Clive D. L. Wynne

Transitive inference formation in pigeons

Pigeons were trained with 4 pairs of visual stimuli in a 5-term series-A+ B-, B+ C-, C+ D-. and D+ E(in which plus[+] denotes reward and minus(-] denotes nonreward)-before the unreinforced test pair B D was presented. All pigeons chose Item 8, demonstrating inferential choice. A novel theory (value transfer theory), based on reinforcement mechanisms, is proposed. In Experiment 2, the series was extended to 7 terms. Performance on test pairs was transitive, and performance on training pairs accorded with the theory. The 7-term series was closed in Experiment 3 by training the flrst and last items together. In accordance with the theory, the Ss could not solve the circular series. The authors suggest that primates, including humans, also solve these problems using the value transfer mechanism, without resorting to the symbolic processes usually assumed.

What did domestication do to dogs? A new account of dogs' sensitivity to human actions

Over the last two decades increasing evidence for an acute sensitivity to human gestures and attentional states in domestic dogs has led to a burgeoning of research into the social cognition of this highly familiar yet previously under‐studied animal. Dogs (Canis lupus familiaris) have been shown to be more successful than their closest relative (and wild progenitor) the wolf, and than mans closest relative, the chimpanzee, on tests of sensitivity to human social cues, such as following points to a container holding hidden food. The “Domestication Hypothesis” asserts that during domestication dogs evolved an inherent sensitivity to human gestures that their non‐domesticated counterparts do not share. According to this view, sensitivity to human cues is present in dogs at an early age and shows little evidence of acquisition during ontogeny. A closer look at the findings of research on canine domestication, socialization, and conditioning, brings the assumptions of this hypothesis into question. We propose the Two Stage Hypothesis, according to which the sensitivity of an individual animal to human actions depends on acceptance of humans as social companions, and conditioning to follow human limbs. This offers a more parsimonious explanation for the domestic dogs sensitivity to human gestures, without requiring the use of additional mechanisms. We outline how tests of this new hypothesis open directions for future study that offer promise of a deeper understanding of mankinds oldest companion.

Reinforcement accounts for transitive inference performance

Transitive inference is the ability, given thatA >B andB >C, to infer thatA >C. Pigeons, rats, chimpanzees, squirrel monkeys, and humans as young as 4 years have all been shown capable of this. In this paper, simple associative learning models are explored as accounts of nonverbal transitive inference performance. A Bush-Mosteller-based model can account for transitive inference under limited conditions. A Rescorla-Wagner-based model can account for transitive inference under all conditions in the literature, but cannot account for some additional nontransitive tests. A final configural model can also account for these nontransitive data. The ability of this model to account for transitive inference formation in humans is also considered.

Can evolution explain how minds work

Biologists have tended to assume that closely related species will have similar cognitive abilities. Johan J. Bolhuis and Clive D. L. Wynne put this evolutionarily inspired idea through its paces.

Ontogeny and phylogeny: both are essential to human-sensitive behaviour in the genus Canis

In responding to Hare et al. (2010), we wish to start by outlining our substantive areas of agreement. We do not disagree that pet domestic dogs have a remarkable sensitivity to human actions, gestures and intentional movements. We also agree with Hare et al. that the most likely reason why the wolves tested in Udell et al. (2008a) were so responsive to human pointing gestures was because these animals were ‘highly socialized [and] [t]his socialization probably gave [these] subjects significant experience responding to actions similar to human pointing, whether the animal handler was aware of this type of exposure or not’ (Hare et al. 2010, page e6). In that paper we argued that ‘that environment and development affect a social animal’s ability to react in situation appropriate ways to the social cues of other individuals’ (Udell et al. 2008a, page 1772). The crux of our disagreement with Hare et al. (2010) is our belief that socialization and experience are essential for all canids to respond to heteroand conspecific cues. Since at least the 1920s scientists have recognized that heredity alone is insufficient to fully explain a phenotype. Phenotypes can only be characterized as the outcome of a complex interaction between heredity, development and environment (Gottlieb 2002). Unfortunately development and environment receive short shrift in the domestication hypothesis as presented by Hare et al. (2010). To be clear, we do not denyan influence of heredity or domestication on the social behaviour of domestic dogs, we simply do not agree that a hypothesis based on genetic inheritance alone is viable without consideration of the interacting developmental and environmental variables that are necessary for the expression of any phenotype. Our response is organized to match Hare et al.’s (2010) commentary. First, we respond to their review of the literature on the sensitivity of dogs, wolves and foxes to human cues. Second, we discuss their reanalysis of our data comparing the performance of wolves and dogs in responding to a human pointing gesture (Udell et al. 2008a). Third, we consider the data on dogs living in a shelter reported in Hare et al. (2010). Fourth we comment briefly on Hare et al.’s response to Wynne et al.’s (2008) reanalysis of Riedel et al.’s (2008) data on the development of following human points in dog pups, before concluding with some general comments on the roles of ontogeny and phylogeny in the expression of complex interspecies social behaviours.

