Memory load and display polarity in visual search performance and EEG response

Area of Science:

• Cognitive Neuroscience
• Human-Computer Interaction
• Neuroscience

Background:

• Electroencephalogram (EEG) measures are sensitive to task variations, but effects of memory load on EEG and Visual Display Terminal (VDT) performance are under-researched.
• Understanding cognitive load's neural correlates is crucial for optimizing human-computer interactions.

Purpose of the Study:

• To investigate the impact of varying memory loads on VDT performance and associated EEG responses.
• To explore the relationship between memory load, frontal lobe activity (theta band), and task completion times.
• To examine the influence of display polarity (positive vs. negative contrast) on EEG signals.

Main Methods:

• Collected EEG data and VDT performance metrics (e.g., finish time) from 19 college students.
• Analyzed EEG power spectrum, focusing on the theta band at specific electrode sites (FP1, FP2, T6).
• Assessed the statistical significance of memory load and display polarity effects on performance and EEG modulation.

Main Results:

• Memory load had a statistically significant effect on task finish times.
• Increased memory load correlated with greater changes in theta band power at frontal electrodes (FP1, FP2), indicating frontal lobe engagement.
• Theta band power changes were more pronounced with positive contrast, but display polarity overall did not significantly affect EEG responses.

Conclusions:

• Memory load is a critical factor influencing both cognitive processing (EEG frontal activity) and task efficiency in VDT use.
• Frontal lobe theta band activity serves as a potential neural indicator of working memory load during VDT tasks.
• Display polarity is not a significant modulator of EEG responses in this context, suggesting focus should remain on cognitive load factors.