Which of the following best defines Weber's Law as it is understood in AP Psychology?

• A. Weber's Law states that the just noticeable difference between two stimuli is a constant proportion of the original stimulus intensity.
• B. Weber's Law states that sensory adaptation occurs when a stimulus is presented repeatedly over time.
• C. Weber's Law states that perception is determined solely by the absolute threshold of a stimulus.
• D. Weber's Law states that the difference threshold increases as the intensity of the stimulus decreases.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the concept of Weber's Law in the context of sensation and perception. Weber's Law relates to how we detect differences between stimuli, specifically focusing on the 'just noticeable difference' (JND).
2. Step 2: Define the 'just noticeable difference' (JND) as the smallest change in stimulus intensity that a person can detect 50% of the time.
3. Step 3: Recognize that Weber's Law states the JND is not a fixed amount but rather a constant proportion relative to the original stimulus intensity. This means the ability to detect differences depends on the ratio between the change and the original stimulus.
4. Step 4: Express Weber's Law mathematically as \(\frac{\Delta I}{I} = k\), where \(\Delta I\) is the change in stimulus intensity (JND), \(I\) is the original stimulus intensity, and \(k\) is a constant proportion specific to the type of stimulus.
5. Step 5: Compare the given answer choices to this understanding and identify the one that correctly states Weber's Law as the constant proportional relationship between the JND and the original stimulus intensity.