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Biomedical subjects

M Calogero

Publications and source records attributed to M Calogero.

7 recordsLinked to original sources
PubMed1998

Memory-scanning task performance in Alzheimer's disease.

Individuals with mild Alzheimer's Disease (AD) and healthy normal control (NC) older adults performed a varied-set version of the Sternberg memory-scanning task with Set Sizes 1, 2, 3, and 4. The AD group (N = 23) had slower and more variable reaction times (RT) than the NC group (N = 38). RT differences between groups were bigger for NO than for YES responses. The linear relationship between RT and set size was not as strong for the AD group as for the NC group. However, in contrast to earlier studies with fewer subjects, participants with AD and healthy older individuals did not differ in the rate at which they scan items in the memory set.

Aged↗
PubMed1992

Letter matching: effects of age, Alzheimer's disease, and major depression.

We compared Alzheimer's disease (AD) patients and Major Depressive Disorder (MDD), Aged normal, and Young normal controls on a letter-matching task designed to measure the time needed to access overlearned linguistic information in long-term memory. Name identity (NI) and physical identity (PI) reaction time and the NI-PI difference were compared for ADs, MDDs, and Aged normals and separately for Aged and Young normal groups. AD subjects had slower NI and PI reaction times and a bigger NI-PI difference than Aged normal and MDD subjects, suggesting that speed of access to overlearned letter-name information in long-term memory is slowed for ADs. There were no reliable differences between Aged normal and MDD subjects. Aged normals had slower NI and PI reaction times and a bigger NI-PI difference than Young normals, suggesting that the highly practiced operations needed to access letter-name information slow with age. A discriminant analysis was used to evaluate the usefulness of the "easy to perform" letter-matching task for diagnostic purposes. Ninety percent of normal and MDD subjects but only 68% of AD subjects were classified correctly.

Adult↗
PubMed1992

Utilization of base-rate information during feeling-of-knowing judgments.

We examined whether subjects use base-rate information about item difficulty when making feeling-of-knowing judgments for items they failed to recall. First, the subjects attempted to recall the answers to general-information questions. Then, for those items they recalled incorrectly, half of the subjects received information about the normative probability of recall of each item while judging their feeling of knowing. The other subjects made their feeling-of-knowing judgments without receiving any base-rate information. Finally, all subjects had a forced-choice recognition test on those items to validate the accuracy of their feeling-of-knowing judgments. Relative to the no-base-rate information group, the base-rate group had lower feelings of knowing for normatively difficult items and higher feelings of knowing for normatively easier items. Subjects who had received base-rate information during the judgment state had greater feeling-of-knowing accuracy than subjects who did not receive base-rate information. However, even the predictions from subjects who received base-rate information were not significantly more accurate for predicting subsequent recognition than were the predictions derived from normative information alone.

Adult↗
PubMed1991

Concentration-related effects of morphine on cognition and motor control in human subjects.

Morphine and other opioid analgesics may interfere with normal cognition and motor function when the drugs are used for long-term treatment of pain. We used individually tailored steady-state drug infusions to identify the nature and extent of cognitive and motor effects of the mu-receptor-selective opioid morphine in healthy volunteers. The tailored infusions allowed evaluation of cognitive and motor effects at three sequential, constant plasma concentrations of morphine in each subject. Compared with functional assessments obtained in a separate saline infusion day, infusions of morphine to plasma concentrations in the usual therapeutic range for analgesia caused significant impairments of some but not all elements of cognitive and motor function. The time needed to encode and process serially presented verbal information increased and the ability to maintain low consistent levels of force decreased during the morphine infusion. We also assessed verbal recall 3 hours after the morphine and saline infusions. Delayed recall of information presented during the morphine infusion was significantly impaired. Our results demonstrate that morphine can interfere with cognitive and motor performance at plasma drug concentrations within the usual therapeutic range.

Adult↗
PubMed1980

Effects of lisuride on body temperature of rats and rabbits: relation to microsomal biotransformation and dopaminergic receptor stimulation.

In rats, lisuride, either administered systemically or intracerebroventricularly induced a dose-related hypothermia. This effect was selectively antagonized by blockade of DA receptors in the CNS but not by inhibition of catecholamine synthesis or blockade of serotoninergic receptors. Also a blocker of "peripheral" DA receptors failed to antagonize the hypothermic effect of lisuride in rats. Induction of rat liver microsomal drug-metabolizing enzymes by phenobarbital counteracted lisuride-induced hypothermia. In rabbits lisuride induced a hyperthermic response which was sensitive to both pimozide and metergoline pretreatment. These findings indicate that stimulation of brain DA receptors involved in thermoregulation is responsible for the changes in body temperature indiced by lisuride in rats and rabbits and that these effects are caused by the drug itself and do not require previous biotransformation into an active metabolite.

Animals↗