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| Volume 7, Number 14, Article 14, Pages 1-13 |
doi:10.1167/7.14.14 |
http://journalofvision.org/7/14/14/ |
ISSN 1534-7362 |
Perceptual load modulates conscious flicker perception
David Carmel |
Institute of Cognitive Neuroscience, University College London, London, UK, Department of Psychology, University College London, London, UK, & Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, London, UK |
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Pascal Saker |
Institute of Cognitive Neuroscience, University College London, London, UK, & Department of Psychology, University College London, London, UK |
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Geraint Rees |
Institute of Cognitive Neuroscience, University College London, London, UK, & Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, London, UK |
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Nilli Lavie |
Institute of Cognitive Neuroscience, University College London, London, UK, & Department of Psychology, University College London, London, UK |
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Abstract
Subjective visual experience depends not only on the spatial arrangement of the environment, but also on the temporal pattern of stimulation. For example, flickering and steady light presented in the same location evoke a very different perceptual experience due to their different temporal patterns. Here, we examined whether the availability of processing resources affected the temporal resolution of conscious flicker perception—the ability to distinguish rapid changes in light intensity, detecting visual temporal patterns. Participants detected flicker in a fixated LED that flickered at or around the individually adjusted critical flicker fusion (CFF) threshold while searching for a target letter presented in the periphery either on its own (low perceptual load) or among other letters (high load). Physically identical flickering stimuli were more likely to be perceived as “fused” under high (compared to low) load in the peripheral letter search. Furthermore, psychophysical measures showed a reduction in flicker detection sensitivity under high perceptual load. These results could not be due to criterion or stimulus prioritization differences or to differential likelihood of forgetting the correct response under different load conditions. These findings demonstrate that perceptual load influences conscious perception of temporal patterns.
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