Biomedical subjects

C McCauley

Publications and source records attributed to C McCauley.

9 recordsLinked to original sources

PubMed1988

In vitro radiobiological parameters of human sarcoma cell lines.

In vitro radiobiologic survival parameters have been determined for 7 human osteosarcoma, 5 human soft tissue and bone sarcomas, and 4 Ewing's sarcoma cell lines. The mean D0 values were 99.5 +/- 11.6 cGy, 90.5 +/- 7.7 cGy and 95.8 +/- 7.9 cGy for osteosarcomas, soft tissue and bone sarcomas and Ewing's sarcomas, respectively. These in vitro survival data do not predict the clinical radiation resistance generally attributed to osteosarcomas and soft tissue and bone sarcomas, and do not differ substantially from the results obtained with the clinically radioresponsive Ewing's sarcomas.

Bone Neoplasms↗

PubMed1988

Phasic alertness and differences in picture encoding speed.

The relation between physical identity and name identity encoding speed was assessed. Correlational analyses indicated that similar processes may be involved in the two types of encoding and, by implication, that differences between mentally retarded and nonretarded subjects' physical identity and name identity encoding speed may result from common factors. Also, we assessed the extent to which differences in preparation for the presentation of external stimuli may account for any observed differences in encoding speed. A difference between retarded and nonretarded subjects in preparation time was apparent; however, this difference did not influence encoding speed.

Adult↗

PubMed1985

Sensation-seeking behavior and the incidence of spinal cord injury.

Professionals in the rehabilitation field differ in their conceptualization of the role of premorbid personality factors as related to risk behavior and incidence of traumatic injury. Some hold that specific premorbid personality traits can be identified for the spinal cord injured population; others argue that no one personality trait or specific combination of traits is descriptive of this heterogeneous population. This study explores the relationship between the sensation-seeking behavioral patterns and incidence of traumatic spinal cord injury (SCI). The Sensation-Seeking Scale (SSS) was administered to 56 patients with spinal cord injury (50 males and 6 females) between the ages of 16 and 50. A description of the incident causing injury was obtained for all 56 patients and subsequently rated by non-medical judges on a dimension of prudence-imprudence. No significant correlations were found between sensation-seeking scores and rated prudence of onset of injury, and sensation-seeking scores were no higher for SCI patients than for a comparable normal population. These findings indicate that spinal cord injury is not related to sensation-seeking, and, more generally, support the view that no premorbid personality trait distinguishes the SCI population from the normal.

Adolescent↗

PubMed1982

Words, pictures, and priming: on semantic activation, conscious identification, and the automaticity of information processing.

We investigated the encoding mechanisms involved in the perceptual recognition of words and pictures. Latencies in naming word and picture targets were analyzed as a function of several characteristics of a preceding prime, including whether it was a word or a picture, its duration of exposure, the interval between the prime and target onset, and whether or not the prime was consciously identified and reported by the subject. Results indicated that a common semantic code is available that can represent the meaning of either a word or a picture. This semantic representation, however, appears to be more easily activated by picture primes than by word primes and seems to benefit the naming of picture targets more than the naming of word targets. Despite the advantage for pictures with respect to semantic activation, overall processing in the naming task was slower and more attention demanding for pictures than for words. Comparison of our data with data on classification, in which an opposite pattern occurs (overall processing appears to be slower and more attention demanding for words than for pictures), suggests that, on the average, pictures have faster and more automatic access to their meanings than to their names but that words have faster and more automatic access to their names than to their meanings. This conclusion concerning the relative ability of stimuli to activate different kinds of internal representations has implications for a theory of the basis and development of automaticity.

Discrimination Learning↗

PubMed1980

Early extraction of meaning from pictures and its relation to conscious identification.

