Figure 2.

(A) Reward-dependent visual response of a right caudate neuron. The data obtained in one block of all-direction rewarded (ADR condition, right) and four blocks of one-direction rewarded (1DR condition, left) are shown in columns. The histograms and rasters are aligned on cue onset for different cue directions (R, right; U, up; L, left; D, down). The rewarded direction is indicated by a “bull’s eye mark”. Polar diagrams show the magnitudes of response for four cue directions. The neuron’s response was strongest for the rewarded direction in any block of 1DR, whereas its preferred direction was to the left in ADR (modified from Kawagoe et al., 1998). (B) Top, an example of central caudate neuronal activity showing a positive reward effect in the biased-reward saccade task (Figure 1A). Bottom, an example dorsal caudate neuron showing a “negative” reward effect. (C) Average activity of three types of neurons in the dorsal striatum of rats participating in a probabilistic Pavlovian conditioning task, in which auditory conditioned stimuli (CS) indicate reward probability. Top, CS phasic neurons; middle, CS tonic neurons; bottom, US build-up neurons. (D) An example neuron showing similar coherence modulation for both contra- and ipsi-lateral choices. Note the positive coherence modulation during dots viewing (STIM) and around saccade onset (SAC), and negative coherence modulation after reward onset (REW).