Table 3.
Volumes of regions within the extended reward and oversight system (reward regions) and non-reward control regions, expressed as a ratio to total cerebrum volume (%).
| Left Hemisphere | Right Hemisphere | |||||
|---|---|---|---|---|---|---|
| Region |
Nonalcoholic Comparison Subjects (n=21) mean ± SD |
Subjects with Alcoholism (n=21) mean ± SD |
ANCOVA Group Effect(a) t-value |
Nonalcoholic Comparison Subjects (n=21) mean ± SD |
Subjects with Alcoholism (n=21) mean ± SD |
ANCOVA Group Effect(a) t-value |
| Subcortical Reward Regions | ||||||
| Nucleus Accumbens | 0.054 ± 0.01 | 0.053 ± 0.01 | −0.5 | 0.054 ± 0.01 | 0.047 ± 0.01 | −2.5* |
| Amygdala | 0.15 ± 0.03 | 0.13 ± 0.02 | −1.8† | 0.14 ± 0.03 | 0.13 ± 0.02 | −1.1 |
| Hippocampus | 0.33 ± 0.04 | 0.31 ± 0.03 | −0.8 | 0.35 ± 0.04 | 0.33 ± 0.03 | −1.2 |
| Ventral Diencephalon | 0.44 ± 0.07 | 0.41 ± 0.05 | −0.9 | 0.43 ± 0.06 | 0.40 ± 0.05 | −1.1 |
| Cortical Reward Regions | ||||||
| Insula, Anterior | 0.42 ± 0.05 | 0.41 ± 0.05 | 0.0 | 0.41 ± 0.03 | 0.38 ± 0.04 | −2.2 * |
| DLPFC | 1.74 ± 0.31 | 1.59 ± 0.41 | −1.5 | 1.76 ± 0.30 | 1.57 ± 0.31 | −2.2 * |
| Insula, Posterior | 0.21 ± 0.04 | 0.19 ± 0.03 | −1.8 ‡ | 0.21 ± 0.02 | 0.21 ± 0.03 | −0.1 |
| Orbitofrontal Cortex | 0.44 ± 0.08 | 0.45 ± 0.12 | 0.8 | 0.46 ± 0.09 | 0.42 ± 0.08 | −1.5 |
| Cingulate Cortex | 0.99 ± 0.15 | 0.96 ± 0.19 | −0.4 | 1.04 ± 0.17 | 1.05 ± 0.15 | 0.6 |
| Subcallosal Cortex | 0.21 ± 0.03 | 0.20 ± 0.04 | −0.7 | 0.20 ± 0.03 | 0.20 ± 0.03 | −0.9 |
| Parahippocampal Gyrus | 0.37 ± 0.05 | 0.35 ± 0.07 | −0.5 | 0.35 ± 0.06 | 0.33 ± 0.07 | −0.5 |
| Temporal Pole | 0.72 ± 0.09 | 0.71 ± 0.12 | −0.3 | 0.69 ± 0.09 | 0.69 ± 0.09 | 0.3 |
| Non-Reward Control Regions | ||||||
| Dorsal Striatum | 0.93 ± 0.07 | 0.91 ± 0.09 | −0.7 | 0.96 ± 0.06 | 0.93 ± 0.08 | −1.3 |
| Frontal Pole | 3.65 ± 0.78 | 3.55 ± 0.53 | −0.3 | 3.85 ± 0.86 | 3.57 ± 0.58 | −0.8 |
| Cuneal Cortex (sensory) | 0.50 ± 0.09 | 0.51 ± 0.11 | 0.7 | 0.55 ± 0.09 | 0.58 ± 0.12 | 0.7 |
Abbreviations: SD - standard deviation; DLPFC - dorsolateral prefrontal cortex.
p < 0.05
p = 0.07, ratio covaried for age p < 0.05
p = 0.08, ratio covaried for age p = 0.2
We show the t-value of the Group effect from the univariate ANCOVA tests on raw volumes, covaried for Total Cerebrum Volume and for Age. The overall ANCOVA (including Group, Age, and Total Cerebrum Volume in the model) is significant for all regions except right amygdala, left ventral diencephalon, left orbitofrontal cortex, left parahippocampal gyrus, left cingulate cortex, and the right frontal pole; Age effects were non-significant except for the right accumbens and left amygdala; Total Cerebrum Volume was a significant covariate in all regions except the left orbitofrontal cortex and the parahippocampal gyrus bilaterally.