EEG Correlates of Decision Making based on Mental Modeling

Raphael, G., Berka, C., (2009) “Interactive Neuro-Educational Technologies (I-NET): Enhanced Training of Threat Detection for Airport Luggage
Screeners” Engineering in Medicine and Biology Society Annual International Conference of the IEEE

The role of an analyst includes scanning of imagery rapidly and accurately in order to identify operational threats. Indices which detect cognitive processing as the user matches their mental model of a threat/nonthreat to the actual image could be used to accelerate learning and/or monitor performance.

A study was conducted to assess the feasibility of integrating real-time analysis of EEG indices of workload, task engagement and attention into the human-computer loop for training new luggage screeners (n=23). X-ray imagery of non-treats and threats (sharp objects and hand guns) with varying degree of detection difficulty were used in the study design.

The results showed a distinct cognitive processing pattern was apparent in 90% of the subjects beginning with the presentation of the image and ending with the threat/nothreat decision. The magnitude of initial theta synchrony and the speed in which the theta activity desynchronized related to the difficulty of the task, whether the image was a threat or non-threat and the region of the brain most activated by the encoding. The desynchronization of theta activity was followed by the synchronization of alpha power which was also influenced by and across stimulus difficulty and response type.

Given these patterns were strongest with easy or target stimuli, weakest with more difficult, non-target stimuli, these findings suggest that the EEG theta and theta synchronization is likely correlated with subject skill acquisition and indicative of the progressive development of the individual’s cognitive mapping of their mental model. The relationship between EEG Alpha and correct vs. incorrect responses suggests a measure of efficient use of attention processes. Theta and alpha synchronization may also help to differentiate between hits, false alarms and correct rejections. The next phase of the research will be to reduce the number of scalp sites and provide a real-time assessment as to when the subject is guessing or actually believes to accurately recognize a target. Additional efforts will focus on neuro-cognitive signatures which profile those more likely to succeed in the role of a fast and accurate luggage screener.