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Biomedical subjects

N Ginsburg

Publications and source records attributed to N Ginsburg.

At least 19 recordsLinked to original sources
PubMed1991

Numerosity estimation as a function of stimulus organization.

It was proposed that stimulus organization of a set of homogeneous items can best be measured by using the mean distance to nearest neighbours. Patterns of dots were generated that fell on four different positions along the cluster continuum, from highly regular, through random, to clustered. When thirty subjects were asked to judge numerosity, their estimates decreased significantly as cluster measures increased. Four possible interpretations of the effect of organization on numerosity perception are discussed.

Adult↗
PubMed1991

Headache and sensation seeking.

According to the cognitive theory of sensation seeking, headache sufferers were predicted to score lower than controls on Zuckerman's Sensation Seeking Scale. 26 subjects who experienced chronic headaches scored significantly lower than a group of 26 controls. The relationships between the Sensation Seeking Scale and a number of personality tests are described. Replication of the findings on this scale with headache patients is encouraged as well as exploration of other personality dimensions which show significant relations with sensation seeking.

Adolescent↗
PubMed1988

Perceived numerosity as a function of item size.

In a sample of 48 subjects, there was a significant inverse relation between item size and estimation of numerosity. This result was shown to be consistent with Gestalt theory. According to this approach, the components of good figures appear more numerous, and smaller items produce better figures.

Adult↗
PubMed1987

Sensation seeking and estimation of numerosity.

In a sample of 81 subjects, significant negative correlations were obtained between scores on Zuckerman's Sensation Seeking Scale and estimates of numerosity. A cognitive view of sensation seeking was suggested, according to which high scores are a function of an underestimation of the amount of stimulation experienced and low scores a function of overestimation. This approach was discussed in relation to motivational theories and those involving strength of the nervous system.

Adult↗
PubMed1987

Measurement of visual cluster.

The cluster continuum is described, along with how to measure degree of cluster and how to generate stimuli that vary along the continuum. Five experiments were performed on cluster discrimination and rating, numerosity estimation, pattern discriminability, and random generation. Difference thresholds were obtained for discrimination between random and clustered patterns, and ratings exhibited a power function with respect to cluster values of the stimuli. Numerosity estimates decreased with increasing degree of cluster, and random patterns were easier to discriminate than clustered ones. When subjects were asked to arrange items so that they appeared random, they erred on the side of regularity. The cluster continuum was discussed in relation to the distribution of living organisms and to the ecological approach of Gibson. The cluster metric was compared with the measures used in the study of response organization in free recall.

Adult↗
PubMed1983

Subjective correlation and the regular-random numerosity illusion.

It has been shown previously that a regular pattern of dots appears more numerous than a random pattern with the same physical number. Birnbaum and Veit's theory of contrast with expectancy has been suggested as a possible interpretation of this illusion. In order to test this theory, three groups (N = 102) were given prior exposure to stimuli with either a positive, negative, or zero correlation between regularity and number. The predicted interaction between correlation and item arrangement was not found. The main effect of regularity was equally strong in all three groups.

Adolescent↗
PubMed1983

Random scaling: an extension of Kraepelin's combined method.

Kraepelin combined the constant method and the method of limits to avoid the inconvenience of the former and the response bias of the latter. The use of this approach together with Guttman scaling provides a method that requires few observations, is easy to administer and score, and can be applied to a variety of measurement situations. Examples are given of its use for point of subjective equality, aesthetic preference, and thresholds.

Humans↗
PubMed1983

Numerosity estimation with successive presentation: item organization.

Previous studies have shown that, with simultaneous presentation, highly organized patterns were overestimated in number compared with random patterns. In an exploratory attempt to apply Das et al.'s model of simultaneous and successive cognitive processes to perception, 62 Ss were asked to estimate the number of items presented visually one at a time. A rate of one item per second was used, and Ss were required to read each item aloud in order to prevent counting. When the stimuli were digits, no difference was found in the estimates for sets of stimuli containing high information vs those containing low information. When words were used as stimuli, estimates were significantly lower for words in sentences than for the same words in random order.

Discrimination Learning↗
PubMed1980

The regular-random numerosity illusion: rectangular patterns.

The overestimation of regular patterns compared with random patterns, previously reported for circular displays, was replicated with the use of rectangular displays of dots and controlling for overall area. Twelve female and four male college students with an average age of 27.3 years estimated the number of elements in 10 patterns containing from 45 to 126 dots. The results were discussed in relation to a suggestion of Frith and Frith, according to which better Gestalten appear more numerous.

Adult↗
PubMed1979

A developmental study of the regular-random numerosity illusion.

Perceived number is influenced by item arrangement. It has been shown previously with adults that a regular pattern of dots appears more numerous than a random pattern with the same physical number. The present study used similar stimuli: two sets of 37 dots arranged within circular areas, one regular and the other random. Forty-eight grade school students were tested; they ranged in age from 5.6 to 14.8 years and included 27 girls and 21 boys. The illusion was found to increase in strength from the second to the eighth grade. The results were discussed in relation to Birnbaum and Veit's theory of contrast with expectancy.

Adolescent↗
PubMed1978

Perceived numerosity, item arrangement, and expectancy.

Ten sets of dots ranging in number from 7 to 91 per set were presented to 54 subjects. Half were arranged regularly and half randomly. The regular sets were overestimated by an average of 22%, while the random were underestimated by 16% compared with the physical number. Evidence was presented showing that subjects expect results in the opposite direction. The findings are discussed in relation to the expectancy-contrast model of Birnbaum and Veit.

Cues↗