You are currently viewing the abstract.View Full Text
Salience, Values, and Decisions
How does the brain make value-based decisions? There are two major competing models: the goodsbased model and the action-based model of value. Leathers and Olson (p. 132) designed a critical experiment to decide between these two views. In the monkey brain, lateral intraparietal neurons responded strongly to stimuli predicting both large rewards and large penalties, encoding the salience of the stimulus rather than reward value, which refutes both models.
In monkeys deciding between alternative saccadic eye movements, lateral intraparietal (LIP) neurons representing each saccade fire at a rate proportional to the value of the reward expected upon its completion. This observation has been interpreted as indicating that LIP neurons encode saccadic value and that they mediate value-based decisions between saccades. Here, we show that LIP neurons representing a given saccade fire strongly not only if it will yield a large reward but also if it will incur a large penalty. This finding indicates that LIP neurons are sensitive to the motivational salience of cues. It is compatible neither with the idea that LIP neurons represent action value nor with the idea that value-based decisions take place in LIP neurons.