Article Figures & Data
Figures
- Fig. 1.
Coronal sections showing the intended lesion (middle column) and the actual extent of damage in four monkeys, A1 and A4 (left column) and A2 and A3 (right column), that received injections of ibotenic acid into the amygdala. Numerals indicate the distance in millimeters from the interaural plane.
- Fig. 2.
Photomicrographs of Nissl-stained coronal sections approximately +16 mm from the interaural plane. A, Section through the left amygdala in monkey A4. B, Section through the left amygdala in an intact monkey. Note virtually complete cell loss in the amygdala of the operated monkey (A), with relative preservation of the underlying entorhinal cortex.
- Fig. 3.
Photomicrographs of Nissl-stained coronal sections through the amygdala lesion in monkey A4. Top,middle, and bottom sections represent the left and right amygdala at approximately +18, +16, and +14 mm from the interaural plane, respectively.
- Fig. 4.
Within-problem learning curves on visual discrimination for auditory secondary reinforcement (Experiment 1) before (PRE-OP) and after (POST-OP) excitotoxic amygdala lesions. Average percent error is shown for the first four trials of new problems (see Table 1).
- Fig. 5.
Group mean difference scores, a measure of the effect on choices of objects of reinforcer devaluation (Experiment 2).CONTROL, Unoperated control monkeys (n = 3); AMYGDALA LESION, monkeys with selective, excitotoxic lesions of the amygdala (n = 4). Vertical lines represent the range of scores of individual monkeys.
Tables
Subject Amygdala Entorhinal cortex Perirhinal cortex L R Mean L R Mean L R Mean A1 92 50 71 4 0 2 2 0 1 A2 54 93 74 0 1 0 0 0 0 A3 100 96 98 42 8 25 6 1 4 A4 93 97 95 3 5 4 0 0 0 Numerals indicate percent damage of left (L), right (R), and total (mean) volume for each of three structures: amygdala, entorhinal cortex, and perirhinal cortex. A1–A4 are monkeys with excitotoxic amygdala lesions.
- Table 2.
Percent error in learning visual discrimination problems for auditory secondary reinforcement
Preoperative learning trials Postoperative learning trials 1 2 3 4 1 2 3 4 A1 49.0 10.5 6.5 2.5 39.5 5.5 2.0 1.0 A2 46.5 15.5 11.5 8.5 39.0 24.0 15.0 10.5 A3 43.0 30.5 17.0 10.0 54.5 28.0 24.0 12.0 A42-a 47.2 37.5 26.2 19.2 46.0 40.5 32.5 25.5 Mean 46.4 23.5 15.3 10.1 44.8 24.5 18.4 12.3 Numerals indicate the mean percent error obtained on trials 1–4 for problems learned in the last 5 of 20 sessions administered before surgery (preoperative learning) and the last 5 of 20 sessions administered after surgery (postoperative learning). A1–A4 are monkeys with excitotoxic amygdala lesions.
↵F2-a Did not reach criterion. Used mean score for last 15 sessions before operation.
Baseline Mean Satiation DS1 DS2 Difference score 1 2 Food-1 Food-2 F1:F2 F1:F2 F1:F2 F1:F2 F1:F2 C1 23:7 20:10 21.5:8.5 10:20 29:1 11.5 7.5 19.0 C2 23:7 21:9 22.0:8.0 6:24 27:3 16.0 5.0 21.0 C3 5:25 10:20 7.5:22.5 1:29 22:8 6.5 14.5 21.0 A1 20:10 19:11 19.5:10.5 10:20 17:13 9.5 −2.5 7.0 A2 12:18 16:14 14.0:16.0 11:19 13:17 3.0 −1.0 2.0 A3 11:19 12:18 11.5:18.5 7:23 15:15 4.5 3.5 8.0 A4 20:10 21:9 20.5:9.5 16:14 24:6 4.5 3.5 8.0 Number of Food-1 (F1) and Food-2 (F2) objects chosen in critical sessions consisting of 30 trials. DS1 represents a difference score between the number of Food-1 objects chosen after Food-1 satiation and baseline; DS2 represents a difference score between number of Food-2 objects chosen after Food-2 satiation and baseline. Difference score is the sum of DS1 and DS2. C1–C3 are unoperated control monkeys; A1–A4 are monkeys with excitotoxic amygdala lesions.
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