UC Merced

The science of decision-making is dominated by tasks which constrain decisions to occur

in fixed intervals of time with minimal movement of the body or environment. While these

constraints have proven useful for understanding perceptual and response competition, they do

not reflect the natural temporal structure of decision-making. To understand how we make

decisions, we must understand how the environment, the body, and the brain interact in time.

The environment both affords and constrains choice. The body reifies choice through movement,

or the lack thereof. The brain maps the dynamics of the environment onto the dynamics of the

body. From the interactions between brain, body, and environment, decisions emerge. This poses

a challenge for understanding decision-making: does one fix the environment and body to study

the mechanisms of the brain? Ignore the body and brain to study the nature of the environment?

Or even cut away the brain and environment to study the movement of the body? The challenge

is how to ground an understanding of decisions without reducing the essential complexity of the

subject. Although no response to this challenge will be fully satisfying, in this dissertation I will

describe a variety of research spanning the disciplines of cognitive and computational

neuroscience, behavioral psychology, ecology, and artificial intelligence with the goal of

generating new insights into decision-making.

The research presented in this dissertation broadly falls under a perspective I refer to as

dynamic decisions. The dynamic decisions perspective is informed by the following two

observations. 1) The consequences of decisions often demand high accuracy, yet neural

processes tend to be fairly noisy. This is reflected by speed-accuracy tradeoffs for many kinds of

decisions, where longer delays reduce errors. Delaying or stopping undesirable actions is

therefore an essential component of accurate decision-making. 2) Decisions are reified through

actions of the body, rather than purely mental or neural commitments. Thus, the relationships

between decision alternatives and ongoing actions, or even simulated actions, of the body are an

important influence on decision-making. Given these two principles, I argue that the outcome of

a decision is determined by when the decision is executed, and the study of decision dynamics

offers viable routes to integrate environment, body, and brain.