PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 85545

A technique for separating endogenous from exogenous human cortical potentials.

E J Hammond·D A Silva·A J Klein·D C Teas
View original source ↗Export metadata ↓

Abstract

In a temporal discrimination paradigm, if signal duration is the stimulus dimension to be discriminated, the moment of subject's decision can be manipulated by varying the duration of the target stimulus. As stimulus duration is lengthened, task-contingent potentials related to the decision process can be separated from those evoked by stimulus onset. Analysis of individual evoked responses indicates that 3 task-contingent components, occurring at 220, 300 and 340 msec are precisely time-locked to the moment of decision.

Explore related subjects

Acoustic StimulationAuditory PerceptionCerebral CortexDecision MakingDiscrimination, PsychologicalElectroencephalographyEvoked PotentialsHumansPsychoacousticsReaction TimeJournal ArticleResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

E J Hammond, D A Silva, A J Klein, D C Teas. 1979. A technique for separating endogenous from exogenous human cortical potentials.. https://doi.org/10.1016/0013-4694(79)90150-0

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1992

Classical conditioning after temporal lobe lesions in man: sparing of simple discrimination and extinction.

Recent reports of impaired conditional discrimination learning in temporal lobectomy subjects have raised the question of response inhibition deficits in these patients. In the present study, left and right temporal lobectomy subjects and healthy controls completed an eyelid conditioning task, which required simple two-tone discrimination learning, followed by extinction. There were no group differences with regard to discrimination learning or extinction. General deficits in response inhibition are therefore not likely to account for the impairment in conditional discrimination observed in temporal lobectomy patients.

Acoustic Stimulation↗
PubMed1992

Behavioral lifetime of human auditory sensory memory predicted by physiological measures.

Noninvasive magnetoencephalography makes it possible to identify the cortical area in the human brain whose activity reflects the decay of passive sensory storage of information about auditory stimuli (echoic memory). The lifetime for decay of the neuronal activation trace in primary auditory cortex was found to predict the psychophysically determined duration of memory for the loudness of a tone. Although memory for the loudness of a specific tone is lost, the remembered loudness decays toward the global mean of all of the loudnesses to which a subject is exposed in a series of trials.

Acoustic Stimulation↗
PubMed1992

Neuroethological evaluation of audiogenic seizures and audiogenic-like seizures induced by microinjection of bicuculline into the inferior colliculus. I. Effects of midcollicular knife cuts.

Audiogenic seizures (AS) are a model of generalized tonic-clonic seizures. The inferior colliculus (IC) and the GABAergic neurotransmission seems to be the most critical site and neurotransmitter system, respectively, of the auditory midbrain involved in AS origin and development. Thus, audiogenic-like seizures are evoked by GABAA antagonists such as bicuculline (BIC). Wistar audiogenic AS resistant (R) rats were sham-transected through the midcollicular line and microinjected with IC bicuculline (BIC; 80 ng/0.2 microliters) (n = 8); transected through the midcollicular line and microinjected with IC saline 0.9% (n = 8); transected through the cortex above the midcollicular line and microinjected with IC BIC (n = 3); transected through the midcollicular line up to 6.0 mm depth and microinjected with IC BIC (80 ng/0.2 microliters or 120 ng/0.3 microliters (n = 8). Wistar AS susceptible (S) rats were submitted to cortical transections (n = 8) and midcollicular transections (n = 7). Animals were studied by means of an ethological method before and after microinjections and/or transections in order to evaluate possible pathways in the AS-like evoked seizures. Bicuculline-evoked seizures were very similar to those evoked by acoustic stimulation, but lacked the tonic-clonic component. No modification in animal behavior was observed in the presence of sound, once the AS-like behavior was initiated. A small percentage of the animals, however, presented procursive behavior which was increased by sound. The IC BIC-evoked patterns were almost totally blocked by midcollicular but not cortical transections. Furthermore, midcollicular but not cortical transections blocked the tonic-clonic component of AS in genetically S animals without modifying the wild running component. These data suggest that the inferior colliculus-superior colliculus connection may be involved in the sensorimotor transduction necessary for AS-like behaviors.

Acoustic Stimulation↗