Cerebral excitation profiles in language processing: The photic probe paradigm

A photic probe paradigm was developed in order to assess the cerebral excitation patterns corresponding to acoustic and linguistic operations independently of specific signal parameters. Average Evoked Potentials (AEPs) to a photic stimulus were recorded at the anterior temporal and posterior regions of both hemispheres of subjects engaged in acoustic, phonetic, and semantic processing of verbal material. Patterns of attenuation and enhancement of the probe AEP amplitudes were observed over the left and right hemispheres, respectively, with the magnitude of change varying reliably as a function of processing task. The implications of these findings for models of cerebral specialization for language are discussed.     

Impaired ranking of semantic attributes in dementia

The present work explored the loss of semantic attributes that is said to occur in dementia. In the first two experiments, subjects had to select attributes that went with concepts like airplane and church. The finding that demented subjects maintained high levels of accuracy when selecting attributes suggested that the semantic content of their concepts was relatively well preserved. The organization of the content was explored in a third experiment by having subjects order attributes according to their relative importance in defining concepts. While demented subjects performed better than chance, they did not rank attributes as well as healthy aged subjects, suggesting a disruption in organization whereby the importance of central attributes is reduced. The hypothesized disruption in organization is viewed in relation to the learning and memory deficit that is the hallmark of the dementias.     

Developmental changes in face processing: results from multidimensional scaling

Multidimensional scaling procedures were used to investigate developmental changes in the ability to process previously unfamiliar faces. Eighty male subjects, aged 7, 9, 12, or adult, rated the similarity of pairs of faces. The faces were presented to subjects in either the upright or the inverted orientation. Multidimensional scaling analyses suggest that subjects of all ages use similar information in judging the similarity of faces. However, for upright faces, individual subjects under age 10 seem to use fewer features at a time. The results argue against a qualitative shift in face processing at age 10, and suggest that the improvement in face recognition ability noted at this age is due at least in part to an increased ability to consider more features simultaneously.     

Onsets and rimes as units of spoken syllables: evidence from children

The effects of syllable structure on the development of phonemic analysis and reading skills were examined in four experiments. The experiments were motivated by theories that syllables consist of an onset (initial consonant or cluster) and a rime (vowel and any following consonants). Experiment 1 provided behavioral support for the syllable structure model by showing that 8-year-olds more easily learned word games that treated onsets and rimes as units than games that did not. Further support for the cohesiveness of the onset came from Experiments 2 and 3, which found that 4- and 5-year-olds less easily recognized a spoken or printed consonant target when it was the first phoneme of a cluster than when it was a singleton. Experiment 4 extended these results to printed words by showing that consonant-consonant-vowel nonsense syllables were more difficult for beginning readers to decode than consonant-vowel-consonant syllables.     

Speeded recognition of ungrammaticality: Double violations

A model of sentence comprehension postulating that Subject-Verb-Object relations are specified prior to Noun-Adjective relations received support from a study of the speed at which sentences with various kinds of violations could be rejected. Compatible with the sequential model was the finding that Noun-Verb and Adjective-Noun double violations did not result in shorter RTs than Noun-Verb single violations — even though sentences with double violations were judged to be less acceptable.     

The logical and empirical bases of conservation judgements

It is argued that conservation judgements are based on a particular combination of logical necessity and empirical belief. The empirical belief is that a given transformation will not alter a particular quantity (Elkind's conservation of identity). The logical aspect is a transitive deductive argument containing an initial equivalence of two quantities and the conservation of identity belief as premises which lead to the conclusion of maintained equivalence (Elkind's conservation of equivalence). In two experiments, it is shown that conservation of identity beliefs can be manipulated in subjects who have long since developed the capacity for transitive deductive inference. Untrained 10 year olds were unaware of how sublimation acts to alter certain quantities over particular transformations of shape. And untrained adults incorrectly believed that both the area and perimeter of a closed figure would be conserved over transformations which elongated the figure. Both groups of subjects could be trained in the correct conservation of identity beliefs and this affected their conservation of equivalence judgements in predicted ways. It is suggested that the locical aspect of conservation is developmentally stable and that the empirical aspect varies widely across problems and individuals because of its dependence on relevant experience.     

Three types of schemata in children's recall of cohesive and noncohesive text

Children, ranging in ages from 7.3 to 9.6 years, were identified according to the type of schemata structure they used to recall picture sequence events. These children were then required to recall several written text passages representing four different conditions: (1) theme first paragraphs, (2) theme final paragraphs, (3) paragraphs with no theme but having thematic structure, and (4) paragraphs with no theme and no thematic structure. It was found that the manner and the amount of the child's recall were a function of how the child's schemata structure interacted with a given paragraph structure. The implications of these findings are discussed in terms of the generally unquestioned assumption that only one “ideal” text grammar is needed to describe children's schemata for processing test.