The Dot-Probe Attention Bias Task as a Method to Assess Psychological Well-Being after Anesthesia: A Study with Adult Female Long-Tailed Macaques (Macaca fascicularis)

Abstract

Understanding the impact routine research and laboratory procedures have on animals is crucial to improving their wellbeing and to the success and reproducibility of the research they are involved in. Cognitive measures of welfare offer insight into animals’ internal psychological state, but require validation. Attention bias - the tendency to attend to one type of information over another – is a cognitive phenomenon documented in humans and animals that is known to be modulated by affective state (i.e., emotions). Hence, changes in attention bias may offer researchers a deeper perspective of their animals’ psychological wellbeing. The dot-probe task is an established method for quantifying attention bias in humans (by measuring reaction time to a dot-probe replacing pairs of stimuli), but has yet to be validated in animals. We developed a dot-probe task for long-tailed macaques (Macaca fascicularis) to determine if the task can detect changes in attention bias following anesthesia, a context known to modulate attention and trigger physiological arousal in macaques. Our task included the following features: stimulus pairs of threatening and neutral facial expressions of conspecifics and their scrambled counterparts, two stimuli durations (100 and 1000 ms), and counterbalancing of the dot-probe’s position on the touchscreen (left, right) and location relative to the threatening stimulus. We tested eight group-housed adult females on different days relative to being anesthetized (baseline and one-, three-, seven-, and 14-days after). At baseline, monkeys were vigilant to threatening content when stimulus pairs were presented for 100 ms, but not 1000 ms. On the day immediately following anesthesia, we found evidence that attention bias changed to an avoidance of threatening content. Attention bias returned to threat vigilance by the third day post-anesthesia and remained so up to the last day of testing (14 days after anesthesia). We also found that attention bias was independent of the type of stimuli pair (i.e., whole face vs. scrambled counterparts), suggesting that the scrambled stimuli retained aspects of the original stimuli. Nevertheless, whole faces were more salient to the monkeys as responses to these trials were generally slower than to scrambled stimulus pairs. Overall, our study suggests it is feasible to detect changes in attention bias following anesthesia using the dot-probe task in non-human primates. Our results also reveal important aspects of stimulus preparation and experimental design.

See no evil: Attentional bias towards threat is diminished in aged monkeys

“…Our data, however, suggest this is not the case; our monkeys fixated on the probe between 0.8 and 3.1 s on average, which is within the time ranges in which humans typically respond while performing dot-probe tasks. A last potential reason is that the dot-probe paradigm is not effective for assessing attentional biases in monkeys-this too does not appear to be the case as several groups have successfully utilized the paradigm in nonhuman primates (Cassidy et al, 2021;King et al, 2012;Kret et al, 2016;Parr et al, 2013; for a review see van Rooijen et al, 2017). It is possible, however, that our stimuli were not potent enough to induce the required capture of attention in order to detect differences in reaction times.…”

See no evil: Attentional bias toward threat is diminished in aged monkeys.

“…Our data, however, suggest this is not the case; our monkeys fixated on the probe between 0.8 and 3.1 s on average, which is within the time ranges in which humans typically respond while performing dot-probe tasks. A last potential reason is that the dot-probe paradigm is not effective for assessing attentional biases in monkeys—this too does not appear to be the case as several groups have successfully utilized the paradigm in nonhuman primates (Cassidy et al, 2023; King et al, 2012; Kret et al, 2016; Parr et al, 2013; for a review see van Rooijen et al, 2017). It is possible, however, that our stimuli were not potent enough to induce the required capture of attention in order to detect differences in reaction times.…”

Familiarity mediates apes' attentional biases toward human faces

“…Attentional bias research thus has the potential to assess both HARs and welfare (e.g. [ 75 , 76 ]) by focusing on what have been termed affect-driven attentional biases [ 73 ], which refer to the stimuli animals attend to as modulated by their affective states. As attentional biases can reflect the affective state of an animal, measuring these biases provides valuable welfare indicators [ 73 ].…”