In the questions below, each passage consists of six sentences. The first and sixth sentences are given in the beginning as (S1) & (S6) respectively. The middle four sentences of each passage have been removed and jumbled up. These are labeled as P, Q, R and S. Find out the proper order for the four sentences. S1: Since the sixties there has been an increasing interest in neurophysiology, which deals with the neural bases of mental activity and behavior. S6: So far the journal has published the mixture of articles including reports and investigations. P: It has format which is very similar to that of Brain and Language, a sister journal. Q: Since then, a number of journals devoted entirely to this area of research have appeared. R: Before the 1960's when this field was the concern of a small number of investigators, research articles were scattered in various neurological journals. S: Brain and cognition is one such journal. The proper sequence should be: