Cognitive and Ocular Factors Jointly Determine Pupil Responses under Equiluminance
Standard
Cognitive and Ocular Factors Jointly Determine Pupil Responses under Equiluminance. / Knapen, Tomas; de Gee, Jan Willem; Brascamp, Jan; Nuiten, Stijn; Hoppenbrouwers, Sylco; Theeuwes, Jan.
In: PLOS ONE, Vol. 11, No. 5, 2016, p. e0155574.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
Harvard
APA
Vancouver
Bibtex
}
RIS
TY - JOUR
T1 - Cognitive and Ocular Factors Jointly Determine Pupil Responses under Equiluminance
AU - Knapen, Tomas
AU - de Gee, Jan Willem
AU - Brascamp, Jan
AU - Nuiten, Stijn
AU - Hoppenbrouwers, Sylco
AU - Theeuwes, Jan
PY - 2016
Y1 - 2016
N2 - Changes in pupil diameter can reflect high-level cognitive signals that depend on central neuromodulatory mechanisms. However, brain mechanisms that adjust pupil size are also exquisitely sensitive to changes in luminance and other events that would be considered a nuisance in cognitive experiments recording pupil size. We implemented a simple auditory experiment involving no changes in visual stimulation. Using finite impulse-response fitting we found pupil responses triggered by different types of events. Among these are pupil responses to auditory events and associated surprise: cognitive effects. However, these cognitive responses were overshadowed by pupil responses associated with blinks and eye movements, both inevitable nuisance factors that lead to changes in effective luminance. Of note, these latter pupil responses were not recording artifacts caused by blinks and eye movements, but endogenous pupil responses that occurred in the wake of these events. Furthermore, we identified slow (tonic) changes in pupil size that differentially influenced faster (phasic) pupil responses. Fitting all pupil responses using gamma functions, we provide accurate characterisations of cognitive and non-cognitive response shapes, and quantify each response's dependence on tonic pupil size. These results allow us to create a set of recommendations for pupil size analysis in cognitive neuroscience, which we have implemented in freely available software.
AB - Changes in pupil diameter can reflect high-level cognitive signals that depend on central neuromodulatory mechanisms. However, brain mechanisms that adjust pupil size are also exquisitely sensitive to changes in luminance and other events that would be considered a nuisance in cognitive experiments recording pupil size. We implemented a simple auditory experiment involving no changes in visual stimulation. Using finite impulse-response fitting we found pupil responses triggered by different types of events. Among these are pupil responses to auditory events and associated surprise: cognitive effects. However, these cognitive responses were overshadowed by pupil responses associated with blinks and eye movements, both inevitable nuisance factors that lead to changes in effective luminance. Of note, these latter pupil responses were not recording artifacts caused by blinks and eye movements, but endogenous pupil responses that occurred in the wake of these events. Furthermore, we identified slow (tonic) changes in pupil size that differentially influenced faster (phasic) pupil responses. Fitting all pupil responses using gamma functions, we provide accurate characterisations of cognitive and non-cognitive response shapes, and quantify each response's dependence on tonic pupil size. These results allow us to create a set of recommendations for pupil size analysis in cognitive neuroscience, which we have implemented in freely available software.
KW - Blinking
KW - Brain
KW - Cognition
KW - Humans
KW - Photic Stimulation
KW - Pupil
KW - Journal Article
U2 - 10.1371/journal.pone.0155574
DO - 10.1371/journal.pone.0155574
M3 - SCORING: Journal article
C2 - 27191166
VL - 11
SP - e0155574
JO - PLOS ONE
JF - PLOS ONE
SN - 1932-6203
IS - 5
ER -