Principles of cognitive neuroscience: PART A

Welcome to Principles of cognitive neuroscience: PART A.
Because of the COVID most of our interaction will be limited. However I’ll be please to answer your question regarding the course on the forum like I use to in class.
I engage you to explore other topic on neurostar as this is a wonderful place to learn Neuroimaging and interact with your future pair and mentors.

Hello professor,
I hope I’m using the forum in the right way.
I have a doubt concerning the lecture on the Epistemology. As you were saying, I acknowledged that there are afferent and efferent tract flows connecting brain regions. I was wondering whether there is a technique more effective than others to detect their directions and whether these flows may have a “strength” that can be used to better understand their functional meaning or to create new theories.

Thank you for the lecture and for your attention,
Alma Magnani, CN2

Dear Alma, Thank you for your question. Not sure what the doubts are about? Nevertheless regarding your question the directionality of connections in the living human brain, this is still not possible. Best alternative is axonal tracing in non-human primates, but this will be an approximation of the functioning of the human brain. Check the work of Deepak Pandya in the 80s cheers. mich.

Thank you! I was also wondering, do you think that some principles of the artificial neural networks could be applied to overcome this limit? For example, do you know of any attempt/study that tried to use the gradient or other types of directional derivatives to investigate the directionality of connections (or if this doesn’t make sense)?

As a matter of fact I am currently reviewing a paper on that subject matter.
It is a bit early to share it (confidentiality + embargo) but if you remind me in 2-4 months it might be published.

Kind regards

michel

That’s great!
Thank you for the reply,
Alma

Good afternoon professor!
I’ve got a question regarding datasets of neuroimages as neurosynth.org.
Sometimes, when I select a topic and open the related set of neuroimages I see studies which are not closely linked to the topic of my interest.
For instance, if I look at “olfactory”, it also presents me results from articles like “Abnormalities in drug-naive boys with attention deficit hyperactivity disorder” and many others, which probably would show more/different active regions than
the ones related to my original topic.
My question is if, in a similar situation, we should keep all the research collected in the dataset or we should exclude some of them. Moreover, in the second case, I was wondering if this could create a bias in our data, based on the exclusion criteria we applied. I hope my question was clear enough, thank youu

Dear professor,
I have a question about the lecture on Brain Plasticity. How the number and the dimension of the astrocytes (especially the last one makes me curious) are involved in the phenomenon of plasticity in the brain?

Thank you,
Federico

So, in neurosynth the maps have been weighed according to their level of contribution to the term so I think it should be fine. check out the original paper from Yarkoni et al. Nature Methods 2011.
cheers

You should watch the lecture on glial cells!!!
IN there I explain that astrocytes provide nutrient to neurons, modulate blood flow (both promoting higher activity) and modulate synaptic exchange (change in the function of the neuron).
Hope this helps.

michel

Good evening professor,
I have another question, this time about the lectures on Brain Evolution/Brain Asimmetries. At the end of the lecture you said that with the increase of the brain size in order to optimize the time of processing in the brain functions got laterlized. So I assumed that in general there is this like an “evolutional push” towards an optimal structure. Why then vision has developed a crossing structure? I mean, wouldn’t be shorter and optimal a pathway eye-ipsilateral emisphere insted of eye-contralateral emisphere?
Thank you,
Federico

This is THE question for which we don’t have an answer in that field.
There are theories but the crossing of functions as well as having it the furthest possible from the sensory input is unknown (see typically visual cortex is in the back of the head and eyes in the front…). Maybe it goes that far to facilitate integration?