Evaluation of Effect on Cognition Response to Time Pressure by Using EEG

Abstract

In our competition society, people have to compete with time. Either official business at workplace or private business at home, to face the stress is become a part of our lives. The purpose of this study is to explore the effect on cognition response on time pressure. By using EEG, two sessions of experimental tasks with different response times including 9 s (long term) and 5 s (short term) for responding mental arithmetic were used to serve as two time pressure conditions. Twenty college students aged from twenty to twenty-eight years old recruited for subjects participated the experiment testing. Before experiment the subjects must fill in NASA-TLX rating scale and undertook their electroencephalography (EEG) measured. The EEG data including event related potential (ERP) and indices of EEG power spectrum reflected respectively the recognition depth and arousal level were used to evaluate the recognition response. Before mental arithmetic tasks, the participants were measured their EEGs and NASA-TLX rating scales. Two sessions of mental arithmetic tasks were performed in counterbalance and the EEGs were measured at the same time during the experimental test. After each session, the participants undertook the flanker tasks to measure their ERP and filled in NASA-TLX rating scales. The results showed the EEG power ratio index β/α were increased, that is, the arousal level arose during mental arithmetic tasks. But there was no significant difference between long term and short term sessions at EEG power indices. For P300 components of ERP, the latency for long term of mental arithmetic task was shorter than that for short term, and the amplitude for long term of mental arithmetic task was higher than that for short term. It manifested that the participants had better treatment for long term of mental arithmetic task. For NASA-TLX rating scales measurement, the participants felt more pressure for short term of mental arithmetic task than that for long term. The study found the participants revealed higher mental workload and deteriorated recognition response under higher time pressure.