Kewenig, Viktor;
(2025)
Semantic Processing in Humans and Machines.
Doctoral thesis (Ph.D), UCL (University College London.
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Abstract
This thesis examines three core dimensions in the neurobiological basis of meaning: localisa- tion, representation, and computation. It focuses on two primary semantic constructs: concepts - which represent the fundamental building blocks of meaning, such as words or categories - and narratives, which represent an extended form of discourse based meaning, such as stories or event sequences. In chapter 2, I present an analysis of functional magnetic resonance imaging (fMRI) data that investigates how concepts are processed in the brain. The results suggest that conceptual processing is distributed across multiple brain regions and modulated by visual context. In chapter 3, I introduce a computational model as a practical demon- stration of these conclusions. The system uses visual, emotional, and linguistic information to predict concreteness in a context-sensitive way - surpassing previous language based ap- proaches. I then move gradually away from concepts towards narratives. In chapter 4, I present behavioural data suggesting that multimodal models predict words from short event sequences in qualitative and quantitative alignment with humans. In chapter 5, I present an fMRI analysis of data recorded during naturalistic story listening. I demonstrate that a multimodal model better predicts activation across the brain, and enables more accurate se- mantic reconstruction of narratives compared to its unimodal, language based counterpart. My conclusion is therefore that semantic processing depends on distributed (rather than localised) processes, is context-dependent (rather than intrinsic), and driven by domain-general (rather than specialised) computations.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Semantic Processing in Humans and Machines |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2025. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > Div of Psychology and Lang Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10213933 |
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