@pineurosci.bsky.social

Neuropsych

New work on the effects of psychedelics on hierarchical cortical propagations out in PNAS! www.pnas.org/doi/10.1073/... Counter to our expectations, psychedelics attenuated bottom-up propagations into the Default Mode Network across substances and species. Thread below:

PNAS

Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...

pnas.org

𝗕𝗿𝗮𝗶𝗻-𝘄𝗶𝗱𝗲 𝗰𝗼𝗺𝗽𝘂𝘁𝗮𝘁𝗶𝗼𝗻𝘀 Spatially distributed and regionally unbound cellular resolution brain-wide processing loops in mice 𝗕𝗿𝗮𝗶𝗻 𝗿𝗲𝗴𝗶𝗼𝗻𝘀 𝗼𝗿 𝗱𝘆𝗻𝗮𝗺𝗶𝗰 𝘁𝗵𝗿𝗲𝗮𝗱𝘀? Dynamical processing winding through most brain regions. Looks like a must read. www.biorxiv.org/content/10.1... #neuroskyence

Spatially distributed and regionally unbound cellular resolution brain-wide processing loops in mice

Until recently, it has been possible to examine activity in the brain globally through regional averaging or locally at cellular resolution. These studies characterized regions as functionally homogen...

biorxiv.org

We are seeking a scientific coordinator for my research group at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig 😊🧠🌈 Could be ideal for a gap year between MSc and PhD or PhD and postdoc! Please out more here: recruitingapp-5218.de.umantis.com/Vacancies/43...?

Scientific Coordinator (m/f/d) Part-time (50%) | Karriereportal Max-Planck-Institut für Kognitions- und Neurowissenschaften

Scientific Coordinator (m/f/d) Part-time (50%) | Karriereportal Max-Planck-Institut für Kognitions- und Neurowissenschaften

recruitingapp-5218.de.umantis.com

Rarely categorical, always high-dimensional: how the neural code changes along the cortical hierarchy www.biorxiv.org/content/10.1... #neuiroscience

Rarely categorical, always high-dimensional: how the neural code changes along the cortical hierarchy

The brain is highly structured both at anatomical and functional levels. However, within individual brain areas, neurons often exhibit very diverse and seemingly disorganized responses. A more careful analysis shows that these neurons can sometimes be grouped together into specialized subpopulations (categorical representations). Organization can also be found at the level of the representational geometry in the activity space, typically in the form of low-dimensional structures. It is still unclear how the geometry in the activity space and the structure of the response profiles of individual neurons are related. Here, we systematically analyzed the geometric and selectivity structure of the neural population from 40+ cortical regions in mice performing a decision-making task (IBL public Brainwide Map data set). We used a reduced-rank regression approach to quantify the selectivity profiles of single neurons and multiple measures of dimensionality to characterize the representational geometry of task variables. We then related these measures within single areas to the position of each area in the sensory-cognitive cortical hierarchy. Our findings reveal that only a few regions (in primary sensory areas) are categorical. When multiple brain areas are considered, we observe clustering that reflects the brain’s large-scale organization. The representational geometry of task variables also changed along the cortical hierarchy, with higher dimensionality in cognitive regions. These trends were explained by analytical computations linking the maximum dimensionality of representational geometry to the clustering of selectivity at the single neuron level. Finally, we computed the shattering dimensionality (SD), a measure of the linear separability of neural activity vectors; remarkably, the SD remained near maximal across all regions, suggesting that the observed variability in the selectivity profiles allows neural populations to maintain high computational flexibility. These results provide a new mathematical and empirical perspective on selectivity and representation geometry in the cortical neural code. ### Competing Interest Statement The authors have declared no competing interest.

biorxiv.org

🎇Join Our Team 🎇 Ted Satterthwaite and I are recruiting a new post-doc or senior scientist to lead a series of meta-analyses focused on clinical trials of PSYCHEDELICS. Expertise in meta-analyses, clinical trials, or psychiatry ideal. Flexible start date/compensation. Please share / DM me!