Atomoxetine modulates the contribution of high- and low-level signals during free viewing of natural images in rhesus monkeys

Abstract

Visuo-spatial attentional orienting is fundamental to selectively process behaviorally relevant information, depending on both low-level visual attributes of stimuli in the environment and higher-level factors, such as goals, expectations and prior knowledge. Growing evidence suggests an impact of the locus-coeruleus-norepinephrine (LC-NE) system in attentional orienting that depends on task-context. Nonetheless, most of previous studies used visual displays encompassing a target and various distractors, often preceded by cues to orient the attentional focus. This emphasizes the contribution of goal-driven processes, at the expense of other factors related to the stimulus content. Here, we aimed to determine the impact of NE on attentional orienting in more naturalistic conditions, using complex images and without any explicit task manipulation. We tested the effects of atomoxetine (ATX) injections, a NE reuptake inhibitor, on four monkeys during free viewing of images belonging to three categories: landscapes, monkey faces and scrambled images. Analyses of the gaze exploration patterns revealed, first, that the monkeys spent more time on each fixation under ATX compared to the control condition, regardless of the image content. Second, we found that, depending on the image content, ATX modulated the impact of low-level visual salience on attentional orienting. This effect correlated with the effect of ATX on the number and duration of fixations. Taken together, our results demonstrate that ATX adjusts the contribution of salience on attentional orienting depending on the image content, indicative of its role in balancing the role of stimulus-driven and top-down control during free viewing of complex stimuli.

The fingerprints of pupillary dynamics

“…Ultimately, it provides a tool to delve deeper into the physiological origin of phasic changes in pupil size. These changes have been clearly implicated in finely-tuning behavior toward maximal utility (Aston-Jones & Cohen, 2005;Reynaud et al, 2019Reynaud et al, , 2021, so that accessing and better characterizing their primitive contribution represents a very appealing challenge.…”

What pupil size can and cannot tell about math anxiety

“…Measuring PS allows one to assess how mental processes unfold in time, with a reasonable temporal resolution along the course of a single trial. Increased PS is associated with phasic activation of the locus coeruleus (Aston-Jones & Cohen, 2005), a major noradrenergic hub involved in the integration of the attentional networks in the brain, as well as in balancing bottom-up and top-down attention (Reynaud et al, 2021). Far from reflecting passively responses to light (Binda et al, 2013;Binda & Murray, 2015), PS provides insights into automatic orienting processes (Blini & Zorzi, 2023;Castaldi et al, 2021;Salvaggio et al, 2022), emotional states (Bogdanova et al, 2022;Dureux et al, 2021), or working memory load (Ahern & Beatty, 1979;Beatty & Kahneman, 1966;Hess & Polt, 1964;Lisi et al, 2015).…”

Pupil size as a robust marker of attentional bias toward nicotine-related stimuli in smokers

“…Pupil diameter changes first and foremost following changes in the amount of light entering the eyes (see, e.g., Binda & Murray, 2015). However, pupil dilation has been associated with phasic activation of the locus coeruleus (Aston-Jones & Cohen, 2005), a major noradrenergic hub involved in the integration of the attentional systems in the brain, as well as in balancing bottom-up and top-down aspects of perception (Reynaud et al, 2021). Pupil dilation reflects, beyond that, the activation of the autonomic system, and as such it ideally probes: affective and emotional responses to visual stimuli (Bogdanova et al, 2022;Dureux et al, 2021); the amount of cognitive effort deployed for a task (e.g., working memory load, Lisi et al, 2015;Mathôt, 2018); and, perhaps in light of the strict dialogue between the locus coeruleus and limbic areas subserving motivation, the subjective value of a given stimulus (Muhammed et al, 2016;Pietrock et al, 2019).…”