Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 18 of 18 for “"multivariate pattern analysis"”.
-
A New Eye On Semantics: Probing the Spatiotemporal Brain Dynamics Underlying Natural Reading
… on single-word semantic representations using multivariate pattern analysis. In two further studies, I tested whether sentence context affects the semantic processing of single words during natural reading. Overall, these studies aimed at testing predictions made by the Controlled Semantic …
-
The Role of the Multiple-Demand System in Fluid Intelligence and Selective Attention: Insights from Lesion and Neuroimaging Studies
… (fMRI) and magnetoencephalography (MEG)), and multivariate pattern analysis techniques to investigate the role of the MD system in fluid intelligence and selective attention. In Chapter 2, I analysed a large neuropsychological dataset from 174 patients with focal brain lesions to identify the …
-
Neural processes underpinning episodic memory
… brain and high spatial resolution fMRI, and multivariate pattern analysis. Episodic memory recall is widely agreed to be a reconstructive process, one that is known to be critically reliant on the hippocampus. I therefore hypothesised that the same neural machinery responsible for …
-
Electrophysiological studies of identifying and modulating the preparatory strategic processes involved in episodic memory retrieval
… that addressed this issue by employing an analysis approach focusing on the pre-stimulus period of retrieval test trials and capitalizing on the increased sensitivity of multivariate pattern analysis (MVPA) of oscillatory activity. Experiment 1 established evidence of a preparatory form of …
-
Decoding the emotional modulation of memory encoding: a multivariate fmri study of arousal and valence
… and arousal (calm/exciting) to the neural patterns supporting memory encoding are not fully understood. We leveraged multivariate pattern analysis (MVPA) to dissociate these influences. We analysed fMRI data from a large cohort of participants during an emotional picture encoding task with …
-
The Neural Processing of Face-like Stimuli
… This dissertation will report an EEG - multivariate pattern analysis (MVPA) study that investigated how emotional expressions are represented in the brain when conveyed through real human faces, symbolic emoji faces, and ambiguous pareidolic faces (face-like objects), across three …
-
Slipping into Sleep: neurodynamics of alertness transitions in humans and fruit flies
… convergent evidence in the neural dynamics using multivariate pattern analysis (MVPA). Next, I probe the effect of handedness on the same task. Handedness affects behaviour only under drowsy condition and I show how neural dynamics are affected by a combination of handedness and alertness. To …
-
Pattern codes for perceived gaze direction revealed by functional MRI
… results. This thesis describes research where multivariate pattern analysis (MVPA) methods are applied to fMRI data in order to better explain how the human brain and particularly STS codes perceived gaze direction. After describing the MVPA methods applied in this thesis, I first demonstrate …
-
Electrophysiological correlates of motor plans and graspability via dorsal/ventral interactions
… High-Density Electroencephalography (HD-EEG), Multivariate Pattern analysis (MVPA) & EEG source localization. In experiment 1, participants viewed images of animate objects (birds & insects) and inanimate objects (tools & graspable objects). The frequency-tagging approach and the Fast Fourier …
-
AMINO ACIDS AS DIAGNOSTICS OF SOIL AND SOIL WATER QUALITY
… suggests that determination of amino acid patterns of distribution may be a useful method for improved understanding of the interaction of microbial synthesis and degradation of organic N in conjunction with soil physical states. A sample pre-concentration technique and an HPLC methodology …
-
Data-driven neuroimaging reveals cognition-circuit pathology prior to diagnosis in psychotic disorders
… The images were processed and evaluated using multivariate pattern analysis (MVPA) to compare brain connectivity to information processing speed. The MVPA calculations generated a map to determine the regions where brain connectivity has the strongest correlation to information processing speed …
-
Neuroeconomics of Reward Information and Motivation
… 3 and 4 employ a nonstandard analysis technique, multivariate pattern analysis (MVPA), to identify brain regions that contain information associated with different types of economic valuation. Chapter 3 uses a combinatoric approach to evaluate how brain regions uniquely …
-
Characterizing the spatiotemporal profile and the level of abstractness of action representations: neural decoding of magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) data
… actions are understood based on a perceptual analysis, with access to action knowledge stored in the conceptual system (cognitive theories of action understanding). It has been argued earlier that areas that play a crucial role for action understanding should be able to (a) distinguish between …
-
Electrophysiological systems underlying human domain-general cognition and selective attention
… By applying irregular-resampling auto-spectral analysis (IRASA) and multivariate pattern analysis (MVPA), I show that both aperiodic (broadband power, slope, and intercept) and oscillatory (theta, alpha, and beta power) components encode task demand and content across three cognitive tasks. …
-
Large-scale Functional Connectivity in the Human Brain Reveals Fundamental Mechanisms of Cognitive, Sensory and Emotion Processing in Health and Psychiatric Disorders
… behavior. In Chapter 2, Independent Components Analysis (ICA), Psychophysiological Interactions (PPI) and Dynamic Causal Modeling (DCM) analyses were used to investigate the hypothesis that expectation and attention-related interactions between ventral and medial prefrontal cortex and …
-
Neural Dynamics of Goal-Directed Action Selection: A Multivariate Approach to Evidence Accumulation and Cognitive Control in Response to Competing Stimuli
… Imaging (fMRI), as well as both univariate and multivariate analysis techniques. In the Introduction, I introduce the background to and motivation for the thesis, exploring the evidence accumulation framework as a tool to understand the latent cognitive processes involved in adaptive …
-
Approaches to Understanding the Function of Intrinsic Activity and its Relationship to Task-evoked Activity in the Human Brain
… has focused on characterizing the topography and patterns of brain activation evoked by specific cognitive or behavioral tasks to understand human brain functions. This activation-based paradigm treated underlying spontaneous brain activity, a.k.a. intrinsic activity, as noise hence irrelevant to …
-
A comparison of imaging modalities and decoding methods for detecting semantic information in the brain
… (3) to evaluate the strengths and limitations of multivariate analysis methods, in particular methods based on regularised regression, for revealing properties of semantic representations. In Chapter 2 I propose a new theoretical framework for describing representations. By posing six questions …