In my research, I explored the behavioral and neural mechanisms behind competing emotional and cognitive processes using EEG imaging and event-related potential (ERP) analysis. Electroencephalography (EEG) is an imaging modality that measures electrical activity from the surface layer of the brain, otherwise known as the cerebral cortex, on a millisecond time scale. Neural responses to specific events can be extracted from EEG data in the form of event-related potentials (ERPs) by averaging activity during a time-locked event (e.g. stimulus onset). By characterizing changes in state of electrical activity, ERPs become useful for evaluating constructs such as attentional processing.
ERP methodology focuses on component analysis by observing amplitude or latency modulation of certain waveform peaks between different trial conditions. Therefore, enhancement and attenuation of a waveform component’s amplitude often represents increased or decreased processing while shifts in latency represent delays or advances in timing of certain events.
For my experiments, I observed how competing negative emotional distraction and cognitive difficulty disrupted working memory of faces through changes in amplitude of waveform components N170 and P300. The N170 ERP component, involved in facial recognition, displays a maximal response to face stimuli at occipito-temporal electrodes. The P300 component is a task-dependent component that is associated with attentional processing, stimulus evaluation, and stimulus categorization, showing maximal activity at midline parietal and occipital electrode sites.
Unlike previous studies that examine top-down control and bottom-up affective processing on these waveform components separately, our current study examines the interaction effects when both competing processes are present. By assessing multiple variables and their interactions on attentional and perceptual processes, we can gather a more detailed understanding of the modulatory factors that interact to influence everyday working memory processes.