Research.

Computational Modeling of Cognition

My primary research interests involve compuational modeling of human cognition, broadly defined. Along with more traditional symbolic modeling, I use a variety of methods ranging from simple Markov models, neurally-plausible computation, and agent-based modeling to understand the structure and function of cognition.


Vigilance, Attention, and Human Performance

Humans display a remarkable ability to sustain their attention to seemingly-mundane tasks for long periods of time. Our research explores questions of how best to measure performance during long vigils and how the complex interplay between executive control, fatigue, and motivation can be captured in simple cognitive models. Our research demonstrates that shifts between states of alertness and rest are governed by simple statistical mechanics and that the equations that govern these traversals are strongly correlated with gamma and beta bands in EEG, reflecting tradeoffs between top-down and bottom-up control.

Vigilant attention and responding as a Markov process.

Relevant Work


Biologically-plausible Models of Cognition

An important shift in cognitive research is the extension of traditional symbolic cognitive architectures to those with biological plausibility. Using Leabra, we have simulated important perceptual processes, such as opponent processes in color vision, that are not typically represented in most cognitive models. Such models are dually capable: They are able to replicate overt behaviors (e.g., response times) while also simulating the neural dynamics that underlie complex cognition.

Model of inhibitory gating in vision using the Leabra architecture.

Relevant Work


Normative Category Typicality

Beta probit model used to examine category typicality estimates.

Relevant Work


Social Systems

Cognitive architectures (CAs) have been instrumental in integrating a wide range of findings in cognitive science into unified theories of cognition. However, much less effort has been devoted to applying CAs to social phenomena, despite the high interdependence between cognitive and social processes in real-world scenarios (e.g., Ecker et al., 2022). We are in the process of investigating the intersections between human cognition and information/misinformation spread, including integrated social sampling theory (SST; Brown et al., 2022) and ACT-R.

Basic computational structure of an SST agent (top) and simulations of polarization (bottom).

Relevant Work


Cognitive Psychology

Much of my graduate work – which I continue to study – investigated the nature of memory and awareness of one’s own memory abilities (metamemory), particularly for individuals that appear to have diminished cognitive functioning, i.e., older adults. Much of this work has examined metacognitive judgments, such as the feeling-of-knowing, and variables that can either improve (e.g., “distinctiveness” encoding) or hinder (e.g., interference during cued recall) jugment accuracy.

The output interference effect in recognition memory between young and older adults.

Relevant Work