Table 1.
Demographic and cognitive characteristics, and MRS values
| N | Mean | SD | |
|---|---|---|---|
| Male/female | 102/127 | ||
| Age | 229 | 30 | 9.2 |
| Years of education | 176 | 16.3 | 2.4 |
| WAIS IQ | 175 | 106.9 | 10.6 |
| Verbal memory factor | 174 | 25.3 | 7.6 |
| N-back factor | 170 | 25.7 | 8.7 |
| Visual memory factor | 141 | 294.1 | 120.6 |
| Processing speed factor | 176 | 3.9 | 0.8 |
| Card sorting factor | 171 | 147.3 | 55.8 |
| %CSF | 225 | 12 | 0.035 |
| %GM/tissue | 229 | 70 | 0.052 |
| GABA+/Cre | 228 | 0.096 | 0.0088 |
Years of education and WAIS IQ are reported to provide a general description of this sample. WAIS IQ was estimated based on four subtests of the Wechsler Adult Intelligence Scale. N = number of subjects for which the information was available or who were included in the study after outlier removal. There were four outliers identified for %CSF and one for GABA/Cre. Means and SD of the factors do not conform to an interpretable scale because of various transformations applied to the data to achieve normal distribution.
CSF cerebrospinal fluid content in the MRS voxel (four statistical outliers rejected), GM/tissue proportion of gray matter in the MRS voxel, Cre creatine