Quantitative Electroencephalography (QEEG) Assessment and Event Related Potential (ERP) Analysis pre and post Cellfield has revealed changes in visual processing and visual attentional control. This case study demonstrates the ability to measure changes to the visual cortex in the case of an Autistic client following 3 rounds of a Cellfield intervention. Results showed statistically significant changes in both continuous EEG, EEG Spectra and ERPs.