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Biomedical subjects

S E Linnville

Publications and source records attributed to S E Linnville.

6 recordsLinked to original sources
PubMed1997

Mismatch negativity: an index of subclinical neurological differences in HIV patients during rapid perceptual processing.

Thirteen asymptomatic HIV-infected (HIV+) and 13 healthy control (HIV-) subjects were instructed to detect "oddball" target tones from among a sequence of nontarget tones delivered rapidly (3 tones/second) in one ear while ignoring a similar sequence delivered simultaneously in the opposite ear. Event-related potentials (ERPs) to all stimuli were recorded from midline scalp sites. Both groups produced ERP correlates, termed the "mismatch negativity" (MMN), to the oddball tones during delivery. However, the HIV+ group produced MMNs that differed in morphology from those of the HIV-group, suggesting that HIV may alter attentional perceptual processing. These results suggest that auditory ERPs elicited by rapid, dichotic stimulus presentations may be useful in monitoring subclinical effects of HIV-related neuropathology on perceptual processing.

Adult↗
PubMed1996

Event-related potentials as indices of subclinical neurological differences in HIV patients during rapid decision making.

The authors examined decision making in HIV patients under slow and rapid information deliveries. Thirteen asymptomatic, HIV-infected (HIV+) subjects with known seroconversion dates and 13 healthy control subjects were instructed to detect the "oddball" target tones among nontarget tones during single-channel (slow) and dual-channel (rapid) deliveries. Event-related potentials (ERPs) from midline scalp sites, reaction time, and "hits" were recorded. Behaviorally, the two groups performed similarly, and during single-channel delivery they produced similar ERPs indexing target detection. However, during dual-channel delivery the HIV+ group showed atypical morphology in the region of the P300 cognitive decision-making component compared with the control group. Auditory ERPs elicited by rapid, dichotic stimulus presentations appeared sensitive to subclinical effects of HIV-related neuropathology in individuals who had been HIV-positive for 3 months to 8 years.

Acoustic Stimulation↗
PubMed1995

Brain-emitted event-related potentials recorded during rapid decision-making may be useful in monitoring the neuropathogenesis of the human immunodeficiency virus (HIV).

Event-related potentials recorded from HIV-infected patients while they detected oddball targets during rapid delivery of dual sequences of tones showed the complete absence of the late, 300-msec., positive (P300) component, suggesting an alteration in the neuronal activity underlying cognitive processing.

AIDS Dementia Complex↗
PubMed1986

Neuroelectrical correlates of categorical perception for place of articulation in normal and lead-treated rhesus monkeys.

Categorical perception of place of articulation contrasts was evaluated in rhesus monkeys. The monkeys had been chronically exposed to subclinical levels of lead, either from conception to birth, or for approximately 6 months beginning at birth, or were never exposed to lead. Auditory evoked responses were recorded from scalp electrodes placed over left and right hemispheres during stimulus presentation. The brain responses recorded from the right hemisphere of the normal control group of monkeys discriminated between the categories of [dae] and [gae]. Categorical discriminations were also noted for monkeys exposed to lead either prenatally or postnatally. These discriminations, in contrast, were found over only the left hemisphere. In additions, postnatal exposure resulted in categorical discrimination associated with slower latency components, suggesting a less mature pattern than that obtained for prenatally exposed monkeys. Finally, the brain responses of the animals in the normal control and postnatal exposure conditions evidenced reliable within-category, as well as between-category, discriminations. These results suggest that the neurocortical mechanisms associated with categorical perception of place information may differ between human and nonhuman primates and that early exposure to lead alters these processes.

Animals↗
PubMed1985

Electrophysiological correlates of handedness and speech perception contrasts.

Auditory evoked responses (AERs) were recorded from left- and right-handed subjects who listened to consonant sounds from different phonetic categories. AERs recorded at parietal scalp regions indicated both groups differentiated categorical differences between speech sounds. However, hand preferences did not affect hemisphere responses to speech sounds.

Adolescent↗