A noisy brain simply means that the brain cells are firing at higher levels, causing changes in brain wave activity, causing changes in cognition. What does this mean for cannabis consumers?
The brain’s resting state is defined as a period of time when one is awake, but not engaged in any tasks. This is used as a baseline measure of the brain’s functional activity. The resting state does not imply mental inactivity, but rather a ‘state of mind’ that responds quickly to any change to external stimuli. Noisy brain is characterized by a brain that has firing times that are random. This can have negative impact on decision making, perception, memory recall, and short-term memory.
It has been reported that cannabis may alter the electrophysiology in the brain and cause “noisy brain.” This has significant impact on cognition.
Investigating a Connection Between Noisy Brain and Cannabis
A recent study used an EEG test to detect differences in electrical charges that reflect the changes in brain cell activity. The test is used to find abnormalities in the electrical activity of the brain that would indicate a brain disorder. EEG signal is separated in differing frequency bands: delta (1-4Hz), theta (4-7Hz), alpha (8-12Hz), beta (13-30Hz) and gamma (30Hz) and above.
Oscillations in these bands vary depending on task engagement or resting state. This allows them to be used as a measure of comparison between a neuro-typical individual versus one using psychoactive stimuli (cannabis, drugs of abuse etc). Actually, differences in the resting state are directly related to cognition, which in term might be related to neuropathology.
The study hosted 38 participants, 17 of whom used cannabis for at least seven days over the past 30 days; and 21 non-using controls, with no use in the 90 days prior to the study. The average age of all the participants was 30 years old.
The aim of the study was to characterize the brain’s resting state, via EEG, in the cannabis users vs non-users, which is related to the cortical activity. This in turn will show if there is any disruption in the cognitive processes resulting in the “noisy” brain in the resting state. Some previous studies suggested dose-dependent effects in theta and beta bands, indicating that these specific frequencies might be more susceptible to the changes in the cortical activity related to the cannabis use.
Changes in Brain Waves of Cannabis Consumers
The EEG results showed that cannabis consumers have decreased power in the delta band, compared to non-users. These are the slowest waves and are associated with sleep. The implications are that cannabis could cause a sleep-like state in regular consumers.
Conversely, power was significantly increased in theta and beta bands for those using cannabis. Theta waves are linked to inefficiency, or daydreaming. These levels also arise from the emotional stress and disappointment. High level in theta is associated with ADHD.
Beta waves are short, fast waves, and are more focused on the memory tasks and concentration. Interestingly, in one study, all alcohol-dependent participants showed an increase in the beta waves. Since this holds true for the cannabis consumer as well, it could be speculated that this hyper-excited state may be a target for addiction treatment.
There was also an increase in the gamma band, compared to non-consuming controls. Gamma is associated with consciousness. Beta and gamma waves are related to perception, cognition, and attention.
The alpha band did not show any difference compared to controls. This band is associated with disengagement and relaxation. The absence of the change in the alpha waves might be a compensatory mechanism to mend the increased neuronal activity. Further studies are required to confirm these speculations.
Is Noisy Brain a Potential Problem for Cannabis Consumers?
To summarize, the study findings suggest that cannabis consumers showed increased cortical activity during the resting state (increase theta, beta and gamma waves, and a decrease in the delta) compared to the controls. Cannabis consumers also demonstrated greater coherence in the frontal regions compared to the non-users.
These results were opposite from the typical frequency dynamics. Increased cortical activation in the resting state has also been observed in the alcohol-dependent and cocaine-dependent users. This shows a significant influence of cannabis on the electrophysiological signals. Perhaps future studies should focus on the differences between the abstinence (long and short-term) and intoxication. This is important to determine the persistence of changes and the long-term effects.