A longitudinal study of sentence context effects in second-grade children: Tests of an interactive-compensatory model

During the first half of the school year and at the end of the school year second-grade children (mean age: 7 years, 4 months at the first testing) completed a task in which they read words preceded by either a congruous sentence context, an incongruous sentence context, or a neutral context. Prior to the first testing, each child was given practice at recognizing one-half of the words in isolation. Word difficulty was varied orthogonally with practice and context condition. The effect of context on reading times decreased with development and practice, and increased with word difficulty. The results were interpreted as supporting an interactive-compensatory model of the development of reading fluency.     

Use of a statistical significance criterion in drawing inferences about hemispheric dominance for language function from dichotic listening data

A dichotic listening test (composed of VCV nonsense syllables) was administered to 31 right-handed subjects. A χ² statistical significance criterion was then applied to the resulting ear differences in subjects. Fifteen subjects had ear differences significant at the p < .10 levels. Of these, 14 had right-ear advantages, an incidence consistent with the incidence of left-hemisphere language dominance derived from neurological data. Incidence for the total group of 31 subjects, however, showed the overabundance of left-ear-superior protocols typical of studies that report ear-dominance scores with no statistical criterion.     

Testing for developmental continuity or discontinuity: Class inclusion and reversal shifts

Often the data in cognitive development consist of continuous cross-sectional increases in the proportion of children who respond in one of two ways to a diagnostic task. Such developmental trends are, however, ambiguous with reference to the course of individual, longitudinal development because they could be the result of either saltatory or gradual ontogenetic change. The present research tested a nonlongitudinal procedure for discriminating between these two alternatives. This procedure involves the administration of several equivalent versions of the diagnostic task at weekly intervals to children within a given age level in order to obtain a frequency distribution of the number of “successes” produced by each child. A bimodal distribution is interpreted as indicating saltatory ontogenetic change, while a unimodal distribution is taken to indicate gradual change. This method was applied to Piaget's class-inclusion problem and to the optional-shift task by administering four versions of each task to a range of different age-level samples. The optional-shift task produced clearly unimodal, bell-shaped distributions at all tested age levels, results which were interpreted to indicate a gradual ontogenetic increase in the probability of making reversal shifts. On the other hand, the frequency distributions for the class-inclusion task, at the appropriate age levels, were distinctly bimodal, and therefore consistent with a discontinuous ontogenetic transition. The capacity of the repeated-measures method to produce reliable within-task results and to differentiate between tasks was thus demonstrated.     

Performance of retarded adolescents and nonretarded children on one- and two-bit logical problems

Groups of adolescents of retarded and borderline intelligence, ranging in IQ from 44 to 80 and in mean MA (mental age) from 8 to 12 yr, and groups of nonretarded children ranging in mean MA from 6 to 12 yr, were given logical problem solving tasks. In the nonretarded groups, on a one-bit problem only the kindergarten children (mean MA = 6 yr) failed to perform above chance, and were not tested further. On a two-bit problem, only the first graders (mean MA = 7 yr) failed to perform above chance.Conversely, in the low IQ groups, only the borderline group (mean MA = 12 yr) performed reliably above chance on the one-bit problem, and none performed above chance on the two-bit problem. There is a profound deficiency in low IQ individuals on certain tasks requiring logic and foresight, and MA markedly over-estimates their performance relative to the performance of nonretarded individuals.     

A stimulus-compounding assay of conditioned inhibition and excitation

Rats were trained in an operant discrimination involving two panel lights, A and B. Group CI (Conditioned Inhibition) was trained to lever press in the presence of A (S+), and not in the presence of the compound AB (S?). The opposite contingencies held in Group CE (Conditioned Excitation). Response rates were higher in Group CE than in Group CI, especially to the positive stimulus. However, the groups acquired the discrimination at comparable rates. In a separate phase of the experiment, a tone (C) was separately trained in the absence of the lights to control responding. All seven possible combinations of A, B, and C were then presented randomly during extinction. The inhibitory effect of B on C in Group CI was comparable in magnitude to the excitatory effect of B on C in Group CE. B's effect on C was not altered by the presence or absence of A, regardless of whether A was inhibitory or excitatory. The symmetry between CI and CE revealed by the stimulus-compounding test may be partly artifactual.     

Auditory perception of speech and speech sounds in recent and recovered cases of aphasia

Auditory perception of speech and speech sounds was examined in three groups of patients with cerebral damage in the dominant hemisphere. Two groups consisted of brain-injured war veterans, one group of patients with high-frequency hearing loss and the other, a group of patients with a flat hearing loss. The third group consisted of patients with recent cerebral infarcts due to vascular occlusion of the middle cerebral and internal carotid artery. Word and phoneme discrimination as well as phoneme confusions in incorrect responses were analyzed from conventional speech audiometry tests with bisyllabic Finnish words fed close to the speech reception threshold of the patient. The results were compared with those of a control group with no cerebral disorders and normal hearing. The speech discrimination scores of veterans with high-frequency hearing loss and patients with recent cerebral infarcts were some 15–20% lower than those of controls or veterans with flat hearing loss. Speech sound feature discrimination, analyzed in terms of place of articulation and distinctive features, was distorted especially in cases of recent cerebral infarcts, whereas general information transmission of phonemes was more impaired in patients with high-frequency hearing loss.     

A Retrospective on Sociobiology

Zygon has been discussing the implications of sociobiology for twenty-five years, ever since E. O. Wilson's book by that name first burst upon the stage. In the course of that discussion there have been many heated exchanges, but in this journal, at least, the heat has also generated light. Thus it is now timely and useful to review and consolidate Zygon 's approach to the sociobiology construct, not only as it was originally presented but as it has changed over time. The goal of this article is to recapitulate and summarize the dialogue that has taken place here. But my aim is not merely to rehash the discussion; it is more precisely to extend and continue it. Specific proposals are offered that are designed to ground future conversations on the solid foundation that has been established over the last quarter century.     

CT scan and neuropsychological correlates of Alzheimer's disease and Huntington's disease

"Cortical" and "subcortical" dementia syndromes differ in areas of primary neuropathology and clinical characteristics. Conventional CT scan interpretation, visual inspection of pictures, has not been useful in studying dementia. Recent studies of the digitally stored CT attenuation values have found systematic variations with normal aging and aphasia subtypes. In this study of numerical CT scan information in four Alzheimer's Disease and two Huntington's Disease patients, a double dissociation of frontal and temporal lobe density values was found, and a significant correlation was found between left temporal lobe density and verbal ability measures in the Alzheimer's Disease patients.