Timothy L. Edwards

Training pouched rats to find people

Giant African pouched rats equipped with video cameras may be a tenable option for locating living humans trapped under debris from collapsed structures. In the present study, 5 pouched rats were trained to contact human targets in a simulated collapsed building and to return to the release point after hearing a signal to do so. During test sessions, each rat located human targets more often than it located similar-sized inanimate targets on which it had not previously been trained and spent more time within 1 m of the human target than within 1 m of the other targets. Overall, the rats found humans, plastic bags containing clothes, and plastic bags without clothes on 83%, 37%, and 11% of trials, respectively. These findings suggest that using pouched rats to search for survivors in collapsed structures merits further attention.

Motivating Operations Affect Stimulus Control: A Largely Overlooked Phenomenon in Discrimination Learning

Several recent studies have explored what Michael (e.g., 1982) termed the value-altering effect and the behavior-altering effect of motivating operations. One aspect of the behavior-altering effect that has garnered no recent attention involves changes in stimulus control produced by motivating operations. To call attention to this aspect of the behavior-altering effect, we herein review 11 studies that are concerned with the influence of varying levels of food or water deprivation on stimulus generalization. These studies suggest that motivating operations influence stimulus control (a) by changing the evocative strength of not just an established discriminative stimulus, but also of stimuli that are physically similar to it; (b) by changing the range of stimuli that evoke the operant in question; and (c) by exerting these effects in a graded fashion. These findings are potentially of conceptual and applied significance, and it appears that further research examining how motivating operations alter stimulus control, including some studies suggested herein, is warranted.

THE MATCHINg LAW

This article introduces the quantitative analysis of choice behavior by describing a number of equations developed over the years to describe the relation between the allocation of behavior under concurrent schedules of reinforcement and the consequences received for alternative responses. Direct proportionality between rate of responding and rate of reinforcement was observed in early studies, suggesting that behavioral output matched environmental input in a mathematical sense. This relation is termed “strict matching,” and the equation that describes it is referred to as “the matching law.” Later data showed systematic departures from strict matching, and a generalized version of the matching equation is now used to describe such data. This equation, referred to as “the generalized matching equation,” also describes data that follow strict matching. It has become convention to refer to either of these equations as “the matching law.” Empirical support for the matching law is briefly summarized, as is the applied and practical significance of matching analyses.

Evaluation of Giant African Pouched Rats for Detection of Pulmonary Tuberculosis in Patients from a High-Endemic Setting.

Background This study established evidence about the diagnostic performance of trained giant African pouched rats for detecting Mycobacterium tuberculosis in sputum of well-characterised patients with presumptive tuberculosis (TB) in a high-burden setting. Methods The TB detection rats were evaluated using sputum samples of patients with presumptive TB enrolled in two prospective cohort studies in Bagamoyo, Tanzania. The patients were characterised by sputum smear microscopy and culture, including subsequent antigen or molecular confirmation of Mycobacterium tuberculosis, and by clinical data at enrolment and for at least 5-months of follow-up to determine the reference standard. Seven trained giant African pouched rats were used for the detection of TB in the sputum samples after shipment to the APOPO project in Morogoro, Tanzania. Results Of 469 eligible patients, 109 (23.2%) were culture-positive for Mycobacterium tuberculosis and 128 (27.3%) were non-TB controls with sustained recovery after 5 months without anti-TB treatment. The HIV prevalence was 46%. The area under the receiver operating characteristic curve of the seven rats for the detection of culture-positive pulmonary tuberculosis was 0.72 (95% CI 0.66–0.78). An optimal threshold could be defined at ≥2 indications by rats in either sample with a corresponding sensitivity of 56.9% (95% CI 47.0–66.3), specificity of 80.5% (95% CI 72.5–86.9), positive and negative predictive value of 71.3% (95% CI 60.6–80.5) and 68.7% (95% CI 60.6–76.0), and an accuracy for TB diagnosis of 69.6%. The diagnostic performance was negatively influenced by low burden of bacilli, and independent of the HIV status. Conclusion Giant African pouched rats have potential for detection of tuberculosis in sputum samples. However, the diagnostic performance characteristics of TB detection rats do not currently meet the requirements for high-priority, rapid sputum-based TB diagnostics as defined by the World Health Organization.

Pouched rats as detectors of tuberculosis: comparison to concentrated smear microscopy.

In 2014, 1.5 million people died of tuberculosis (TB), a disease that can be cured in nearly every case if detected in time. Rapid and accurate detection of TB is a crucial component of the World Health Organizations 2016–2035 End TB Strategy [1]. Pouched rats, Cricetomys ansorgei (previously called Cricetomys gambianus [2]), are able to detect Mycobacterium tuberculosis by sniffing sputum samples [3]. Since 2007, they have been used for second-line screening of sputum samples previously evaluated by Ziehl–Neelsen microscopy (ZN) at clinics in Tanzania. Use of the rats increases new case detections by ∼40% [3]. Pouched rats find 60% of TB patients that are missed by clinics but identifiable with concentrated smear microscopy http://ow.ly/jnUr300i2I7

Landmine-detection rats: an evaluation of reinforcement procedures under simulated operational conditions.

Because the location of landmines is initially unknown, it is impossible to arrange differential reinforcement for accurate detection of landmines by pouched rats working on actual minefields. Therefore, provision must be made for maintenance of accurate responses by an alternative reinforcement strategy. The present experiment evaluated a procedure in which a plastic bag containing 2,4,6-trinitrotoluene (TNT), the active ingredient in most landmines, was placed in contact with the ground in a disturbed area, then removed, to establish opportunities for reinforcement. Each of five rats continued to accurately detect landmines when extinction was arranged for landmine-detection responses and detections of TNT-contaminated locations were reinforced under a fixed-ratio 1 schedule. The results of this translational research study suggest that the TNT-contamination procedure is a viable option for arranging reinforcement opportunities for rats engaged in actual landmine-detection activities and the viability of this procedure is currently being evaluated on minefields in Angola and Mozambique.

