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Biomedical subjects

E Hardman

Publications and source records attributed to E Hardman.

7 recordsLinked to original sources
PubMed1999

Learned control of slow potential interhemispheric asymmetry in schizophrenia.

We report on the feasibility of teaching 16 (DSM-IV) schizophrenic patients, subdivided by syndrome, self-regulation of interhemispheric asymmetry having demonstrated efficient learning of interhemispheric control in normal subjects. Reversal of asymmetry may be important to treatment and recovery in schizophrenia for following improvement on neuroleptic drugs functional hemispheric asymmetries have reversed, with directions of reversal and pre-existing asymmetry dependent on syndrome. Asymmetry reversal in animals, manifested by spatial turning tendencies, has been used as a marker of neuroleptic action and involves striatal dopamine under reciprocal hemispheric control. We gave as feedback the left right asymmetry in slow potential negativity recorded from the sensory motor strip (C3,4). Feedback took the form of a rocket on a screen which rose or fell with leftward or rightward shifts in negativity. Patients were able to learn control (P < 0.01). In those patients with lesser ability this was due to inability to sustain concentration throughout the session rather than slow initial learning. Active syndrome patients were better able to shift negativity rightward and withdrawn patients leftward, directions associated with drug reversal of functional asymmetry and symptom recovery for each syndrome. Accordingly our demonstration that many symptomatic schizophrenic patients are capable of learning control opens the door to electrocortical operant conditioning training in schizophrenia with therapeutic regimens.

Adult↗
PubMed1998

State-dependent memory produced by aerobic exercise.

In a free recall experiment, participants learned lists of words in two physiological states: at rest and while exercising aerobically on a bicycle ergometer. Recall of the words was required in either the state consistent with learning or in the alternative state. Word lists learned during aerobic exercise were recalled best during aerobic exercise and vice versa. Greater changes in heart rate in the changed state conditions were associated with greater retrieval decrements. Recall levels for words both learned and recalled at exercise were equivalent to those for words both learned and recalled at rest. This finding rules out the possibility that exercise per se interfered with the original learning. The study is consistent with the view that state-dependent memory should be viewed as a particular form of cue-dependent memory.

Adolescent↗
PubMed1997

Frontal interhemispheric asymmetry: self regulation and individual differences in humans.

Sixteen subjects naive to biofeedback learned lateralised interhemispheric control of slow cortical potentials (SCPs) across electrode sites F3-F4 during three sessions of visual electroencephalograph (EEG) biofeedback. Subjects were required to generate slow negativity shifts either towards the left or the right hemisphere in sixty pseudorandomly ordered trials per session. Group 1 (n = 8) were told to use emotional strategies in the task (positive emotions for left hemisphere activation, negative emotion for right hemisphere activation), group 2 received no guidance. Both groups received feedback in the form of an on-screen rocket-ship, initially centrally placed, which rose to indicate an increase in left hemisphere negativity (relative to the right hemisphere) and fell to indicate an increase in right hemisphere negativity (relative to the left hemisphere). A 2 x 3 x 3 x 2 ANOVA (group x session x block x trial) showed no performance differences between the strategy and no strategy groups. Both groups learned to produce correct direction shifts in the final third of each session during both trial types (P < 0.001). The no strategy group showed a particularly strong within session learning effect (P < 0.0037) with poor performance in the early part of the sessions, and strong shifts at the end. Subjects high on withdrawal showed stronger rightward shifts in keeping with right hemisphere involvement in behavioural withdrawal. This is the first demonstration of self regulation of interhemispheric frontal asymmetry.

Adult↗
PubMed1990

Blood conservation in major orthopedic surgery.

During an eight-year period, intraoperative autotransfusion was performed in 1922 operations. There were 476 primary hip arthroplasties, 1017 revision hip arthroplasties, 339 spinal procedures, and 90 vascular cases. There were no known complications related to autotransfusion in any of the cases. With proper technique, red cell salvage is approximately 58% effective, and intraoperative blood loss can be reduced by that amount. The first four years' experience with the preoperative autogeneic blood program is as follows. Using a combined program of predonation and primary hip arthroplasty, 72% of the revision hip arthroplasties and 81% of the spinal instrumentations required only autologous blood. A combined program of autologous donation and intraoperative autotransfusion is an excellent alternative to allogeneic blood replacement and a means of eliminating transfusion-related disease.

Blood Preservation↗