Hemispheric Asymmetries in Emotion-Cognition Interactions

The purpose of this study is to investigate the effect of fearful emotion on the cognitive oddball task using electroencephalogram (EEG) technology. The study aims to deepen the understanding of the emotion-cognition interaction in humans. Emotions are fundamental to human behavior, and they can have a significant impact on cognitive processes such as attention, memory, and decision-making. Furthermore, the relationship between emotion and cognition has been implicated in numerous psychiatric disorders, including anxiety, depression, and post-traumatic stress disorder. Therefore, understanding the mechanisms by which emotions affect cognition is essential for the development of effective treatments for these disorders.

Electroencephalography (EEG) is a non-invasive and widely-used technique that measures the electrical activity of the brain, making it an excellent tool for studying the relationship between emotion and cognition. This study will use EEG to examine the neural correlates of attentional processing in response to emotional stimuli. Specifically, the investigators will use an emotional oddball task to investigate the effect of fearful emotions on the attention of deviant stimuli, which is an established paradigm in the study of emotion and cognition.

Furthermore, this study will explore the impact of the location of the deviant stimuli presentation (i.e., in the left or right visual field) on the emotion-cognition interaction. This variable is crucial because previous research has suggested hemispheric asymmetries in emotion processing and contralateral visual processing. By including this variable in the study, the investigators will be able to examine whether the emotion-cognition interaction is influenced by the location of stimulus presentation.

Additionally, the investigators will include 2 groups: older adults with anxiety and/or depression, and older adults without mental health issues. By examining these different groups, the investigators aim to elucidate how mental health status may modulate emotion-cognition interactions.

The inclusion of novel variables, such as the location of stimulus presentation and mental health status, makes this study innovative and likely to produce novel findings that will contribute to the existing literature on this topic. It is hypothesized that the presentation of fearful images in the cognitive oddball task will result in greater changes in brain electrical activity as compared to neutral images. Specifically, the investigators expect to observe increased activity in the ventral affective system (e.g., amygdala) and other regions of the brain associated with emotional processing. The investigators also hypothesize that the location of the shape presentation (whether on the left or right visual field) may modulate the effect of emotion on cognition by influencing the event-related potentials (ERPs) in dorsal executive system (e.g., dorsal lateral prefrontal cortex (dlPFC)).

The objectives of this study are:

• To investigate the effect of fearful emotion on the cognitive oddball task using EEG technology.
• To analyze changes in brain electrical activity in response to fearful and neutral stimuli.
• To investigate whether the location of shape presentation (left or right visual field) modulates the effect of emotion on cognition.
• To explore how mental health status may modulate emotion-cognition interactions.

Research Method/Procedures:

Participants who meet the inclusion criteria (strong handedness) will be scheduled for a one-hour session in the EEG lab. During the session, participants will wear an EEG cap with 256 channels that record their brain electrical activity while they complete an emotional oddball task. The task will consist of fearful and neutral pictures and black circles that are shown in the middle, left, or right visual field of the screen. The frequency of shapes appearing in the left or right visual field will be varied to investigate the impact of visual field location. The task duration will be approximately 1 hour with 8 short breaks during the processing.

For data analysis, the investigators will analyze the EEG data using time-frequency analysis to identify changes in brain electrical activity in response to fearful and neutral stimuli. The investigators will compare the results of the odd stimulus after fearful images with that after neutral images to isolate the effect of emotions on cognitive processing. The investigators will also use statistical analysis to identify any significant differences in the impact of visual field location on the effect of emotion on cognition. Finally, the investigators will interpret our findings in the context of existing literature on the emotion-cognition interaction in humans, and conduct cross-sectional comparisons between different mental health conditions to investigate the generalizability of the findings.

Inclusion criteria

• The healthy older adult group is composed of participants aged over 60 who do not exhibit mental health issues and demonstrate healthy aging from a cognitive perspective.
• The older adults with mental health issues group will consist participants aged over 60 diagnosed with these conditions are included while still demonstrating healthy aging from a cognitive standpoint.

Exclusion criteria

• Participants currently taking medication known to affect brain activity and/or cognitive processing.
• Participants with a history of alcohol or substance abuse.
• Participants with a history of head injury or concussion that may impact brain activity and/or cognitive processing.
• Participants with Neurological Disorders.
• Participants with Edinburgh Handedness Inventory scores falling within the range of [-40, 40].