Periodic shock with added clock.

Hendry et al. (1969) tested how warning cues change the way animals respond to periodic shocks.

They used a clock that ticked faster as the next shock got closer.

The team watched response rates with and without these clock cues.

When the clock was added, response rates went up.

Lower shock intensity produced slower responding; higher intensity sped it up.

The pattern of responding curved differently depending on both intensity and cues.

Leaf et al. (2012) later showed the same thing: shock intensity can either slow or speed responses, proving the 1969 result was not a fluke.

DARDANO et al. (1964) had already seen mixed effects with shocks inside ratio schedules, so the 1969 paper extends that idea to periodic shocks plus warning cues.

Lattal (1974) found positive effects when combining light and tone cues with shock, while P et al. saw mixed effects with clock cues. The difference is simple: A used food plus shock, P used shock only, so the cues served different functions.

Warning stimuli can flip the effect of aversive events from suppression to acceleration.

When you add a visual or auditory timer before a difficult task, clients may work faster instead of shutting down.

Try pairing a fading cue with low-level aversive events next session and watch response patterns change.