Altered fronto-occipital connectivity during visual selective attention in regular cannabis users

Area of Science:

• Neuroscience
• Cognitive Psychology
• Addiction Research

Background:

• While acute cannabis use is linked to cognitive deficits, evidence on chronic use is mixed.
• Neuroimaging studies suggest selective attention differences in chronic cannabis users, but underlying neural dynamics remain unclear.

Purpose of the Study:

• To investigate the neural dynamics of selective attention in chronic, regular cannabis users.
• To compare brain activity and functional connectivity during a visual attention task between cannabis users and controls.

Main Methods:

• Magnetoencephalography (MEG) was used to record brain activity in 24 regular cannabis users and 24 matched controls during a visual selective attention task.
• A data-driven method identified time-frequency windows, and beamforming imaged spectrally specific neural activity.

Main Results:

• All participants performed within the normal range on the cognitive task.
• Cannabis users exhibited aberrant theta (4-8 Hz) interference activity in the right occipital cortex (0-250 ms post-stimulus onset).
• Altered functional connectivity was observed between the right prefrontal and occipital cortices in cannabis users.

Conclusions:

• Regular cannabis use is associated with abnormal theta-band neural activity and prefrontal-occipital connectivity during visual selective attention.
• These neural differences may represent compensatory processing, as task performance was comparable to controls.
• Understanding these neural dynamics offers insights into how long-term cannabis use impacts cognitive networks.