Table 2.

Comparing Group Performance on Motion Coherence and Equivalent Noise Tasks

		t	df*	PValue†	Cohen'sd
Coherence	Th	−2.37	37	0.01‡	0.78
Motion	σint	−2.33	33.02	0.03	0.71
	nsamp	−0.04	41	0.97	0.02
Orientation	σint	1.21	41	0.23	0.38
	nsamp	1.82	32.56	0.08	0.59
Size	σint	0.22	39	0.83	0.07
	nsamp	−0.67	38	0.51	0.22

Migraine and control group performance were compared using independent t-tests. Bonferroni corrections were made for three multiple comparisons in the analysis of equivalent noise measures, reflecting the three different visual dimensions tested (corrected α = 0.0167). t, t-statistic; Cohen's d, effect size; Th, motion coherence threshold; σ_int, internal noise; n_samp, sampling.

^* Appropriate corrections were made to df, where equal variances could not be assumed.

^† P values reported are for 2-tailed tests, with the exception of the analysis of motion coherence thresholds, for which a single-tailed test was used (corrected α = 0.1) (see Motion Coherence Thresholds section for further details).

^‡ Significant effect at the stated α level.