Early receptive and productive language skills in preterm and full-term 8-month-old infants

Early receptive and productive language skills were examined for preterm low birthweight infants and full-term normal birthweight infants from middle-class homes. Nineteen preterm infants and 19 full-term infants were observed in a laboratory setting at the gestationally corrected age of 8 months. To avoid the frequent confound between prematurity and low socioeconomic status, mothers of the two groups of infants were matched on educational levels. Regression analyses were used to assess the relative influence of infant cognitive skills, infant sociability, infant birth status, and the mothers' language input as possible predictors of infant receptive language and vocal behavior. Receptive language skills were associated with higher cognitive performance, greater sociability, and preterm birth. Productive language skills were associated with higher cognitive performance. On the basis of this research, the prognosis for language development in preterm infants raised in middle-class homes appears to be excellent.This research was aided by Social and Behavioral Sciences Research grant No. 12-11 from the March of Dimes Birth Defects Foundation and supported by DHHS Grant HD03352. Computing was provided by the Waisman Center Computing Facility at the University of Wisconsin-Madison. Donna Boylan, Sue DaPra, Maria Kleczewski, Michal Rubin, Susan Silverber, and Paula VanLaanan assisted with data collection.     

Facilitation of word recognition by semantic priming in schizophrenia

Schizophrenic (n = 21), bipolar (n = 18), and normal control subjects (n = 21) were compared on a word recognition measure of semantic priming. The task involved the presentation of related, neutral, and unrelated word pairs; the second word (target word) in each pair was presented in a degraded form. Facilitation was defined as the accuracy of target word recognition for the related word pairs minus accuracy for the neutral word pairs. Titration, achieved by manipulating the degradation of the target word, was used to maintain each subject's overall accuracy for related and neutral items at approximately 50%. This procedure minimized the artifactual effects of overall accuracy on the difference score. Schizophrenics exceeded both normal control subjects and bipolar subjects on facilitation. Bipolar subjects did not differ from control subjects. The results support Maher's hypothesis that semantic priming effects are heightened in schizophrenia.     

Schizophrenic deficit in span of apprehension

We investigated two hypotheses about the span of apprehension task in schizophrenia: (a) schizophrenics show performance deficit on the forced-choice (FC) version but not on the full-report (FR) version, and (b) schizophrenic impairment on the FC version is greater when the display subtends a wide visual angle than when it subtends a narrow one. Schizophrenic (n = 21) and normal (n = 22) groups were tested on 3 versions of the task. A narrow-angle FC version was matched psychometrically with a wide-angle one by use of a greater number of noise letters in the narrow version. Schizophrenics reported fewer correct letters than normals on the FR version but did not differ on either the wide or the narrow FC versions. The results imply that schizophrenic deficit is not specific to the FC version and that on the FC version, visual angle is not more important than number of noise letters for demonstrating schizophrenic deficit.     

EP Component Identification and Measurement by Principal Components-Analysis

Between the acquisition of Evoked Potential (EP) data and their interpretation lies a major problem: What to measure? An approach to this kind of problem is outlined here in terms of Principal Components Analysis (PCA). An important second theme is that experimental manipulation is important to functional interpretation. It would be desirable to have a system of EP measurement with the following characteristics: (1) represent the data in a concise, parsimonous way; (2) determine EP components from the data without assuming in advance any particular waveforms for the components; (3) extract components which are independent of each other; (4) measure the amounts (contributions) of various components in observed EPs; (5) use measures that have greater reliability than measures at any single time point or peak; and (6) identify and measure conponents that overlap in time. PCA has these desirable characteristics. Simulations are illustrated. PCA′s beauty also has some warts that are discussed. In addition to discussing the usual two-mode model of PCA, an extension of PCA to a three-mode model is described that provides separate parameters for (1) waveforms over time, (2) coefficients for spatial distribution, and (3) scores telling the amount of each component in each EP. PCA is compared with more traditional approaches. Some biophysical considerations are briefly discussed. Choices to be made in applying PCA are considered. Other issues include misallocation of variance, overlapping components, validation, and latency changes.     

