Alpha rhythms recorded at which frequencies may indicate abnormal EEG activity in younger populations?

The choice indicating that 9 Hz in O1 and 11.5 Hz in O2 may signify abnormal EEG activity in younger populations is based on the understanding of age-related variations in brain wave patterns. In younger individuals, alpha rhythms typically peak within the range of 8 to 12 Hz, with the most common frequencies being around 10 Hz. However, when specific frequencies, such as 9 Hz and 11.5 Hz, are observed in distinct electrode placements like O1 and O2, they can signify atypical brain activity when compared to expected norms.

These variations can potentially indicate abnormal cortical function or a deviation from the typical alpha activity observed in healthy younger individuals, which generally should be more consistent throughout the alpha band without distinct peaks at unusual frequencies. The reason 9 Hz and 11.5 Hz are particularly noted is that while they reside within the alpha range, they may reflect less stable brain wave patterns associated with certain developmental or neurological conditions in young populations.

In contrast, the other choices either describe frequencies that fall within the normal range while not giving specific values of concern like the selected option, or present patterns that do not directly correlate with abnormal EEG activity in a younger demographic, such as theta frequencies, which are usually