Flicker thresholds as determined by a modified conditioned suppression procedure.

Schusterman (1966) built a tiny flicker test for pigeons.

The birds pecked for food on a steady light.

When the light began to flicker, a brief shock followed.

Soon the birds froze when they saw the flicker start.

By slowly changing how fast the light blinked, the team found the exact speed each bird could still see.

All three birds showed clear flicker thresholds.

The slowest bird saw 6 blinks per second.

The fastest saw 77 blinks per second.

Brighter lights let the birds see faster flicker.

The conditioned-suppression method gave clean, repeatable numbers.

Zimmerman (1969) copied the same shock-freeze trick but used smell instead of light.

The pigeons again showed sharp thresholds, proving the method works across senses.

Hodos et al. (1976) later swapped flicker for motion and still got tidy thresholds near 5 mm/s.

Together these papers show one procedure can map vision, smell, and motion limits in the same animal.

No contradictions appear; each study just tests a new sensory line.

You now have a quick, sensitive way to check if a client can detect a signal.

Use conditioned suppression to find the dimmest light, softest sound, or faintest smell the person notices.

Start with a safe warning stimulus, pair it with a brief mild event, then fade the intensity until responding stops.

The threshold you record becomes the exact place to begin teaching or to adjust the environment.