According to Mackintosh, no conditioning occurs to the newly inserted second CS in phase II of the typical blocking experiment because:

Question

Quizplus · Accepted Answer

Mackintosh's theory suggests that attention to a stimulus is crucial for conditioning to occur. In the blocking experiment, the second CS introduced in phase II does not gain attention because the first CS already predicts the unconditioned stimulus (US) effectively, leading to the second CS being ignored or not attended to.

According to Mackintosh, No Conditioning Occurs to the Newly Inserted