The relationship of limb apraxia severity to motor and language deficits

Ipsilateral motor and symbolic/linguistic skills were examined in normals and three left hemisphere damaged groups with no, mild, or moderate-severe limb apraxia. When the two apraxic groups were pooled they demonstrated poorer response inhibition and reading relative to the nonapraxic group. There were no significant group differences on motor or language tasks when the three brain damaged groups were separately compared. These results indicate there is a limited relationship between limb apraxia and some motor and linguistic skills, but the relationship was not greater for motor than linguistic skills.     

Limb apraxia and motor performance

This study was desinged to determine if motor deficits in limb apraxia are task specific. Non-brain-damaged patients and apraxic and nonapraxic patients with left hemisphere damage performed language and limb apraxia tests and six motor tasks with the left hand. Contrary to previous data, no significant group differences occurred on a finger tapping task. Although task complexity or sequencing requirements affected group differences, greatest apraxic impairment was noted on a task of precise steadiness, but only when its response inhibition requirements were increased. This pattern of deficits appears to be associated with greater involvement of the premotor area in the apraxic group.     

The different types of limb apraxia errors made by patients with left vs. right hemisphere damage

Limb apraxia errors were compared among normal controls and right- or left-hemisphere-damaged patients as they imitated gestures with the ipsilateral hand. Both brain-damaged groups made similar errors on nonrepresentative and representative/intransitive movements. In contrast for pretended object use movements (transitive), the left-hemisphere-damaged group made more arm position and classical body-part-as-object errors while the right hemisphere group made as many partial errors and more less-primitive, body-part-as-object errors than the left-hemisphere-damaged group. These results help explain why a certain percentage of right-hemisphere-damaged patients are labeled apraxic, but also suggest that the left hemisphere is more important for integrating intrapersonal space and the “representation” of extrapersonal space.     

Quantitative CT scan studies in aphasia. I. Infarct size and CT numbers

Infarct si?e (number of 1-mm² pixels in the lesion) on CT scans of 30 aphasia patients was obtained with a semiautomated computer program. The mean number of lesion pixels present per slice containing lesion was approximately 500 for mild aphasias (transcortical motor and conduction), 700 for Wernicke's, 1000 for Broca's, 1500 for mixed, and 2000 for globals. These differences were significant for $\text{11}\text{15}$ of the group pairwise comparisons. When lesion locus was controlled for in the anterior/posterior plane, 73–100% of the aphasia patients were correctly classified as to type of aphasia by a discriminant analysis utilizing only the number of lesion pixels present on two CT slices. Different slice combinations were used for different aphasia group comparisons. There was a significant correlation between severity of aphasia and lesion size. There was a significant correlation between lesion size and the CT numbers in the lesion. This type of analysis may be useful to predict the prognosis for recovery potential in aphasics who have CT scans performed at 2 months poststroke.     

Preservation of orthographic knowledge in aphasia

A simple untimed lexical decision task was designed to test implicit letter recognition in aphasic patients. Half of the nonwords used in this task were orthographically regular pronounceable pseudowords, and half were orthographically irregular unpronounceable letter strings. Twenty-five randomly chosen aphasic patients with mild to severe degrees of aphasia participated in the study. Although only six of the patients performed the lexical decision task successfully, all 25 demonstrated the ability to distinguish orthographically regular from irregular letter strings and, by implication, the ability to recognize and make use of the identities of written letters.     

Reconstructive retrieval deficits in Broca's aphasia

Anterior aphasic patients' ability to utilize the phonemic and/or semantic features of verbal material for retention purposes was investigated. In the first experiment, patients were asked to either detect word repetitions, phoneme repetitions, or rhymes in a list of items. The aphasics performed well on word and phoneme repetition detection but below both normals and amnesic Korsakoffs on rhyme detection. In the second experiment the patients were instructed to analyze either the physical, phonemic, or semantic features of words they were later asked to recognize. Aphasics were differentially affected (as were normals) by these instructions: semantic feature analysis resulted in the best performance, followed by phonemic feature analysis. It was concluded that anterior aphasics can analyze, recirculate, and even store the phonemic features of words, but find difficulty in reconstructing the originally presented item from these features.     

Temporal ordering deficits following anterior temporal lobectomy

Subjects were required to report the pitch sequence of two 10-msec tones of different frequency presented monaurally while the stimulus onset asynchrony (SOA) between the two tones was varied. The value of the SOA at which the subjects achieved an 80% correct sequence report was determined by an adaptive procedure without feedback. This measure was compared in the right and left ears, on subjects with a right or left anterior temporal lobectomy and on a normal control group. The results reveal an elevated threshold for performing temporal order judgments in the ear contralateral to the surgical lesion.     

