The processing of the sounds and meanings of ongoing speech by aphasic subjects

The ability of aphasic subjects to process the sounds and meanings of ongoing speech was tested. Subjects, 10 aphasic and 20 control, heard test sentences which contained one member of phonemically similar word pairs in one of three semantic contexts: congruent, neutral, and noncongruent. Immediately after hearing a sentence, subjects were to indicate which member of the word pair had been in the sentence. All subject groups had similar overall patterns of response to the different semantic contexts. The division of aphasic subjects into groups of high and low comprehenders revealed response differences. High comprehending aphasic subjects, like control subjects, demonstrated interactive processing of the sounds and meaning of speech while low comprehending aphasic subjects did not.     

Voice onset time in aphasia: Thai II. Production

The aim of this study was to investigate voice onset time (VOT) production in homorganic word-initial stops in Thai in order to explore the nature of speech production deficits across clinical varieties of aphasia. Thai exhibits a three-category distinction in bilabial (/b,p,ph/) and alveolar (/d,t,t,h/) stops, and a two-category distinction in velar (/k,kh/) stops. Subjects included three Broca asphasics, one transcortical motor asphasic, two global asphasics, one conduction aphasic, one Wernicke aphasic, one nonaphasic dysarthric patient, one right-brain-damaged patient, and five normal controls. Test stimuli consisted of eight monosyllabic real words. The results of VOT measurements indicated that Broca and global asphasics exhibited a more severe production disorder than Wernicke, conduction, or transcortical motor asphasics. The right-brain-damaged patient showed no impairment in VOT production. Comparisons are drawn to earlier studies of VOT production in aphasia in two-category languages. Issues concerning the underlying basis of the production deficit for nonfluent aphasics, fluent aphasics, and nonaphasic dysarthrics as well as the relation between perception and production of VOT are discussed.     

Comprehension of main ideas and details in coherent and noncoherent discourse by aphasic and nonaphasic listeners

Aphasic and nonaphasic listeners' comprehension of main ideas and details within coherent and noncoherent narrative discourse was examined. Coherent paragraphs contained one topic to which all sentences in the paragraph related. Noncoherent paragraphs contained a change in topic with every third or fourth sentence. Each paragraph contained four main ideas and one or more details that related to each main idea. Listeners' responses to yes/no questions following each paragraph yielded the following results: (1) Nonaphasic listeners comprehended the paragraphs better than aphasic listeners. (2) Both aphasic and nonaphasic listeners comprehended main ideas better than they comprehended details. (3) Coherence did not affect comprehension of main ideas for either group. (4) Coherence did not affect comprehension of details by nonaphasic subjects. (5) Coherence affected comprehension of details by aphasic subjects, and their comprehension of details in coherent paragraphs was worse than their comprehension of details in noncoherent paragraphs. There was no significant correlation between Token Test scores and measures of paragraph comprehension.     

Sensitivity to lexical denotation and connotation in brain-damaged patients: A double dissociation?

Sets of words can be grouped in terms of their denotation (cold and warm both refer literally to temperature) or in terms of their connotation (cold and warm connote remoteness and intimacy, respectively). To assess whether these two facets of meaning are dissociable, unilaterally left- and right-hemisphere-damaged patients were presented with word triads and asked to group together the two words that were closest in meaning. Right-hemisphere-damaged patients showed a preserved sensitivity to denotation, and a selective insensitivity to connotative facets of meanings. In contrast, left-hemisphere-damaged patients exhibited a preserved sensitivity to connotation as well as a selective insensitivity to denotative aspects of meanings. Inasmuch as normal control subjects displayed a flexible sensitivity to both denotative and connotative aspects of meaning, the results suggest that unilateral brain damage selectively curtails use of one or the other major aspect of word meaning.     

The nature of the phonological disorder in conduction aphasia

Sequences of attempts to name pictured objects were used to examine phonological dysfunction in three diagnostic subgroups of aphasia. A prevalence of "phonologically-oriented sequences" (i.e., those sequences that contained only attempts with a phonological resemblance to the target word) was found to be a diagnostic criterion for conduction aphasia. When compared to a group of Broca's (n = 7) and Wernicke's (n = 5) aphasics, all the conduction aphasics (n = 6) produced proportionately more of such phonologically-oriented sequences on a picture naming test. An examination of the phonologically-oriented sequences produced by the conduction aphasics indicates that speech production in conduction aphasia involves dysfunction at an early stage of sound-encoding. The theoretical implications of this view are discussed.     

