Project

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Selective attention and eye movements: An integrative cognitive neuropsychological approach

English title Selective attention and eye movements: An integrative cognitive neuropsychological approach
Applicant Krummenacher Joseph
Number 133888
Funding scheme R'EQUIP
Research institution Département de Psychologie Université de Fribourg
Institution of higher education University of Fribourg - FR
Main discipline Psychology
Start/End 01.12.2010 - 30.11.2011
Approved amount 58'378.00
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Keywords (8)

Attention; Eye movements; Saliency; Attention guidance; Oculomotor control; selection; saccades; saccade control

Lay Summary (English)

Lead
Lay summary
The project aims at investigating the mechanisms common to the control of selective visual attention and eye movements. Cognitive, neuropsychological and neuroscience research suggests that selective visual attention and eye movements are controlled by networks of brain areas that show large overlap.Own behavioral research using visual search tasks has contributed to a cognitive model of the processes underlying dimension-based selection assuming that search is based on a saliency representation that guides focal attention. Mechanisms of saliency generation and integration were shown to be susceptible to stimulus-driven (bottom-up) and knowledge-based (top-down) modulations. Bottom-up and top-down effects are explained by implicit (repetition vs. change of stimulus characteristics) or explicit (semantic cue) shifts of processing resources.A first objective is to investigate the bottom-up and top-down modulations of eye movement parameters (saccade latencies, fixation durations, location errors, prevalence of eye movements) in a number of visual search tasks (feature, conjunction, and compound search).Comparisons of the patterns of manual reaction times and oculomotor latencies are expected to reveal whether visual selection and eye movements are controlled by the same or different saliency representations. Dependent on whether there is overlap in the result patterns or not, the brain areas likely to underlie the relevant control mechanisms can be identified. Theoretical analysis is guided by recent reports of brain areas underlying spatial visual attention (e.g., Corbetta et al., 2002) and eye movement control (e.g., Munoz et al., 2004). A second objective is the application of empirical and theoretical results to the issue of attention impairments. People suffering from Attention Deficit Hyperactivity Disorder (ADHD) and people with difficulties in social interactions such as those diagnosed with Asperger's syndrome are of particular interest for the understanding of selective processes. Individuals diagnosed with high-functioning autism or Asperger's syndrome have been reported to show advantages in visual search tasks in comparison to normal observers; the same may also be true for people with ADHD. Behavioral measures and eye movement parameters of a selection of visual search tasks are compared with the results of investigations of unimpaired participants. The project is expected to contribute significantly to the issue of which aspects of selective attention and eye movements are governed by the same or different underlying networks. Further, brain areas likely to underlie attentional disorders are expected to be identified.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
4th Rovereto Attention Workshop 2011 27.10.2011 Rovereto
12th Congress of the Swiss Psychological Society 2011 12.09.2011 Fribourg
16th European Conference on Eye Movements 2011 (ECEM) 21.08.2011 Marseilles


Associated projects

Number Title Start Funding scheme
125205 Development of the mechanisms underlying feature-based selective perception in children and young adults 01.06.2009 Project funding (Div. I-III)
127261 Visual Search and Eye Movements in Autism Spectrum Disorder and ADHD 01.10.2009 ProDoc
130306 Selective visual processing: An integrative neurocognitive account based on psychological research methods 01.09.2010 SNSF Professorships

Abstract

The present research project aims at investigating the mechanisms common to the control of selective visual attention and eye movements. Recent research in the fields of cognitive psychology and cognitive neuropsychology using behavioral methods as well as single cell recording and imaging methods suggests that selective visual attention and eye movements are controlled by networks of sub-cortical and cortical areas that show some degree of overlap.Own recent behavioral research into dimension-based selection using the visual search method has contributed to a cognitive model of the processes underlying control of dimension-based attention and perception. The model assumes that visual search for target objects the identity of which is unknown is based on an overall saliency representation that guides focal attention to the spatial location of the most conspicuous item in a visual scene. Overall saliency results from the integration of feature contrast signals that are generated by a limited set of dimension-based modules representing visual features such as color, orientation or spatial frequency. The mechanisms of saliency generation and integration were shown to be susceptible to stimulus-driven (bottom-up) and knowledge-based (top-down) modulations. Repetitions of the target-defining dimension across visual search trials expedite search reaction times relative to changes of the target dimension across trials. Indicating the relevant target dimension by semantic cues also accelerates reaction times. These bottom-up and top-down effects are explained by implicit (repetition vs. change of target dimension) or explicit (semantic cue) shifts of processing resources across dimension-based modules, respectively.The present research project comprises of two main components. The objective of the first component is to investigate, in detail, bottom-up and top-down modulations of eye movement parameters in a number of different visual search tasks such as feature search, feature conjunction search and compound search. Eye movement parameters are saccade latencies, fixation durations, fixation location errors as well as the prevalence of eye movements in the various search tasks. In particular, comparisons of the patterns of manual reaction times and oculomotor latencies are expected to reveal whether visual selection and eye movements are controlled by the same or different saliency representations. In the case of overlap between attention and eye movement results, it can be concluded that attention and eye movement are controlled by the same (saliency) representations, and candidate cortical regions underlying the relevant control mechanisms can be identified. Theoretically, the analysis is guided by two recent models of the brain areas underlying spatial visual attention by Corbetta and Shulman (2002) and the control of eye movements by Munoz and Everling (2004). In the second component project, the findings of the empirical and theoretical work of first component are applied to the question of which mechanisms underlying visual selective perception are impaired in people with attention disorders. People suffering from Attention Deficit Hyperactivity Disorder (ADHD) and people with difficulties in social interactions such as those diagnosed with Asperger's syndrome (an autism spectrum disorder) are of particular interest for the understanding of selective processes. Individuals diagnosed with high-functioning autism or Asperger’s syndrome have been reported to shown advantages in visual search tasks in comparison to normal observers; the same may also be true for persons with ADHD. In order to contribute to the understanding of the cognitive processes responsible for the difficulties and advantages observed in the two conditions, it is proposed to analyze both behavioral measures and eye movement parameters in a variety of visual search tasks and to compare the results to the findings of unimpaired participants. Both of these research issues are addressed in the SNF ProDoc research module titled “Visual Search and Eye Movements in Autism Spectrum Disorder and ADHD” (PDFMP1_127261).It is expected that the planned studies will contribute significantly to the question of whether selective attention and eye movements are governed by the same or different underlying networks. Further, brain areas potentially underlying attentional and social disorders are expected to be revealed by explanations of the results in terms of cognitive models of visual selection as well as models of the brain areas involved in the control of selective attention and, respectively, eye movements.
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