The theoretical backdrop for the study is arousal-biased competition theory, developed by Mara Mather and Mary Sutherland and colleagues. According to this framework, arousal increases the competitive advantage of whatever information already dominates mental processing. If a person is focused narrowly on a specific location, arousal should further strengthen that narrow focus; if attention is broadly distributed, arousal should broaden it further. The theory draws on neuroscientific work suggesting that norepinephrine, released by the locus coeruleus during states of heightened arousal, ignites local hotspots of neuronal excitation that amplify the most active representations while suppressing weaker competitors. Earlier experiments had reported that arousal amplifies selectivity in perception and memory, and classic studies from the 1950s through the 1970s, including work by John Easterbrook on cue utilization and by Donald Cornsweet on peripheral cues under arousal, had suggested that stress and noise narrow the useful field of view.

Kolnes and Nieuwenhuis set out to test this amplification hypothesis directly for the spatial dimension of attention. Thirty-nine participants performed a visual search task specifically designed to measure the breadth of attention across the visual field. The critical manipulation involved tonic arousal, the relatively stable background level of physiological activation that fluctuates over minutes rather than seconds. In half of the experimental blocks, continuous auditory white noise was played to participants, a well-established method for raising tonic arousal without startling them or triggering phasic alerting responses. The researchers reasoned that if arousal genuinely amplifies the dominant attentional scope, then the difference in search performance between narrow-attention and broad-attention conditions should grow larger under noise than under quiet conditions.

Before each trial, the experimenters used a procedure intended to induce either a narrow or a broad breadth of attention. This manipulation of attentional scope is central to the design, because the amplification hypothesis makes a specific prediction: arousal should not change the baseline scope itself, but should exaggerate whatever scope is currently dominant. The team also drew on their own earlier findings, including a 2023 study showing that broadening attention dilates the pupil, suggesting a close relationship between attentional breadth and the autonomic arousal system. That relationship made the null result they ultimately obtained all the more theoretically pointed, since it indicates that the coupling between arousal physiology and attentional breadth does not translate into arousal-driven amplification of scope.

A crucial strength of the study lies in its manipulation checks. The researchers measured pupil size continuously, exploiting the well-documented link between pupil diameter and locus coeruleus-norepinephrine activity. Pupil measurements confirmed that the white-noise manipulation successfully raised tonic arousal, and task performance confirmed that the scope-induction procedure successfully shifted the breadth of attention between narrow and broad states. In other words, the experiment was not undermined by failed manipulations. Both arousal and attentional scope were demonstrably altered, yet the predicted interaction between them simply did not appear. The effect of attentional breadth on visual search remained statistically indistinguishable between high-arousal and low-arousal blocks.

The analysis relied on Bayesian statistical methods, which allow researchers to quantify evidence in favor of a null hypothesis rather than merely failing to reject it. The authors report strong Bayesian evidence against an amplifying effect of arousal on the dominant attentional scope. This distinction matters in the ongoing debate about replication and statistical practice in psychology, where nonsignificant p-values are often ambiguous. A Bayes factor indicating strong support for the null hypothesis means the data actively favor the absence of an amplification effect, not simply that the study lacked power. The researchers also used mixed-effects models with maximal random effects structures, following methodological recommendations for confirmatory hypothesis testing, and conducted simulation-based power analyses to ensure the design was sensitive enough to detect a plausible amplification effect if one existed.

The null result is not without precedent. Ásgeirsson and Nieuwenhuis had previously reported no arousal-biased competition in focused visuospatial attention in a 2017 study published in Cognition, and a 2019 follow-up examining attention and short-term memory produced similarly mixed support for the theory. The new findings extend this line of work by showing that even when both arousal and attentional scope are successfully manipulated and verified through physiological and behavioral measures, the amplification predicted by arousal-biased competition theory fails to materialize for spatial attention. This convergence across independent experiments and paradigms suggests that the earlier classic findings of arousal-induced narrowing, such as those from noise studies in the 1970s, may reflect mechanisms other than amplification of dominant attentional scope, such as changes in response bias, strategy, or the relative salience of stimuli.

The authors discuss the implications for arousal-biased competition theory in measured terms. The theory remains influential and has generated a large body of research on how emotion and arousal shape perception and memory, including findings that emotional arousal strengthens high-priority memory traces while weakening low-priority ones. However, the present results suggest that the amplification principle may not generalize to the spatial scaling of attention. Alternative accounts of arousal’s effects, including models emphasizing adaptive regulation of arousal and the inverted-U relationship described by the Yerkes-Dodson law, may better accommodate the full pattern of findings. Recent work on pharmacologically shifting the peak of the Yerkes-Dodson curve through catecholaminergic enhancement indicates that arousal’s effects on cognition are complex and state-dependent, defying simple amplification rules.

For everyday intuition, the study suggests that being stressed, caffeinated, or startled does not automatically zoom your mental spotlight further in or out. The spatial distribution of attention appears to be governed by its own control mechanisms, relatively insulated from the background hum of bodily arousal. This dissociation has practical implications for domains ranging from driving safety to sports performance and the design of warning systems, where it is often assumed that high arousal inevitably produces tunnel vision. The evidence here indicates that assumption is too simple. The study was not preregistered, a limitation the authors acknowledge, but subject-level data and analysis code are openly available in the Open Science Framework repository, allowing other researchers to scrutinize and extend the findings. Funded by the Estonian Research Council and the Dutch Research Council, the work exemplifies how careful manipulation checks, physiological validation, and Bayesian inference can turn an apparently negative result into a substantive theoretical contribution about how attention and arousal are, and are not, connected.

Subject of Research: Whether tonic arousal modulates the spatial scope of visual attention

Article Title: Arousal does not enhance the dominant spatial scope of attention

Article References: Kolnes, M., & Nieuwenhuis, S. (2026). Arousal does not enhance the dominant spatial scope of attention. Attention, Perception, & Psychophysics, 88(7), Article 184. https://doi.org/10.3758/s13414-026-03327-3

Image Credits: AI Generated

DOI: 10.3758/s13414-026-03327-3

Keywords: arousal, attentional scope, visual attention, arousal-biased competition, pupil size, norepinephrine, visual search, Bayesian inference, psychophysics, locus coeruleus, breadth of attention, tonic arousal