Language and the young stutterer: A new look at old theories and findings

The major theories and research approaches as to the etiology and development of stuttering are reviewed from a historical perspective. Findings are drawn from different sources indicating that language deficits are an initial contributing factor and a continuing component of this disorder. Those subsets of children which constitute high-risk groups are identified. It is suggested that researchers begin investigating the underlying organic bases of stuttering and its relationship to stages of language development. Finally, clinicians are encouraged to employ a therapy program that is concerned with all areas of language, rather than emphasizing treating only the symptoms of stuttering behavior.     

The intelligent infant: Theoretical implications

In the present essay, the fact that preferences for visual novelty during infancy are related to later performance on intelligence tests was interpreted to mean that intelligence is continuous from infancy. It was suggested that the bases of both continuity and the general factor in intelligence reside in the same small set of basic cognitive processes. It was also noted that intelligent behavior on the part of the infant raises a question about the relative importance of automatic and effortful processes in intelligence. The development of a valid test of infant intelligence was seen as an aid to clarifying the role of hereditary and environmental influences on intelligence and in furthering our understanding of mental retardation. In brief, the manner in which infants distribute their attention to novel and previously exposed stimuli reveals the origins of cognition. The origins of cognition are the origins of intelligence.     

A unifying model for the structure of intellectual abilities

Models of the structure of cognitive abilities suggested by Spearman, Thurstone, Guilford, Vernon and Cattell-Horn are reviewed. It is noted that some of the models include a general intellectual factor (g) while others do not. It is also noted that some models are nonhierarchical, while in others more narrow abilities are subsumed under broader abilities in a hierarchical pattern. An empirical study in which a test battery of 16 tests was administered to some 1000 subjects in the 6th grade is reported. Using the LISREL technique to test different models, good support is obtained for oblique primary factors in the Thurstone tradition as well as for the second-order factors fluid intelligence, crystallized intelligence, and general visualization hypothesized by Cattell and Horn. It is also found, however, that the second-order factor of fluid intelligence i is identical with a third-order g-factor. On the basis of these results a three-level model (the HILI-model) is suggested, with the g-factor at the top, two broad factors reflecting the ability to deal with verbal and figural information, respectively, at the second-order level, and the primary factors in the Thurstone and Guilford tradition at the lowest level. It is argued that most previously suggested models are special cases of the HILI-model.     

Adaptive reasoning: Componential and eye movement analysis of geometric analogy performance

The present study explored individual differences in performance of a geometric analogies task. Whereas past studies employed true/false or two-alternative items, the present research included four-alternative items and studied eye movements and confidence judgements for each item performance as well as latency and error. Item difficulty proved to be a function of an interaction between the number of response alternatives and the number of elements in items, especially for subjects lower in fluid-analytic reasoning ability. Results were interpreted using two hypothesized performance strategies: constructive matching and response elimination. The less efficient of these, response elimination, seemed to be used more by lower ability subjects on more difficult items. While two previous theories resemble one or the other of these strategies, neither alone seems to capture the complexity of adaptive problem solving. It appears that a comprehensive theory should incorporate strategy shifting as a function of item difficulty and subject ability.Componential models, based in part on past research, revealed that a justification component was activated and deactivated depending upon the nature of the analogy being solved. In addition, two new components, spatial inference and spatial application, were identified as important on some items, suggesting that different geometric analogy items invoke different cognitive processing components. Thus, a comprehensive theory should also describe component activation and deactivation.     

Information processing abilities in twins reared apart

A battery of information processing measures and psychometric tests of specific and general cognitive abilities was administered to a sample of 105 individuals which included 34 monozygotic and 13 dizygotic reared apart twin pairs or triplets. Correlations between information processing parameters and psychometric abilities as well as twin resemblances for the information processing parameters were examined. In a principal components analysis of the information processing parameters, three components were identified which accounted for 67% of the total variation; Overall Speed of Response (OSR), Speed of Information Processing (SIP), and Speed of Spatial Processing (SSP). OSR was significantly correlated with WAIS IQ, and psychometric measures of verbal reasoning, spatial ability, and perceptual speed and accuracy. SIP was significantly correlated with WAIS IQ, measures of verbal reasoning, and one of the perceptual speed and accuracy measures. SSP was significantly correlated with measures of both spatial ability and perceptual speed and accuracy. Due to the small size of the dizygotic twin sample, no strong conclusions could be drawn regarding the magnitude of their resemblance. The correlation between component scores of reared apart monozygotic twins was significant for OSR, but not for SIP or SSP.