Article Figures & Data
Figures
- Figure 1.
Excitotoxic lesions of Walker's area 11/13. The left column shows the extent of the intended lesion (blue) on standard coronal sections through the frontal lobe of a macaque brain 36–28 mm rostral to the interaural plane. The middle and right columns show coronal images at corresponding levels taken from T2-weighted MRI scans obtained within 1 week of surgery from cases 1 and 4 (Area 11/13 – Case 1 and Case 4). White hypersignal is associated with edema that follows injections of the excitotoxin ibotenic acid into area 11/13 and indicates the extent of the lesion.
- Figure 2.
Excitotoxic lesions of Walker's area 14. The left column shows the extent of the intended lesion (red) on standard coronal sections through the frontal lobe of a macaque brain 36–28 mm rostral to the interaural plane. The middle and right columns show coronal images at corresponding levels taken from T2-weighted MRI scans obtained within 1 week of surgery from cases 2 and 4 (Area 14 – Case 2 and Case 4). White hypersignal is associated with edema that follows injections of the excitotoxin ibotenic acid into area 14 and indicates the extent of the lesion.
- Figure 3.
Reinforcer devaluation. A, Mean ± SEM. difference score for reinforcer devaluation tests 1 (solid bars) and test 2 (hatched bars). B, Mean ± SEM. difference score for reinforcer devaluation test 3 (food only). The difference scores for each group are represented by different symbols; unfilled circles, CON group; light gray filled squares, area 11/13 group; dark gray filled triangles, area 14 group.
- Figure 4.
Object reversal learning. A, Mean ± SEM. number of errors to criterion for initial discrimination learning (ACQ) and nine serial reversals for CON (open circles), area 11/13 (light gray squares), and area 14 lesion (dark gray triangles) groups. B, Mean ± SEM. total errors summed across reversals (Total errors), the number of errors scored before the first correct response (Errors before first correct), and the number of errors scored after the first correct response (Errors after first correct). C, Performance (percentage correct, ± SEM) during object reversal learning on trials following a correct (Correct + 1) or an erroneous response (Error + 1) by control (white bars), area 11/13 (light gray bars) and area 14 (dark gray bars) groups. Symbols show scores of individual monkeys: unfilled circles CON group; light gray filled squares, area 11/13 group; dark gray filled triangles, area 14 group.
- Figure 5.
Preference test. Mean ± SEM cumulative preference disparity score, a measure of the inconsistency of the monkey's choices, for the CON (white bar), area 11/13 (light gray bar), and area 14 (dark gray bar) groups is shown. Symbols show scores for individual monkeys: unfilled circles CON group; light gray filled squares, area 11/13 group; dark gray filled triangles, area 14 group.
- Figure 6.
Object extinction. A, Mean ± SEM. number of object displacements during the acquisition phase (ACQ) and across five consecutive extinction sessions (1–5). B, Mean ± SEM number of unrewarded object displacements within the first 30-trial extinction session divided into five blocks of six trials each is shown. The performance of the CON group is represented by unfilled circles, the area 11/13 group by light gray squares, and the area 14 group by dark gray triangles.
Tables
- Table 1.
Percentage of damage sustained to areas 11/13 and area 14 for each of the operated monkeys
Monkey (Group-case) Area 11/13 Area 14 Left Right Mean Left Right Mean Area 11/13-1 80.8 82.7 81.7 7.5 4.1 5.8 Area 11/13-2 89.7 93.8 91.8 3.8 3.0 3.4 Area 11/13-3 79.4 86.7 83.1 1.7 3.0 2.3 Area 11/13-4 89.6 84.1 86.8 3.9 5.2 4.6 Mean 85.9 4.0 Area 14-1 12.7 17.0 14.9 98.6 93.4 96.0 Area 14-2 7.7 8.2 8.0 77.8 76.5 77.1 Area 14-3 29.3 3.6 16.4 42.3 75.2 58.7 Area 14-4 13.2 4.1 8.7 90.6 79.8 85.2 Mean 12.0 79.3 Area 11/13, cases 1-4: monkeys with injections of ibotenic acid targeting Walker's areas 11 and 13. Area 14, cases 1-4: monkeys with injections of ibotenic acid targeting Walker's area 14. Left, Left hemisphere; Right, right hemisphere; Mean, average of the damage to left and right hemispheres.