Motivating Operations in the Journal of Organizational Behavior Management: Review and Discussion of Relevant Articles

Every article published in the Journal of Organizational Behavior Management from 1982 through 2012 that contained the term motivating operation (or a related term) was examined. Seventy-six articles used a relevant term. Authors used the term in attempts to categorize and explain the behavioral effects of many aspects of interventions (e.g., rules, feedback, goal-setting), everyday occurrences in organizations (e.g., nicotine deprivation, top management support), and characteristics of behaving individuals (e.g., optimism, personality state), which on the one hand suggests that the motivating operation concept has been of value in organizational behavior management research as published in the journal. On the other hand, none of the articles demonstrated the successful use of a motivating operation as the term was initially defined, which suggests that the MO concept has been substantially expanded or widely misused by authors of the evaluated articles.

Translational Research: It's not 1960s Behavior Analysis.

We like Critchfield’s (2011) article,which is scholarly, clear, and insight-ful. In it, Critchfield provides anexcellent overview of translationalresearch in behavior analysis andsuggests several general strategiesfor increasing the likelihood that suchresearch, which has been scarce inpast years, will become more com-mon and benefit the discipline as wellas humanity at large. As he pointsout, a small number of people havebeen responsible for most of thetranslational research that has ap-peared, and relatively few behavioranalysts are well trained in both thebasic science and applied areas of ourdiscipline. In an attempt to provide acrude index of how many contempo-rary behavior analysts are produc-tive, and hence at least somewhatskilled, in the basic science andapplied areas of our discipline, weused PsycINFO to determine thenumber of people who authored atleast one article in both the Journal ofthe Experimental Analysis of Behavior(JEAB) and the Journal of AppliedBehavior Analysis (JABA)from2006through 2010 (i.e., in the last 5 years).Thirty-eight people did so. This is asubstantial number, but it is impor-tant to note that during this period381 people were listed as JEABauthors and 718 people were listedas JABA authors. Thus, only 3.6% ofthe total number of authors (38 of1,061) published in both journals.Their names and the number ofarticles they published in each journalduring this period are shown inTable 1.Although publishing in a givenarea is not strong evidence of exper-tise in that area (an author could,e.g., contribute just by collectingdata), it is likely that most, andprobably all, of these people knowquite a bit about both the basicscience and applied areas of ourdiscipline and hence could play lead-ership roles in increasing the amountand quality of translational researchproduced. Some of them, such asTom Critchfield and Bud Mace,obviously do so (e.g., Mace & Critch-field, 2010).Both Critchfield (2011) and Poling(2010) suggested that current gradu-ate training programs might be inad-equate for producing competenttranslational researchers, but neitheroffered specific strategies for im-provement. Examining the formaland informal training received bythe researchers listed in Table 1 couldprovide clues regarding the experienc-es that develop the repertoire neededto bridge the basic-to-applied chasm.Critchfield pointed out that he wasinfluenced by Bill Redmon in a coursethat combined basic and appliedreadings, and our hunch is that manyof those listed in Table 1 studied withmentors who had broad interests. Forwhat it’s worth, one of us (Poling) wasmentored by Andy Lattal and TravisThompson, both of whom have pub-lished applied, basic, and translation-al studies, and Poling has donelikewise. Many of his students, in-cluding the coauthor of this article(Edwards), are also generalists.As generalists, they use a variety ofresearch methods while they retain acommitment to the tactics and strat-egies characteristic of behavior anal-ysis (e.g., Poling, Methot, & LeSage,1995; Sidman, 1960) and to use them

Giant African pouched rats (Cricetomys gambianus) that work on tilled soil accurately detect land mines

Pouched rats were employed as mine-detection animals in a quality-control application where they searched for mines in areas previously processed by a mechanical tiller. The rats located 58 mines and fragments in this 28,050-m(2) area with a false indication rate of 0.4 responses per 100 m(2) . Humans with metal detectors found no mines that were not located by the rats. These findings indicate that pouched rats can accurately detect land mines in disturbed soil and suggest that they can play multiple roles in humanitarian demining.

Animal olfactory detection of human diseases: Guidelines and systematic review

ABSTRACT Animal olfactory detection of human diseases has attracted an increasing amount of interest from researchers in recent years. Because of the inconsistent findings reported in this body of research and the complexity of scent‐detection research, it is difficult to ascertain the potential value of animal detectors in operational diagnostic algorithms. We have outlined key factors associated with successful training and evaluation of animals for operational disease detection and, using these key factors as points for comparison, conducted a systematic review of the research in this area. Studies that were published in peer‐reviewed outlets and that described original research evaluating animals for detection of human diseases were included in the review. Most relevant studies have assessed dogs as detectors of various forms of cancer. Other researchers have targeted bacteriuria, Clostridium difficile, hypoglycemia, and tuberculosis. Nematodes and pouched rats were the only exceptions to canine detectors. Of the 28 studies meeting inclusion criteria, only 9 used operationally feasible procedures. The most common threat to operational viability was the use of a fixed number of positive samples in each sample run. Most reports included insufficient information for replication or adequate evaluation of the validity of the findings. Therefore, we have made recommendations regarding the type of information that should be included when describing research in this area. The results of this systematic review suggest that animal detectors hold promise for certain diagnostic applications but that additional research evaluating operationally viable systems for olfactory detection of human diseases is necessary.