Learningrelated effects and functional neuroimaging
(1999) In Human Brain Mapping 7(4). p.43234 Abstract
A fundamental problem in the study of learning is that learningrelated changes may be confounded by nonspecific time effects. There are several strategies for handling this problem. This problem may be of greater significance in functional magnetic resonance imaging (fMRI) compared to positron emission tomography (PET). Using the general linear model, we describe, compare, and discuss two approaches for separating learningrelated from nonspecific time effects. The first approach makes assumptions on the general behavior of nonspecific effects and explicitly models these effects, i.e., nonspecific time effects are incorporated as a linear or nonlinear confounding covariate in the statistical model. The second strategy makes no a priori... (More)
A fundamental problem in the study of learning is that learningrelated changes may be confounded by nonspecific time effects. There are several strategies for handling this problem. This problem may be of greater significance in functional magnetic resonance imaging (fMRI) compared to positron emission tomography (PET). Using the general linear model, we describe, compare, and discuss two approaches for separating learningrelated from nonspecific time effects. The first approach makes assumptions on the general behavior of nonspecific effects and explicitly models these effects, i.e., nonspecific time effects are incorporated as a linear or nonlinear confounding covariate in the statistical model. The second strategy makes no a priori assumption concerning the form of nonspecific time effects, but implicitly controls for nonspecific effects using an interaction approach, i.e., learning effects are assessed with an interaction contrast. The two approaches depend on specific assumptions and have specific limitations. With certain experimental designs, both approaches may be used and the results compared, lending particular support to effects that are independent of the method used. A third and perhaps better approach that sometimes may be practically unfeasible is to use a completely temporally balanced experimental design. The choice of approach may be of particular importance when learningrelated effects are studied with fMRI.
(Less)
 author
 Petersson, K M; Elfgren, C ^{LU} and Ingvar, M
 organization
 publishing date
 1999
 type
 Contribution to journal
 publication status
 published
 keywords
 Adult, Brain Mapping, Conditioning (Psychology), Hippocampus, Humans, Magnetic Resonance Imaging, Male, Mental Recall, Photic Stimulation, Temporal Lobe, Tomography, EmissionComputed, Journal Article, Research Support, NonU.S. Gov't
 in
 Human Brain Mapping
 volume
 7
 issue
 4
 pages
 43  234
 publisher
 WileyBlackwell
 external identifiers

 scopus:0032970169
 ISSN
 10659471
 DOI
 10.1002/(SICI)10970193(1999)7:4<234::AIDHBM2>3.0.CO;2O
 language
 English
 LU publication?
 yes
 id
 e0fc1c5298e44ed9b3088104eea6ab7e
 date added to LUP
 20161029 16:02:32
 date last changed
 20190106 12:39:31
@article{e0fc1c5298e44ed9b3088104eea6ab7e, abstract = {<p>A fundamental problem in the study of learning is that learningrelated changes may be confounded by nonspecific time effects. There are several strategies for handling this problem. This problem may be of greater significance in functional magnetic resonance imaging (fMRI) compared to positron emission tomography (PET). Using the general linear model, we describe, compare, and discuss two approaches for separating learningrelated from nonspecific time effects. The first approach makes assumptions on the general behavior of nonspecific effects and explicitly models these effects, i.e., nonspecific time effects are incorporated as a linear or nonlinear confounding covariate in the statistical model. The second strategy makes no a priori assumption concerning the form of nonspecific time effects, but implicitly controls for nonspecific effects using an interaction approach, i.e., learning effects are assessed with an interaction contrast. The two approaches depend on specific assumptions and have specific limitations. With certain experimental designs, both approaches may be used and the results compared, lending particular support to effects that are independent of the method used. A third and perhaps better approach that sometimes may be practically unfeasible is to use a completely temporally balanced experimental design. The choice of approach may be of particular importance when learningrelated effects are studied with fMRI.</p>}, author = {Petersson, K M and Elfgren, C and Ingvar, M}, issn = {10659471}, keyword = {Adult,Brain Mapping,Conditioning (Psychology),Hippocampus,Humans,Magnetic Resonance Imaging,Male,Mental Recall,Photic Stimulation,Temporal Lobe,Tomography, EmissionComputed,Journal Article,Research Support, NonU.S. Gov't}, language = {eng}, number = {4}, pages = {43234}, publisher = {WileyBlackwell}, series = {Human Brain Mapping}, title = {Learningrelated effects and functional neuroimaging}, url = {http://dx.doi.org/10.1002/(SICI)10970193(1999)7:4<234::AIDHBM2>3.0.CO;2O}, volume = {7}, year = {1999}, }