Degree

Bachelor of Science (B.S.)

Major(s)

Psychology

Document Type

Immediate Open Access

Abstract

Abstract: Attention may not solely be restricted to a spatial area or a feature of an object, but rather can “spread” across all parts of an object in space, enhancing the processing of its features collectively (Duncan, 1984). This phenomenon suggests that attention operates at the level of whole objects, enhancing the representation of all features associated with the attended object while suppressing competing stimuli. Building on this object-based framework, the present thesis examines the functional and neural dissociation between attention and awareness using steady-state visually evoked potentials (SSVEPs) as a frequency-tagging method in EEG. Leveraging the high temporal resolution of EEG and the frequency specificity of SSVEPs, the study investigates how attentional allocation modulates neural responses across objects. articipants were exposed to multiple spatially distinct flickering stimuli (3 Hz, 5 Hz, 12 Hz, and 20 Hz) under varying attentional conditions—cued, not cued within the same visual field, and not cued outside the attended region. Signal-to-noise ratios (SNRs) at stimulus frequencies were computed using FFT to quantify attentional enhancement independent of perceptual awareness. Results show that attention selectively boosts and depresses SSVEP responses at certain attended frequencies, but shows no ability for attention to spread across distinctly connected objects.

DOI

https://doi.org/10.54718/FRWX9918

Date Defended

5-1-2025

Funding Source

This work was supported by the National Institutes of Health, National Institute of Mental Health grant R15MH113075.

Thesis Director

Michael Pratte

Second Committee Member

David Van den Heever

Third Committee Member

David Hoffman

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