Smoking induced changes in EEG two-dimensional maps and blood gas analysis

Area of Science:

• Neuroscience
• Psychophysiology
• Toxicology

Background:

• Smoking is a prevalent habit with known health consequences.
• Its effects on cognitive function and brain activity, particularly electroencephalography (EEG) patterns, require further elucidation.
• Understanding these effects is crucial for public health and individual well-being.

Purpose of the Study:

• To investigate the acute effects of smoking on mental function using two-dimensional EEG mapping.
• To analyze the relationship between EEG changes and blood gas parameters, specifically partial pressure of carbon dioxide (pCO2) and carboxyhemoglobin (%COHb).
• To differentiate the impact of smoking on EEG in fast versus slow smokers.

Main Methods:

• Healthy medical students underwent EEG recordings with eyes closed, before and after smoking.
• Two-dimensional EEG maps of alpha activity were generated using unbiased polynomial interpolation.
• Blood gas analysis, including pCO2 and %COHb, was performed simultaneously with EEG.
• Subjects abstained from smoking for 24 hours between testing sessions.

Main Results:

• Smoking induced a widespread decrease in alpha activity amplitude on EEG maps.
• Alpha amplitude increased after 24 hours of smoking withdrawal but decreased upon resuming smoking.
• No significant correlation was found between EEG amplitude changes and %COHb levels.
• A clear negative correlation (r ≈ -0.7) was observed between EEG amplitude changes and pCO2 in quick smokers, but not in slow smokers.

Conclusions:

• Acute smoking alters brain activity, evidenced by reduced alpha EEG amplitude.
• The observed correlation between EEG changes and pCO2 in quick smokers suggests a potential role of hyperventilation.
• These findings highlight the complex physiological responses to smoking and individual variability in its effects on mental function.