Q1:

S₁: Since the sixties there has been an increasing interest in neurophysiology, which deals with the neural bases of mental activity and behaviour.

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.

S₆: So far the journal has published the mixture of articles including reports and investigations.

The Proper sequence should be:

Question

S₁:	Since the sixties there has been an increasing interest in neurophysiology, which deals with the neural bases of mental activity and behaviour.
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.
S₆:	So far the journal has published the mixture of articles including reports and investigations.

The Proper sequence should be:

Ordering of Sentences