Skip to main content
. Author manuscript; available in PMC: 2015 Jan 15.
Published in final edited form as: Biol Psychiatry. 2013 Jun 20;75(2):10.1016/j.biopsych.2013.05.023. doi: 10.1016/j.biopsych.2013.05.023

Figure 1.

Figure 1

Task, behavior and recording/lesion locations. A. An example of the sequence of events in each trial block. For each recording session, one fluid well was arbitrarily designated as short (500ms delay before reward) and the other designated as long (1–7s delay before reward) (Block 1). After the first block of trials (~60 trials), contingencies unexpectedly reversed (Block 2). With the transition to block 3, the delays to reward were held constant across wells (500ms), but the size of the reward was manipulated. The well designated as ‘long’ during the previous block now offered 2–3 fluid boli whereas the opposite well offered one bolus. The reward stipulations again reversed in block 4. Free-choice odors signal that either well could be selected for reward, whereas forced-choice odors signaled that reward would only be delivered in the well that the rat was instructed to go to. B. The impact of delay length and reward size manipulations on choice behavior during free-choice trials. Percent choice is calculated by taking the number of choices made and divided by the total number of well entries on free-choice trials, multiplied by 100. C. Impact of value on forced-choice trials for short vs. long delay and big vs. small reward. D. Reaction times (odor offset to nose unpoke from odor port) on forced-choice trials comparing short vs. long delay trials and big vs. small reward trials. High value = short and large. Low value = long and small. E–F. Location of recording sites and unilateral lesions based on histology for sham (E) and lesioned rats (F). Recordings and lesions were performed in the same hemisphere (3 lefts; 4 rights). Filled gray boxes mark the locations of electrodes based on histology and initial recording site. Black dot marks the bottom of the recording tract. Transparent gray areas mark lesions for each animal. Shown are representative slices at 1.7, 1.0 and 0.7 anterior to bregma taken from Paxinos and Watson (1997). Asterisks indicate planned comparisons revealing statistically significant differences (t test, p<0.05). # indicates a main effect of lesion in the ANOVA (p < 0.05). Error bars indicate standard error of the mean (SEM).