After an 8-month-old successfully solved the object-under-the-blanket task several times, Piaget introduced a second blanket next to the first, showed the infant the object, and this time placed it under the second blanket. Infants at this age then looked for the object _

under the first blanket    

Explanation:

In the question above, the eight-month-old child is in the sensorimotor stage of cognitive development and more specifically in the second sub-stage of sensorimotor stage i.e, secondary circular reaction.

According to Piaget, a child who is in the secondary circular reactions' sub-stage possesses the age between four to eight months. In this sub-stage, a child is more focused towards the world around him or her and therefore purposefully repeat a specific behavior in order to get a similar response from the surrounding environment. A child often becomes "object-oriented" at this stage.

explanation:

allergens: overstimulate the nerve system

neurotics: attack nerve cells

mutagens: damage or otherwise alter dna sequence

generators: cause defects during growth and development  

carcinogens: cause unchecked cell growth

i hope you get the idea according to me these are the effects that happened.