Table 2.

Overview of neural response patterns in adolescent substance users

Response in Substance Users
		IFC	DLPFC	Parietal
Working memory tasks	Cannabis users 71	⬇	⬆	–
	Cannabis users 72 (abstinent)	–	⬇	–
	Alcohol users 71, 73	–	–	⬆
	Alcohol users 74 (long term use)	–	–	⬇
	Alcohol users vs. Comorbid alcohol/cannabis users 72	⬆	–	–
		IFC	DLPFC
Inhibitory control tasks	Cannabis users 79, 80	–*	⬆
		IFC	OFC	Limbic	ACC
Substance signaling stimulus tasks	Alcohol users 85–86	⬇	⬆	⬆	⬆

⬇ = less neural response; ⬆ = greater neural response; – = no neural response difference

Overview of neural response patterns in adolescent substance users. Unless otherwise noted, all groups represent the comparison between adolescent substance users and non-user adolescents. The IFC is typically implicated in inhibitory control processes, DLPFC in working memory function, and parietal cortex in attention. The OFC, as well as limbic system structures, are involved in reward processes, and the ACC in both emotion and cognitive (e.g., conflict monitoring) processes.

^*Though no inhibition related differences is reported, cannabis users showed a greater IFC response during the no-inhibition trials in this study. This pattern may represent a hyperactive basal tone in the IFC of cannabis users.

IFC: Inferior Frontal Cortex; DLPFC: Dorsal Lateral Prefrontal Cortex; OFC: Orbital Frontal Cortex; ACC: Anterior Cingulate Cortex