Table 1.

Derived measures in the object recognition task

Trial number	Exploration time (s)	Discrimination index
T1	e1 = a1 + a2	Not applicable
T2	e2 = a3 + b	d2 = (b − a3)/e2

e1 is the measure of the time spent in exploring both identical object locations (a1 and a2) during T1, and e2 is the measure of the time spent in exploring both the familiar (a3) and new object location (b) in T2; d2 corresponds to the ability to discriminate between the old and new object location during T2. The d2 index is corrected for exploration time during T2.