Some aspects of language comprehension in anterior aphasia

The competency of language comprehension was evaluated in three groups: anterior aphasics, posterior aphasics, and normal control subjects. Test material was divided into two sentence groups (Fill in the Blank and True/False) emphasizing either (1) semantic, “real world,” identity words or (2) syntactic, relational words, and one paragraph interpretation task. Matching auditory and visual (written) presentations were given. The control subjects performed almost flawlessly but many errors were made by each aphasia group. Qualitative study revealed a marked difference in the comprehension problem of the two groups. The anterior aphasic group performed well on semantically weighted sentences but made errors on syntactically weighted material, regardless of mode of presentation. In contrast, the posterior aphasics made almost the same number of errors on both types of material, regardless of mode of presentation. These findings support the concept of defective language comprehension in anterior aphasia and further suggest that the defect centers on the syntactical structures which are also poorly handled in expressive output.     

Organizational features of a young child's behaviors

The study was designed to investigate the nature of response-class phenomena and the possibility of indirect contingency control. A single subject was employed. Prior to the start of the study, the experimenter established the process of maintaining stimulus constancy during a preexperimental phase. Subsequent to the first baseline phase, a factor analysis was done to define the response class and the behavior categories constituting the class. Manipulating a single adult consequence to a response-class category over subsequent baseline and manipulation phases revealed frequency changes in all behavior categories in the response class. The data gave support to indirect behavior control. Search for possible explanations of frequency changes showed that the direction of the frequency changes were predictable from the results of the factor analysis.     

Turning a penrose triangle inside out

Why do impossible figures, which cannot exist in three dimensions, appear to make threedimensional sense? In order to shed some light on this question the limits may be tested to which three-dimensional operations on these figures can be performed. In this paper a particularly difficult operation, viz., torus eversion is attempted. Not only is an eversion found to be possible but an unfamiliar impossibility develops. The regular form of the eversion is shown to be unique.     

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.     

Factors affecting judgments of fluency: II. Word repetitions

Six speech samples containing varying amounts of whole-word repetitions were tape-recorded and presented to 36 male and 36 female listeners. For each sample, listeners were asked to make judgments of fluent, disfluent, and stuttered speech, and to answer the question, “Would you recommend speech therapy?” Results showed that samples containing 5% or more word repetitions were not judged fluent speech by a majority of listeners. Judgments of disfluent and stuttered speech were nearly equal for speech samples containing word repetitions from 5% to 15%. At 20%, however, the judgments of stuttered speech were found to be more likely than judgments of disfluent speech. A majority of listeners recommended clinical services for speech samples containing 5% or more word repetitions. Generally, the results indicated that (1) the presence of whole-word repetitions is not normal regardless of frequency, (2) fluent speech may not contain 5% or more word repetitions, and (3) with 20% word repetitions the judgments of stuttering may be more likely than judgments of disfluency.     

Semantic aphasia: A neglected entity

Three cases of semantic aphasia are reported. Computerized brain tomography showed bilateral temporo-parieto-occipital junction hemorrhages in one patient, and left parieto-occipital junction infarctions in the other two patients. The auditory comprehension defect of the three patients was characterized by preserved understanding of single words and impaired understanding of grammatically complex constructions. It is suggested that this comprehension defect reflects an inability to fully grasp the meaning of words and grammatical constructions imbued with spatial or quasi-spatial significance. Each of the three patients showed a complex spatial disorder that included constructional apraxia, spatial agnosia, and elements of Gerstmann's syndrome. The aphasic as well as the spatial disorder of semantic aphasics may be manifestations of a common defect in the perception of spatial relationships produced by left temporo-parieto-occipital region damage.     

Do alcoholic amnesic patients passively rehearse verbal information?

Recently it has been claimed that alcoholic amnesic patients mainly engage in passive repetitive rehearsal during spontaneous learning and that this contributes to their memory problem. To test this hypothesis further, two experiments were conducted which compared list learning in amnesic patients and normal controls. In Experiment I both groups of subjects were required either to learn a list which was presented five times consecutively with free recall following each presentation, or they were asked to repeat each word out loud as they saw it and carry on doing so until the next word was shown. Five presentation trials were given and free recall was again tested after each presentation. It was predicted that if the amnesics' spontaneous form of learning involved only passive repetition there should be no difference between learning and repetition for this group while the controls should show an impairment in repeating compared to learning. The results showed that both groups of subjects were impaired to the same extent with repeating compared to learning and it was concluded that spontaneous learning was similar in both groups and that neither group merely passively rehearsed during spontaneous learning. A second experiment examined recognition performance of the two groups of subjects after learning or repeating lists of 20 words. Recognition was tested with distractors which were irrelevant, acoustically similar, graphemically similar, or semantically similar to the target word. It was found there were no differences between either of the groups in the pattern of errors made over the different distractor types. It was thus concluded that there was no encoding or rehearsal abnormality in the amnesic group. The possibility of differences between groups of alcoholic amnesics was discussed as well as the putative role of slow cognitive processing in their memory problems.