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L C Oatman

Publications and source records attributed to L C Oatman.

14 recordsLinked to original sources
PubMed1985

Event-related potentials elicited by automatic targets: a dual-task analysis.

The role of limited capacity processes in the detection of automatic targets was investigated in a dual-task paradigm using both behavioral and event-related brain potential (ERP) measures. An automatic detection task was paired with another concurrent discrimination while the relative importance of each task was systematically varied. The resulting performance operating characteristic (POC) showed that both the speed and accuracy of automatic detection responses were affected by the allocation of attention. Reductions in the accuracy of each task were accompanied by reductions in the amplitude of a late-positive component of the ERP (P300). In addition, the latency of the P300 component elicited by automatic targets was increased in dual-task conditions. A comparison of behavioral and ERP measures suggested the involvement of two separate limited-capacity processes in automatic detection: one concerned with the formation of an episodic representation of target occurrence and the other with the execution of rapid motor responses.

Attention↗
PubMed1980

Suppression of the auditory frequency following response during visual attention.

Frequency-following responses (FFRs) were recorded from unanesthetized cats with electrodes chronically implanted in the cochlear nucleus and on the round window. Tone bursts of different frequencies (irrelevant stimuli) were presented repetitively (85 dB SPL, 1/sec) as background before, during, and after the presentation of a visual discrimination task (relevant stimuli) which attempted to alter the attentive state of the animals. The mean peak-to-peak amplitudes of the FFRs from the cochlear nucleus were significantly reduced in amplitude during attention to the visual discrimination stimuli when compared with the amplitudes of the pretest- and posttest-control periods. However, at the round window (cochlear microphonic) no significant differences in amplitude were observed for the same periods. Although the amplitudes of the FFRs were reduced in amplitude at all frequencies during visual attention, much greater suppression occurred at the middle frequencies (700-2000 Hz) than at higher or lower frequencies. These data suggest that during visual attention the FFRs are attenuated by a central inhibitory mechanism.

Animals↗
PubMed1980

Auditory and visual evoked potentials to irrelevant stimuli during conditioning to a visual stimulus.

Amplitude changes of evoked responses to irrelevant auditory (click) and visual (optic tract stimulation) stimuli were examined during appetitive conditioning to a flashing light. Four female cats, with chronically implanted electrodes along the visual and auditory pathways, were conditioned with pairings of a flashing light and food reinforcement. The results showed that, as conditioning progressed, the auditory evoked potentials were attenuated while the visual evoked potentials did not change significantly. The data seem to indicate possible differences in the neural processing of irrelevant information.

Animals↗
PubMed1976

Relevant stimuli and auditory evoked potentials.

Four cats, classically conditioned to a flashing light paired with food reinforcement, were tested for amplitude changes of click-evoked potentials during increasing hours of deprivation. Signal averaged evoked potentials from the auditory cortex, cochlear nucleus, and round window electrodes showed no significant changes in amplitude, but significant changes were found in the variance as food deprivation increased. Such changes are more consistent with expected changes in the CNS than the amplitude changes of the auditory cortex found by Saunders and Chabora.

Acoustic Stimulation↗