Effect of Caffeine Intake on Visual and Cognitive Functions

Introduction: In this paper, the effect of caffeine intake on the efficiency of the visual and cognitive processing measured through the assessment of the cognitive ERP components (i.e. P100 and P300), is studied and analyzed. This study is conducted through the measurement of amplitudes and latencies of P100 at Oz and P300 at Pz and Cz, respectively before and after caffeine intake.
Method: Data is collected using 128 channel EEG machine from 8 subjects (4 males and 4 females) aged between 21 and 24 with normal vision and no known neurophysiological impairments. Subjects are assessed using oddball paradigm experiment. The subjects are asked not to take any caffeine related drink during day time from morning till 6 PM. The ERP signals are measured early morning and late afternoon at 5:30 PM before caffeine intake, using aforementioned arrangement. At 6 PM the subjects are stimulated with 60 mg of caffeine. The ERP signals are measured after 15 minutes of stimulation.
Results: The results show a decrease in amplitude and increase in latency for P300 due to mental and physical fatigue over the day. Results for the amplitude variation over morning and afternoon measurements (before caffeine intake) for different subjects are shown in Figure 1. After caffeine stimulation, results show increase in amplitude and decrease in latency in general. Figure 2 shows the increase in amplitude of P300 at Cz for the different subjects.
Conclusion: The experimental results show that caffeine improves cognitive performance by increasing alertness and attention and reducing fatigue.