On the Category's Edge: Event-Related Potential Correlates of Novelty and Conflicting Information in Rule-Based Categorization

Persistent Link:
http://hdl.handle.net/10150/195807
Title:
On the Category's Edge: Event-Related Potential Correlates of Novelty and Conflicting Information in Rule-Based Categorization
Author:
Folstein, Jonathan Robert
Issue Date:
2007
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
This dissertation consists of a review of the N2 component of the ERP and five experiments investigating the role of complex visual object categorization in modulating the N2 and two other ERP components: the P300, and a late prefrontal positivity. In the review, we focus on paradigms that elicit N2 components with an anterior scalp distribution, namely cognitive control, novelty, and sequential matching, arguing that the anterior N2 should be divided into separate control- and mismatch-related subcomponents. The experiments manipulated categorical typicality and the presence of conflicting information as participants categorized multi-featured artificial animals. In Experiments 1 and 2, rule-irrelevant features were correlated with particular categories during training. During transfer, participants applied a one- dimensional rule to stimuli with category-congruent, category-incongruent, or novel rule-irrelevant features. Category-incongruent and novel features delayed RT and P300 latency, but had no effect on the N2. Experiment 3 used a two-dimensional rule to create conflict between rule-relevant features. Conflict resulted in prolonged RTs, P300 latency, and larger amplitudes of a prefrontal positive component, but had no impact on the N2. Novel features did enhance the N2 relative to frequent features. In Experiments 4 and 5, participants categorized stimuli using a more complex three dimensional rule. Conflicting stimuli shared two features with one prototype and one feature with a second prototype while prototypes contained no conflicting information. A third category contained stimuli with either common or novel features. Again, perceptual novelty, but not conflict, increased the amplitude of the N2. Compared to prototypes, stimuli with conflicting information slowed reaction times but had no effect on P300 latency, instead enhancing a late prefrontal positive component. These results suggest limitations on the generality of the N2's sensitivity to conflicting information, while confirming its sensitivity to attended visual novelty. We suggest that, while P300 latency tracks stimulus evaluation time, application of a complex categorization rule requires a later stage of evaluation involving prefrontal cortex. In very complex rules, computations indexed by the P3 may be terminated early in favor of computations in PFC.
Type:
text; Electronic Dissertation
Keywords:
ERP; event related potentials; categorization; N2; P300
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Psychology; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Van Petten, Cyma
Committee Chair:
Van Petten, Cyma

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleOn the Category's Edge: Event-Related Potential Correlates of Novelty and Conflicting Information in Rule-Based Categorizationen_US
dc.creatorFolstein, Jonathan Roberten_US
dc.contributor.authorFolstein, Jonathan Roberten_US
dc.date.issued2007en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThis dissertation consists of a review of the N2 component of the ERP and five experiments investigating the role of complex visual object categorization in modulating the N2 and two other ERP components: the P300, and a late prefrontal positivity. In the review, we focus on paradigms that elicit N2 components with an anterior scalp distribution, namely cognitive control, novelty, and sequential matching, arguing that the anterior N2 should be divided into separate control- and mismatch-related subcomponents. The experiments manipulated categorical typicality and the presence of conflicting information as participants categorized multi-featured artificial animals. In Experiments 1 and 2, rule-irrelevant features were correlated with particular categories during training. During transfer, participants applied a one- dimensional rule to stimuli with category-congruent, category-incongruent, or novel rule-irrelevant features. Category-incongruent and novel features delayed RT and P300 latency, but had no effect on the N2. Experiment 3 used a two-dimensional rule to create conflict between rule-relevant features. Conflict resulted in prolonged RTs, P300 latency, and larger amplitudes of a prefrontal positive component, but had no impact on the N2. Novel features did enhance the N2 relative to frequent features. In Experiments 4 and 5, participants categorized stimuli using a more complex three dimensional rule. Conflicting stimuli shared two features with one prototype and one feature with a second prototype while prototypes contained no conflicting information. A third category contained stimuli with either common or novel features. Again, perceptual novelty, but not conflict, increased the amplitude of the N2. Compared to prototypes, stimuli with conflicting information slowed reaction times but had no effect on P300 latency, instead enhancing a late prefrontal positive component. These results suggest limitations on the generality of the N2's sensitivity to conflicting information, while confirming its sensitivity to attended visual novelty. We suggest that, while P300 latency tracks stimulus evaluation time, application of a complex categorization rule requires a later stage of evaluation involving prefrontal cortex. In very complex rules, computations indexed by the P3 may be terminated early in favor of computations in PFC.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectERPen_US
dc.subjectevent related potentialsen_US
dc.subjectcategorizationen_US
dc.subjectN2en_US
dc.subjectP300en_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePsychologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorVan Petten, Cymaen_US
dc.contributor.chairVan Petten, Cymaen_US
dc.contributor.committeememberRyan, Leeen_US
dc.contributor.committeememberForster, Kennethen_US
dc.contributor.committeememberGomez, Rebeccaen_US
dc.identifier.proquest2222en_US
dc.identifier.oclc659747392en_US
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