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- Grandy, Thomas H., et al.
(författare)
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Individual alpha peak frequency is related to latent factors of general cognitive abilities
- 2013
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Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 79, s. 10-18
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Tidskriftsartikel (refereegranskat)abstract
- Some eighty years after the discovery of the human electroencephalogram (EEG) and its dominant rhythm, alpha (similar to 10 Hz), the neurophysiological functions and behavioral correlates of alpha oscillations are still under debate. Similarly, the biological mechanisms contributing to the general factor of intelligence, or g, have been under scrutiny for decades. Individual alpha frequency (IAF), a trait-like parameter of the EEG, has been found to correlate with individual differences in cognitive performance and cognitive abilities. Informed by large-scale theories of neural organization emphasizing the general functional significance of oscillatory activity, the present study replicates and extends these findings by testing the hypothesis that IAF is related to intelligence at the level of g, rather than at the level of specific cognitive abilities. Structural equation modeling allowed us to statistically control for measurement error when estimating the association between IAF and intellectual functioning. In line with our hypothesis, we found a statistically reliable and substantial correlation between IAF and g (r = .40). The magnitude of this correlation did not differ significantly between younger and older adults, and captured all of the covariation between IAF and the cognitive abilities of reasoning, memory, and perceptual speed. The observed association between IAF and g provides a parsimonious explanation for the commonly observed diffuse pattern of correlations between IAF and cognitive performance. We conclude that IAF is a marker of global architectural and functional properties of the human brain.
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| 2. |
- Grandy, Thomas H., et al.
(författare)
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Peak individual alpha frequency qualifies as a stable neurophysiological trait marker in healthy younger and older adults
- 2013
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Ingår i: Psychophysiology. - : Wiley. - 0048-5772 .- 1469-8986 .- 1540-5958. ; 50:6, s. 570-582
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Tidskriftsartikel (refereegranskat)abstract
- The individual alpha frequency (IAF) of the human EEG reflects systemic properties of the brain, is highly heritable, and relates to cognitive functioning. Not much is known about the modifiability of IAF by cognitive interventions. We report analyses of resting EEG from a large-scale training study in which healthy younger (2031 years, N=30) and older (6580 years, N=28) adults practiced 12 cognitive tasks for approximate to 100 1-h sessions. EEG was recorded before and after the cognitive training intervention. In both age groups, IAF (and, in a control analysis, alpha amplitude) did not change, despite large gains in cognitive performance. As within-session reliability and test-retest stability were high for both age groups, imprecise measurements cannot account for the findings. In sum, IAF is highly stable in healthy adults up to 80 years, not easily modifiable by cognitive interventions alone, and thus qualifies as a stable neurophysiological trait marker.
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| 3. |
- Werkle-Bergner, Markus, et al.
(författare)
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Coordinated within-Trial Dynamics of Low-Frequency Neural Rhythms Controls Evidence Accumulation
- 2014
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Ingår i: Journal of Neuroscience. - 0270-6474 .- 1529-2401. ; 34:25, s. 8519-8528
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Tidskriftsartikel (refereegranskat)abstract
- Higher cognitive functions, such as human perceptual decision making, require information processing and transmission across widespread cortical networks. Temporally synchronized neural firing patterns are advantageous for efficiently representing and transmitting information within and between assemblies. Computational, empirical, and conceptual considerations all lead to the expectation that the informational redundancy of neural firing rates is positively related to their synchronization. Recent theorizing and initial evidence also suggest that the coding of stimulus characteristics and their integration with behavioral goal states require neural interactions across a hierarchy of timescales. However, most studies thus have focused on neural activity in a single frequency range or on a restricted set of brain regions. Here we provide evidence for cooperative spatiotemporal dynamics of slow and fast EEG signals during perceptual decision making at the single-trial level. Participants performed three masked two-choice decision tasks, one each with numerical, verbal, or figural content. Decrements in posterior alpha power (8 - 14 Hz) were paralleled by increments in high-frequency (>30 Hz) signal entropy in trials demanding active sensory processing. Simultaneously, frontocentral theta power (4 - 7 Hz) increased, indicating evidence integration. The coordinated alpha/theta dynamics were tightly linked to decision speed and remarkably similar across tasks, suggesting a domain-general mechanism. In sum, we demonstrate an inverse association between decision-related changes in widespread low-frequency power and local high-frequency entropy. The cooperation among mechanisms captured by these changes enhances the informational density of neural response patterns and qualifies as a neural coding system in the service of perceptual decision making.
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