In each question, the first and the last sentences of the passage are numbered S1 and S6 respectively. The rest of the passage is split into four parts. These four sentences are jumbled. Read the sentences and identify their correct and logical order.

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S1: Yawning or its absence has been related to various clinical conditions.
P: Interestingly, some clinicians claim that those with acute physical illness don't yawn until they are on road to recovery.
Q: It can be a symptom of brain lesions, haemorrhage, motion sickness and encephalitis.
R: But what is currently known about yawning is essentially anecdotal, mostly because the yawn has not got the respect it deserves.
S: On the other hand, it has been reported that psychotics rarely yawn, except those suffering from brain damage.
S6: It is in reality a releasing stimulus.
The Proper sequence should be: