Fechner’s Law

Definition: Fechner’s Law, proposed by Gustav Fechner, is a psychological theory that relates the intensity of a physical stimulus to the subjective perception of that stimulus. It establishes a logarithmic relationship between the physical magnitude of a stimulus and the psychological experience generated by it.

Key Points:

• Psychophysics: Fechner’s Law is a fundamental concept in the field of psychophysics, which explores the quantitative relationship between physical stimuli and psychological responses.
• Logarithmic Scaling: According to Fechner’s Law, our perception of a stimulus does not increase linearly with its physical intensity. Instead, it follows a logarithmic function, meaning that the perceived magnitude of a stimulus increases proportionally to the logarithm of its physical intensity.
• Thresholds: Fechner’s Law also suggests the existence of absolute and difference thresholds. The absolute threshold refers to the minimum intensity required for a stimulus to be consciously detected, while the difference threshold is the minimum amount of change in stimulus intensity needed for a person to perceive a difference.
• Weber’s Law: Fechner’s Law builds upon Weber’s Law, which states that the difference threshold is a constant proportion of the initial stimulus intensity. Fechner expanded on this principle and developed a logarithmic equation to describe the relationship between physical stimuli and psychological experience more precisely.
• Sensation and Perception: Fechner’s Law contributes to our understanding of how sensory information is received and processed by the human brain, highlighting the complex interplay between physical reality and subjective experience.

Overall, Fechner’s Law provides a mathematical framework for studying the connection between physical stimuli and our psychological perception of them. It has broad implications in various fields, including psychology, neuroscience, marketing, and design.