Biomedical subjects

D W Kline

Publications and source records attributed to D W Kline.

29 records · Page 2Linked to original sources

PubMed1980

The estimation of short time intervals as a function of age and metronome pacing.

The accuracy of estimation of short time intervals was studied in old institutionalized and young college male and female participants as a function of three levels of audible background metronome rate (0, 40 and 90 beats/min). The main effects of metronome and interval length, as well as the age by metronome rate interaction, were significant. Unlike the young participants, the time judgments of the older participants were significantly and systematically determined by metronome rate. These results are consistent with the notion of increased field-dependence among older persons and suggest that their greater social conformity and their inability to ignore irrelevant stimuli might also be explicable in the same theoretical terms.

Acoustic Stimulation↗

PubMed1978

Stimulus persistence in CFF: overarousal or underactivation?

The physiological basis of hypothesized adult age increases in the persistence of stimuli was studied in 16 young (X age 19.1 years) and 16 old (X age 70.1 years) male and female subjects. Changes in CFF threshold and skin conductance were measured as a function of loud white noise activation and artificial pupil. CFF was significantly lower in the old group and with artificial pupil in both age groups. Significant effects were also found for activation x sex and activation x age x sex. Skin conductance change was significant for activation, activation x sex, artificial pupil x age, artificial pupil x order and artificial pupil x order x activation. The results were interpreted as supporting an overarousal basis of an age increase in stimulus persistence.

Adolescent↗

PubMed1978

Examination of stimulus persistence as the basis for superior visual identification performance among older adults.

Visual identification performance of sequentially presented corresponding word-halves was studied in 12 young (mean 18.9 years, range 18-21) and 12 old (mean 68.0 years, range 59-78) male and female subjects. Corresponding word-halves were composed of straight horizontal and vertical line segments and when superimposed tachistoscopically formed clear, fully closed 3-letter words. Stimulus duration and interstimulus interval (ISI) were systematically varied. Correct word recognition was found to be an inverse function of ISI and stimulus duration for both young and old subjects. An interaction was found between age, sex, and stimulus duration. Recognition scores were significantly higher among older subjects, an effect which was particularly prominent at greater ISIs. The data offer strong support for the stimulus-persistence model as applied to age differences in the sequential integration of form.

Adolescent↗

PubMed1977

Persistence of complementary afterimages as a function of adult age and exposure duration.

The persistence of complementary afterimages was studied in 36 young (X age 18.8 years) and old (X age 62.1 years) male and female subjects. Afterimage persistence was found to be a direct function of exposure duration and to be greater for the older subjects as compared with the younger ones. The interactions between age and duration and between presentation order and duration were also significant. The data extend support for the "stimulus persistence" model to age differences in retinal function.

Adolescent↗

PubMed1977

Differences in unconspicuous word identification as a function of age and reversible-figure training.

Inconspicuous word identification was studied in 48 young (X age 19.3 years), middle-aged (X age 44.5 years) and old (X age 69.5 years) male and female subjects. Although this task appeared to be an easy one for the young subjects, it was strikingly difficult for the middle-aged and elderly subjects. Reversible-figure training apparently led to a small but significant overall improvement in inconspicuous word identification but did not at all diminish the age differences in such performance. The interactions of sex by reversible-figure training and age by first set-second set of words were also significant. Further research will be needed to fully examine the remediability of age-related perceptual skill deficits.

Adult↗

PubMed1976

Differences in the sequential integration of form as a function of age and interstimulus interval.

The sequential integration of visual stimuli was studied in 12 young (18-28 years) and 12 old (51-62 years) men and women. Stimuli were constructed as corresponding word halves and inter-stimulus intervals (ISI's) of varied duration (0-150 msec.) were introduced between the presentation of the two halves. Correct word identification was found to be an inverse function of ISI for both young and old subjects. The number of stimuli correctly identified was significantly lower for the older subjects at all levels of ISI. None of the interactions of age, sex, and ISI was significant. The data appear to question the "stimulus persistence" model as applied to age differences in the temporal organization of form.

Adult↗

PubMed1975

Age differences in backward dichoptic masking.

An investigation of age differences in backward dichoptic visual noise masking was carried out with young, middle-aged and old subjects. Older subjects were found to be significantly more susceptible to the backward masking effect over longer delays between the target and masking stimuli. These results indicate a decrease with age in the rate at which stimuli can be cleared through the central mechanisms concerned with perceptual processing. These data appear to support the "stimulus persistence" and "arousal" models of aging.

Adult↗

PubMed1975

Age differences in backward monoptic visual noise masking.

An investigation of age differences in backward monoptic visual noise masking was carried out with young and old adult subjects. It was found that the older subjects were susceptible to the backward masking effect over significantly longer delays between the target and masking stimulus. The masking effect seems to be, at least in part, attributable to age changes in the central mechanisms concerned with perceptual processing which limit the rate at which stimuli can be "cleared" through the nervous system. Backward masking studies of different types seem to hold considerable promise for assessment of the peripheral and central components of age change in visual perceptual processing.

Adult↗

PubMedDate not supplied

Age and the discrimination of visual successiveness.

Using a visual successiveness paradigm, young and old adult subjects were compared as to their ability to judge the order of offset of briefly-presented visual stimuli. Consistent with the stimulus-persistence hypothesis and a possible age-related increase in the period of a central perceptual scanning mechanism, old subjects required significantly greater levels of stimulus asynchrony to discriminate order of offset. More generally, these data indicate an age-related loss in the mechanisms which process visual "transients".

Adolescent↗

PubMedDate not supplied

Optimizing the visibility of displays for older observers.

Aging is associated with a variety of decremental visual changes, including reductions in retinal illuminance, color discrimination, static and dynamic acuity, near focus, contrast sensitivity, smooth and saccadic eye movements, visual field, visual search, and the ability to see in and recover from glare. Laboratory research, field studies, and self-report data all indicate that many older persons experience significant difficulty in carrying out tasks that depend on these visual functions. It is also increasingly clear that older observer's performance in finding, extracting, and using visual information can be enhanced significantly by designing task environments to minimize the effects of visual deficits. Recent research indicates that optical simulation of visual loss and contrast sensitivity testing, used in conjunction with image processing, may be very powerful tools for designing displays for the elderly and others with diminished spatial vision. These developments are reviewed, and general guidelines for creating ergonomically correct visual task environments for older observers are offered.

Aged↗

PubMedDate not supplied

Age differences in the temporal continuity of gratings as a function of their spatial frequency.

This study compared young and elderly observers on the continuity of sinusoidal grating-pairs as a function of interstimulus interval (ISI) and spatial frequency (.5, 1.0, 2.0, 4.0, 8.0, and 12.0 c/deg). Consistent with prior research, the maximum ISI over which pattern continuity was maintained increased with spatial frequency. In addition, among older observers, grating continuity occurred at significantly longer ISI's at the two lowest spatial frequencies; no age difference was observed at the higher spatial frequencies. These results could not be attributed to an age difference in retinal illumination associated with pupillary miosis. However, they do indicate an age-related decline in detecting visual offset and are consistent with the hypothesis of a decline in the effectiveness of the transient visual channels.

Adolescent↗