The Effect of Context on Choice and Value

Publisher Summary This chapter focuses on the neural computations underlying choice behavior in situations where the contextual information is manipulated exogenously by the experimenter. This chapter also discusses how the underlying value signals are modulated by contextual information, focusing in particular on how reference-dependent and reference-independent values are represented in the orbitofrontal cortex. The task that the algorithm needs to perform is simply to multiply these two pieces of information, calculate what is called the expected value (EV) of the gamble, and choose the gamble with higher EV. It is irrelevant to the outcome of the algorithm whether the probability is entered as a number between 0 and 1 or stated as a percentage or, similarly, whether the monetary reward is expressed in dollars or euros. Exactly how the medial orbitofrontol cortex mOFC exerts a control on behavior, enabling a less context-dependent pattern of choice, has still not been fully understood. The critical manipulation was changing the default: in one condition subjects were required to hold down a button if the ball landed inside the two lines (IN) but to switch and press another button if the ball was outside (OUT).