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Biomedical subjects

L Costa

Publications and source records attributed to L Costa.

9 recordsLinked to original sources
PubMed1992

Pure alexia and right hemiachromatopsia in posterior dementia.

A 66 year old, right handed woman presented with pure alexia and right hemiachromatopsia (PARH) in the context of a posterior dementia. PARH was accompanied by prosopagnosia, 2-D object agnosia, and environmental agnosia. Visual fields were normal to confrontation testing. The pathological anatomy of PARH involves circumscribed damage to the lingual and fusiform gyri and paraventricular white matter of the left occipital cortex, two contiguous cortical regions functionally specialised for processing colour and word form information, respectively.

Aged↗
PubMed1979

Dichotic perception: evidence for right hemisphere dysfunction in affective psychosis.

The association between lateralized hemispheric dysfunction and psychiatric diagnosis was investigated with a measure of summation of dichotic clicks and with a dichotic competing message task. Ear asymmetries of affective psychotic patients were similar to those of right temporal lesioned controls and differed from those of schizophrenic patients and normal controls. In contrast, schizophrenic patients did not display abnormal auditory perceptual asymmetries.

Adult↗
PubMed1979

Dimensions of the subjective marijuana experience.

A Drug History Questionnaire and a Marihuana Effects Questionnaire were completed by 91 male volunteers who were experienced marijuana smokers. A factor analysis was performed on the frequency of occurrence data for the Marihuana Effects Questionnaire. The resultant factors were similar to those reported previously in the literature supporting the existence of a stable, verbally definable marijuana experience. In comparison to the drug history variables of marijuana smokers in the late 1960s, our population showed increased multiple drug use, an earlier age of introduction to cannabis, and heavier use of cannabis. An analysis of the interaction of drug history variables with experienced marijuana effects suggested that the more frequently one uses cannabis, the less pronounced the experienced effects tend to be.

Adolescent↗
PubMed1978

Odor and marijuana intoxication.

Assigned 48 volunteer adult males to four groups: a marijuana high dose, a marijuana low dose, a placebo, and a coltsfoot group. Each S participated in two 80-minute sessions; one involved listening to music, socializing, and smoking the drug, and the second was identical to the first with the addition of two extra placebo cigarettes which contained finely cut amounts of human hair. The odor of burning hair was rated previously as quite aversive by non-intoxicated Ss. Contrary to expectation, Ss in the odor condition indicated on self-ratings that they became significantly more intoxicated after the smoking of the hair cigarette. The opposite effect was found with a pulse rate measure. An additional 24 Ss were divided into high and low dose marijuana groups and run in an odor session, in which they were informed prior to smoking of the hair content. Heart rate for these Ss decreased significantly more than for the comparable uninformed Ss, although self-ratings continued to reflect increased intoxication.

Adult↗
PubMed1977

The discrimination of marijuana intoxication.

Forty Ss, 20 males and 20 females, observed a videotape that showed four males interacting in a social setting under four different drug conditions; coltsfoot, placebo, marijuana low dose, and marijuana high dose. The observers attempted to discriminate the level of intoxication of the four males in each condition. The observers accurately detected the level of intoxication in the high dose condition. While marijuana experienced users were more successful in detecting levels of intoxication, the sex of the observer was not significant. Behaviors used to discriminate intoxication and the implications of these results to defining intoxication are discussed.

Adolescent↗