Research Interests

I am a cognitive psychologist studying the dynamic interaction between attention and memory, with special emphasis on individual differences. I use experimental and correlational methods to explore 4 central questions:

  1. How do individuals control attention, in selectively processing goal-relevant information amidst distraction, in processing multiple information sources simultaneously, or in switching between different information sources or task objectives?
  2. What are the consequences of attention-control failures for remembering, reasoning, and goal-directed action?
  3. To what degree does maintaining information in active memory constrain our ability to focus attention and control action?
  4. Why do “span” tests of working-memory capacity (WMC) do such a good job of predicting individual differences in general cognitive ability?

In short, my research explores the nature of WMC's predictive power, in order to understand cognitive individual differences and the functioning of the core attention and memory processes that are broadly important to “real world” cognition.

Cognitive psychologists use the scientific method to study the processes of thought, such as those involved in perceiving, attending, remembering, comprehending, and acting. An important general insight from this work is that, whereas some mental processes are “automatic,” occurring outside of awareness with little effort or control, other processes are “conscious,” being more available to awareness and requiring substantial volition and control for their implementation. Although current research suggests that a surprising proportion of our mental life and behavior is automatic and unconscious, cognitive control remains important to success in complex cognitive activities, such as reasoning and comprehension, and in avoiding mental errors. For example, failures to counteract automatic or habitual response tendencies may yield consequences as mundane as arriving at home without having picked up the dry cleaning, or as tragic as accidentally leaving a toddler strapped into a car seat to eventually die of heat stroke.

My research program attempts to understand the volitional control of thought and behavior by studying the attention and memory processes that make such control possible but also are disturbingly susceptible to disruption and failure. In short, what seems critical to successful control is the ability to keep the mental representations of goals in an active, accessible state in the face of distractions from mental and environmental events.

Most cognitive psychologists, including myself, were trained in the experimental tradition, where problems of human thought and behavior are tested in the laboratory. Extraneous variables are controlled, variables of interest are systematically manipulated, and theoretically relevant outcomes are measured. The experimental approach has served my field well by permitting causal inferences about the relations among environmental and outcome/response variables, but what we have gained from empirical rigor we also have lost in scope. By focusing almost entirely on experimentation, and relegating individual variation in performance to “measurement error,” cognitive psychology has largely missed the important data provided by “nature's experiments” in human variability (Cronbach, 1957). Fortunately, other areas of psychology have seen individual differences as a central interest, for example in the study of intelligence and personality, and they have developed correlation-based analytic techniques to quantify the strength of associations that already exist in nature among theoretically interesting variables.

My approach to the study of cognitive control has been to harness the strengths of both experimental and correlational approaches, by examining the ways in which human variation in attention and memory responds to experimentally imposed contexts and cognitive demands. For example, if correlational data indicate performance on a memory task to be associated with particular intellectual or control skills, then an experiment may be able to link that correlation to a unique cognitive process and/or to a specific environmental context. Said another way, in my research I examine “treatment-by-organism” interactions, and I use individual differences as a means to test the predictions of basic cognitive theory in the laboratory.