The Relationship between Evoked Potential Component Amplitude, Latency, Contour Length, Variability, Zero-crossings, and Psychometric Intelligence

Two hundred subjects provided data from within three separate studies that attempted to replicate correlations between averaged evoked potential (AEP) indices and psychometric IQ. In addition, AEP zero-cross analysis was undertaken as a specific test of a proposition made within the Weiss quantum theory of intelligence. Measures of AEP variability, mean individual epoch amplitude, and P180 component latencies were found to correlate negatively with IQ at around -0.50 across the three studies. However, the consistency and size of relationship in the results was found to be a function of selecting subjects whose AEP P180 component amplitude was greater than some specified, sample dependent, target value. The zero-cross analysis, contrary to predictions, yielded no correlations with IQ. Robinson’s cerebral arousability theory was noted as a possible explanatory framework for the results. In addition, it was noted that if Robinson is correct in his assertion of the complex analogue nature of the evoked response, conventional AEP analysis is no longer relevant.