Cognitive energetic mechanisms and neural basis of alertness regulation
type: CreativeWork
description: Human cognition is influenced by "energetic" factors like effort or fatigue. Interestingly, seemingly easy or well-practiced tasks that still require a continuous attentional engagement, have been found especially susceptible to the effects of such energetic variables. Particularly in monotonous and cognitively little challenging tasks, impaired performance, from reduced efficiency to catastrophic errors, often results from temporary deficits in sustaining attention. A classic paradigm with minimal cognitive demands that is used for examining the most basic form of sustained attention is simple reaction-time tasks. These tasks require a rapid motor response to predefined stimuli. The reaction upon stimulus detection is always the same, and the only unknown variable is the exact moment of stimulus occurrence. Attaining and maintaining a state of readiness to respond in such tasks has been termed "alertness." This thesis investigates cognitive-energetic mechanisms that contribute to alertness and its decrease over time as well as the neurobiological basis of alertness regulation. The first investigation (Study 1) examined in three 25-min simple reaction-time tasks, which posed different demands on attention via manipulations of stimulus salience, whether performance decrements with time on task can be better explained with increasing drifts of the attentional focus away from the task (distraction hypothesis) or with a depletion of attentional resources (mental-fatigue hypothesis). The performance and questionnaire data largely corroborated the latter explanation, since decrements and subjective fatigue increased more with higher attentional demands. The increase of self-reported task-unrelated thoughts over time, however, provided some evidence for the distraction hypothesis as well. Based on these findings, an approach is developed that incorporates both explanations in a hierarchical model of self-regulation. Study 2 examined the question as to what extent the mecha…
abstract: Human cognition is influenced by "energetic" factors like effort or fatigue. Interestingly, seemingly easy or well-practiced tasks that still require a continuous attentional engagement, have been found especially susceptible to the effects of such energetic variables. Particularly in monotonous and cognitively little challenging tasks, impaired performance, from reduced efficiency to catastrophic errors, often results from temporary deficits in sustaining attention. A classic paradigm with minimal cognitive demands that is used for examining the most basic form of sustained attention is simple reaction-time tasks. These tasks require a rapid motor response to predefined stimuli. The reaction upon stimulus detection is always the same, and the only unknown variable is the exact moment of stimulus occurrence. Attaining and maintaining a state of readiness to respond in such tasks has been termed "alertness." This thesis investigates cognitive-energetic mechanisms that contribute to alertness and its decrease over time as well as the neurobiological basis of alertness regulation. The first investigation (Study 1) examined in three 25-min simple reaction-time tasks, which posed different demands on attention via manipulations of stimulus salience, whether performance decrements with time on task can be better explained with increasing drifts of the attentional focus away from the task (distraction hypothesis) or with a depletion of attentional resources (mental-fatigue hypothesis). The performance and questionnaire data largely corroborated the latter explanation, since decrements and subjective fatigue increased more with higher attentional demands. The increase of self-reported task-unrelated thoughts over time, however, provided some evidence for the distraction hypothesis as well. Based on these findings, an approach is developed that incorporates both explanations in a hierarchical model of self-regulation. Study 2 examined the question as to what extent the mecha…
author: Langner, Robert
language: eng
keywords: info:eu-repo/classification/ddc/150, Neuropsychologie, Kognitive Psychologie, Bildgebendes Verfahren, Experimentelle Psychologie, Reaktionszeit, Psychologie, Aufmerksamkeit, funktionelle Kernspintomographie, Neuropsychology, Experimental Psychology, Neuroimaging, Attention, fMRI
date published: 2010
date modified: 2026-07-30T19:43:35Z
provider: RWTH Aachen University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Publikationsserver der RWTH Aachen University