Two experiments were conducted in which subjects labeled target pictures preceded by either semantically related or unrelated prime pictures. The exposure duration of each prime was varied around a threshold value, established separately for each subject, that represented the minimum viewing time necessary to identify the prime picture with 100% accuracy. The results of the first study indicated that semantic-priming effects can be obtained with pictures at prime exposure durations too brief for conscious identification of the prime to occur. Data from the second experiment provided an estimate of the minimum exposure time necessary for priming under these conditions. There was evidence from both experiments that attaching a name to a picture is an attended operation that can interfere with naming a subsequent picture, independent of any semantic priming that might occur. This indicates that extracting the meaning from a picture and consciously identifying it may be separate processes. The results are discussed in terms of current models of picture perception.

Adult↗

PubMed1979

Perception of contingency and mental retardation.

It is argued that the general learning difficulties exhibited by mentally retarded persons are similar in many respects to the learning difficulties of nonretarded persons who are in a state of learned helplessness (Seligman, 1975) or who are external in locus of control orientation. It is suggested that studies of locus of control and learned helplessness as theoretical constructs both directly concern the perceiving of relationships between behavior and outcomes, and that a systematic investigation of perception of contingency might increase our understanding of some of the learning difficulties of mentally retarded persons. An overview is given of the results of the few studies that have addressed perception of contingency and mental retardation, and suggestions for future research are offered.

Humans↗

PubMed1978

Category structure and semantic priming in retarded adolescents.

This study was designed to investigate the internal structure of semantic categories in mentally retarded adolescents as reflected in naming times to pictures of common objects. Pictures were presented in pairs that consisted of either categorically related or unrelated items. For related pairs, both the primes (first pictures) and targets (second pictures) varied in rated "typicality" (Rosch, 1975), being either typical or relatively atypical members of their primary superordinate category. An analysis of naming times to targets revealed a semantic-priming effect; targets in related pairs were named faster than those in unrelated pairs. Of major importance was the finding that naming times varied as a function of both prime typicality and target typicality. The data suggest that the semantic categories of retarded persons have an internal structure generally similar to that of the nonretarded persons from whom the typicality ratings were obtained and that even relatively atypical exemplars are functional category members for retarded persons.

Adolescent↗

PubMed1978

Verification of property statements by retarded and nonretarded adolescents.

Educable mentally retarded and nonretarded adolescents verified true and false statements about the properties of common objects. For the true sentences, one-half contained properties rated as highly salient to the given object, and half contained less salient properties. Further, at each level of salience, one-half of the properties were static (physical) properties, e.g., "Carrots are orange," and half were action properties, e.g., "Rabbits can hop." True verification times were more rapid for all subjects when sentences contained highly salient properties. In addition, sentences containing action properties were verified faster than those containing static properties, but only by the retarded subjects (whose response times were slower overall). Additional analyses indicated that the retarded subjects responded particularly rapidly to action properties that designate "what can be done to an object" (extrinsic-action properties) as opposed to "what an object can do" (intrinsic-action properties). These findings were discussed in relation to the organization of semantic knowledge and the apparent group differences in the weighting of semantic features.

Adolescent↗

PubMed1976

Reassessment of category knowledge in retarded individuals.

We investigated retarded individuals' knowledge of conceptual categories as reflected by semantic priming effects. In the first experiment, retarded individuals were shown pairs of pictures, one picture at a time, and asked to name each picture as rapidly and accurately as possible. The pictures in each pair were objects that were either categorically related or unrelated. The major finding was that second pictures in related pairs were named significantly faster than those in unrelated pairs. This reduction in naming-latency, or priming effect, was interpreted as indicating that information about categorical relationships is established in the memory structure of retarded individuals. In the second experiment, subjects were again given the picture-naming task plus two concept-usage tasks designed to test the recognition and verbalization of categorical relationships. Correlational analyses indicated that while performance on both usage tasks varied with intelligence, neither intelligence nor category usage correlated with the magnitude of the priming effect. This suggests that intelligence-related differences in category usage do not result from corresponding differences in conceptual competence but, rather, are related to the ability to use category information that is potentially available.

Adolescent↗