Day 128 MCAT Practice Question

Correct answer is C

In a person’s daily interactions with the world, the body is flooded with a deluge

of sensory stimuli in a variety of forms: auditory, visual, tactile, etc. If the body

attempted to perceive and understand everything it sensed, the brain would quickly

become overwhelmed by the volume and diversity of stimuli. As a result, the brain

has a variety of mechanisms that allow it to “focus” on particular stimuli and sort

through what is truly important while ignoring less relevant details.

One of these mechanisms is the sensory threshold, which is the body’s way of

distinguishing between the low-level, unimportant, or constant stimuli and stimuli

that constitutes a significant change from the background. The sensory threshold

theory states that there are certain thresholds a stimuli must overcome in order

to be perceived by the brain. For example, if someone is staring out into a field of

green grass, there must be a particular threshold of difference in color that a bird

must overcome in order for the brain to understand that there is a distinct animal

worth noting against the green background. This concept is also known as the

difference threshold or just noticeable difference. Because the sensory threshold

theory does account for the amount of novel stimuli required to overcome the

background stimuli, answer C is correct.