Table 1.

Parameter Values Averaged over Participants

Session	a	Ter	η	sz	v1	v2	v3	v4	po	st	vc	z	χ2
Experimental Group
Baseline	.151	.428	.171	.066	.546	.416	.271	.093	.003	.138	.007	.075	101
Sleep-deprived	.189	.401	.216	.130	.403	.318	.198	.083	.101	.165	.011	.089	163
Recovery	.151	.420	.209	.083	.615	.491	.308	.110	.001	.113	.005	.076	101
Control Group
Baseline	.152	.428	.179	.069	.558	.452	.300	.097	.007	.139	.004	.073	88
Control	.136	.426	.165	.061	.549	.453	.294	.099	.012	.127	.005	.064	79
Recovery	.132	.412	.156	.061	.579	.456	.311	.100	.014	.119	−.002	.064	81

Note—a, upper boundary of accumulation of information over time; T_er, mean of the distribution of times taken up by the nondecision component, in seconds. η, s_z, and s_t represent across-trial variability in drift rate, in starting point, and in the nondecision component, respectively. v₁, v₂, v₃, and v₄ represent the four distinct drift-rate parameters for the eight numerosity categories (see the text for details). p_o, proportion of contaminants; v_c, drift criterion; z, starting point of accumulation of information over time. χ² represents the goodness-of-fit index with critical value 102 for 76 degrees of freedom. For a total of k numerosity categories and a model with m parameters, the degrees of freedom are k(12 − 1) − m, where 12 comes from the number of bins between and outside the response time quantiles for correct and error responses for a single category (minus 1, because the total probability mass must be 1). There were k = 8 numerosity categories in the experiment and m = 12 parameters in the model, so df = 88 − 12 = 76.