Semantic field,naming, and auditory comprehension in aphasia

The status of semantic fields for 16 target nouns was compared in high and low comprehension aphasics, brain damaged, and normal controls, by measuring latency and miss rate for recognition of six classes of associates, which were presented orally on tape. The ability to name each target was also examined as a function of the integrity of the subject's semantic field for that word. Low comprehension aphasics showed both quantitative and qualitative changes in semantic fields, while milder aphasics showed only mild quantitative impairment, as compared to controls. Both latency and miss rate measures indicated that failure to name a word is associated with reduced semantic field for that word. This result is interpreted as supporting the view that nameing is, in part, determined by the convergence of associations.     

Comprehension disorders in aphasia: a historical review.

This paper reviews the clinical reports and theoretical inferences made by early scientists in regard to the impairment of auditory comprehension so often found in aphasics. It first presents an analysis of the literature on and the interpretation of comprehension disorders in aphasia up to the time of Pierre Marie and Arnold Pick. It then reviews early attempts to assess and quantify receptive impairment. Finally, it discusses the historical origin of some of the questions on comprehension currently under investigation by contemporary researchers.     

Mechanisms underlying writing and speech in aphasia

As a parallel to the dual decoding concept for processing of written language we proposed that phonological encoding does not necessarily occur in writing and that the phonemic and graphemic subsystems can be independent on the one-word level. This hypothesis was tested by comparing oral and written performance in a picture-naming task in Broca's and Wernicke's aphasics. In addition, the residual tacit knowledge of the orthographic properties of the names of the pictures was examined with a multiple-choice recognition task. The principal finding is that Broca's aphasics who were better in written than in oral naming showed more graphemically and semantically motivated errors than aphasics who were better in oral than in written naming, the latter producing more phonemically motivated errors. This result supports the dual encoding concept for writing on the singleword level, implying a direct route from the mental lexicon to the graphemic system in parallel with a route mediated by the phonemic system. Multiple-choice recognition was found to be superior to both oral and written performance in both Broca's and Wernicke's aphasics.     

An investigation of repetition and language processing in a case of conduction aphasia

A study is reported of a single case of conduction aphasia. A battery of tasks designed to investigate the parameters of the patient's severe repetition deficit is supplemented by tests of several language functions. The results provide extensive information on a wide range of the patient's language abilities and are used to evaluate the adequacy of four models that have been offered to account for conduction aphasia. An argument is made in support of the suggestion that the syndrome of conduction aphasia should be divided into two subgroups based on patients' ability to select and realize phonemes in speech output. It is concluded that the best explanation for the disorder of patients with repetition deficit but without significant speech output problems is the hypothesis that repetition ability is compromised by a pathological limitation of auditory-verbal short-term memory. This hypothesis is extended to account for the pattern of results obtained in the language tasks.     

Qualitative aspects of pantomime recognition defect in aphasia

This study investigated the performance pattern of aphasic patients on a pantomime recognition test in which one of the four response alternatives was an object semantically related to the correct choice. Aphasics with defective pantomime recognition made 71% of their total errors on the semantic foils, and for the majority of such patients, semantic errors represented 80 to 100% of total errors. Only aphasies with objective evidence of confusion failed to make highly frequent semantic errors. The findings suggest that most aphasies who fail pantomime recognition are impaired because of semantically vague understanding of the pantomimes' intended meaning rather than complete lack of understanding of the pantomime.     

The role of the right hemisphere in the apprehension of complex linguistic materials

To secure information on which aspects of linguistic functioning might be mediated by the nondominant hemisphere, a test battery assessing sensitivity to narrational and humorous materials was administered to a population of right-hemisphere-damaged patients, as well as relevant control groups of normal, aging, and aphasic individuals. While elementary linguistic functioning was adequate, the right-hemisphere-injured groups exhibited consistent difficulties in respecting the boundaries of a fictive entity, assessing the plausibility of elements within a story or joke, selecting the appropriate punch line for a joke, and integrating elements of a story into a coherent narrative. Certain elements—specifically emotional content and noncanonical facts injected into a narrative—also posed characteristic difficulties for these patients. The results suggest that, in contrast to the other populations, right-hemisphere patients exhibit special difficulties in processing complex linguistic entities and in utilizing the surrounding context as they assess linguistic messages.     

