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Biomedical subjects

S E Newman

Publications and source records attributed to S E Newman.

14 recordsLinked to original sources
PubMed1996

Does recoding interfering material improve recall?

In 4 experiments, the authors attempted to replicate an improvement in recall of target memories produced by a post-learning clue enabling participants to reorganize and segregate interfering material, as shown by G. H. Bower and T. Mann (1992). The 1st three experiments studied retroactive interference (RI) in free recall of an initial word list after participants were informed post-learning of a way to categorize a second, interfering list. In each case, the reorganizing clue failed to reduce RI. In the 4th experiment, interference during serial recall of an initial list of letters from a 2nd list was examined. Again, the reorganizing clue given after learning failed to reduce RI. Clearly, if the post-information effect is genuine, then better experimental arrangements will be required to demonstrate it more reliably.

Humans↗
PubMed1984

Experimental studies on different thresholds for epileptiform activity.

This investigation was carried out to clarify the mechanisms for production of different seizure threshold. To study this problem changes of a single cell activity were examined by means of penicillin iontophoretical application to a single cell of both low seizure threshold hippocampus and the high seizure threshold olfactory bulb, and also topical application to the surface of hippocampus and olfactory bulb. Penicillin was applied iontophoretically using five barrel glass micropipettes. Extracellular recordings from 58 hippocampal pyramidal cells and 68 olfactory bulb mitral cells were analyzed. Penicillin increased the firing rate in most of both hippocampal pyramidal and olfactory bulb mitral cells. This suggests that penicillin finally had an excitatory effect on both cells. The results from the experiments of intermittent and continuous GABA application on a cell during penicillin iontophoresis revealed that GABA inhibitory action was reduced by penicillin in both cells. A progressively shortened duration of the post-discharge inhibition during penicillin iontophoresis also suggested that penicillin may reflect a decrease of GABA inhibitory action. No obvious seizure activity and/or no change of firing pattern were observed even after long penicillin iontophoresis. There was no significant different responses to penicillin iontophoresis in the hippocampus and the olfactory bulb single cell. Extracellular activity from 64 hippocampal pyramidal cells and 32 olfactory bulb mitral cells was recorded. The effects of penicillin topical application on single cell function were examined. From hippocampus surface, paroxysmal activity begun to appear within 6 min after topical application, and became more regular and stereotyped in form. The firing rate initially decreased in the majority of cells, with no increase prior to interictal or ictal events. The unit responses to both intermittent and continuous GABA iontophoresis was suppression in unit firing incidence, except for the burst patterns associated with the surface interictal or ictal discharges. Post-discharge inhibition was not significantly different either before or after the onset of the surface interictal discharges. These results indicate the firing rate and inhibitory function of the hippocampal pyramidal cells were not significantly changed during and following the development of interictal and/or ictal epileptiform activity. Olfactory bulb surface activity was not significantly changed and no epileptiform activity was observed even several hours after topical penicillin application.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Learning as a function of haptic discriminability among items.

In Experiment 1, braille symbols for the letters A-J were found to be more haptically discriminable from one another than braille symbols for the letters K-T. In Experiment 2, subjects learned the names for the A-J symbols faster than for the K-T symbols. Experiment 3 demonstrated that faster learning of the names for the A-J than for the K-T symbols is attributable to characteristics of the symbol sets themselves (probably to the discriminability of the items from one another) and not to what they are called. The effects of discriminability on learning in these experiments are similar to those from experiments in which other modalities have been used.

Blindness↗
PubMed1978

The EEG manifestations of chronic ethanol abuse: relation to cerebral cortical atrophy.

Eleven chronic alcoholic patients without other nonneurological or traumatic disease were evaluated by a simultaneous electroencephalogram and computerized axial tomogram. The findings suggested that chronic abusers of approximately 60 years of age or less may have a normal EEG despite the presence of cerebral cortical atrophy or dementia. In alcoholics over 60 years of age, the greater the severity of cerebral cortical atrophy, the greater the slowing in background frequency of the EEG. Voltage diminution and slow-wave transients also occurred more frequently in the older patients. The incidence of EEG abnormalities was greater than the incidence of CAT scan evidence for cerebral cortical atrophy in alcoholics over 60 years of age with dementia.

Adult↗