Topography of brain electrical activity: a bioengineering approach.

The aim of this work is to describe a system for the mono- and bi-dimensional analysis of brain electrical activity. The analysis was carried on either by visual inspection of mono- and bi-dimensional data, or by automatic feature extraction from the bidimensional data. Because of the importance of visual inspection for the analysis of experimental data, particular care was devoted to optimize the displayed data perceptually. For automatic screening of large amounts of data (and to allow long term studies of clinical records), statistical facilities were also provided. One purpose of the system was to develop image processing algorithms oriented toward biomedical images, that could be easily implemented on special purpose, low cost hardware, like VLSI or microcomputer arrays. This was possible because of the modularity of the larger part of bidimensional processing, such as interpolation and statistical analysis. Results of an experiment on Visual Evoked Response are presented, showing that through abidimensional analysis of the recorded data the resolution achievable in the localization of brain electrical activity can be increased to less than 1 cm.