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Biomedical subjects

D C Park

Publications and source records attributed to D C Park.

At least 73 records · Page 4Linked to original sources
PubMed1982

Spatial memory in older adults: effects of intentionality.

College students and elderly adults were presented with drawings for study that were placed on the left or right side of a photographic slide. Persons in the items-only condition studied only the target drawings, whereas persons in the items-position condition studied both the target drawing and its location to determine whether intentionality affected picture recognition or position recall. Half of the drawings were presented with an irrelevant adjacent drawing to assess the effect of presenting the target item relative to another drawing. The principal finding was that, although special memory was well above chance, the Hasher and Zack's criteria for automatic processing of this dimension were not met. Specifically, an age-related decline in spatial memory was observed, and intentionality to learn position affected item recognition and position recall. It was also found that older persons' memory for position was enhanced by the irrelevant drawings. Results are discussed primarily in terms of the Hasher and Zacks model of automatic processing and possible encoding strategies utilized by the elderly.

Adult↗
PubMed1980

Processing of visually presented clock times.

The encoding and representation of visually presented clock times was investigated in three experiments utilizing a comparative judgment task. Experiment 1 explored the effects of comparing times presented in different formats (clock face, digit, or word), and Experiment 2 examined angular distance effects created by varying positions of the hands on clock faces. In Experiment 3, encoding and processing differences between clock faces and digitally presented times were directly measured. Same/different reactions to digitally presented times were faster than to times presented on a clock face, and this format effect was found to be a result of differences in processing that occurred after encoding. Angular separation also had a limited effect on processing. The findings are interpreted within the framework of theories that refer to the importance of representational codes. The applicability to the data of Bank's semantic-coding theory, Paivio's dual-coding theory, and the levels-of-processing view of memory are discussed.

Discrimination Learning↗
PubMed1980

Item and attribute storage of pictures and words in memory.

In two experiments, subjects memorized either line drawings or matching words during acquisition and then judged either pictures or words during recognition, creating four groups (picture-picture, picture-word, word-word, word-picture). The color and spatial location of the acquisition items varied, so that subjects' memory for attribute information could be assessed. The main findings were (a) subjects remembered semantic item information best, followed by spatial and then color information, (b) there was no interaction of distractor type with the format conditions, and (c) overall performance in the picture-word condition was inferior to the picture-picture condition, but word-word and word-picture groups did not differ. The implications of these findings for different representational and processing theories of picture memory are discussed.

Color Perception↗
PubMed1976

A study of the growth inhibition of Lactobacillus casei by N-alkyl homologs of N-nitro-N-nitrosoguanidine.

N-methyl-(MNNG), N-ethyl-(ENNG), and N-propyl-(PNNG) derivatives of N'-nitro-N-nitrosoguanidine inhibited the growth of Lactobacillus casei in the order of potency, MNNG greater than ENNG greater than PNNG. L-Cysteine, gluathione, and dithioerythritol reversed the inhibition on a molar basis. The -SH compounds accelerated the loss of the N-nitroso group in vitro, yielding non-inhibitory N-alkyl nitroguanidines. The significance of the loss of the nitroso group and the size of the N-alkyl group is discussed.

Cell Division↗
PubMed1971

Serum creatine kinase studies in the detection of carriers of Duchenne dystrophy.

A number of methods which might improve the detection of carriers of Duchenne muscular dystrophy, based on the estimation of serum creatine kinase (CK), have been tried in an attempt to improve the 70% detection rate obtained with random samples. One series of experiments involved controlled exercise on a bicycle ergometer, the second series was based on sampling of muscle venous blood after controlled ischaemic exercise, and a third series of experiments was carried out to see whether the rate of enzyme inactivation was different in carriers of Duchenne dystrophy compared with controls. These methods were not found to improve the carrier detection rate based upon serum CK estimation.

Adolescent↗