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Putting the brakes on inhibitory models of frontal lobe function.

Hampshire A - Neuroimage (2015)

Bottom Line: However, there is growing evidence to support the alternative view that response inhibition is just one prominent example of the many cognitive control processes that are supported by the same set of 'domain general' functional networks.The results demonstrate that there is no inhibitory module within the RIFC.Instead, response inhibition recruits a functionally heterogeneous ensemble of RIFC networks, which can be dissociated from each other in the context of other task demands.

View Article: PubMed Central - PubMed

Affiliation: The Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, Imperial College London, London, United Kingdom. Electronic address: a.hampshire@imperial.ac.uk.

No MeSH data available.


Independent components analyses conducted separately on data from each of the three studies produced a highly consistent parcellation of the RIFC.
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f0010: Independent components analyses conducted separately on data from each of the three studies produced a highly consistent parcellation of the RIFC.

Mentions: In a recent article, Aron and colleagues proposed that the coordinates of the inhibition module are at x = 48, y = 16, z = 18 in MNI space (Aron et al., 2014b); this was based on the results of a meta-analysis conducted by another group (Levy and Wagner, 2011). In order to determine whether there was any evidence for a functionally distinct region of the RIFC at these proposed coordinates, ICA decompositions were generated separately for each of the three studies. MELODIC was set to extract 10 components; this initial model order was selected based on previous studies that have indicated approximately 7 components within this volume when applying the Akaike information Criteria (Erika-Florence et al., 2014) and was intended to allow for the possibility of additional noise components, which are often extracted by this method, e.g., due to movement. Two of the components from study 1, three from study 2 and two from study 3, appeared to capture movement artefacts. There was a close conformity between seven of the remaining components across the three studies (Fig. 2). None of the components from any of the studies centred on the proposed coordinates of the inhibition module; however, 5 of them had mean peak values within 3 cm of those coordinates with the closest being dorsal by approximately 1 cm. Three of the components had clusters of peak activation that appeared to overlap with the coordinates of the inhibition module in all three studies (Fig. 3 upper and Table 1). Increasing the dimensionality of the ICA to 20 components also did not identify a component with closer peak coordinates in any of the three studies. However, in study 3, one of the proximal clusters was broken down into two further components (Fig. 3 lower). These results demonstrated that the data-driven parcellation of RIFC was robust across studies and at multiple levels of ICA dimensionality. 10 mm radius ROIs were defined for further analysis at the peak coordinates of the 7 components, averaged across studies. For completeness, an additional 10 mm radius ROI (Aron ROI) was defined at the exact proposed coordinates of the inhibition module.


Putting the brakes on inhibitory models of frontal lobe function.

Hampshire A - Neuroimage (2015)

Independent components analyses conducted separately on data from each of the three studies produced a highly consistent parcellation of the RIFC.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4441092&req=5

f0010: Independent components analyses conducted separately on data from each of the three studies produced a highly consistent parcellation of the RIFC.
Mentions: In a recent article, Aron and colleagues proposed that the coordinates of the inhibition module are at x = 48, y = 16, z = 18 in MNI space (Aron et al., 2014b); this was based on the results of a meta-analysis conducted by another group (Levy and Wagner, 2011). In order to determine whether there was any evidence for a functionally distinct region of the RIFC at these proposed coordinates, ICA decompositions were generated separately for each of the three studies. MELODIC was set to extract 10 components; this initial model order was selected based on previous studies that have indicated approximately 7 components within this volume when applying the Akaike information Criteria (Erika-Florence et al., 2014) and was intended to allow for the possibility of additional noise components, which are often extracted by this method, e.g., due to movement. Two of the components from study 1, three from study 2 and two from study 3, appeared to capture movement artefacts. There was a close conformity between seven of the remaining components across the three studies (Fig. 2). None of the components from any of the studies centred on the proposed coordinates of the inhibition module; however, 5 of them had mean peak values within 3 cm of those coordinates with the closest being dorsal by approximately 1 cm. Three of the components had clusters of peak activation that appeared to overlap with the coordinates of the inhibition module in all three studies (Fig. 3 upper and Table 1). Increasing the dimensionality of the ICA to 20 components also did not identify a component with closer peak coordinates in any of the three studies. However, in study 3, one of the proximal clusters was broken down into two further components (Fig. 3 lower). These results demonstrated that the data-driven parcellation of RIFC was robust across studies and at multiple levels of ICA dimensionality. 10 mm radius ROIs were defined for further analysis at the peak coordinates of the 7 components, averaged across studies. For completeness, an additional 10 mm radius ROI (Aron ROI) was defined at the exact proposed coordinates of the inhibition module.

Bottom Line: However, there is growing evidence to support the alternative view that response inhibition is just one prominent example of the many cognitive control processes that are supported by the same set of 'domain general' functional networks.The results demonstrate that there is no inhibitory module within the RIFC.Instead, response inhibition recruits a functionally heterogeneous ensemble of RIFC networks, which can be dissociated from each other in the context of other task demands.

View Article: PubMed Central - PubMed

Affiliation: The Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, Imperial College London, London, United Kingdom. Electronic address: a.hampshire@imperial.ac.uk.

No MeSH data available.