Elevated arousal levels enhance contrast perception

Dongho Kim,Savannah Lokey,Sam Ling

doi:10.1167/17.2.14

Abstract

Our state of arousal fluctuates from moment to moment-fluctuations that can have profound impacts on behavior. Arousal has been proposed to play a powerful, widespread role in the brain, influencing processes as far ranging as perception, memory, learning, and decision making. Although arousal clearly plays a critical role in modulating behavior, the mechanisms underlying this modulation remain poorly understood. To address this knowledge gap, we examined the modulatory role of arousal on one of the cornerstones of visual perception: contrast perception. Using a reward-driven paradigm to manipulate arousal state, we discovered that elevated arousal state substantially enhances visual sensitivity, incurring a multiplicative modulation of contrast response. Contrast defines vision, determining whether objects appear visible or invisible to us, and these results indicate that one of the consequences of decreased arousal state is an impaired ability to visually process our environment.

Highlights

How do arousal states govern behavior? Arousal levels are largely regulated by the locus coeruleus– norepinephrine system, a component of the ascending reticular activating system (Aston-Jones & Cohen, 2005b; Moruzzi & Magoun, 1949; Sara, 2009)
We examined how reward-driven arousal states affect the human contrast response
Arousal state has been linked to pupil changes (McGinley et al, 2015; Reimer et al, 2014; Vinck, Batista-Brito, Knoblich, & Cardin, 2015), with previous work showing a strong link between pupil diameter and neural responses within the locus coeruleus–norepinephrine system (Wang & Munoz, 2015)

Summary

Introduction

Arousal levels are largely regulated by the locus coeruleus– norepinephrine system, a component of the ascending reticular activating system (Aston-Jones & Cohen, 2005b; Moruzzi & Magoun, 1949; Sara, 2009) This system, which is believed to play a role in governing vigilance (Berridge, 2008; Carter et al, 2010) and stress responses (Valentino & Van Bockstaele, 2008), projects widely throughout the brain and is believed to influence a host of cognitive processes (Sara, 2009). H. Lee, Sakaki et al, 2014; Lojowska, Gladwin, Hermans, & Roelofs, 2015; Phelps et al, 2006; Woods, Philbeck, & Wirtz, 2013), very little work has directly explored how arousal levels might influence the contrast response profile (Cano et al, 2006; Zhuang et al, 2014), in humans (Song & Keil, 2014). This differs from traditional reward paradigms, allowing for purer arousal manipulation (Kim, Seitz, & Watanabe, 2015; O’Doherty, Deichmann, Critchley, & Dolan, 2002)

Participants

Procedure

Results