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Cognitive Neuroscience

Scott D Slotnick
In an editorial (this issue), I argued that Eklund, Nichols, and Knutsson's 'null data' reflected resting-state/default network activity that inflated their false-positive rates. Commentaries on that paper were received by Nichols, Eklund, and Knutsson (this issue), Hopfinger (this issue), and Cunningham and Koscik (this issue). In this author response, I consider these commentaries. Many issues stemming from Nichols et al. are identified including: (1) Nichols et al. did not provide convincing arguments that resting-state fMRI data reflect null data...
April 19, 2017: Cognitive Neuroscience
William A Cunningham, Timothy R Koscik
We seek to balance the need to minimize false positives with the need to maximize power. We propose a compartmentalized series of analyses that a priori selects regions of voxels that have different degrees of predicted involvement. Alpha thresholds are allocated based on the strength of expected theoretical relationships. For example, confirmatory studies might allocate most of the error to the regions predicted from the literature and thus use a relatively more liberal threshold on these voxels. Simulations reveal that this technique increases power for hypothesized regions, while maintaining a constant false-positive rate and allowing exploratory analysis...
March 13, 2017: Cognitive Neuroscience
Joseph B Hopfinger
Slotnick (2017) makes a strong case that any attempt to assess the reliabiltiy of statistical correction procedures should use truly random data. In addition, however, there is an important side effect of the over-reliance on any given threshold to determine the worth of an experiment. Placing too much faith in any method of correction obscures the point that replication across labs remains a most critical part of scientific study. Especially for expensive methods, such as fMRI, an overemphasis on increasingly conservative thresholds can negatively impact the potential for replication of studies and the pursuit and reporting of innovative results...
March 7, 2017: Cognitive Neuroscience
Thomas E Nichols, Anders Eklund, Hans Knutsson
A recent Editorial by Slotnick (2017) reconsiders the findings of our paper on the accuracy of false positive rate control with cluster inference in fMRI (Eklund et al, 2016), in particular criticising our use of resting state fMRI data as a source for null data in the evaluation of task fMRI methods. We defend this use of resting fMRI data, as while there is much structure in this data, we argue it is representative of task data noise and such analysis software should be able to accommodate this noise. We also discuss a potential problem with Slotnick's own method...
January 31, 2017: Cognitive Neuroscience
Joseph B Hopfinger
Mechanisms of attention are a prime target for investigating the plasticity of the adult brain, as these core mechanisms act at the intersection of top-down and bottom-up processing, and the wide variety of methods used in attention research can be utilized to elucidate the mechanisms of plasticity. This special issue of Cognitive Neuroscience presents three new empirical papers and a discussion paper with peer commentaries. In the first article, Voelker, Sheese and colleagues investigate the influence of genetic variation on the effectiveness of attention training...
January 20, 2017: Cognitive Neuroscience
Scott D Slotnick
Analysis of functional magnetic resonance imaging (fMRI) data typically involves over one hundred thousand independent statistical tests; therefore, it is necessary to correct for multiple comparisons to control familywise error. In a recent paper, Eklund, Nichols, and Knutsson used resting-state fMRI data to evaluate commonly employed methods to correct for multiple comparisons and reported unacceptable rates of familywise error. Eklund et al.'s analysis was based on the assumption that resting-state fMRI data reflect null data; however, their 'null data' actually reflected default network activity that inflated familywise error...
January 5, 2017: Cognitive Neuroscience
Avery A Rizio, Nancy A Dennis
Intentional forgetting is posited to utilize both encoding and inhibition to control what information enters long-term memory. Within the context of the directed forgetting paradigm, evidence for the role of inhibition to support forgetting has been examined primarily during encoding. Specifically, past studies have shown that when encoding processes are intentionally inhibited, information is less likely to be remembered. Despite the recruitment of such inhibitory processes, not all items are successfully forgotten...
January 2017: Cognitive Neuroscience
Pin-Hao Andy Chen, Robert S Chavez, Todd F Heatherton
Failure to maintain a healthy body weight may reflect a long-term imbalance between the executive control and reward systems of the brain. The current study examined whether the anatomical connectivity between these two systems predicted individual variability in achieving a healthy body weight, particularly in chronic dieters. Thirty-six female chronic dieters completed a food-cue reactivity task in the scanner. Two regions-of-interest (ROIs) were defined from the reactivity task: the inferior frontal gyrus (IFG), which engages cognitive control and the orbitofrontal cortex (OFC), which represents reward value...
October 11, 2016: Cognitive Neuroscience
Pascale Voelker, Denise Piscopo, Aldis P Weible, Gary Lynch, Mary K Rothbart, Michael I Posner, Cristopher M Niell
We appreciate the many comments we received on our discussion paper and believe that they reflect a recognition of the importance of this topic worldwide. We point out in this reply that there appears to be a confusion between the role of oscillations in creating white matter and other functions of oscillations in communicating between neural areas during task performance or at rest. We also discuss some mechanisms other than the enhancement of white matter that must influence reaction time. We recognize the limited understanding we have of transfer and outline some future directions designed to improve our understanding of this process...
August 2, 2016: Cognitive Neuroscience
Alexandra M Gaynor, Elizabeth F Chua
Previous research has implicated the prefrontal cortex (PFC) in successful associative encoding and subjective awareness of one's memory performance. We tested the causal role of the PFC in these processes by applying transcranial direct current stimulation (tDCS) during a verbal associative encoding and judgment-of-learning (JOL) task. tDCS over the PFC impaired associative encoding compared to sham and parietal tDCS, as shown by fewer hits on a subsequent associative recognition test. There were no effects of tDCS on the magnitude or accuracy of JOLs...
