Luca Kolibius

Happening today! #HSN25

#SfN Poster ⬇️
We report rate-independent, location-specific phase locking in human hippocampus, and episode-specific phase coding during memory.
Bring your critique - any feedback welcome! Poster attached.
#SfN25 | PSTR362.24 (Human Navigation) — Tue Nov 18, 1–5 pm, SDCC Halls B–H.

Come and visit my poster at HSN (Poster B12; Fri Nov 14, 12:45–2:30)!
Neuropixels in human hippocampus (anesthesia). Neurons show strong tracking of the auditory envelope of sound cues. No evidence for sound-evoked spatial reactivation. Come and have a look! Poster attached.

#HSN25

Read Quirogas Letter here: tinyurl.com/2zffa3dd
Read our original Opinion piece here: tinyurl.com/wm8m52pn

Despite recent criticism from Quiroga to our claim that Concept Neurons emerge from Conjunctive Coding Neurons we claim: “And yet, the hippocampus codes conjunctively!”.
We hope it sparks a smile (and maybe a few debates).

Read here: tinyurl.com/3ycv3vj2

Movie-watching evokes ripple-like activity within events and at event boundaries Nature Communications - The neural processes involved in memory formation for realistic experiences remain poorly understood. Here, the authors found that ripple-like activity in the human...

🧠 Paper out!

We investigated how hippocampal and cortical ripples support memory during movie watching. We found that:

🎬 Hippocampal ripples mark event boundaries
🧩 Cortical ripples predict later recall

Ripples may help transform real-life experiences into lasting memories!

rdcu.be/eui9l

New preprint from the team at BCM Neurosurgery, led by superstar neuroscientist / neurosurgeon Vigi Katlowitz! “Attention is all you need (in the brain): semantic contextualization in human hippocampus” 🧵

www.biorxiv.org/content/10.1...

Cholinergic blockade reveals role for human hippocampal theta in encoding but not retrieval Cholinergic dysfunction is a hallmark of Alzheimer's disease and other memory disorders. Yet, the neurophysiological mechanisms linking cholinergic signaling to memory remain poorly understood. In thi...

Hi Bluesky! First post here. Kicking things off with a new preprint.

🧠 Using human iEEG + pharmacology, we asked: is hippocampal theta required for retrieval?

Turns out it’s not. Instead, it may reflect a reinstated encoding mode.

Thread below.
www.biorxiv.org/content/10.1...

Cool finding!
As a side question, do you know if aphantasics dream visually? I.e., is the lack of visual imagery tied to being awake or is it a general experience?

Professor, Senior Lecturer/Lecturer and Lecturer posts - Glasgow City (GB) job with University of Glasgow | 12838283 University of Glasgow College of Medical, Veterinary and Life Sciences  School of Psychology & Neuroscience Professor in Cognitive Neuroscience/Psy...

We are recruiting for 5 permanent staff positions (Prof, Senior-, Lecturer) including for 7T-MRI. Please have a look and share widely.
(Closing date: May 12)

www.nature.com/naturecareer...

Did you give Fiverr a go? I have had good experience with them for illustrations.

Congratulations of the new position!!

Thank you, Sarah!

Thank you to my fantastic co-authors on this project: Sheena Josselyn and Simon Hanslmayr who have been an absolute joy to work with. 15/15

On the origin of memory neurons in the human hippocampus The hippocampus is essential for episodic memory, yet its coding mechanism remains debated. In humans, two main theories have been proposed: one suggests that concept neurons represent specific elemen...

Check out our opinion paper for more on engrams, and the role of hippocampal subfields, inherent connectivity, inhibitory neurons, and schemas in the hippocampus: www.cell.com/trends/cogni... 14/15

We believe that focusing on computational principles allows a more fruitful discourse between researchers studying different species. 13/15

This process shows how index neurons, initially coding for specific episodes, may semanticize over repeated experiences into concept neurons linked to the shared element across all episodes: the friend. 12/15

Meeting the same friend at the movies repeats this process, a subset of neurons now codes for all three episodes. 11/15

Meeting a friend in a cafe is allocated to more excitable green neurons.
Later seeing the same friend in the park reactivates the cafe memory, increasing the excitability of the initially allocated neurons. A subset of these neurons are also allocated to the park episode. 10/15

Overlapping memories transform a subset of index neurons into concept neurons. Keep in mind according engram research, more excitable neurons are more likely to be allocated to an episodic memory and recently active neurons become more excitable. 9/15

Center: Over time, excitability normalizes (smaller green circles).
Right: Reactivation (e.g., seeing the café again) boosts excitability allowing linking of memories. 8/15

Left: When an episodic memory (e.g., meeting a friend at a café) is formed, certain neurons in a heightened excitability state form an engram (larger green circles). 7/15

Right panel: Under the concept neuron framework, each neuron codes a distinct element, and their concurrent activity represents the entire event. 6/15

Left panel: According to the Indexing Theory, index neurons in the hippocampus conjunctively link various elements of an episode (e.g., loungy jazz music, your friend, the waiter). 5/15

Engram literature supports this process: neurons are allocated to a memory trace based on excitability, and reactivation boosts excitability—linking and updating memories. 4/15

We integrate new findings of index neurons in humans and animals with the concept-specific memory framework, proposing that index neurons transform into concept neurons through overlapping memories. 3/15

The hippocampus is essential for episodic memory. There are two main theories: one proposes that concept neurons represent specific elements of an episode, while another posits a conjunctive code where index neurons code the entire episode (Kolibius et al., Nat Hum Behav). 2/15

On the origin of memory neurons in the human hippocampus The hippocampus is essential for episodic memory, yet its coding mechanism remains debated. In humans, two main theories have been proposed: one suggests that concept neurons represent specific elemen...

New manuscript published! ✍️👀

Concept neurons evolve from index neurons through overlapping memories.

Check it out here: www.cell.com/trends/cogni... 1/15

On the origin of memory neurons in the human hippocampus The hippocampus is essential for episodic memory, yet its coding mechanism remains debated. In humans, two main theories have been proposed: one suggests that concept neurons represent specific elemen...

www.cell.com/trends/cogni...