Executive Functions as Measured by the Dog Executive Function Scale (DEFS) over the Lifespan of Dogs.

Executive Functions (EFs) are needed for effortful self-regulation of behaviour and are known to change over the lifespan in humans. In domestic dogs, EFs can be assessed through behavioural rating scales, such as the Dog Executive Function Scale (DEFS). The primary aim of this study was to investigate whether the DEFS, developed initially using a sample of adult dogs, can be used in juvenile (<1 year) and senior (>8 years) dogs. Confirmatory factor analysis of a juvenile and senior dog sample led to good model fit indices, indicating that juvenile and senior dogs' EF structure follows the same functional organisation as found in the DEFS. The secondary aim was to analyse the lifespan development of EFs. Analysis of subscale scores revealed multifaceted relationships with age for four subscales. Working Memory and Attention Towards Owner showed the u-shaped curve traditionally associated with the lifespan development of EFs. Forms of inhibition showed complex associations with age, i.e., Delay Inhibition declined in aging and Motor Regulation increased during aging. Training history and Working Status influenced performance independent of age. More highly trained dogs and working dogs exhibited higher EF skills. Training history appeared more important for EF in non-working dogs than working dogs, perhaps because all working dogs receive a high level of training.

Development of the dog executive function scale (DEFS) for adult dogs.

Executive functions (EFs) are cognitive processes that are used to effortfully self-regulate behaviour and might be important for dogs' success in working and pet roles. Currently, studies are assessing dogs' EF skills through often laborious cognitive measures, leading to small sample sizes and lacking measures of reliability. A complementary method is needed. The aim of this study was to develop a dog executive function scale (DEFS) for adult dogs. Focus groups were held with people working with dogs professionally to refine a pool of items describing dog behaviours related to EF. A survey was distributed online to a convenience sample of N = 714 owners of adult dogs. Exploratory and confirmatory factor analysis identified six distinguishable factors named behavioural flexibility, motor inhibition, attention towards owner, instruction following, delay inhibition and working memory. These factors appear similar to factors identified in human EF scales. Working dogs exhibit higher EF scores on the DEFS than non-working dogs. Dogs sourced from breeders exhibited higher DEFS scores than dogs sourced from shelters, and the amount of training received positively correlated with dogs' DEFS scores. The DEFS requires further validation with cognitive measures. The DEFS could then be used by researchers to complement assessment of dogs' EF skills through cognitive measures or assess dogs' EF skills in large samples.

Environmental influences on development of executive functions in dogs.

Executive functions (EFs) are a set of cognitive processes used for effortful self-regulation of behaviour. They include inhibition, working memory, cognitive flexibility and, in some models, attention. In humans, socioeconomic factors and life experiences shape development of EFs. Domestic dogs (Canis familiaris) must often regulate their behaviour in the human environment (e.g. no jumping up on humans or chasing cats), and life experiences also probably influence the development of EFs in dogs. Research into dog cognition and behaviour has been thriving, and some methods used to explore these concepts (e.g. object-choice task, questionnaires measuring traits like distraction and aggression) are likely to be sensitive to differences in EFs, even if that is not their stated aim. Here we examine relevant studies to identify experiential factors which may influence the development of EFs in dogs living in human care. These are early experience, training, housing and stress. We conclude that the development of dogs' EFs may be negatively affected by hardships, and positively by surmountable challenges, early in life. Training methods appear important, with punishment-based methods leading to poorer dog EFs. Kennel environments seem to affect dog EFs negatively. While mild stressors might enhance the development of EFs, too much stress seems to have negative effects. Regulation of behaviour, a key outcome of EFs, is crucial for dogs' integration into human society. We should, therefore, strive to better understand how the environment shapes dogs' EFs.