How will changing the time base from 10 seconds to 20 seconds affect a 12Hz alpha rhythm?

Changing the time base from 10 seconds to 20 seconds affects the visual representation of the alpha rhythm on an EEG record. Specifically, a 12Hz alpha rhythm consists of approximately 12 cycles per second. By extending the time base, each cycle of this rhythm will take up more horizontal space on the display.

When the time base is increased, the waveform is effectively spread over a longer duration, which means that the individual peaks and troughs of the alpha waves become more separated. This visual effect can be described as the waveform becoming compressed in terms of the spacing of the cycles, while simultaneously the duration of the entire recording extends.

This alteration allows for a clearer view of the oscillatory patterns, making it easier for practitioners to analyze the waveform without introducing additional cycles within the same timeframe. It enhances the representation of the rhythm, making it more distinct.

Therefore, increasing the time base from 10 seconds to 20 seconds allows for clearer visualization of the alpha rhythm, confirming that the waveform will be compressed in its representation on the EEG.