What type of brain waves are characterized by low amplitude and a frequency of about 8 to 13 cycles per second?

Alpha waves are indeed characterized by low amplitude and a frequency of about 8 to 13 cycles per second. They are typically associated with a state of relaxed wakefulness, often seen when a person is calmly resting or meditating. When individuals close their eyes and reduce their sensory input, alpha wave activity increases, reflecting a state of relaxation without deep sleep.

In contrast, beta waves, which have a higher frequency, are associated with active thinking, problem-solving, and high alertness. Delta waves are very low frequency and are linked to deep sleep. Theta waves occur at a lower frequency than alpha waves and are often associated with lighter stages of sleep or deep relaxation. Recognizing these different wave types helps in understanding how brain activity relates to varying states of consciousness and alertness.