Seminar Papers

[Article] Neurofeedback of core language network nodes modulates connectivity with the default-mode network:a double-blind fMRI neurofeedback study on auditory verbal hallucinations.

Summary: The auditory-verbal hallucination by change of brain network function has been reported from schizophrenia patients. The goal of the paper is to investigate the modulation by neurofeedback in resting-state connectivity. They demonstrated the coupling increased between language and DMN node after the down-regulation NF. Also, they showed the possibility of NF as a therapeutic intervention

Zweerings, Jana, et al. (2019) “Neurofeedback of core language network nodes modulates connectivity with the default-mode network: a double-blind fMRI neurofeedback study on auditory verbal hallucinations.” NeuroImage 189 : 533-542.

[Article] natomical and functional properties of the foot and leg representation in areas 3b, 1 and 2 of primary somatosensory cortex in humans: A 7T fMRI study

Summary: In this paper, lower limb somatotopy mapping was investigated whether each mapped representation also responded to the stimulation of other body parts (i.e., response selectivity) and conducted dissimilarity analysis relating these anatomical and functional properties of S1 to the physical structure of the lower limbs. They found only minor differences between the properties of the three BAs of somasensory areas (i.e., BA 3,1,2), suggesting that S1 maps for the lower limbs differ from those described for the hand. Furthermore, this paper suggested a possible homology between the first digit of upper and lower extremity in humans, and report different patterns of selectivity in the foot representations (i.e. lower selectivity) compared to the other leg representations (i.e. greater selectivity)

Akselrod, Michel, et al. (2017) Anatomical and functional properties of the foot and leg representation in areas 3b, 1 and 2 of primary somatosensory cortex in humans: A 7T fMRI study. Neuroimage 159, 473-487.

How sex differences play a role in neurological diseases

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Separating vascular cell data based on sex helps researchers make new discoveries about why males and females are affected by neurodegenerative* diseases differently. Findings point to differences in the blood-brain barrier between males and females.

*neurodegenerative : the progressive loss of structure or function of neurons, including their death

Weber, Callie M., and Alisa Morss Clyne. “Sex differences in the blood–brain barrier and neurodegenerative diseases.” APL Bioengineering 5.1 (2021): 011509.

Study links genes with function across the human brain

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A new study, that utilized machine learning tools, provides a new map that links genetic signatures to functions across the human brain!

Interestingly, they found a clear genetic signal that separated cognitive processes, like attention, from more affective processes, like fear. This separation can be traced to gene expression in specific cell types and molecular pathways, offering key insights for future research into psychiatric disorders.

Cognition, for example, was linked more to the gene signatures of inhibitory or excitatory neurons. Affective processes, however, were linked to support cells such as microglia and astrocytes, supporting a theory that inflammation of these cells is a risk factor in mental illness. The genetic signature related to affect was centred on a brain region called the anterior cingulate cortex, which has been shown to be vulnerable in mental illness.

See the https://www.nature.com/articles/s41562-021-01082-z
Published in the journal Nature Human Behaviour on March 25, 2021
(this study draws a direct link between gene expression and higher brain function, by mapping gene signatures to functional processes across the human brain.)

The evolution of overconfidence

Johnson, D. D., & Fowler, J. H. (2011). The evolution of overconfidence. Nature, 477(7364), 317-320.

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Interestingly, the authors found that overconfidence maximizes individual fitness and populations tend to become overconfident.

[Article] How Our Visual System Avoids Overloading

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The human brain has limited capacity in terms of the data it is able to process and save in its memory. Researchers sought to answer the following question: is the visual system capable of automatic object categorization (i.e., without attention)? To this end, they tested whether the rapid categorical parsing is automatic or requires attention. They found that spatially intermixed objects are parsed into distinct categories automatically.

How Our Visual System Avoids Overloading

“Spatially intermixed objects of different categories are parsed automatically” by Vladislav A. Khvostov, Anton O. Lukashevich & Igor S. Utochkin. Scientific Reports

[Article] Is What I See, What I Imagine? The Neural Overlap Between Vision and Imagination

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Using generative networks and functional magnetic resonance imaging (fMRI), researchers found that brain uses similar visual areas for mental imagery and vision, but it uses low-level visual areas less precisely with mental imagery than with vision. Namely, there are distinct codes for seen and mental images in the brain which can be captured by generative networks.

Is What I See, What I Imagine? The Neural Overlap Between Vision and Imagination
Breedlove, J. L., St-Yves, G., Olman, C. A., & Naselaris, T. (2020). Generative Feedback Explains Distinct Brain Activity Codes for Seen and Mental Images. Current Biology.

[Article] Meditation for mind-control

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Alpha power contrast between motor imagery and rest is widespread. (A) The Fisher score was used to plot the difference between the distributions of alpha power during motor imagery versus rest at each electrode throughout training (x-axis = session number). During the UD task, the control group (top row) displayed the expected pattern in that the difference between motor imagery and rest is determined by the presence or absence of activity over the motor cortex. However, the MBSR group produced an entirely different pattern of contrast that evolves throughout training. Brighter colors represent greater differences in alpha power between trial types. (B) Comparing the change in Fisher score across the cortex during UD control revealed the MBSR group learned to generate greater alpha power contrast between motor imagery and rest than controls across a wide range of electrodes (CBPT, P = 0.01). (C) Source imaging of the group difference in Fisher score change during the UD task again confirms the differences in learned alpha power modulation are widespread (CBPT, P < 0.001).

The team found that those with training in mindfulness-based attention and training (MBAT) were more successful in controlling the BCI, both initially and over time. Interestingly, the researchers found that differences in brain activity between the two sample groups corresponded directly with their success. The meditation group showed significantly enhanced capability of modulating their alpha rhythm, the activity pattern monitored by the BCI system to mentally control the movement of a computer cursor.

His findings are very important for the process of BCI training and the overall feasibility of non-invasive BCI control via EEG. This work shows that just a short period of MBAT training can significantly improve a subject’s skill with a BCI. This suggests that education in MBAT could provide a significant addition to BCI training.

https://neurosciencenews.com/meditation-mind-control-17071/
Mindfulness Improves Brain–Computer Interface Performance by Increasing Control Over Neural Activity in the Alpha Band James R Stieger, Stephen Engel, Haiteng Jiang, Christopher C Cline, Mary Jo Kreitzer, Bin He

[Article] Researchers Uncover Network Mechanism Underlying Rumination

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Researchers have uncovered the neural mechanism underlying rumination. The study reports when rumination occurs, coupling between the core and medial temporal lobe subsystems of the default mode network becomes elevated while coupling between the core and dorsomedial prefrontal cortex decreases. According to this study, they computed the Pearson’s correlation during the activity among different brain regions. Results revealed that couplings between the core and the medial temporal lobe (MTL) subsystems of the default mode network (DMN) were elevated while the other couplings were decreased.

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