August 1, 2016: Cognitive Neuroscience
Chiara Della Libera, Riccardo Calletti, Jana Eštočinová, Leonardo Chelazzi, Elisa Santandrea
Recent evidence indicates that the attentional priority of objects and locations is altered by the controlled delivery of reward, reflecting reward-based attentional learning. Here, we take an approach hinging on intersubject variability to probe the neurobiological bases of the reward-driven plasticity of spatial priority maps. Specifically, we ask whether an individual's susceptibility to the reward-based treatment can be accounted for by specific predictors, notably personality traits that are linked to reward processing (along with more general personality traits), but also gender...
August 1, 2016: Cognitive Neuroscience
Shenbing Kuang
Voelker et al. (this issue) discuss the idea of linking white matter (WM) plasticity to improved reaction time (RT) during training. While compelling, this argument has important confounds and should be taken with cautions. RT is constrained not only by the speed of signal transmission in WM, but also by the properties of synaptic and neural processing in cortical gray matter. It is still unclear to what extent RT variability could be explained by WM plasticity and cortical plasticity. Future studies should examine both WM plasticity and cortical plasticity in relation to RT changes, to fully understand the brain mechanisms underlying RT improvement during training...
July 29, 2016: Cognitive Neuroscience
J Michael Williams
For many tasks, an increase in competence is associated with faster response time. Voelker et al (this issue) explore the possible role of white matter reorganization as a mechanism underlying this relationship. With such a strong focus on this possible interpretation and the limits of current neuroimaging methods, the authors constrained their options to the point of only considering simplified models of how training might result in faster responses.
July 27, 2016: Cognitive Neuroscience
Danielle Farrar, Andrew E Budson
While the relationship between diffusion tensor imaging (DTI) measurements and training effects is explored by Voelker et al. (this issue), a cursory discussion of functional magnetic resonance imaging (fMRI) measurements categorizes increased activation with findings of greater white matter integrity. Evidence of the relationship between fMRI activation and white matter integrity is conflicting, as is the relationship between fMRI activation and training effects. An examination of the changes in fMRI activation in response to training is helpful, but the relationship between DTI and fMRI activation, particularly in the context of white matter changes, must be examined further before general conclusions can be drawn...
July 26, 2016: Cognitive Neuroscience
Daniela Aisenberg, Zahira Ziva Cohen, Omer Linkovski
Voelker et al. (this issue) discuss how training improves task speed. They suggest two constraints when exploring how training changes cognition through transfer: (1) a link between improved connectivity and response speed and (2) the transfer task should use pathways altered by training. Looking at the literature on aging, we believe the latter constraint should be reconsidered. We discuss evidence from developmental aging, questioning whether the transfer task necessarily requires using training task pathways...
July 22, 2016: Cognitive Neuroscience
Olga Kepinska, Niels O Schiller
In response to Voelker et al. (this issue), we argue for a wide array of neural oscillatory mechanisms underlying learning and practice. While the authors propose frontal theta power as the basis for learning-induced neuroplasticity, we believe that the temporal dynamics of other frequency bands, together with their synchronization properties can offer a fuller account of the neurophysiological changes occurring in the brain during cognitive tasks.
July 22, 2016: Cognitive Neuroscience
Helena Bujalka, Ben Emery
Voelker and colleagues propose that we may illuminate learning-associated phenomena such as generalization by considering white matter plasticity. Consistent with this idea, human neuroimaging studies reveal learning-induced changes in adult white matter. Animal studies reveal that some forms of learning induce, and are dependent on, generation of new oligodendrocytes. Nevertheless, it remains unclear which alterations to myelin structure are most relevant to learning, and humans and rodents may profoundly differ in their capacity for oligodendrogenesis in adulthood...
July 22, 2016: Cognitive Neuroscience
Constantinos I Siettos, Nikolaos Smyrnis
Many studies focus on anatomical brain connectivity in an effort to explain the effect of practice on reaction time (RT) that is observed in many cognitive tasks. In this commentary, we suggest that RT reflects a stochastic process that varies in each single repetition of any cognitive task and cannot be attributed only to anatomical properties of the underlying neuronal circuit. Based on recent evidence from Magnetoencephalographic, Electroencephalographic, and fMRI studies, we further propose that the functional properties of key brain areas and their self-organization into functional connectivity networks contribute to the RT and could also explain the effects of training on the distribution of the RT...
July 18, 2016: Cognitive Neuroscience
Dipanjan Roy, V S Chandrasekhar Pammi
Here, we argue systematically about the promises and pitfalls of relating Human Connectome to cognitive enhancement. We also highlight three key areas where further resolution is required before the generalization of the white-matter-related cause of cognitive enhancement across a variety of cognitive modalities is made. These key areas are: (a) inherent limitations in estimating of diffusion-weighted anisotropy index near volumes with high abundance of crossing fibers; (b) species differences in cell types and only a putative link between brain rhythms and modulation of activity in precursor cells in rodents;...
July 15, 2016: Cognitive Neuroscience
Heleen A Slagter, Marlies E Vissers, Lotte J Talsma, K Richard Ridderinkhof
Voelker et al. (2016) discuss the intriguing possibility that faster response times after training result from changes in white matter pathways, and propose that frontal theta activity is important for inducing these changes. We argue that, depending on the specific cognitive processes and brain networks targeted by training, oscillatory activity in other frequency bands could produce similar changes in white matter. Such changes can have a profound effect on brain function and performance if they optimize the timing of information transmission through neural networks...
July 14, 2016: Cognitive Neuroscience
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