Global activity distribution in the cortex: A look on how a global network handles information and perturbations
(2025) In Lund University, Faculty of Medicine Doctoral Dissertation Series- Abstract
- Studies on cortical function have been a cornerstone in research trying to understand our brains for a long time. For many years now a basic feature of cortical processing has been the idea of a functional localization, with different areas or even neurons in the cortex having clear, individual, functions. This idea has been challenged from the outset, and with new methods to study the cortex the idea of functionality in the cortex depending on a globally interconnected network has gained support.
In this thesis both modern and more traditional analysis methods were used to examine how cortical activity is distributed across multiple cortical areas during the processing of somatosensory stimulus. Investigations were also made on how... (More) - Studies on cortical function have been a cornerstone in research trying to understand our brains for a long time. For many years now a basic feature of cortical processing has been the idea of a functional localization, with different areas or even neurons in the cortex having clear, individual, functions. This idea has been challenged from the outset, and with new methods to study the cortex the idea of functionality in the cortex depending on a globally interconnected network has gained support.
In this thesis both modern and more traditional analysis methods were used to examine how cortical activity is distributed across multiple cortical areas during the processing of somatosensory stimulus. Investigations were also made on how the distribution was affected by D-amphetamine. For this, an experimental set-up using anesthetised rats was used in which neural activity was recorded using Electrocorticograms (ECoG) in eight cortical areas simultaneously. Data during spontaneous activity, during sensory skin stimulation, and after D-amphetamine administration, was analysed with methods for dimensionality reduction, classification learning and more traditional frequency analysis.
It was observed that ECoG data from spontaneous activity and activity during stimulation could be separated based on its activity distribution. This separation persisted when data containing an evoked field potential from the stimulation was excluded. Based on the analysis of activity distributions, ECoG data could also be separated based on if D-amphetamine had been administered or not. Finally, investigations found that there appear to be set internal ranges of globally preferred frequencies in the cortex. These remained consistent during external sensory stimulation but could be disrupted by D-amphetamine. These results are discussed in the context of a globally interconnected network in the cortex, where the processing of external inputs is distributed across several cortical areas. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/ab9ab8ad-5e3f-4306-9779-b6f3176d3232
- author
- Mellbin, Astrid LU
- supervisor
- opponent
-
- docent Hammar, Ingela, University of Gothenburg
- organization
- publishing date
- 2025
- type
- Thesis
- publication status
- published
- subject
- keywords
- somatosensory, Tactile, Distributed information processing, Neocortex, Function
- in
- Lund University, Faculty of Medicine Doctoral Dissertation Series
- issue
- 2025:86
- pages
- 80 pages
- publisher
- Lund University, Faculty of Medicine
- defense location
- Segerfalksalen, BMC A10, Sölvegatan 17 i Lund
- defense date
- 2025-09-26 10:00:00
- ISSN
- 1652-8220
- ISBN
- 978-91-8021-739-2
- language
- English
- LU publication?
- yes
- id
- ab9ab8ad-5e3f-4306-9779-b6f3176d3232
- date added to LUP
- 2025-08-21 15:00:38
- date last changed
- 2025-08-26 10:01:42
@phdthesis{ab9ab8ad-5e3f-4306-9779-b6f3176d3232,
abstract = {{Studies on cortical function have been a cornerstone in research trying to understand our brains for a long time. For many years now a basic feature of cortical processing has been the idea of a functional localization, with different areas or even neurons in the cortex having clear, individual, functions. This idea has been challenged from the outset, and with new methods to study the cortex the idea of functionality in the cortex depending on a globally interconnected network has gained support.<br/>In this thesis both modern and more traditional analysis methods were used to examine how cortical activity is distributed across multiple cortical areas during the processing of somatosensory stimulus. Investigations were also made on how the distribution was affected by D-amphetamine. For this, an experimental set-up using anesthetised rats was used in which neural activity was recorded using Electrocorticograms (ECoG) in eight cortical areas simultaneously. Data during spontaneous activity, during sensory skin stimulation, and after D-amphetamine administration, was analysed with methods for dimensionality reduction, classification learning and more traditional frequency analysis.<br/>It was observed that ECoG data from spontaneous activity and activity during stimulation could be separated based on its activity distribution. This separation persisted when data containing an evoked field potential from the stimulation was excluded. Based on the analysis of activity distributions, ECoG data could also be separated based on if D-amphetamine had been administered or not. Finally, investigations found that there appear to be set internal ranges of globally preferred frequencies in the cortex. These remained consistent during external sensory stimulation but could be disrupted by D-amphetamine. These results are discussed in the context of a globally interconnected network in the cortex, where the processing of external inputs is distributed across several cortical areas.}},
author = {{Mellbin, Astrid}},
isbn = {{978-91-8021-739-2}},
issn = {{1652-8220}},
keywords = {{somatosensory; Tactile; Distributed information processing; Neocortex; Function}},
language = {{eng}},
number = {{2025:86}},
publisher = {{Lund University, Faculty of Medicine}},
school = {{Lund University}},
series = {{Lund University, Faculty of Medicine Doctoral Dissertation Series}},
title = {{Global activity distribution in the cortex: A look on how a global network handles information and perturbations}},
url = {{https://lup.lub.lu.se/search/files/225820580/Astrid_Mellbin_-_WEBB.pdf}},
year = {{2025}},
}