Biomedical subjects

E De Haan

Publications and source records attributed to E De Haan.

3 recordsLinked to original sources

PubMed1992

Selective loss of imagery in a case of visual agnosia.

Experiments were designed to examine the imagery abilities of an agnosic patient, M.S., who has consistently shown more severe deficits in recognizing visually, and in retrieving knowledge of living as compared with non-living items. Judgements of visual similarity were required for named objects and for object-pictures, as well as for the factual properties of these stimuli. The same disproportionate difficulty in processing living ('natural') objects was found in these tasks as well as in forced-choice recognition. In contrast, no deficit was found on analogous tasks concerned with word-shape similarities. These findings have a bearing on concepts of semantic memory.

Adult↗

PubMed1989

Implicit access to semantic information.

Three experiments investigating the patient M.S.'s semantic memory are reported. Experiments 1 and 2 involved a category-membership decision task, in which M.S. was asked to determine whether a noun was a member of a specified semantic category. His performance in Experiment 1 was impaired for nouns from living categories in comparison with nouns from nonliving categories, and this impairment was especially marked for nouns of low typicality. Experiment 2 demonstrated an equivalent pattern of very poor performance to nouns of low familiarity from living categories. In Experiment 3 the effect of a category label on lexical decision was examined, using category labels as primes preceding nouns or pronounceable nonwords. Facilitation from related category label primes was found for typical and untypical members of living and nonliving semantic categories. These findings demonstrate that M.S. has impaired knowledge of the structure of living semantic categories when explicit access to this information is required (Experiments 1 and 2), but that some form of preserved category structure can be demonstrated in tasks which assess this implicitly (Experiment 3).

Agnosia↗

PubMed1987

Exposure and response prevention in patients with obsessions.

The outpatient treatment of patients with obsessions alone is often said to be less successful compared to the outpatient treatment of patients with both obsessions and compulsive symptoms. This article presents the outcome of the treatment of 26 obsessive patients. The success rate, measured after 10 treatment sessions, was 73%. At follow-up after 12-36 months, improvement appeared to have been maintained or to have increased in 61.5% of the patients, figures comparable to the outcome of patients with both obsessions and compulsions.

Adolescent↗