Flexible structure learning under uncertainty.

Experience is known to facilitate our ability to interpret sequences of events and make predictions about the future by extracting temporal regularities in our environments. Here, we ask whether uncertainty in dynamic environments affects our ability to learn predictive structures. We exposed participants to sequences of symbols determined by first-order Markov models and asked them to indicate which symbol they expected to follow each sequence.

Memory transmission in small groups and large networks: An empirical study.

When people try to remember information in a group, they often recall less than if they were recalling alone. This finding is called collaborative inhibition, and has been studied primarily in small groups because of the difficulty of bringing large groups into the laboratory. To study the dynamics of collaborative inhibition in large groups (Luhmann & Rajaram, Psychological Science, 26, 1909-1917, 2015) constructed an agent-based model that extrapolated from previous laboratory experiments with small groups.

A rational model of people's inferences about others' preferences based on response times.

There's a difference between someone instantaneously saying "Yes!" when you ask them on a date compared to "…yes." Psychologists and economists have long studied how people can infer preferences from others' choices. However, these models have tended to focus on what people choose and not how long it takes them to make a choice.

Relationship to CBT outcome and dropout of decision support tools of the written case formulation, list of treatment goals and plot of symptom scores.

Many patients who receive cognitive behavior therapy (CBT) for mood and anxiety disorders fail to respond or drop out of treatment. We tested the hypotheses that therapist use of each of three decision support tools, a written case formulation, a list of treatment goals, and a plot of symptom scores, was associated with improved outcome and reduced dropout in naturalistic CBT provided to 845 patients in a private practice setting. We conducted regression analyses to test the hypotheses that the presence of each tool in the clinical record was associated with lower end-of-treatment scores on the Beck Depression Inventory (BDI) and the Burns Anxiety Inventory (BurnsAI), and lower rates of premature and uncollaborative dropout.

How to Be Helpful to Multiple People at Once.

When someone hosts a party, when governments choose an aid program, or when assistive robots decide what meal to serve to a family, decision-makers must determine how to help even when their recipients have very different preferences. Which combination of people's desires should a decision-maker serve? To provide a potential answer, we turned to psychology: What do people think is best when multiple people have different utilities over options? We developed a quantitative model of what people consider desirable behavior, characterizing participants' preferences by inferring which combination of "metrics" (maximax, maxsum, maximin, or inequality aversion [IA]) best explained participants' decisions in a drink-choosing task. We found that participants' behavior was best described by the maximin metric, describing the desire to maximize the happiness of the worst-off person, though participant behavior was also consistent with maximizing group utility (the maxsum metric) and the IA metric to a lesser extent.