Profiles of symbol-reading skills in organic patients

One (unitary) school of thought views all symbolic competences as closely related, while a rival (pluralistic) approach underscores the relative differences among modes of symbolic processing. To secure information on the plausibility of these competing hypotheses, matched groups of left- and right-hemisphere patients were given a visual symbol-recognition test. Subjects were required to choose the correctly depicted symbol among a set of four. The results challenge a strong version of the “unitary” hypothesis. What emerges instead is a view of symbol systems as a continuum: relatively linguistic symbol systems prove challenging for left-hemisphere patients, relatively nonlinguistic systems pose comparable difficulties for right-hemisphere patients. Contrary to hypothesis, the processing of numerical symbols poses special difficulty for right-hemisphere patients. Performance on trademarks—items which can be processed by linguistic or nonlinguistic strategies—suggests that organic patients with contrasting pathologies may adopt different processing strategies when confronting identical physical stimuli.     

Phonemic imperception in aphasia

This study investigated characteristics of 14 aphasics with impaired phoneme discrimination identified from a population of 100 patients with left hemisphere lesions. All patients with impaired phoneme discrimination were significantly impaired in aural comprehension, but many showed intact sound recognition and some showed normal reading comprehension. Defects in phoneme discrimination were typically seen in the acute stage of aphasia resulting from stroke; and in most instances, defects in phoneme discrimination were no longer apparent 4 months postonset. All patients who recovered normal phoneme discrimination also made significant improvement in aural comprehension. The findings support the concept that some aural comprehension defects result from a specific disturbance in phoneme discrimination.     

Gerstmann syndrome without aphasia: a longitudinal study

A case of "pure" and complete Gerstmann syndrome resulting from a focal vascular lesion in the posterior parietal area of the left hemisphere and not associated with aphasic disorder or general mental impairment is described. The initial symptom presentation of this patient supported the concept of the autonomous nature of the Gerstmann aggregate but longitudinal findings suggested that these symptoms did not in fact represent a coherent syndrome.     

Surprise but not coherence: Sensitivity to verbal humor in right-hemisphere patients

Verbal humor deficits were investigated in right-hemisphere-damaged patients. It was hypothesized that the appreciation of jokes presupposes two elements: sensitivity to the surprise element entailed in the punch line of a joke and apprehension of the coherence which results when the punch line has been integrated with the body of the joke. The possible dissociation between these elements was tested by asking subjects to select from four alternatives the appropriate ending to a joke. Right-hemisphere patients exhibited a selective attraction to endings which contained an element of surprise but which were not otherwise coherent with the body of the joke. This finding suggests that right-hemisphere patients have difficulty in integrating content across parts of a narrative and confirms the psychological reality of the proposed distinction between the surprise and coherence elements of humor processing.     

Picture-naming in aphasia

The distribution of picture-naming errors for Broca's aphasics (n = 9), Wernicke's aphasics (n = 9), conduction aphasics (n = 9), frontal anomics (n = 7), and posterior anomics (n = 9) was examined to determine the diagnostic power of error types in picture-naming. Negated responses were associated with Broca's aphasia, whole-part errors ("hose" for nozzle) were associated with frontal anomia, and poor phonemic cuing was associated with Wernicke's aphasia. In addition, the relative distribution of the three most prominent naming errors-phonemic errors, semantic errors, and multiword circumlocutions-tended to distinguish the two anomic subgroups from the other aphasia subgroups. Anomic aphasics produced the fewest phonemic errors and the most multiword circumlocutions; this pattern suggests minimal word-production difficulty in anomic aphasia relative to the other aphasia syndromes. Despite such group differences, the overall picture indicates that there is considerable similarity among aphasia syndromes in terms of picture-naming behavior.     

Effects of massed practice and meprobamate on spasmodic torticollis: an experimental analysis

In recent years a variety of behavioral techniques have been used in the treatment of spasmodic torticollis including negative practice (Agras and Marshall, 1965). faradic aversion (Brierly, 1967). instructions and negative feedback (Bernhardt et al., 1972). and systematic desensitization (Meares. 1973). However, in most of the aforementioned reports the controlling effects of the particular technique over dependent measures (voluntary and/or involuntary evocations of the tic) have not been demonstrated experimentally (see Hersen and Eisler, 1973 for review). In the present single case experimental analysis (Barlow and Hersen. 1973; Hersen and Barlow, 1974). the effects of massed practice (see Yates. 1958) and meprobamate on a subject exhibiting spasmodic torticollis were systematically examined. Following Bernhardt. Hersen and Barlow (1972). treatment efficacy was evaluated by monitoring rate of involuntary torticollis movements per 10-min videotaped recording sessions.