New Caledonian crows plan for specific future tool use.

The ability to plan for future events is one of the defining features of human intelligence. Whether non-human animals can plan for specific future situations remains contentious: despite a sustained research effort over the last two decades, there is still no consensus on this question. Here, we show that New Caledonian crows can use tools to plan for specific future events. Crows learned a temporal sequence where they were (a) shown a baited apparatus, (b) 5 min later given a choice of five objects and (c) 10 min later given access to the apparatus. At test, these crows were presented with one of two tool-apparatus combinations. For each combination, the crows chose the right tool for the right future task, while ignoring previously useful tools and a low-value food item. This study establishes that planning for specific future tool use can evolve via convergent evolution, given that corvids and humans shared a common ancestor over 300 million years ago, and offers a route to mapping the planning capacities of animals.

Exploring individual and social learning in jackdaws (Corvus monedula).

Information about novel environments or foods can be gathered via individual or social learning. Whereas individual learning is assumed to be more costly and less effective than social learning, it also yields more detailed information. Juveniles are often found to be more explorative than adults. Still under the protection of their parents, this allows them to sample their environment in preparation for later in life. We tested individual and social learning in jackdaws (Corvus monedula) of different age groups in a semi-natural group setting. Juvenile and adult jackdaws differed in their learning propensity. Juveniles spent more time at the test apparatus, were more explorative, and caused the apparatus to open. Almost all the openings at the apparatus matched the demonstrated method. As more observers became available, the juveniles could observe each other. Individuals preferentially watched successful conspecifics and those they could scrounge food from. Lower-ranking individuals tended to watch higher ranking ones; higher ranking individuals preferentially watched conspecifics of similar rank. The control group did not manipulate the apparatus. Due to the lack of this baseline, it was difficult to determine for certain whether the opening technique was acquired via individual or social learning. We conclude that if social learning played a role, the underlying mechanism was most likely local or stimulus enhancement. It is, however, more parsimonious to assume that juveniles were more explorative than adults, and that their opening technique was potentially easier to acquire than the one demonstrated to adults.

A meta-analytic review of brief guided self-help education for chronic pain.

Up to 30% of the population in Western countries suffer from chronic pain. The treatment of chronic pain causes medical and socioeconomic problems. Guided self-help (GSH) might be an effective supplementary treatment, however, the size of this effect is unclear. This meta-analysis quantifies the effect of GSH on chronic pain. A systematic literature search was conducted using PubMed, Cochrane, Psyndex, Psycinfo and Scopus. Studies that investigated GSH in chronic pain conditions (children and adults) were included. Disability, quality of life and pain severity were defined as main outcomes. We conducted random effects models to calculate standardized mean differences (SMDs). By applying mixed models and subgroup analyses, we examined the moderating effects of sample characteristics (age; pain region), GSH format (online; face-to-face contact) and study characteristics (study quality; control condition). We identified 16 eligible studies, including 739 subjects. Between-group analyses resulted in a medium, but heterogeneous effect size for pain severity (SMD = 0.51; CI95 : 0.21, 0.81). After excluding two samples suggesting small study bias, the effect on pain severity was small but homogeneous (SMD = 0.34; CI95 : 0.13, 0.54). We found a small effect size for disability (SMD = 0.30; CI95 : 0.10, 0.50). The pooled effect size for quality of life did not reach significance (SMD = 0.24; CI95 : -0.07, 0.54). We conclude that GSH has a small but robust effect on pain severity and disability in chronic pain patients. This applies to various GSH formats and patient populations. It seems reasonable to integrate GSH into clinical practice as a supplemental treatment option. WHAT DOES THIS REVIEW ADD?: The present meta-analytic review found small but robust effects of guided self-help interventions for the treatment of chronic pain.