Table 2.

Unbounded models: nested model hierarchical analysis

	NLL		LLR
	${\mathcal{U}}_{\text{b}}$	${\mathcal{U}}_{+1}=\hspace{0.17em}\left\{{\mathcal{U}}_{\text{b}},\eta \right\}$	$\frac{{\mathcal{U}}_{+1}}{{\mathcal{U}}_{\text{b}}}$	$\frac{{\mathcal{U}}_{+2}=\left\{{\mathcal{U}}_{+1},\mu \right\}}{{\mathcal{U}}_{+1}}$	$\frac{{\mathcal{U}}_{+2}\hspace{0.17em}=\hspace{0.17em}\{{\mathcal{U}}_{+1},z_0\}}{{\mathcal{U}}_{+1}}$	$\frac{{\mathcal{U}}_{+2}\hspace{0.17em}=\hspace{0.17em}\left\{{\mathcal{U}}_{+1},z\right\}}{{\mathcal{U}}_{+1}}$	Resulting Model Parameters
pDDM, cbDDM ${\mathcal{U}}_{\text{b}}=\hspace{0.17em}\left\{\sigma \right\}$	313 [309, 387]	303*** [291, 376]	12** [9.0, 14]	−412 [−485, −308]	−31 [−48, −1.4]	1.5* [0.2, 2.1]	$\mathcal{U}=\left\{\sigma ,\eta \right\}$
usDDM ${\mathcal{U}}_{\text{b}}=\left\{\sigma ,{\lambda }_{\infty },{\tau }_{\lambda }\right\}$	433*** [387, 483]	501 [460, 571]	−65 [−120, 2.7]				$\mathcal{U}=\left\{\sigma ,{\lambda }_{\infty },{\tau }_{\lambda }\right\}$
hpfDDM§ ${\mathcal{U}}_{\text{b}}=\left\{\sigma ,\tau \right\}$	302*** [290, 375]			−459 [−783, −276]	−212 [−251, −164]	0.00 [−0.00, 0.00]	$\mathcal{U}=\left\{\sigma ,\tau \right\}$

Values are medians [quartiles].

^*Marginally significant improvement (0.05 > P > 0.01) for 4 subjects.

^**Significant improvement (P < 0.01, ${\chi }_1^2>6.6$) for 11 subjects. For the remaining 1 subject, additional free parameter did not alter the fit (χ² = 0).

^***(Bold) High statistical significance (P < 0.01, ${\chi }_1^2>6.6$) for all 12 subjects.

^§For hpfDDM, threshold expression Eq. 15 is undefined when τ = 0.