What defines an ascending series in psychophysics?

An ascending series in psychophysics specifically refers to a method where the intensity of a stimulus is progressively increased until it reaches the point of detection by a subject. This approach is commonly used to establish thresholds in sensory perception. In this context, the ascending series allows researchers to determine the minimum intensity at which a stimulus is perceived, which is critical for understanding sensory systems and their thresholds.

In psychophysical experiments, the ascending series often starts from a lower intensity that is clearly sub-threshold, meaning the stimulus is undetectable, and continues to increase until the participant reports being able to perceive it. This creates a systematic way to measure perceptual sensitivity, effectively mapping out how changes in stimulus intensity correlate with changes in perception.

While other methods in psychophysics, such as descending series or adaptive techniques, focus on different mechanisms of determining thresholds, the ascending series specifically highlights the systematic increase in intensity to ascertain detection levels. This concept is integral to various fields, including psychology, neuroscience, and sensory physiology, as it helps to define how we understand the relationship between stimulus characteristics and perceptual experiences.