Lucia Lazarowski | Auburn University (original) (raw)

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Papers by Lucia Lazarowski

Domestic dogs, Canis familiaris, are highly responsive to human communicative cues and can utiliz... more Domestic dogs, Canis familiaris, are highly responsive to human communicative cues and can utilize gestures, such as pointing, to locate hidden rewards. This ability is thought to be the product of both genetic and behavioural selection, allowing dogs to adapt to life with humans. Dogs' responsiveness to human gestures can also lead to suboptimal choices when dogs readily follow misleading cues despite directly contradicting perceptual information such as odour cues. However, this bias likely reflects pet dogs' enculturation with humans and thus may not be representative of other populations of dogs. We investigated the ability of young dogs in training for explosives detection (N ¼ 77) to locate a hidden reward using olfactory cues when presented in conflict with a deceptive communicative gesture in an object-choice task. We assessed performance at 3, 6 and 11 months of age using both cross-sectional and longitudinal designs. We found that, contrary to previous findings with pet dogs, responsiveness to human pointing decreased with age, whereas the ability to locate the reward by scent increased. Furthermore, a lack of susceptibility to deceptive social cues was predictive of future success as a detection dog. These findings further indicate the influence of ontogenetic effects on canine social cognition and demonstrate potential applications for the identification of suitable detection dogs.

A critical aspect of canine explosive detection involves the animal's ability respond to novel, u... more A critical aspect of canine explosive detection involves the animal's ability respond to novel, untrained odors based on prior experience with training odors. In the current study, adult Labrador retrievers (N = 15) were initially trained to discriminate between a rewarded odor (vanillin) and an unrewarded odor (ethanol) by manipulating scented objects with their nose in order to receive a food reward using a canine-adapted discrimination training apparatus. All dogs successfully learned this olfactory discrimination task (C80 % correct in a mean of 296 trials). Next, dogs were trained on an ammonium nitrate (AN, NH 4 NO 3 ) olfactory discrimination task [acquired in 60-240 trials, with a mean (±SEM) number of trials to criterion of 120.0 ± 15.6] and then tested for their ability to respond to untrained ammonium-and/or nitrate-containing chemicals as well as variants of AN compounds. Dogs did not respond to sodium nitrate or ammonium sulfate compounds at rates significantly higher than chance (58.8 ± 4.5 and 57.7 ± 3.3 % correct, respectively). Transfer performance to fertilizer-grade AN, AN mixed in Iraqi soil, and AN and flaked aluminum was significantly higher than chance (66.7 ± 3.2, 73.3 ± 4.0, 68.9 ± 4.0 % correct, respectively); however, substantial individual differences were observed. Only 53, 60, and 64 % of dogs had a correct response rate with fertilizer-grade AN, AN and Iraqi soil, and AN and flaked aluminum, respectively, that were greater than chance. Our results suggest that dogs do not readily generalize from AN to similar AN-based odorants at reliable levels desired for explosive detection dogs and that performance varies significantly within Labrador retrievers selected for an explosive detection program.

The United States Marine Corps (USMC) uses Labrador retrievers as improvised explosive device det... more The United States Marine Corps (USMC) uses Labrador retrievers as improvised explosive device detection dogs (IDDs). Of critical importance is the selection of dogs that are emotionally suited for this highly specialized application. The goal of our study was to develop an emotional reactivity test (ERT) as a screening tool for the selection of IDDs. The ERT included a series of subtasks that expose each dog sequentially to visual, auditory, and experiential stimuli with an associated grading scale used by trained observers to rate individual dog responses. In this study, 16 Labrador retrievers that met initial selection criteria as candidate IDDs were assessed using the ERT, measurement of plasma and salivary cortisol concentrations (pre-and post-ERT), and an independent open-field test of anxiety in response to sound stimuli. Based on the sum of its responses, each dog was assigned an aggregate ERT score. Aggregate ERT scores from independent trained observers were highly concordant [Shrout-Fleiss's intraclass correlation (2,1) ¼ 0.96] suggesting excellent inter-rater reliability. The aggregate ERT scores were also negatively correlated with the dogs' scores on the open-field anxiety test (Spearman rank correlation, n ¼ 16, r ¼ À0.57, P ¼ 0.0214). In addition, there were significant increases in salivary (Wilcoxon signed rank, n ¼ 16, S ¼ 38.5, P ¼ 0.0458) and plasma (Wilcoxon signed rank, n ¼ 16, S ¼ 68, P < 0.0001) cortisol levels after the ERT, compared with baseline, suggesting that exposure to the ERT test elements produced a physiological stress response. We conclude that the ERT is a useful pre-training screening test that can be used to identify dogs with a low threshold of emotional reactivity for rejection, and dogs with a high threshold of emotional reactivity for entry into the IDD training program.

