[The spectral correlations of human brain electrical activity (the EEG) in the alpha-rhythm range occurring while...

Changes in perception of a stimulus and impairment of retrieval of memory trace resulted from the stimulus loss of novelty are called the latent inhibition (LI). The present study was undertaken to investigate the human LI using the analysis of changes in frequency power and coherence of the alpha rhythm. The results indicate that the loss of novelty of a stimulus is accompanied by a significant increase in the power of the upper alpha in the frontal regions of the right hemisphere and temporal regions of both hemispheres resulting in an impairment of memory retrieval in the frontal regions. Analysis of coherence changes revealed the reduction of interaction between the right temporal region and anteriofrontal, temporo-occipital, and right parietooccipital regions in response to administration of the conditioned words in comparison with the control ones. The findings suggest that the LI is a manifestation of the more general physiological process--the hidden inhibition.