Human Perception & Sensory Physiology Flashcards

Weber's law states that the just-noticeable difference (JND) is:

Answer: A constant proportion of the original stimulus intensity

Weber's law states ΔI/I = k, so the JND grows proportionally with the baseline intensity.

Fechner's law describes perceived sensation magnitude as a function of stimulus intensity that is:

Answer: Logarithmic

Fechner proposed sensation increases with the logarithm of stimulus intensity.

In Stevens' power law (S = kI^n), an exponent n less than 1 indicates that:

Answer: Perceived intensity grows more slowly than physical intensity

Exponents below 1 compress perception, so doubling the stimulus less than doubles perceived intensity.

The lowest concentration at which a stimulus is detected (but not necessarily identified) 50% of the time is the:

Answer: Detection (absolute) threshold

The detection threshold is typically defined as the concentration detected on 50% of presentations.

Compared with the detection threshold, the recognition threshold for a tastant is usually:

Answer: Higher

More stimulus is needed to identify a quality than merely to detect its presence.

The concentration above which further increases produce no change in perceived intensity is the:

Answer: Terminal threshold

The terminal threshold marks saturation, beyond which intensity no longer rises.

In signal detection theory, the d' (d-prime) statistic measures:

Answer: Sensory discriminability independent of response bias

d' quantifies the separation between signal and noise distributions, independent of the criterion.