Eliciting children’s and adults’ accounts of road accidents

Psychological knowledge from eye-witness research is applied here to the particular problem of reporting road accidents. Thereby the paper highlights some of the assumptions in eye-witness research. The interface between that research and the reporting of road accidents is examined by reference to existing social psychological notions. These are notions about questioning and about hypothesis testing. The paper makes special reference to the questioning of child witnesses because problems therein are particularly acute.     

The impact of socially projected group composition on behavior in a commons dilemma: A self-attention perspective

Socially projected group compositions, based on subjects’ expectancies about the behavior of others and the number of subjects taking part on the resource use task, were indexed using Mullen’s Additive Other-Total Ratio (Mullen, 1987) and used to predict harvesting behavior in a commons dilemma. One-hundred forty-three males took part in a resource use task in groups ranging in size from two to six members. Just prior to harvesting trials, subjects indicated the number of those taking part that they expected to overharvest and to underharvest, and indicated to which of these groups they had assigned themselves. Results indicated that harvesting behavior varied as a function of the number of others expected to behave differently from self, and conformed to patterns predicted by Self-Attention Theory. With increases in the number of others expected to underharvest, indexing an increase in self-attention, subjects who indicated they would overharvest become more conservative in resource use. However, subjects who indicated they would underharvest did not significantly decrease harvest size with increases in the number of others expected to overharvest. These subjects were already harvesting at an optimal or sub-optimal rate, and therefore had no need to reduce the size of their harvests to match their behavior to standards stressing conservatism in resource use.     

Dimensional separability or flexibility of attention? Age trends in perceiving configural stimuli

The hypothesis that perceptual development proceeds from less to greater dimensional separability was tested by giving a speeded classification task to first and fouth graders. In Experiment 1, children sorted line drawings of a cartoon figure into two piles according to his eyes (open or closed) or his mouth (smiling or frowning). First graders exhibited the pattern characteristic of integral dimensions: An interference effect was found when dimensions were combined orthogonally and a facilitation effect when dimensions were correlated, relative to a condition in which only one dimension varied. Fourth graders exhibited an optional separable pattern: There was facilitation in the correlated condition but no interference in the orthogonal condition. These results support the hypothesis that development proceeds toward greater flexibility of attention rather than simply toward increasing separability. A flexible field hypothesis of visual attention was suggested to explain how older children can exercise such optional separability. This hypothesis correctly predicted the asymmetrical relation between dimensions found in Experiments 2 and 3: For both first and fourth graders, the eyes of a cartoon figure (open or closed) and his location (right or left) were nonseparable when the eyes were relevant and separable (or optional separable) when location was relevant.     

Social enhancement of laughter: an experimental analysis of some companion variables.

Three experiments, investigate companion influences on humorous laughter and smiling. Boys and girls, aged 7 to 9 years, were played humorous recordings through headphones in dyadic and solitary conditions. Experiment I demonstrates that social facilitation effects in laughter and smiling reported in Chapman (1973) generalize to cases where a 2-year age/status difference exists between naturalistic coactors. In Experiments II and III companions were confederates, 2 years senior to subjects. They responded to directions relayed through headphones (coaction conditions) or a concealed speaker (audience conditions). It is shown in Experiment II that subjects' laughter, smiling, and looking are facilitated by increases in the laughter and smiling of coactors and, in Experiment III, that audiences are less effective in promoting high levels of responses. While increments in the coactor's looking enhance smiling and looking, corresponding increases in laughter are not statistically significant. Humor-ratings are associated with behavioral responses in Experiment II, but not Experiment III. Interaction data and results from subsidiary conditions are discussed.     

Brain responses related to semantic meaning

Evoked Potentials from electroencephalogram (EEG) recording were averaged to many visually presented word stimuli whose semantic meanings were specified along Osgood's semantic dimensions of Evaluation, Potency, and Activity [Miron &; Osgood, 1966, in R. B. Cattell (Ed.), Handbook of multivariate experimental psychology, Chicago: Rand-McNally; Osgood, 1971, Journal of Social Issues, 27, 5–63; Osgood, May, &; Miron, 1975, Cross-cultural universals of affective meaning, Urbana, Ill.: University of Illinois Press]. Multivariate analyses classified the Evoked Potentials to six semantic classes with success rates more than twice chance expectation. The pattern of brain activity related to the six semantic classes was similar for (i) two sets of words, (ii) 10 subjects used to develop the analyses, and (iii) an added, new subject.