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Biomedical subjects

J Cerella

Publications and source records attributed to J Cerella.

13 recordsLinked to original sources
PubMed2001

Cognitive skill acquisition and transfer in younger and older adults.

The acquisition of cognitive skills often depends on 1 of (or a combination of) 2 processes, the execution of an algorithm, and the retrieval of problem instances. This study examined the effects of age and repetition of problem instances on the production and verification of solutions to 2 serially presented sets of alphabet arithmetic problems. Analyses of the parameters derived from power-function fits for individuals revealed age differences favoring young adults in improvement span, learning rate, and asymptote. For both age groups, the beneficial effects of repetitions on 1st-set response times were attributable to algorithmic speedup and to the retrieval of instances, whereas improvements in the speed of 2nd-set response times were attributable primarily to item retrieval.

Adolescent↗
PubMed1994

The rise and fall in information-processing rates over the life span.

We surveyed studies that measured information-processing durations in groups of experimental subjects (children or elderly adults) and a group of college-aged control subjects. Some studies varied the type of processing while keeping the age of a subject group fixed. Process-durations in experimental subjects could be described by a multiplicative function of the control durations, regardless of the type of processing. Other studies varied the age of the subject groups while keeping the type of processing fixed. Process-durations declined during childhood, in a manner that could be described by a negative exponential function of age. Process-durations increased throughout middle- and old-age, in a manner that could be described by a positive exponential function of age. The sum of the two exponentials defined a U-shaped function that described process-durations over the life span. The most important studies varied both the type of processing and the age of the subject groups. An array of measurements of this kind could be described by a two-dimensional function that combined the multiplicative effect of process-duration and the exponential effects of age. The multiplicative effect of process-duration suggested that the execution of a processing sequence was conditioned by a single developmental parameter in both the experimental subject and the control subject. The exponential components determined the magnitude of the developmental parameter as the age of the subject changed. Given the global character of these effects, it seemed to us that the developmental mechanism may operate at a more elementary level than the information-processing stages conceived by cognitive theories. In a developmental framework, information processing may be reducible to a large number of small steps of a homogeneous duration or reliability, such as might be realized on a neural network. The exponential rate constants may be related to constant-probability hazards that act on one or another population of neural elements to create minute defects or incremental improvements. Their cumulative effects alter the functioning of the network over its lifetime, in a way that parallels the observed changes in process-durations.

Adolescent↗
PubMed1994

Generalized slowing in Brinley plots.

The logic of generalized slowing theories is explored. Existing theories are reviewed briefly and put in a common format. The format is readily generalized to define a class of one-dimensional aging theories, a tiny subset of all possible aging theories. A corresponding class of compatible data is demonstrated, in terms of allowable configurations of a Brinley plot. Nonconforming configurations have the force of disconfirming the entire class of aging theories. Information processing theories can be cast in a similar format. It is shown that, for a slowing theory to be indisputably general, it must be associated with a multidimensional information processing theory.

Adolescent↗
PubMed1991

Age effects may be global, not local: comment on Fisk and Rogers (1991)

A series of analyses of variance on target search times allowed Fisk and Rogers (1991) to reject the null hypothesis that age had a uniform, additive effect across search conditions. It does not, however, follow that age affected some conditions in an exceptional way, as Fisk and Rogers concluded. Age may have had a uniform but nonadditive effect across conditions. In this article, it is shown that age had a uniform linear, or perhaps slightly curvilinear, effect on search times. This "null hypothesis" adequately accounted for the age effects in all 27 search conditions. Indeed, it accounted for the age effects in 107 conditions abstracted from other visual search studied and for the age effects in 154 conditions abstracted from a miscellaneous collection of nonsearch processing-time studies. The only variation in age outcomes across studies was consistent with sampling error, given the known variance in response times. It is concluded that age is experienced as a generalized slowing of the central nervous system uniformly affecting all information processes.

Aged↗
PubMed1990

Pigeon pattern perception: limits on perspective invariance.

