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Biomedical subjects

C D Field

Publications and source records attributed to C D Field.

10 recordsLinked to original sources
PubMed1997

Computer-aided cognitive rehabilitation: possible application to the attentional deficit of schizophrenia, a report of negative results.

The cognitive deficits associated with schizophrenia commonly include impairment in attention, which may contribute to difficulties with learning, memory, and executive function. This study evaluated the effectiveness of computer-aided training of attentional skills in schizophrenia. Two groups of schizophrenic subjects (9 men and 1 woman) were matched for age, estimated premorbid IQ, and positive and negative symptom scores. Both groups were assessed using a battery of attentional tests. Subjects then received either six 1-hr. computer-aided cognitive rehabilitation sessions (experimental condition) or six sessions of graphics-based computer games (control condition). Both groups were reassessed with attentional measures. There was significant improvement on only one test, a letter-cancellation task. This improvement was evident in both groups suggesting that this was a practise effect. Apart from the letter-cancellation test, subjects undertaking the computer-aided rehabilitation treatment did not show significant improvement on any attentional tasks.

Adult↗
PubMed1991

Changing patterns of electroconvulsive therapy use: results of a five-year survey.

Despite its proven efficacy and safety, electroconvulsive therapy (ECT) continues to be a controversial treatment. Ongoing scrutiny is therefore particularly important. We reviewed 315 patients who received 3903 ECT treatments over a five year period, and found a gradual decline in the use of ECT, due mainly to a reduction in ECT for schizophrenic patients. Eighty percent of treatments were given with bilateral electrode placement, although we did find the incidence of adverse effects to be greater with bilateral ECT. Most patients concurrently received medications which raise the seizure threshold. The administration of ECT to patients unable or unwilling to give informed consent raises ethical and medicolegal issues. We found that such difficulties had arisen with at least 16% of patients.

Adult↗
PubMed1987

Learning and memory impairment with benzhexol.

A double-blind trial to determine the effects of a single dose of 2 mg benzhexol on cognitive functioning was undertaken using normal volunteers. Ninety minutes after the drug or placebo was taken, subjects completed a battery of psychological tests designed to measure learning, memory and motor skills. Benzhexol ingestion was associated with significant impairment of short-term memory and slowing of the rate of new learning.

Adult↗
PubMed1976

Electrical properties of Valonia ventricosa.

The cytoplasmic electrical potential and membrane resistance of mature cells of Valonia ventricosa have been measured by inserting a microelectrode concentric with another electrode into the vacuole of the cell. The cytoplasmic region was investigated by advancing the microelectrode into the cell wall from the vascuolar side. The results revealed a unique region where the vascuolar electric potential and membrane resistance changed in a simultaneous single step to values close to zero. The measured potential always remained positive immediately after the step. At no time was a highly negative potential region encountered. Further penetration of the microelectrode revealed a low resistance negative potential region of --12.6 +/- 1.1 mV associated with the cell wall. Experiments were also carried out on aplanospores of V. ventricosa to compare mature and immature cells. The chemical composition of the vacuolar and protoplasmic phases of mature cells was determined. The results agreed with previous results except that the C1- ion content of the protoplasm was significantly higher at 381 +/- 20 mmoles/liter (H2O). It was concluded that mature cells of Valonia are significantly different from immature cells in that no highly negative potential cytoplasmic region was found in mature cells. It was considered that the measured step change in electric potential and membrane resistance occurred at the plasmalemma and that the tonoplast was a region of very low resistance. The implications of these findings in terms of models of ion transport into Valonia are discussed.

Cell Membrane↗