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J Rohrbaugh

Publications and source records attributed to J Rohrbaugh.

13 recordsLinked to original sources
PubMed1997

P300 topography of amplitude/latency correlations.

The correlational association from 19 electrode sites between peak amplitude and latency for the P3(00) event-related brain potential (ERP) for n = 80 homogeneous subjects was assessed using a simple auditory discrimination task. The correlation strength varied systematically across scalp topography in different ways for the various ERP components. For the target stimuli, P3 amplitude and latency were negatively correlated and most tightly coupled over the frontal-central and right medial/lateral recording sites. In contrast, the N1 produced negative correlations that were strongest over the left and right central/lateral locations; P2 demonstrated a positive correlation that was strongest frontally and centrally; N2 demonstrated a positive correlations that was strongest over the central and parietal sites. ERPs from the standard stimuli produced generally similar patterns for the P3 and P2 components, with only weak or no reliable effects observed for the N1 and N2 potentials. Taken together, the findings suggest that analysis of amplitude/latency correlational relationships can provide information about ERP component generation. Theoretical implications are discussed.

Adult↗
PubMed1995

Multi-center N400 ERP consistency using a primed and unprimed word paradigm.

A word priming paradigm involving primed, unprimed, and non-word experimental conditions was used to elicit event-related potentials (ERPs) in normal, young adult males in identically equipped electrophysiology laboratories located in 6 different cities in the USA. Analyses of the average amplitude of a specified latency window containing the N400, the N400 peak amplitude, or the latency of the N400 peak amplitude found no differences among laboratory locations. The shape of the N400 ERP wave form was also found to be highly correlated across laboratory sites for each experimental condition. Comparison of the data with analogous word priming paradigms revealed similar patterns for the N400 components and response times in both the primed and unprimed experimental conditions. These findings suggest that the data from all 6 laboratory locations are consistent with each other and are congruous with those found in other N400 studies and will permit pooling of subject data for future research.

Adolescent↗
PubMed1995

P300 hemispheric amplitude asymmetries from a visual oddball task.

The P3(00) event-related potential (ERP) was elicited in 80 normal, right-handed male subjects using a simple visual discrimination task, with electroencephalographic (EEG) activity recorded at 19 electrodes. P3 amplitude was larger over the right than over the left hemisphere electrode sites primarily at anteromedial locations (F3/4, C3/4) for target, novel, and standard stimuli. The N1, P2, and N2 components also demonstrated hemispheric asymmetries. The strongest P3 hemispheric asymmetries for all stimuli were observed at anterior locations, suggesting a frontal right hemisphere localization for initial stimulus processing, although target stimuli produced larger P3 amplitudes at parietal locations that did novel stimuli. The relationships of hemispheric asymmetries to anatomical variables, background EEG activity, and neurocognitive factors are discussed.

Adult↗
PubMed1994

P300 from an auditory oddball task: inter-laboratory consistency.

Event-related potentials (ERPs) were recorded from normal subjects for the purpose of evaluating measurement consistency among six laboratories located in different cities within the United States. At each laboratory location 15 male subjects were tested using a simple auditory stimulus discrimination task and identical electrophysiological equipment and recording methods. Assessment of the N1, P2, N2, and P3(00) potentials from both the target and standard stimuli resulted in no reliable differences among laboratories for component amplitudes, latencies, and scalp distributions. Quantitative evaluation of overall waveform and specific component morphology yielded good to excellent agreement across laboratories. The findings suggest that large-scale inter-laboratory human electrophysiological studies are feasible and may prove of value when using ERPs to evaluate cognitive function in humans.

Adult↗
PubMed1987

Alcohol intoxication in humans: effects on vigilance performance.

Effects of ethanol on vigilance in tasks requiring continuous performance are reviewed. Evidence is presented to indicate that ethanol has adverse effects on both the overall level of performance and the rate of performance decrement over time. The effects on performance level are attributed to nonspecific sedative properties of ethanol whereas the effects on rate of decrement are interpreted as a more specific loss in cognitive processing capacity.

Alcoholic Intoxication↗
PubMedDate not supplied

Hemispheric differences for P300 amplitude from an auditory oddball task.

The P3(00) event-related potential (ERP) was elicited in 80 normal, right-handed male subjects using a simple auditory stimulus discrimination task, with electroencephalographic (EEG) activity recorded at 19 electrodes. P300 amplitude was larger over the right compared to left hemisphere electrode sites primarily at anterior-medial locations (F3/4, C3/4) for both target and standard stimuli. The N100, P200, and N200 components also demonstrated several similar, albeit less robust, hemispheric asymmetries. No hemispheric effects for P300 latency were observed, with few consistent latency findings for any of the other components obtained. The results suggest that the discrimination process underlying P300 generation may originate with right frontal activation.

Acoustic Stimulation↗
PubMedDate not supplied

Visual P300: an interlaboratory consistency study.

The P300 component of the event-related potential is reduced in both abstinent alcoholics and in males at high risk for developing alcoholism. Here, 96 males (mean = 22.1 years) who were part of an interlaboratory (n = 6) consistency study in the national COGA (Collaborative Study on the Genetics of Alcoholism) Project were subjects in a visual target selection paradigm. Each of the participating laboratories used the same experimental design, hardware and software. Each subject received a randomized series of target, nontarget and novel visual stimuli, and upon detecting the target stimulus, was required to make a button press as quickly as possible. Statistical analyses indicated that there were no significant differences in P300 amplitude and latency at the Pz electrode under any of the aforementioned conditions across laboratories. Thus, the interlaboratory consistency of the visual P300 indicates that it may be of utility in a national collaborative study on the genetics of alcoholism.

Adolescent↗