Impulsivity is a trait related to inhibitory control which is expressed in a range of behaviours. Impulsive individuals show a decreased ability to tolerate delay of reinforcement, and more impulsive behaviour has been linked to decreased levels of serotonin and dopamine in a number of species. In domestic dogs, impulsivity is implicated in problem behaviours that result from a lack of self control, but currently there are no published studies that assess behavioural and physiological measures of impulsivity in relation to this trait. Impulsivity scores were calculated for 41 dogs using an owner-report assessment, the Dog Impulsivity Assessment Scale (DIAS).Twenty-three of these subjects completed an operant choice task based on a delayed reward paradigm, to assess their tolerance to delay of reinforcement. High Pressure Liquid Chromatography (HPLC) with Fluorometric Detection was used to detect levels of the metabolites of serotonin (5-HIAA) and dopamine (HVA) in the urine of 17 of the subjects. Higher impulsivity scores were found to be significantly correlated with more impulsive behaviour (reduced tolerance to delay of reinforcement) in the behaviour tests and lower levels of urinary 5-HIAA and 5-HIAA/HVA ratio. The results demonstrate convergent validity between impulsivity (as assessed by the DIAS) and behavioural and physiological parameters.

Respondents revealed knowledge gaps pertaining to conditions that masquerade as AD, increase ones vulnerability to AD, and exacerbate AD symtomatology. Educational campaigns that specifically target these issues may help reduce the impact of AD.

This study investigated whether training-related improvements in facial expression categorization are facilitated by spontaneous changes in gaze behaviour in adults and nine-year old children. Four sessions of a self-paced, free-viewing training task required participants to categorize happy, sad and fear expressions with varying intensities. No instructions about eye movements were given. Eye-movements were recorded in the first and fourth training session. New faces were introduced in session four to establish transfer-effects of learning. Adults focused most on the eyes in all sessions and increased expression categorization accuracy after training coincided with a strengthening of this eye-bias in gaze allocation. In children, training-related behavioural improvements coincided with an overall shift in gaze-focus towards the eyes (resulting in more adult-like gaze-distributions) and towards the mouth for happy faces in the second fixation. Gaze-distributions were not influenced by the expression intensity or by the introduction of new faces. It was proposed that training enhanced the use of a uniform, predominantly eyes-biased, gaze strategy in children in order to optimise extraction of relevant cues for discrimination between subtle facial expressions.

Wells and remaining participants who wished to remain anonymous. We would also like to thank all of the dog owners who filled out the 'Dog Personality Questionnaire'.

One of the processes thought to underlie visual selection works by biasing attention away from either recently examined locations or objects. The extent of this “inhibition” is greatest when the inhibited object and the inhibited location coincide. In Experiment 1, rectangles are presented stereoscopically at different depths but at similar positions horizontally and vertically. Here, any inhibition should be based solely on a spatial code, as the objects, the rectangles are clearly separate objects. In Experiment 2, the corners of the rectangles are joined to produce a single cuboid that extends in depth space. Now inhibition based on both spatial and object codes should be seen because even when on different depth planes the cue and target are associated with the same object. Consistent with our understanding of the additive effects of inhibition of space and object codes, the extent of inhibition in the second study is almost double that of the first. The results further suggest that space-based inhibition operates within a two-dimensional representation while object-based inhibition utilizes a three-dimensional representation