According to Weber's law, which of the following best describes how the just noticeable difference (JND) relates to the intensity of a stimulus?

• A. The JND decreases as the stimulus intensity increases.
• B. The JND is unrelated to the original stimulus intensity.
• C. The JND remains the same regardless of the stimulus intensity.
• D. The JND is a constant proportion of the original stimulus intensity.

Answer: (D)

Verified step by step guidance

1. Understand that Weber's law describes the relationship between the just noticeable difference (JND) and the intensity of the original stimulus.
2. Recall that Weber's law states the JND is proportional to the original stimulus intensity, meaning the ratio of the JND to the stimulus intensity is constant.
3. Express this relationship mathematically as \(\frac{\Delta I}{I} = k\), where \(\Delta I\) is the JND, \(I\) is the original stimulus intensity, and \(k\) is a constant called the Weber fraction.
4. Interpret this formula to mean that as the stimulus intensity \(I\) increases, the JND \(\Delta I\) also increases proportionally, maintaining a constant ratio.
5. Conclude that the JND does not remain the same or decrease with increasing stimulus intensity, but instead changes in direct proportion to it, which aligns with the correct answer.