Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Collaboration between Birmingham and Bonn yields new insights into associative memory

03.04.2019

When looking at a picture of a sunny day at the beach, we can almost smell the scent of sun screen. Our brain often completes memories and automatically brings back to mind the different elements of the original experience. A new collaborative study between the Universities of Birmingham and Bonn now reveals the underlying mechanisms of this auto-complete function. It is now published in the journal Nature Communications.

The researchers presented participants with a number of different scene images. Importantly, they paired each scene image with one of two different objects, such as a raspberry or a scorpion.


Participants first saw images of scenes together with one of two objects. Later they only saw the scene images and were asked to remember which object was associated with the particular scene.

© Cognitive and Clinical Neurophysiology Group/Uni Bonn

Participants were given 3 seconds to memorise a given scene-object combination. After a short break they were presented with the scene images again, but now had to reconstruct the associated object image from memory.

„At the same time, we examined participants‘ brain activation“, explains Prof. Florian Mormann, who heads the Cognitive and Clinical Neurophysiology group at the University of Bonn Medical Centre. „We focused on two brain regions – the hippocampus and the neighbouring entorhinal cortex.“

The hippocampus is known to play a role in associative memory, but how exactly it does so has remained poorly understood.

The researchers made an exciting discovery: During memory recall, neurons in the hippocampus began to fire strongly. This was also the case during a control condition in which participants only had to remember scene images without the objects.

Importantly, however, hippocampal ativity lasted much longer when participants also had to remember the associated object (the raspberry or scorpion image). Additionally, neurons in the entorhinal cortex began to fire in parallel to the hippocampus.

„The pattern of activation in the entorhinal cortex during successful recall strongly resembled the pattern of activation during the initial learning of the objects“, explains Dr. Bernhard Staresina from the University of Birmingham.

Indeed, the similarity between recall and learning was so strong that a computer algorithm was able to tell whether the participant remembered the raspberry or the scorpion. „We call this process reinstatement“, Staresina says: „The act of remembering put neurons in a state that strongly resembles their activation during initial learning.“

The researchers think that such reinstatement is driven by neurons in the hippocampus. Like a librarian, hippocampal neurons might provide pointers telling the rest of the brain where particular memories (such as the raspberry and the scorion) are stored.

Looking into the brain of Epilepsy patients

The brain recordings were conducted at the University Clinic of Epileptology in Bonn – one of Europe’s biggest epilepsy centres. The clinic specialises on patients who suffer from severe forms of medial temporal lobe epilepsy. The goal is to surgically remove those parts of the brain that cause the epileptic seizures.

In order to localise the origin of the seizures, some patients are implanted with electrodes. These electrodes are able to record brain activation. Researchers can use this rare opportunity to closely monitor the brain while it remembers.

This is also what the current study did: The 16 participants were all epilepsy patients who had small electrodes implanted in their medial temporal lobe. „With these electrodes we were able to record the neurons‘ response to visual stimuli“, Prof. Mormann explains. These methods allows fascinating insights into the mechanisms of our memory system. They might also be used to better understand the causes for memory deficits.

Wissenschaftliche Ansprechpartner:

Dr. Bernhard Staresina
School of Psychology
University of Birmingham
Tel.: +44 (0)121 414 8690
E-Mail: b.staresina@bham.ac.uk

Prof. Florian Mormann, MD, PhD
Dept. of Epileptology
University of Bonn
Tel.: +49 228 287 15738
E-Mail: florian.mormann@ukbonn.de

Originalpublikation:

Bernhard P. Staresina, Thomas P. Reber, Johannes Niediek, Jan Boström, Christian E. Elger und Florian Mormann: Recollection in the human hippocampal-entorhinal cell circuitry; Nature Communications; dx.doi.org/10.1038/s41467-019-09558-3

Dr. Andreas Archut | idw - Informationsdienst Wissenschaft
Further information:
http://www.uni-bonn.de/

More articles from Life Sciences:

nachricht New CRISPR-based system targets amplified antibiotic-resistant genes
16.12.2019 | University of California - San Diego

nachricht New yeast species discovered in Braunschweig, Germany
13.12.2019 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Uranium chemistry and geological disposal of radioactive waste

New insights using the diamond light

A new paper to be published on 16 December provides a significant new insight into our understanding of uranium biogeochemistry and could help with the UK's...

Im Focus: Virus multiplication in 3D

Vaccinia viruses serve as a vaccine against human smallpox and as the basis of new cancer therapies. Two studies now provide fascinating insights into their unusual propagation strategy at the atomic level.

For viruses to multiply, they usually need the support of the cells they infect. In many cases, only in their host’s nucleus can they find the machines,...

Im Focus: Cheers! Maxwell's electromagnetism extended to smaller scales

More than one hundred and fifty years have passed since the publication of James Clerk Maxwell's "A Dynamical Theory of the Electromagnetic Field" (1865). What would our lives be without this publication?

It is difficult to imagine, as this treatise revolutionized our fundamental understanding of electric fields, magnetic fields, and light. The twenty original...

Im Focus: Highly charged ion paves the way towards new physics

In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.

Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...

Im Focus: Ultrafast stimulated emission microscopy of single nanocrystals in Science

The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.

Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Uranium chemistry and geological disposal of radioactive waste

16.12.2019 | Earth Sciences

New CRISPR-based system targets amplified antibiotic-resistant genes

16.12.2019 | Life Sciences

Supporting structures of wind turbines contribute to wind farm blockage effect

13.12.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>