Answer:
perceptual sets.
Step-by-step explanation:
Perceptual set: In psychology, the term perceptual set is determined as an individual's susceptibility or predisposition to perceive or recognize specific things in a certain manner or way. In other words, the perceptual set is described as an individual's propensity to notice only a few aspects of a particular object and therefore ignoring all other aspects or details.
In the question above, the given statement signifies that Professor Brandt is conducting a study on the perceptual sets.