Table 7.

Results of mixed-design ANOVAs testing the effects of group and working memory load on maximum pupil diameter (A), and the onset time of maximum pupil diameter (B) during n-back trials

Age group	Effect	df	F	η2p	p
A. Maximum pupil diameter on n-back trials
Younger	Group	1, 39	0.68	.017	.415
Younger	Load	2.65, 103.26	53.31	.578	<.001
Younger	Group × Load	2.65, 103.26	1.49	.037	.224
Older	Group	1, 31	0.31	.010	.579
Older	Load	1.89, 58.71	17.28	.358	<.001
Older	Group × Load	1.89, 58.71	2.22	.067	.120
B. Onset time of maximum pupil diameter on n-back trials
Younger	Group	1, 39	2.25	.055	.142
Younger	Load	2.57, 100.1	4.21	.097	.011
Younger	Group × Load	2.57, 100.1	0.79	.020	.484
Older	Group	1, 31	0.37	.012	.546
Older	Load	1.72, 53.41	2.48	.074	.101
Older	Group × Load	1.72, 53.41	0.36	.011	.670

Note. Because older participants did not complete the 3-back load, these analyses were performed for each age group separately. Pupil diameter values during each trial were baseline-corrected prior to analysis based on the mean pupil diameter in the fixation period at the start of the respective block, before participants were aware of the working memory load tested on that block. ANOVAs included only trials for which participants made a correct response or correctly withheld a response.