Correlation between the Psychological Significance of Stimuli and the Magnitudes of the Startle Blink and Evoked EEG Potentials in Man1

Abstract

Larsson, L.‐E. Correlation between the psychological significance of stimuli and the magnitude of the startle blink and evoked EEG potentials in man.The effect of variations in the psychological significance of stimuli on evoked potentials in the EEG and on the startle blink has been studied in man. Three different experimental conditions were set up under which the stimuli were assumed to have a high, a moderate and a low significance, respectively. It was found that the magnitudes of the startle blink and the non‐specific EEG response were directly correlated to the degree of significance thus defined. The differences between the responses under the three experimental conditions were statistically significant. The short‐latency response to peripheral nerve stimulation recorded from the contra‐lateral somatosensory region was more resistant. The cardiac and respiratory rates as well as the EEG from the posterior scalp regions were also recorded under the three experimental conditions. It was found, among other things, that under the condition in which the subjects tensely waited for a stimulus and accordingly must have been highly alert the EEG contained a large amount of alpha waves in contrast to the desynchronization of the record which occurs under other conditions of wide‐awakeness.