Project overview
Dr Tina Seabrooke's PhD project, funded by the School of Psychology, University of Plymouth.
The research aimed to further current knowledge on the psychological processes
that underpin human outcome-selective Pavlovian-instrumental transfer (PIT) effects.
PIT reflects the capacity of a Pavlovian stimulus to selectively potentiate an
instrumental response that predicts a common rewarding outcome. PIT effects are often
suggested to reflect a relatively automatic S-O-R mechanism, where the stimulus
activates the sensory properties of the outcome, which then automatically triggers
associated instrumental responses. The current research tested this S-O-R account of
PIT against a propositional expected utility theory, which suggests that PIT effects
reflect verbalizable inferences about the probability and value of each outcome. Chapter
1 reviewed the relevant literature. Chapters 2-4 then reported 11 experiments that aimed to
set the S-O-R and propositional theories against one another. In Chapter 2, two
experiments demonstrated that PIT is sensitive to a reversal instruction (Experiment 2),
but is robust against a time pressure (Experiment 1) and concurrent load (Experiment 2)
manipulation. Chapter 3 detailed the development of a novel outcome devaluation
procedure, and reported four experiments that examined the effect of both outcome
devaluation and verbal instructions on PIT. These experiments demonstrated that a
typical PIT procedure produces PIT effects that are insensitive to a very strong
devaluation manipulation. Furthermore, PIT effects were observed for a devalued
outcome even when an S-O-R mechanism was unlikely to control behaviour. Chapter 4
reported five experiments that show that PIT is highly sensitive to outcome devaluation
when multiple outcomes and responses are cued on every transfer test trial. Chapter 5
therefore concluded that, on balance, the results provide converging support for the
propositional expected utility theory of PIT.
The research aimed to further current knowledge on the psychological processes
that underpin human outcome-selective Pavlovian-instrumental transfer (PIT) effects.
PIT reflects the capacity of a Pavlovian stimulus to selectively potentiate an
instrumental response that predicts a common rewarding outcome. PIT effects are often
suggested to reflect a relatively automatic S-O-R mechanism, where the stimulus
activates the sensory properties of the outcome, which then automatically triggers
associated instrumental responses. The current research tested this S-O-R account of
PIT against a propositional expected utility theory, which suggests that PIT effects
reflect verbalizable inferences about the probability and value of each outcome. Chapter
1 reviewed the relevant literature. Chapters 2-4 then reported 11 experiments that aimed to
set the S-O-R and propositional theories against one another. In Chapter 2, two
experiments demonstrated that PIT is sensitive to a reversal instruction (Experiment 2),
but is robust against a time pressure (Experiment 1) and concurrent load (Experiment 2)
manipulation. Chapter 3 detailed the development of a novel outcome devaluation
procedure, and reported four experiments that examined the effect of both outcome
devaluation and verbal instructions on PIT. These experiments demonstrated that a
typical PIT procedure produces PIT effects that are insensitive to a very strong
devaluation manipulation. Furthermore, PIT effects were observed for a devalued
outcome even when an S-O-R mechanism was unlikely to control behaviour. Chapter 4
reported five experiments that show that PIT is highly sensitive to outcome devaluation
when multiple outcomes and responses are cued on every transfer test trial. Chapter 5
therefore concluded that, on balance, the results provide converging support for the
propositional expected utility theory of PIT.
Staff
Lead researchers
Research outputs
Tina Seabrooke, Lee Hogarth & Chris J. Mitchell,
2016, Quarterly Journal of Experimental Psychology, 69(12), 2452-2470
Type: article