A simple system for the remote detection and analysis of sniffing in explosives detection dogs

In this article, we describe a device that we have developed, for both research and operational purposes, to assist handlers of sniffer dogs and improve efficiency of search. The device transmits sounds from the dog’s muzzle area to a listener, enabling determination of whether the dog is actually sniffing during a search. Both the aural and the computerized sound analyses enable study of the dog’s sniffing behavior under a variety of situations. Correlation of these data with the visually monitored behavior of the working dog contributes additional and important information and leads to a greater under-standing of detector dogs’ behavior and abilities.     

The role of context specificity in learning: the effects of training context on explosives detection in dogs

Various experiments revealed that if an animal learns a stimulus–response–reinforcer relationship in one context and is then tested in another context there is usually a lessening of stimulus control, and the same discriminative stimuli that reliably controlled the behavior in the first context will have less effect in the new context. This reduction in performance is known as the context shift effect. The effect of changing context on the probability of detecting explosives was investigated in seven highly trained explosives detection dogs (EDDs). In experiment 1 the dogs were trained alternately on path A, which always had five hidden explosives, and on a very similar path B, which never had any explosives. Within a few sessions the dogs showed a significant decrease in search behavior on path B, but not on path A. In experiment 2 the same dogs were trained only on path B with a target density of one explosive hidden every 4th day. The probability of the dogs now detecting the explosive was found to be significantly lower than in experiment 1. In experiment 3 the effect of the low target density as used in experiment 2 was investigated on a new but very similar path C. Both the detection probability for the one explosive every 4th day on the new path and the motivation to search were significantly higher than found in experiment 2. Finally, in experiment 4, an attempt was made to recondition the dogs to search on path B. Although trained for 12 daily sessions with one explosive hidden every session, the dogs failed to regain the normal levels of motivation they had shown on both new paths and on the paths that they knew usually contained explosives. The findings reveal that even a very intensively trained EDD will rapidly learn that a specific stretch of path does not contain explosives. The dog will then be less motivated to search and will miss newly placed targets. This learning is specific to the formerly always-clean path and is to some extent irreversible. However, the dog will search and detect normally on new paths even if they are very similar to the always-clean path. The data are discussed in terms of variables affecting renewal. The results suggest that following training designed to make a behavior context independent, any extinction training will not generalize beyond that specific context used during the extinction training. In addition, if the behavior is extinguished in a specific context, it will be very difficult to restore that behavior in that context. These conclusions should be considered by anyone attempting to extinguish well-established trans-context behaviors.This research reports portions of a doctoral dissertation submitted by Irit Gazit to Tel Aviv University.     

Attentional bias for threat: Evidence for delayed disengagement from emotional faces

This study examined cognitive aspects of coping with stress, how these related to religiosity, and how they related to outcomes (positive mood and distress). Participants (n=126) were of Protestant or Jewish background, and had all experienced recent major stress. They were assessed on measures of religiosity, religious coping, perception of the consequences of the stressful event, attributions for its occurrence, and distress, intrusive unpleasant thoughts, and positive affect. Religiosity affected ways of thinking about the stressful situation, namely: Belief that G-d is enabling the individual to bear their troubles (religious/spiritual support), belief that it was all for the best, and (more weakly) belief that all is ultimately controlled by G-d. Religiosity affected neither the proportion of positive consequences perceived as outcomes of the event, nor the causal attributions examined. Religious background (Protestant vs. Jewish) had negligible effects on the cognitions measures. Causal pathway analysis suggested that religion-related cognitions might directly affect positive affect, but not distress. Problems of design and interpretation are discussed. The study suggests some cognitively mediated means by which religion may have comforting effects.