Final answer:
Allison's pupils constricting to the sound of a camera click without an actual flashbulb is a conditioned response, an anticipation learned from repeated exposure to flashes coupled with the camera's sound. a. A conditioned response.
Step-by-step explanation:
The constriction of Allison's pupils in anticipation of camera flashes, even when no flash is actually used, is an example of a conditioned response. This type of response occurs because Allison has conditioned her pupils to prepare for the bright light of a flash whenever she hears the click of a camera, which acts as a conditioned stimulus. Through repeated associations between the two stimuli, the sound of the camera by itself now triggers a reflexive constriction of the pupils.
The pupillary light reflex is an involuntary reflex that controls the diameter of the pupils. It involves the optical sensory input sending signals for the muscles of the iris to contract or relax, depending on the intensity of light. In Allison's case, her autonomic system has learned to anticipate the flash of a camera, resulting in a slight constriction of the pupils upon hearing the camera click. This constriction helps protect the eyes from sudden changes in brightness.