Attention to objects: exploring reward associations, neurophysiological indices and conceptual representations in the human brain through behaviour, neuroimaging and machine learning

Grignolio, Damiano ORCID: 0000-0001-7699-2390 (2025). Attention to objects: exploring reward associations, neurophysiological indices and conceptual representations in the human brain through behaviour, neuroimaging and machine learning. University of Birmingham. Ph.D.

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Abstract

Object-based attention (OBA) refers to the preferential processing of information within an object. Despite extensive research, questions remain regarding how OBA interacts with reward systems, its neural basis, and its role in semantic processing. This thesis addresses these gaps through experiments investigating: (1) the interaction between reward and OBA; (2) neural indices reflecting OBA; and (3) how attention to objects relates to semantic processing. In Chapter 2, using modified two-rectangle paradigms, we found that OBA and reward associations coexist, with the latter enhancing the irrelevant-object capture of attention and effects persisting even after rewards were discontinued. Chapter 3 used EEG to measure the effects of task-irrelevant objects on neural markers of attentional deployment–i.e. alpha oscillations and the anterior directing attention negativity (ADAN) component–. Results showed these indices reflect OBA independently of attentional anisotropies or perceptual clutter, indicating that OBA modulates neural attentional deployment even when not evident behaviourally. In Chapter 4, employing a novel analysis method involving machine learning on concurrent EEG-fMRI data, we investigated how attention influences semantic representations. We found that attention to objects modulates the enhancement and suppression of semantic information in specific brain regions with alpha oscillations correlating with target representations in the orbitofrontal cortex and distractor information in working memory network regions. Overall, the findings establish the object prioritisation as a robust attentional mechanism resistant to reward manipulations and tracked by alpha oscillations and ADAN ERP. Furthermore, this work advances the understanding of how attention modulates semantic information in the human brain.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):