Turhan Canli on Neuroimaging - Dictionary of Arguments
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Neuroimaging/Canli: One approach is to report the results of whole-brain analyses, in addition to analyses from a priori regions of interest.((1)-(6))
Another approach is to conduct functional connectivity analyses, to investigate how activation across spatially distinct regions is correlated. For example, in our study of state-trait associations of Extraversion and Neuroticism with ACC activation (Canli, Amin, Haas et al. 2004)(7).
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We have developed a third approach (Omura, Aron and Canli 2005)(8), which represents an alternative to the traditional regions of interest (ROI) approach, which we termed the ‘regions of variance’ (ROV) approach. The ROI approach focuses on regions that have been shown to be consistently activated across prior studies that employed a similar task paradigm.
VsROI: brain regions that exhibit a great deal of variance from one study participant to another may never show sufficient group-level activation to pass statistical thresholds in traditional imaging studies, and therefore not ever be reported. We therefore developed an alternative methodology that identifies regions of variance (ROVs), i.e., areas that display the most variability across subjects for a given within-subject contrast. We then treat these ROVs as regions of interest to assess whether particular variables of interest can explain the variance exhibited in these regions. The conceptual difference between the ROV and ROI approaches is considerable: ROVs are empirically derived and therefore devoid of any theoretical assumptions or biases about the neural substrate and its relation to the cognitive process under study. In contrast, ROIs typically represent considerable assumptions about the cognitive functions they are believed to play a role in.
Problems/VsROV: we also discovered that the ROV approach does, on occasion, miss interesting brain-behaviour correlations.
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For example, the ROV approach missed the association between Extraversion and ACC response to positive stimuli in the left hemisphere. It turned out that, although the correlation between Extraversion and ACC activation was highly significant, the actual range of values that contributed to this correlation was relatively narrow, producing a low degree of between-subject variance.
1. Phan, K. L., Wager, T., Taylor, S. F. et al. 2002. Functional neuroanatomy of emotion: a meta-analysis of emotion activation studies in PET and fMRI, Neuroimage 16: 331–48
2. Phillips, M. L., Drevets, W. C., Rauch, S. L. et al. 2003a. Neurobiology of emotion perception I: The neural basis of normal emotion perception, Biological Psychiatry 54: 504–14
3. Phillips, M. L., W. C. Drevets, et al. 2003b. Neurobiology of emotion perception II: Implications for major psychiatric disorders. Biological Psychiatry 54: 515–28
4. Wager, T. D., Phan, K. L., Liberzon, I. et al. 2003. Valence, gender, and lateralization of functional brain anatomy in emotion: a meta-analysis of findings from neuroimaging, Neuroimage 19: 513–31
5. Baas, D., Aleman, A. and Kahn, R. S. 2004. Lateralization of amygdala activation: a systematic review of functional neuroimaging studies, Brain Research Reviews 45: 96–103
6. Phan, K. L., T. D. Wager, et al. 2004. Functional neuroimaging studies of human emotions, CNS Spectrums 9: 258–66
7. Canli, T., Amin, Z., Haas, W. et al. 2004. A double dissociation between mood states and personality traits in the anterior cingulate. Behavioral Neuroscience 118: 897–904
8. Omura, K., Aron, A. and Canli, T. 2005. Variance maps as a novel tool for localizing regions of interest in imaging studies of individual differences, Cognitive Affect and Behavioural Neuroscience 5: 252–61
Turhan Canlı,“Neuroimaging of personality“, in: Corr, Ph. J. & Matthews, G. (eds.) 2009. The Cambridge handbook of Personality Psychology. New York: Cambridge University Press_____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. The note [Author1]Vs[Author2] or [Author]Vs[term] is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition.
Philip J. Corr
The Cambridge Handbook of Personality Psychology New York 2009
Philip J. Corr (Ed.)
Personality and Individual Differences - Revisiting the classical studies Singapore, Washington DC, Melbourne 2018