Table 1.

Participant Demographics and Task Performance

	Low Aβ	High Aβ	Total
N (% Female)	50 (64.00)	18 (44.44)	68 (58.82)
Mean Age (SD)	66.62 (11.12)*	74.06 (7.40)	68.59 (10.73)
Mean Education (SD)	15.30 (2.68)	16.33 (2.50)	15.57 (2.66)
Mean MMSE (SD)	28.84 (0.82)	28.83 (0.71)	28.84 (0.78)
Mean CESD (SD)	3.88 (3.78)	3.44 (3.71)	3.77 (3.74)
fMRI Task Accuracy
0-Back (SD)	94.00 (10.65)	93.80 (9.90)	98.33 (10.38)
2-Back (SD)	83.70 (11.92)	83.75 (10.42)	83.17 (11.50)
3-Back (SD)	76.75 (8.68)	72.82 (5.83)	75.71 (8.17)
4-Back (SD)	74.77 (7.84)	73.01 (5.88)	74.30 (7.37)
fMRI Task RT (sec)
0-Back (SD)	0.68 (0.14)	0.63 (0.07)	0.66 (0.13)
2-Back (SD)	0.90 (0.20)	0.82 (0.16)	0.88 (0.19)
3-Back (SD)	1.01 (0.23)	0.90 (0.18)	0.98 (0.22)
4-Back (SD)	1.00 (0.25)	0.88 (0.17)	0.97 (0.23)
EF Composite (SD)	0.04 (0.56)	−0.09 (0.56)	0.00 (0.56)
WM Composite (SD)	0.02 (0.83)	−0.06 (0.72)	0.00 (0.80)

Note: Low Aβ – less than 1.11 standardized uptake value ratio; High Aβ – greater than or equal to 1.11 standardized uptake value ratio. MMSE - Mini Mental State Exam; CESD – Center for Epidemiologic Study-Depression; Accuracy reported as mean percent accuracy; Response time (RT) reported as a mean of medians such that a median RT is taken across all trials in a given condition for each subject and averaged across subjects; SD – standard deviation; sec – seconds; EF – executive function; WM – working memory; both are averages of standardized test measures reported as z-scores;

^*p < .05.