The whirligig of time: Some thoughts on Staddon and Higa.

Malone (1999) wrote a short, sharp note about Staddon and Higa's timing model. The paper checks whether their equations really match the stimulus events that control behavior in time-based schedules.

No animals, no data sheets—just a conceptual audit. The author asks: does the model track what actually happens to the organism, or does it sneak in an invisible clock?

The model is found wanting. J argues it invents extra steps that have no environmental support. In plain words, the math looks tidy but the story it tells about 'how time is sensed' does not line up with observable reinforcement events.

The takeaway warning: if a timing theory adds hidden gears, you can’t test or falsify them.

Same-year allies Green et al. (1999) and Zeiler (1999) reach similar ‘no-clock’ verdicts. W shows timing can pop out of simple neural traces, while D says timing is just memory—no internal stopwatch needed. Together they form a 1999 wave against timer-based explanations.

Staddon et al. (2002) pick up the baton. Their tuned-trace model keeps the anti-clock spirit but adds one-back decay rules that predict most interval curves. It is a successor: it keeps the critique, then offers a working replacement.

Sherwell et al. (2014) extend the idea into the lab. They prove that brief added cues sharpen animals’ discrimination of when reinforcer ratios flip—empirical support that environmental signals, not hidden clocks, drive temporal control.

When you write a protocol that relies on ‘sense of time’—like increasing a DRO interval or thinning FI schedules—check what stimuli the learner actually receives. Replace vague ‘internal timer’ talk with observable cues: signals, changes in reinforcer quality, or correlated exteroceptive events. If the schedule can’t be described without inventing unseen clocks, redesign it until it can.