Baseline differences,attention, and age differences in time-sharing performance

The purpose of this experiment was to determine whether age differences noted when two tasks are performed concurrently can be accounted for in terms of age differences in single task baseline performance. Two groups of 12 8-year-olds and one group of 12 13-year-olds performed a compensatory tracking task and an auditory matching task, first alone and then time shared. The 8- and 13-year-old baseline groups performed baseline trials on each task prior to time-sharing trials. Each training group 8-year-old was randomly paired with a 13-year-old and given sufficient single task practice before time sharing to equate the 8- and 13-year-old pair members' baselines on both tasks. Results showed trained 8-year-olds to be indistinguishable from 13-year-olds in time sharing, whereas the 8-year-old baseline group showed significantly greater decrements in time-sharing and higher baseline scores on both tasks. These data provide support for the hypothesis that time-shared performance is directly related to level of baseline performance.     

Discriminative vocal conditioning in rhesus monkeys: Evidence for volitional control?

Both emotional and volitional systems are invoked in explaining the control of human vocalizations, but vocal behavior of nonhuman primates is often believed to be totally under emotional control. Monkeys' poor performance on conditioning tasks, especially discriminative conditioning of vocalization (DCV), has been cited as evidence against volitional control. In Experiment 1, rhesus monkeys failed a DCV task in which food was given for vocalizations emitted during an arbitrary visual stimulus, but in Experiment 2, monkeys showed clear discriminative performance when an otherwise comparable shock-avoidance DCV procedure was used. This evidence that monkeys possess some degree of volitional control has implications for the relation between animal vocalizations and the origin of human speech.     

Computer tomographic localization, lesion size, and prognosis in aphasia and nonverbal impairment.

Computerized tomography scans (80) were used to localize infarcts in 70 patients. Twenty-three aphasics were scanned within 35 days from onset, 39 beyond a year, and 18 were nondominant cases. Aphasics were also grouped according to test scores obtained within 35 days of scan. Chronic global aphasics have larger lesions than persisting Broca's aphasics. The area of persisting Broca's aphasia is similarly anterior but larger than that of recovered motor aphasia. Anomic aphasics evolve from Broca's and Wernicke's types with differing localization. Lesion size correlated with severity and recovery, and comprehension among the subtests.     

Shift of visual field preference for English words in native Hebrew speakers.

Lateralization for visual verbal material was tested with Hebrew and English stimuli presented to Israeli adolescents in their second, fourth, and sixth years of study of English as a second language. Seventy-two children, 12 male and 12 female subjects in each class, were tested by means of a target-word recognition task. Laterality scores derived from reaction-time measures resulted in: (1) a left visual field preference for the English stimuli in the youngest group which decreased with increasing age, becoming a right visual field preference in the oldest group, and (2) a significant and equal right visual field preference for Hebrew stimuli for all groups. The data suggest right hemisphere involvement in acquiring the reading skills of a new language.     

A prospective naturalistic study of the impact of an intensive medical treatment on the social behavior of child and adolescent cancer patients

The impact of intensive chemotherapy and prolonged hospitalization on the social behavior of child and adolescent cancer patients was assessed. Twenty-three patients, aged 18 months to 21 years, were observed while they received chemotherapy in a protected environment or in a regular hospital room. Single-subject analyses were used to examine changes on six behaviors in relation to changes in physiological status. Fourteen patients showed significant change in the frequency of at least one behavior. Play and sleep were the behaviors most likely to change. The changes began to occur as patients experienced the systemic toxic effects of the drugs, although a dissipation of drug toxicity generally was not accompanied by a corresponding behavior change. The findings are discussed in relation to age-developmental and interindividual heterogeneity in response to treatment.     

Extinction after aversive conditioning: An associative or nonassociative process?

A series of three eyelid-conditioning experiments with rabbits examined the traditional extinction procedure in which the CS is presented in the absence of US presentations. The first study employed a savings test to demonstrate that the rate of reacquisition is faster after a conventional extinction procedure than after a procedure in which the CS and US have been unpaired. The second experiment indicated that this readiness to respond in reacquisition was related to a carry-over effect from the initial acquisition trials. The third study demonstrated that acquisition and reacquisition are similar when the US is maintained in extinction but not when it is omitted. These results imply that procedures which retain the US during extinction are more effective than the conventional CS-alone extinction procedure in eliminating or inhibiting the associative connection between the CS and the US.     

Sorting out what's in a word from what's not: Evaluating Clark's Semantic Features Acquisition theory

The Semantic Features Acquisition theory of semantic development which is due to E. Clark (e.g., 1973b) is reviewed and evaluated against the recent experimental literature, with special reference to the acquisition of English antonyms. The review critically examines the three major ontogenetic principles of Clark's theory in light of numerous recent findings, many of which are at variance in some major way with predictions from the theory. In many instances, new data are available which call into question previous findings. A recurrent problem has been that children's comprehension task performance is confounded with their response biases which are specific to the linguistic and nonlinguistic contexts in which the lexical terms are presented. Methodological implications are discussed, with recommendations for employing the logic of converging operations.     

Test theory without true scores?

This paper traces the course of the consequences of viewing test responses as simply providing dichotomous data concerning ordinal relations. It begins by proposing that the score matrix is best considered to be items-plus-persons by items-plus-persons, and recording the wrongs as well as the rights. This shows how an underlying order is defined, and was used to provide the basis for a tailored testing procedure. It also was used to define a number of measures of test consistency. Test items provide person dominance relations, and the relations provided by one item can be in one of three relations with a second one: redundant, contradictory, or unique. Summary statistics concerning the number of relations of each kind are easy to get and provide useful information about the test, information which is related to but different from the usual statistics. These concepts can be extended to form the basis of a test theory which is based on ordinal statistics and frequency counts and which invokes the concept of true scores only in a limited sense.1979 Psychometric Society presidential address.I want to recognize the contributions which others have made to whatever I have accomplished. First to mention here are my teachers: principally Harold Gulliksen, Ledyard Tucker, and the late Edith Jay. Second, I would like to recognize the importance of my graduate students. Tom Reynolds has been especially important in developing the ideas that I will talk about here today, but at various times, the others have made major contributions in this and other topics. I would like to express also a debt to my family, primarily my wife, Rosemary, who herself has a longterm interest in the psychometric area. Finally, I must acknowledge the financial support of the NIMH some time ago, the Office of Naval Research, until about a year ago, and of the James McKeen Cattell Fund this past year.     

Knowing what a novel word is not: Two-year-olds 'listen through' ambiguous adjectives in fluent speech

Three studies investigated how 24-month-olds and adults resolve temporary ambiguity in fluent speech when encountering prenominal adjectives potentially interpretable as nouns. Children were tested in a looking-while-listening procedure to monitor the time course of speech processing. In Experiment 1, the familiar and unfamiliar adjectives preceding familiar target nouns were accented or deaccented. Target word recognition was disrupted only when lexically ambiguous adjectives were accented like nouns. Experiment 2 measured the extent of interference experienced by children when interpreting prenominal words as nouns. In Experiment 3, adults used prosodic cues to identify the form class of adjective/noun homophones in string-identical sentences before the ambiguous words were fully spoken. Results show that children and adults use prosody in conjunction with lexical and distributional cues to ‘listen through’ prenominal adjectives, avoiding costly misinterpretation.