Journal Article

PreJuSER-19836

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Mental Fatigue Modulates Dynamic Adaptation to Perceptual Demand in Speeded Detection

Langner, R.FZJ* ; Eickhoff, S. B.FZJ* ; Steinborn, M.

2011
PLoS Lawrence, Kan.

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Please use a persistent id in citations: http://hdl.handle.net/2128/11175  doi:10.1371/journal.pone.0028399

Abstract: When stimulus intensity in simple reaction-time tasks randomly varies across trials, detection speed usually improves after a low-intensity trial. With auditory stimuli, this improvement was often found to be asymmetric, being greater on current low-intensity trials. Our study investigated (1) whether asymmetric sequential intensity adaptation also occurs with visual stimuli; (2) whether these adjustments reflect decision-criterion shifts or, rather, a modulation of perceptual sensitivity; and (3) how sequential intensity adaptation and its underlying mechanisms are affected by mental fatigue induced through prolonged performance. In a continuous speeded detection task with randomly alternating high- and low-intensity visual stimuli, the reaction-time benefit after low-intensity trials was greater on subsequent low- than high-intensity trials. This asymmetry, however, only developed with time on task (TOT). Signal-detection analyses showed that the decision criterion transiently became more liberal after a low-intensity trial, whereas observer sensitivity increased when the preceding and current stimulus were of equal intensity. TOT-induced mental fatigue only affected sensitivity, which dropped more on low- than on high-intensity trials. This differential fatigue-related sensitivity decrease selectively enhanced the impact of criterion down-shifts on low-intensity trials, revealing how the interplay of two perceptual mechanisms and their modulation by fatigue combine to produce the observed overall pattern of asymmetric performance adjustments to varying visual intensity in continuous speeded detection. Our results have implications for similar patterns of sequential demand adaptation in other cognitive domains as well as for real-world prolonged detection performance.

Keyword(s): Adaptation, Physiological (MeSH) ; Adult (MeSH) ; Attention: physiology (MeSH) ; Female (MeSH) ; Humans (MeSH) ; Male (MeSH) ; Mental Fatigue: physiopathology (MeSH) ; Reaction Time: physiology (MeSH) ; Signal Detection, Psychological (MeSH) ; Visual Perception: physiology (MeSH) ; Young Adult (MeSH) ; J

Note: SBE was supported by the Human Brain Project (R01-MH074457-01A1), the Initiative and Networking Fund of the Helmholtz Association within the Helmholtz Alliance on Systems Biology (Human Brain Model), and the Deutsche Forschungsgemeinschaft (IRTG 1328). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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Contributing Institute(s):

1. Molekulare Organisation des Gehirns (INM-2)

Research Program(s):

1. Funktion und Dysfunktion des Nervensystems (FUEK409) (FUEK409)
2. 89571 - Connectivity and Activity (POF2-89571) (POF2-89571)

Appears in the scientific report 2011

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