Controlling for dogs’ (Canis familiaris) use of nonmnemonic strategies in a spatial working memory task.

Abstract

Short assessments of spatial working memory (SWM) in dogs are becoming popular evaluations of canine aging and individual differences. In a typical SWM task, an experimenter hides a reward inside of a bucket at a specific stimulus position while the dog watches. Then, following a varying delay interval, the dog is released to choose a bucket. The longest delay at which the dog can successfully choose the bucket containing the reward is considered to reflect the dog's SWM duration. Although past studies were informative, the tasks often lacked a valid measure of SWM due to dogs' ability to use nonmnemonic strategies, such as body orientation or sustained attention, to successfully solve these tasks without relying on working memory mechanisms. Therefore, we designed the first study to assess the internal validity of these tasks by directly comparing dogs' performance on two experimental conditions. We found that dogs performed worse in a control condition in which nonmnemonic strategies were eliminated compared with a typical SWM task condition. In addition, our results indicate a strong relationship between the percentage of delay time that a dog spends orienting its head or body to the correct bucket and performance in a typical SWM task. These findings were the first to show a difference in SWM performance when dogs' use of nonmnemonic strategies was controlled and stress the importance of considering the internal validity of these tasks if used to examine SWM in future work.

A preliminary analysis of the effect of individual differences on cognitive performance in young companion dogs

“…This finding contrasts our hypothesis that performance across tasks would be related, which would have suggested that both tasks were measuring aspects of EF. Previous studies have used these tasks as measures of EF in dogs (Bray et al 2021 ; Foraita et al 2021b ; Krichbaum et al 2021 ; Lazarowski et al 2020b ; Osthaus et al 2010 ); however, some studies also found no relationships between these two tasks (Lazarowski et al 2020 ) or other tasks purported to measure similar aspects of EF (Foraita et al 2021b ), while others either only used one task (Krichbaum et al 2021 ; Osthaus et al 2010 ) or did not evaluate relationships between tasks (Bray et al 2021 ). Several studies have even found that tasks expected to measure the same component of EF, namely inhibitory control, exhibit no relationships between each other (Bray et al 2014 ; Brucks et al 2017 ; Fagnani et al 2016 ; Vernouillet et al, 2018), with other factors such as variations in task demands influencing performance across tasks.…”

“…Reversal tasks are also used to measure flexibility because participants must shift responding in one direction in favor of responding in the opposite direction (Olsen 2018 ). The DST (other names include the visible displacement task, the delayed response task, and the object choice task) has previously been used as a measure of spatial working memory in dogs (Bray et al 2021 ; Foraita et al 2021b ; Krichbaum et al 2021 ). In this task, a reward is hidden in one of two or three locations, and the dog is released to make a choice after a specified delay.…”

“…While some studies with dogs have attempted to control for other strategies apart from working memory that may be used during this task (i.e., placing a screen between the subject and the reward locations during the delay to prevent fixation on the location of the reward as in Foraita et al ( 2021b )), other studies posit that without controlling for cues related to body orientation, this task may allow dogs to use aspects of attention in addition to working memory (Krichbaum et al 2021 ; Lazarowski et al 2020b ). Krichbaum et al ( 2021 ) demonstrated that even with a screen placed in front of the reward locations during the delays, dogs that oriented their head or body in the direction of the correct location for a greater percentage of the delay time also achieved a higher percentage of correct trials. However, dogs never oriented towards the reward location for the entire delay duration, indicating performance on this task may rely on a combination of working memory and attention.…”

Comparative cognition—Conceptual and methodological advancements.

“…Vila et al (2021) discuss the use a novel 'hide-and-seek' task in preschool age children to study episodic-like memory; their work illustrates how memory dynamics can change over time in a manner not very unlike what has been demonstrated in other nonhuman research paradigms. The paper by Krichbaum et al (2021) discusses some of the methodological difficulties one faces in studying spatial cognition in canines. These authors introduce a method to control for intervening motor processes in accounting for spatially directed control in matching-to-sample tasks with dogs.…”