A laboratory model of canine search vigilance decrement, I
Rare targets crash detection fast, but tail drop and slow starts give you an early warning.
01Research in Context
What this study did
Eighteen dogs searched for a target smell in a lab olfactometer. The machine gave the smell on 90% of trials, then dropped it to only 10%.
The team flipped the odds back and forth in an ABAB design. They watched accuracy, tail height, and how long each dog took to start sniffing.
What they found
When targets became rare, every dog missed more smells. Accuracy fell hard, but tail drops and slower starts showed the slump right away.
Bringing targets back to 90% quickly fixed the problem. The drop and rebound were large and reversible for all dogs.
How this fits with other research
Mattson et al. (2024) say latency is a useful measure when responses are hard to count. Aviles-Rosa puts that idea in dogs: search delay flagged the vigilance slip before misses piled up.
Dougherty et al. (1996) saw pigeons stay sharp on "no-signal" trials while miss rates rose on rare signals. The same low-signal trap hurt dogs, showing the effect crosses species and senses.
Rincover et al. (1975) found that reinforcing wrong choices hurt perceptual sensitivity. Here, no extra rewards were given, yet rare hits alone were enough to erode accuracy, so prevalence matters as much as payoff.
Why it matters
If you train detection dogs, security teams, or even teach kids to spot rare items, keep hit rates high during early practice. Watch latency and body cues; they warn the learner is about to check out. When the real world will thin out targets, fade prevalence slowly and mix in easy wins so vigilance does not crash.
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02At a glance
03Original abstract
Previous studies have found that infrequent targets can reduce dogs' vigilance. The purpose of this study was to develop a laboratory model to evaluate the effects of infrequent targets on dogs' search behavior and performance. Dogs (n = 18) were trained to detect smokeless powder in an automated olfactometer in two distinct rooms ("operational" and "training"). During baseline, the dogs received five daily sessions at a high target odor frequency (90%) in both rooms. Subsequently, the frequency of the target odor was decreased to 10% only in the "operational" room but remained at 90% in the training room. Last, the odor prevalence was returned to 90% in both rooms. All dogs showed a significant decrement in detection performance in the operational room when the target odor frequency was decreased but simultaneusly mantained high performance in the training room. This decrement was largely due to decreases in adequate search behavior. All dogs recovered performance when the odor frequency was increased again to 90%. Trial accuracy was associated with tail position, search score, latency, and duration of environmentally directed behaviors. The data show that low target odor prevalence significantly reduced search behavior and performance and that there are behaviors that can be used by handlers to assess their dog's search state.
Journal of the Experimental Analysis of Behavior, 2023 · doi:10.1002/jeab.832