This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sleep Disorders, Subject name: Psychiatry
[{'content': 'In which stage of the sleep we can see spindle complexes and sleep spindles in EEG? \nSelect and explain. \nA. Stage N1, B. Stage N2, C. Stage N3, D. REM', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. Stage N2Sleep is scored in epochs of 30 seconds, with stages of sleep defined by visual scoring of 3 parameters: electroencephalogram (EEG), electrooculogram (EOG) & electromyogram (EMG) recorded beneath chin.1. NREM:* Stage 1: 1st stage, light sleep, loss of alpha waves (eyes closed but awake) and predominant theta waves* Stage 2: Maximum time spent. Findings in EEG include- Sleep spindles: bursts of waves of frequency of 11-16Hz- K-complexes: high voltage spikes, negative sharp waves followed by positive waves* Stage 3: Deepening of sleep, appearance of delta waves.* Stage 4: Deep sleep characterized by delta waves- New NREM stages: N1 (stage 1), N2 (stage 2), N3 (stage 3+4)2. REM sleep: (aka paradoxical sleep)* EEG: beta wave (similar to awake state), alpha wave', 'role': 'assistant'}]