Final answer:
The stimuli used in Study 1 most likely vary in wavelength.
Step-by-step explanation:
The stimuli used in Study 1 most likely vary in wavelength.
In Study 1, the physical dimension that is likely to vary in the stimuli is wavelength. Wavelength refers to the length of a wave from one peak to the next. Different stimuli can have different wavelengths, leading to variations in their appearance or characteristics.
For example, in the electromagnetic spectrum, visible light consists of waves with wavelengths between 380 nm and 740 nm. The perceived color of light is associated with different wavelengths, with longer wavelengths appearing as red and shorter wavelengths appearing as blue or violet.