Abstract
When faced with decisions, rats sometimes pause and look back and forth between possible alternatives, a phenomenon termed
vicarious trial and error (VTE). When it was first observed in the 1930s, VTE was theorized to be a mechanism for exploration. Later theories suggested
that VTE aided the resolution of sensory or neuroeconomic conflict. In contrast, recent neurophysiological data suggest that
VTE reflects a dynamic search and evaluation process. These theories make unique predictions about the timing of VTE on behavioral
tasks. We tested these theories of VTE on a T-maze with return rails, where rats were given a choice between a smaller reward
available after one delay or a larger reward available after an adjustable delay. Rats showed three clear phases of behavior
on this task: investigation, characterized by discovery of task parameters; titration, characterized by iterative adjustment of the delay to a preferred interval; and exploitation, characterized by alternation to hold the delay at the preferred interval. We found that VTE events occurred during adjustment
laps more often than during alternation laps. Results were incompatible with theories of VTE as an exploratory behavior, as
reflecting sensory conflict, or as a simple neuroeconomic valuation process. Instead, our results were most consistent with
VTE as reflecting a search process during deliberative decision making. This pattern of VTE that we observed is reminiscent
of current navigational theories proposing a transition from a deliberative to a habitual decision-making mechanism.
vicarious trial and error (VTE). When it was first observed in the 1930s, VTE was theorized to be a mechanism for exploration. Later theories suggested
that VTE aided the resolution of sensory or neuroeconomic conflict. In contrast, recent neurophysiological data suggest that
VTE reflects a dynamic search and evaluation process. These theories make unique predictions about the timing of VTE on behavioral
tasks. We tested these theories of VTE on a T-maze with return rails, where rats were given a choice between a smaller reward
available after one delay or a larger reward available after an adjustable delay. Rats showed three clear phases of behavior
on this task: investigation, characterized by discovery of task parameters; titration, characterized by iterative adjustment of the delay to a preferred interval; and exploitation, characterized by alternation to hold the delay at the preferred interval. We found that VTE events occurred during adjustment
laps more often than during alternation laps. Results were incompatible with theories of VTE as an exploratory behavior, as
reflecting sensory conflict, or as a simple neuroeconomic valuation process. Instead, our results were most consistent with
VTE as reflecting a search process during deliberative decision making. This pattern of VTE that we observed is reminiscent
of current navigational theories proposing a transition from a deliberative to a habitual decision-making mechanism.
- Content Type Journal Article
- Pages 1-14
- DOI 10.3758/s13415-012-0097-7
- Authors
- Andrew E. Papale, Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
- Jeffrey J. Stott, Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
- Nathaniel J. Powell, Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
- Paul S. Regier, Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
- A. David Redish, Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
- Journal Cognitive, Affective, & Behavioral Neuroscience
- Online ISSN 1531-135X
- Print ISSN 1530-7026