Two experiments are reported in which the response of pigeons to perspective transformations of a pattern target was measured. In the first experiment an alphabet letter was taken as the pattern target (the 'positive') and the response to its perspective transforms was compared to the response to nontarget letters ('negatives') over the course of discrimination training. In the second experiment irregular quadrilaterals were used as positives and the responses to slight perspective deformations of the prototypes were compared to the responses to random transformations of the same magnitude under steady-state conditions. The amount of differential responding depended on the type of transformation. There was no differential response to targets rotated in the picture plane or around the horizontal axis in either experiment. There was differential response to small reductions and enlargements of the target. There was also differential response to translated targets, and this was seen irrespective of the amount of displacement. Results from targets rotated around the vertical axis were erratic, some target-plus-angle combinations elicited differential responding, but most did not. The erratic responses are attributed to symmetries in pattern elements that were abstracted as critical features. Pigeons therefore exhibit no true rotation invariance, limited size invariance, and complete shift invariance. It is argued that size invariance, but not position invariance, may depend on prior exposure to the alternatives.

Animals↗
PubMed1987

Radial localization in the aged.

Elderly subjects were 41% less accurate than young subjects in localizing a point in the frontal plane. The decline could be ascribed neither to an age difference in image formation or skill acquisition nor to a difference in motivational level or trace retention. Evidently the "ambient" or "transient" visual system is compromised at an elementary level. Reasons why this deficit may not be compounded at more complex levels of spatial processing are suggested.

Adult↗
PubMed1986

Age differences in depicting and perceiving tridimensionality in simple line drawings.

Twelve young adults (M = 21 years) and twelve elderly adults (M = 67 years) were asked to draw a solid cube. The depictions produced by elderly adults were rated by judges as less accurate than the depictions produced by young adults. Both age groups were also asked to evaluate cube drawings that were deliberately distorted in ways characteristic of the depictions produced by older adults. Compared to younger participants, the elderly were more likely to accept distorted drawings as accurate. Control tasks demonstrated that older adults were able to draw and evaluate simpler two-dimensional patterns on par with younger adults. Apparently the mental representation of tridimensional information deteriorates with age leading to deficits in both production and recognition.

Adolescent↗
PubMed1985

Age-related decline in extrafoveal letter perception.

Peripheral vision is constricted in elderly adults. Experiment 1 showed that the age deficit in letter recognition time increased as the target moved off the fovea. Experiment 2 showed a corresponding reduction in angular threshold. Thus, the outer elements in a multicharacter display are seen with greater difficulty or not at all by the elderly adult. Experiment 3 showed this restricted field protected elderly adults from eccentric distractors, as found by Wright and Elias (1979). At the same time, elderly adults showed more, not less, interference on foils matched on discriminability with younger adults, in keeping with the larger literature on age and noise. Similar perceptual limitations may confound other array-processing experiments.

Adult↗
PubMed1982

Age and iconic read-out.

Letter recognition was investigated in 16 young adults (mean age = 21) and in 16 older men (mean age =64) by exposing seven-letter strings for brief periods followed by a mask. Young adults were able to identify three letters at a rate of 27 msec per letter, a value which is typical of other reports. Any additional letters were identified at a much slower rate. In contrast, older adults were able to identify only two letters, at a rate of 35 msec per letter. Older men thus showed a decline in both the amount of and rate at which information was encoded from the icon within a fixation period. These findings have implications for experiments involving visual arrays.

Adolescent↗
PubMed1981

Mental rotation and age reconsidered.

Research has established that subjects required to identify tilted patterns do so by first rotating them mentally into an upright position. Gaylord and Marsh (1975) found that the rate of mental rotation of elderly subjects was 84% slower than young subjects. Using simpler patterns and college-enrolled "elderly," Jacewicz and Hartley (1979) found no age difference in rotation rates. Using Jacewicz and Hartley's patterns, and a subject sample more similar to Gaylord and Marsh's, the present study found that although absolute rates were increased, an age-decline of 96% was still in evidence.

Adult↗
PubMed1979

Visual classes and natural categories in the pigeon.

After being trained on an oak leaf pattern, pigeons responded to other oak leaf patterns but not to leaf patterns of other species. Thus, graphic variation among the instances of a species is "transparent" to the visual system. At this taxonomic level, concept formation is spontaneous rather than inductive. It is argued that such immediate generalization may be critical to the survival of the organism.

Animals↗
PubMedDate not supplied

Age-related differences in the time course of encoding.

The speed with which normal elderly and young subjects encoded digits in a speeded same/different matching task was investigated. One condition required a judgment based on physical identity, while in a second condition judgments were based on an odd/even dichotomy. The pattern of results demonstrated a slowing in the speed of encoding in the older subjects. This effect, while statistically significant, was slight.

Adolescent↗