Several studies have shown that domestic dogs respond to human social cues such as pointing. Some... more Several studies have shown that domestic dogs respond to human social cues such as pointing. Some experiments have shown that pet dogs outperformed wolves in following a momentary distal point. These findings have lent support to the hypothesis that domestication is responsible for domestic dogs’ ability to utilize human gestures. Other studies demonstrating comparable performance in human-socialized wolves suggest this skill depends on experience with relevant human stimuli. However, domestic dogs lacking thorough exposure to humans are underrepresented in the comparative literature. The goal of this study was to evaluate pet and kennel-reared research domestic dogs on their ability to follow two types of point in an object-choice task. This study used young adult, intact male research dogs (n = 11) and a comparison group of pet dogs living in human homes (n = 9). We found that while pet dogs followed the momentary distal point above chance levels, research dogs did not. Both groups followed the simpler dynamic proximal point; however, pet dogs outperformed research dogs on this task. Our results indicate that ontogenetic experiences may influence a domestic dog's ability to use human gestures, highlighting the importance of testing different sub-populations of domestic dogs.

Optimal cognitive ability is likely important for military working dogs (MWD) trained to detect e... more Optimal cognitive ability is likely important for military working dogs (MWD) trained to detect explosives. An assessment of a dog's ability to rapidly learn discriminations might be useful in the MWD selection process. In this study, visual discrimination and reversal tasks were used to assess cognitive performance in Labrador retrievers selected for an explosives detection program using a modified version of the Toronto General Testing Apparatus (TGTA), a system developed for assessing performance in a battery of neuropsychological tests in canines. The results of the current study revealed that, as previously found with beagles tested using the TGTA, Labrador retrievers (N = 16) readily acquired both tasks and learned the discrimination task significantly faster than the reversal task. The present study confirmed that the modified TGTA system is suitable for cognitive evaluations in Labrador retriever MWDs and can be used to further explore effects of sex, phenotype, age, and other factors in relation to canine cognition and learning, and may provide an additional screening tool for MWD selection.

The training of scent detection dogs using samples of explosives or their chemical precursors is ... more The training of scent detection dogs using samples of explosives or their chemical precursors is a well-established and documented practice. However an area of canine odor detection that remains under-studied regards a trained dog's perception of an explosive odor when more than one odorant is combined to produce a mixture. The first objective of our study was to determine whether training adult Labrador Retrievers (n = 20) to detect the scent of chemically pure potassium chlorate (PC) was sufficient to produce generalization to PCbased explosive mixtures that contained a novel component. We found that the majority of dogs (87%) trained with pure PC alone did not correctly signal the presence of one or more of four PC-based explosive mixtures. Our second objective was to determine whether training dogs using the separated components found in the PC-based explosives would subsequently enhance detection. Dogs were then trained using a novel static odor delivery device that safely segregated the PC and non-PC components and presented a merged odor to the dog. A statistically significant improvement in percentage of dogs detecting PC-based mixtures after training with the separated components compared to training with PC alone was seen with Mixture 1 (27-100%, P < 0.0001), Mixture 2 (40-81%, P = 0.0229), Mixture 3 (38-94%, P = 0.0004), and Mixture 4 (69-100%, P < 0.005). The results of this study highlight the potential limitations of dogs trained to detect a single odor to then recognize the odor when mixed with other substances. The odor delivery device developed for this study represents an important and effective training option that may reduce the need for using a final PC explosive mixture in canine training.

Books by Lucia Lazarowski

Previously thought to be unique to humans, abstract-concept learning has been demonstrated in a v... more Previously thought to be unique to humans, abstract-concept learning has been demonstrated in a variety of species spread across the phylogenetic tree. A parameter important to abstract-concept learning is the number of training exemplars. For numerous species, increasing the number of training exemplars of the concept facilitates full transfer to novel stimuli. However, the number of training exemplars required to fully acquire the concept can vary between species. These findings have offered support for Darwin's assertion that cognitive differences between species are matters of degree rather than matters of kind. In light of these findings, some concern has grown over whether stimulus generalization can account for the functional relationship between training exemplars and transfer performance. The current chapter examined the viability of the generalization hypothesis for solving the non-matching-to-sample task. We tested the generalization hypothesis using a pre-existing model to simulate rates of acquisition (Wright & Katz, 2007). Our results indicate generalization cannot account for acquisition or transfer of non-matching abstract-concept learning. These findings further demonstrate the importance of training exemplars on concept formation.