Final answer:
In this experiment, Jillian is least likely to detect changes in the signals presented to her right ear while shadowing a message presented to her left ear in a dichotic listening task measuring selective attention.
Step-by-step explanation:
In this experiment, Jillian is participating in a task known as dichotic listening, where she listens to a message presented to the left ear while ignoring a message presented to the right ear. The purpose of this task is to measure selective attention, which refers to the ability to focus on a specific stimulus while ignoring others.
Based on the information provided, Jillian is LEAST likely to detect changes in the signals that are presented to the right ear. Since she is instructed to ignore the message presented to the right ear, her attention and focus are directed towards the message presented to the left ear. As a result, her ability to detect changes in the signals presented to the right ear is diminished.
It is important to note that the specific changes in the signals are not mentioned in the question, so we cannot provide specific examples.