Question

The least possible level of sensation is called as _______

• A. Olfaction
• B. Threshold
• C. Hearing
• D. Smell

Hint:

Think of a threshold like a doorway. You must step over the bottom beam (the minimum energy) to actually enter the room (the state of being sensed). If the energy is below the beam, you stay outside and feel nothing.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question relates to the field of psychophysics and sensory biology, asking for the technical term used to describe the minimum intensity of a stimulus required for detection.
Step 2: Detailed Explanation:

Concept of Threshold: In sensory science, a "threshold" refers to the boundary between perceivable and unperceivable stimuli. It is the minimum level at which a sense organ can detect a change or the presence of a stimulus.

Absolute Threshold: More specifically, this refers to the "Absolute Threshold," defined as the lowest intensity of a stimulus (light, sound, touch, etc.) that an organism can detect at least $50%$ of the time. For instance, the absolute threshold for vision is the dimmest light that can be seen in a completely dark room.

Psychophysical Significance: Understanding thresholds helps researchers determine the sensitivity of different human senses and how they might vary based on age, health, or environmental factors.

Distinguishing Options: Olfaction (A) and Smell (D) are synonyms referring to the specific sense of detecting chemicals in the air; they are types of sensation, not the "level" of detection. Hearing (C) is the sensory modality for sound. None of these describe a generalized quantitative level of detection.

Sensory Processing: Sensation begins when a stimulus reaches the threshold level, triggering a neural impulse in the receptors, which is then transmitted to the brain for perception. Without reaching this threshold, the stimulus remains "subliminal."

Step 3: Final Answer:
The term "Threshold" correctly defines the quantitative limit or least possible level required for a sensation to occur in the nervous system.

Answer 2

Picture slowly turning up the volume on a radio from complete silence. At some very low volume, you suddenly start to notice sound where a moment ago you heard nothing. That exact tipping point is the idea this question is describing, and checking it against each option confirms which one fits.

1. Olfaction: This word just labels the sense of smell as a whole, it says nothing about a tipping or detection point, so it doesn't match the description.
2. Threshold: The tipping point in the radio example, the exact minimum intensity at which a stimulus first becomes noticeable, is precisely what "threshold" (specifically the absolute threshold) means in sensory science. It applies whether the stimulus is sound, light, touch, or any other input.
3. Hearing: Hearing names the sensory channel being used (sound), not the minimum intensity needed to trigger a response through that channel.
4. Smell: Like olfaction, this is just the everyday name for one sense, unrelated to describing a minimum detection level.

The radio example only illustrates one of these four ideas, the point where a stimulus becomes just barely detectable, which is the threshold.

Therefore, the correct answer is Threshold.