Chronic cannabis use alters the spontaneous and oscillatory gamma dynamics serving cognitive control.
Human brain mapping August 1, 2024 Mikki Schantell, Jason A John, Anna T Coutant et al.
Regular cannabis use is linked to suppressed spontaneous gamma brain activity in regions that support cognitive control, specifically the left frontal eye fields (FEF) and left temporoparietal junction (TPJ). In a study of 34 cannabis users and 33 nonusers performing a flanker task during magnetoencephalography, cannabis users showed no difference in gamma oscillations between incongruent and congruent trials, whereas nonusers exhibited stronger gamma during incongruent trials. Spontaneous gamma activity was sharply reduced in cannabis users in both brain regions, and greater cannabis use was associated with weaker spontaneous gamma activity in the left TPJ. These findings suggest that regular cannabis use dampens baseline gamma activity in cognitive control networks, and the degree of suppression may scale with the amount of use.