexible conceptual combination: Electrophysiological correlates and consequences for associative memory. Psychophysiology, 54(6), 833-847.

 

Stress, Anxiety, and Memory

Anxiety and stress trigger a cascade of neurophysiological processes that can impact cognition in complex ways. Acute stress tends to enhance attention and memory for information that is itself inherently stressful or threatening, but its impact on threat-irrelevant information is less clear. For example, how does mild ongoing stress that is unrelated to an upcoming exam impact the ability to study for that exam? Current ongoing research is investigating the effects of acute stress on the ability to monitor, assess, and regulate memory encoding and retrieval of information.

Other work focuses specifically on memory-related worry in older adults. Memory failures can be a source of distress for older adults, particularly in light of the increasing prevalence and awareness of age-related memory disorders such as Alzheimer’s Disease. In addition, compared to younger adults, older adults report more negative beliefs about their abilities to use memory effectively. Work in our laboratory investigates how these psychosocial facets of aging influence older adults’ approaches and reactions to learning and memory activities.

Representative publications:

  • Chaisson, F.C., Cox, C.R., Alford, A.M. Burleigh, L.M., Greening, S.G., Lucas, H.D. (accepted pending minor revisions). The impact of threat of shock on memory for threat-irrelevant information: Evidence for a mediating role of semantic organization.
  • Lucas, H.D., Monti, J.M., McAuley, E., Watson, P.D., Kramer, A.F., & Cohen, N.J. (2016). Relational memory and self-efficacy measures reveal distinct profiles of subjective memory concerns in older adults. Neuropsychology, 30(5), 568-578.

 

Memory Heuristics

There is ample evidence that we monitor and act on not only the content of our memories, but also the degree of fluency (ease or difficulty) associated with processing memory-relevant information. In this line of research, we investigate the roles that fluency-based heuristics play in encoding and retrieval decisions. In particular, our work examines ways in which peoples’ inferences about why processing is fluent contributes to their tendency to use that sense of fluency during memory judgments.

Representative publications:

  • Lucas, H.D., & Paller, K.A. (2013). Manipulating letter fluency for words alters electrophysiological correlates of recognition memory. NeuroImage, 83, 849-861.
  • Lucas, H.D., Taylor, J.R., Henson, R.N. & Paller, K.A. (2012). Many roads lead to recognition: Electrophysiological correlates of familiarity derived from short-term masked repetition priming. Neuropsychologia, 50(13), 3041-3052.
  • Voss, J.L., Lucas, H.D., & Paller, K.A. (2012). More than a feeling: Pervasive influences of memory without awareness of retrieval. Cognitive Neuroscience, 3(0), 193-207.