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W T Liberson

Publications and source records attributed to W T Liberson.

45 records · Page 3Linked to original sources
PubMedDate not supplied

Mapping of somato-sensory evoked potentials (SEP): new findings suggesting the role of brain waves as a "temporal analyzer of the stimulus".

For a number of years we have been reporting a relationship between the mid components of the somato-sensory evoked potentials and basic brain waves. Recently we suggested that when the primary spike occurs it elicits a train consisting of beta, alpha, theta and delta single waves, originating at the same point in time and overlapping one with the other. The half periods of each of these waves are equal to the latencies of mid and late SEP components. Thus the latter are in fact the classical brain waves. They are present bilaterally but are of higher amplitude on the parietal region contralateral to the side of the stimulus applied to the median nerve. Presumably at that side the brain wave amplitude is increased by the delayed potentials due to the conduction of some components of the signal travelling in the thin myelinated fibers. Indeed this study revealed the presence of recurrent delayed positive and negative foci in the parietal region contralateral to the side of the stimulus in addition to the late vertex components. Thus brain waves contribute to the temporal analysis of the stimulus.

Adolescent↗
PubMedDate not supplied

Contributions to the history of the discovery of brain stem somato-sensory potentials.

The presence of an earlier latency of 12 msec of a somato-sensory evoked potential elicited by the stimulation of the median nerve at the wrist was discovered in 1963 by Liberson and Kim. They suggested its origin in the cervical spine or in the brain stem and possibly the cerebellum. Liberson, Voris and Uematsu recorded directly these potentials from the cervical spine and from the mesencephalon during surgery for pain in 1969 and published some of the findings in 1970. Cracco and Bickford confirmed in 1968 the findings of Liberson and Kim.

Animals↗
PubMedDate not supplied

Contributions to the history of the discovery of P300.

Discovery of P300 was preceded by a number of EEG findings related to expectancy of a stimulus, starting with a classical paper of Adrian and including the well known publication of Grey Walter. Our own studies published with Ellen in 1960 demonstrated the occurrence of positive waves occurring in the hippocampus at the time of expected but non-existing stimuli.

Electroencephalography↗