Can your dog read your mind? Understanding the causes of canine perspective taking

Prior studies have documented the domestic dog’s (Canis lupus familiaris) sensitivity to human attentional state, including a tendency to preferentially beg for food from attentive individuals and an ability to selectively perform forbidden behaviors when humans are not looking. Due to the success of dogs on perspective-taking tasks, some have hypothesized that domestic dogs may have theory of mind, or the ability to infer what other individuals know. Here we provide the first evidence that nondomesticated canids, grey wolves (Canis lupus), are also sensitive to human attentional state under some conditions. We also demonstrate that dogs do not display an undifferentiated sensitivity to all visual cues of attentional state. Rather, dogs are more sensitive to stimuli encountered in their home environment. Some dogs perform poorly on perspective-taking tasks. These findings have important implications for the interpretation of research designed to understand complex social cognition across species.

Learning for life: Training marsupials to recognise introduced predators

Raising endangered species in captivity for reintroduction necessarily results in animals that lack appropriate skills for coping with problems to be faced in the wild, such as predators. Using classical conditioning techniques involving linking fear of a live dog with the image of a fox, we demonstrate an adjusted fear response for two wallaby species (rufous bettongs Aepyprymnus rufescens, quokkas Setonix brachyurus). No differences in response to the fox were found for wild-caught and captive-born bettongs, even though wild-caught subjects were likely to have encountered canids prior to capture. Attempts to condition a fear response by quokkas to an odour were unsuccessful. An attempt to induce fear of the stuffed fox by linking to fear of humans in quokkas was unsuccessful, but quokkas generalised from fear of the dog to fear of the fox, despite a delay of several weeks. Trained dogs offer a valuable and ethically acceptable mechanism for improving the ability of captive-reared (or sequestered) animals to recognise and cope with predators.

ERP correlates of response inhibition to elemental and configural stimuli in a negative patterning task

OBJECTIVE The present experiment examined the ERP correlates of response inhibition to elemental and configural Nogo stimuli in a Go/Nogo task. DESIGN AND METHODS Event-related potentials (ERPs) were recorded while 8 subjects completed a visual Go/Nogo task. Nogo stimuli required the inhibition of a response to stimuli that differed from Go stimuli (A+, B+) either on the basis of each of two physical features (elemental Nogo stimuli; CD-) or on the basis of the conjunction of features represented in the Go stimuli (configural Nogo stimuli; AB-). Behavioural data and ERP component measures (amplitude and latency) were analysed using analysis of variance. RESULTS An enhanced N2 component and an enhanced fronto-centrally distributed P3 component were elicited following elemental Nogo stimuli relative to Go stimuli, consistent with a number of studies examining ERPs during Go/Nogo tasks. In contrast, an enhanced late frontal negative/parietal positive slow wave was elicited following configural Nogo stimuli relative to Go stimuli. CONCLUSIONS These results cast doubt on the interpretation of the N2 enhancement as reflecting response inhibition processes per se. The pattern of results was interpreted as providing support for the unique cue model of learning rather than the configural model of learning and was discussed in the context of a recent model of executive functioning.

Dynamics of time discrimination.

Pigeons tracked sinusoidal sequences of interfood intervals (IFIs) by pausing in each interval for a time proportional to the preceding interval. Schedules with either long (30-90 s) or short (5-15 s) values, with variable numbers of cycles and starting phase each day, were tracked about equally well. Tracking was apparently immediate and did not improve across sessions. Experiment 2, in which long and short series were presented on alternate days, showed that tracking on long was more impaired than on short. Experiment 3 showed that occasional presentation of a short IFI in a series of fixed, longer IFIs caused a reduction in waiting time in the next IFI. These effects are evidence for a fast-acting timing mechanism in which waiting time in the IFI N + 1 is strongly determined by the preceding IFI, N. Earlier IFIs have some cumulative effect, but the details remain to be elucidated.

Breed differences in dogs sensitivity to human points: A meta-analysis

The last decade has seen a substantial increase in research on the behavioral and cognitive abilities of pet dogs, Canis familiaris. The most commonly used experimental paradigm is the object-choice task in which a dog is given a choice of two containers and guided to the reinforced object by human pointing gestures. We review here studies of this type and attempt a meta-analysis of the available data. In the meta-analysis breeds of dogs were grouped into the eight categories of the American Kennel Club, and into four clusters identified by Parker and Ostrander [Parker, H.G., Ostrander, E.A., 2005. Canine genomics and genetics: running with the pack. PLoS Genet. 1, 507-513] on the basis of a genetic analysis. No differences in performance between breeds categorized in either fashion were identified. Rather, all dog breeds appear to be similarly and highly successful in following human points to locate desired food. We suggest this result could be due to the paucity of data available in published studies, and the restricted range of breeds tested.