Verbal retention deficits in aphasic and amnesic patients.

Five different groups of patients (aphasics, alcoholic Korsakoffs, nondominant hemisphere patients, alcoholics, and control patients) were asked to detect either repeated letters, repeated words, rhyming words, or words from the same category during the reading of a list. It was discovered that the number of intervening words had a greater effect on the aphasics for all conditions than it did for the other groups. However, when the rate of presentation was slowed, the aphasics showed considerable improvement while the other groups maintained their same level of performance. The Korsakoff patients were impaired only on the semantic task (same category inclusion) and did not improve at the slower presentation rate. An interpretation based on speed and level of information processing abilities is given.     

Crossed aphasia: analysis of four cases

Data from the Rehabilitation Institute of Chicago was used to contrast a sample of 358 aphasics with data from a Boston aphasia and aging study (L. Obler, M. Albert, H. Goodglass, and F. Benson, Brain and Language, 6, 318–322, 1978). Unlike the females, Chicago males showed remarkable similarity to the Boston male sample for the Broca, Wernicke, and Global groups with ratios of approximately four Broca's to every two Wernicke's and Global aphasics. Similar to the Boston Sample, Wernicke's aphasics were 11.6 years older (p < .001) than Broca's aphasics.     

Selective preservation of a lexical category in aphasia: Dissociations in comprehension of body parts and geographical place names following focal brain lesion

Abstract

The selective dissociation of memory for proper names is discussed in the context of a review of dissociations involving broadly defined vs narrowly defined semantic categories in brain damaged adults. Two narrowly defined categories for which dissociations have been reported are body parts (selectively impaired in comprehension) and geographical place names (selectively preserved in comprehension). In this study, 167 aphasic patients were tested for their ability to correctly identify body parts and map locations from spoken names, relative to a baseline for correct responses on general word discrimination (object identification). Wernicke's aphasics and Global aphasics both had significantly more success in pointing to named map locations and significantly worse performance in pointing to named body parts than they had in selecting other objects from multiple choice. Anomic aphasics showed precisely the opposite pattern of results. Other aphasic subgroups (Broca's aphasics. Mixed Nonfluent aphasics. Conduction aphasics, Transcortical Motor and Transcortical Sensory aphasics, and Mixed Fluent aphasics) did not show significant deviations in either direction. We suggest that the selective preservation for place names may be related to their status as proper names.     

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.     

The perception of emotionally toned sentences by right hemisphere-damaged and aphasic subjects

The perception of 60 emotionally toned sentences, divided into meaningful and meaningless utterances, by high- and low-verbal aphasics and right hemisphere-damaged subjects who were not aphasic was investigated. The intended moods were happiness, sadness, and anger. Results indicated (a) significant differences between the aphasic groups in identifying the intended emotion but none between groups in identifying the intended emotion but none between either of these groups and the right hemispheric dysfunction subjects; (b) sentence meaningfulness only affected the responses of high-verbal aphasics; and (c) while the happy mood seemed to be the least frequently selected among the three moods, closer inspection indicated that the subjects in absence of response bias were distinguishing among the three moods with equal success.     

Aphasic adults' understanding of complex adverbial sentences

Twelve aphasics with relatively preserved auditory comprehension were tested for their understanding of four adverbial sentence types expressing the temporal order of events. The relative effects of order of mention, adverbial choice, and adverbial clause placement on subjects' comprehension were investigated. Only adverbial choice was significant with aphasics producing more errors of temporal order on after than before sentences. Subjects' error patterns were not similar to those of children acquiring language. The results are discussed with respect to the theory of lexical marking and the regression hypothesis.     

Organization of and access to semantic memory in aphasia

Previous experiments with picture sorting and matching tasks have shown aphasics to give more deviant responses than controls when decisions require the identification of single features of concepts, whereas their responses are close to normal whenever decisions have to be based on the relative overlap of broad associative fields. The present experiment was designed to compare picture matching based on single features (property verification) with picture matching based on category membership (category verification). Fifty-five aphasics (14 amnesics, 18 Brocas, 13 Wernickes, 10 global aphasics) and 29 right-brain-damaged control patients served as subjects. Aphasics were poorer than right hemisphere controls on property as well as on category sortings, especially when the sorting criterion was not a dominant property of the object or when the object in question was not a typical member of the criterion category. Contrary to other studies, the "semantic distance" variable did not differentially affect Brocas as compared to Wernickes aphasics. Verbal labels denoting the sorting criterion and added to the picture presentation did not affect the performance of the right hemisphere controls but significantly improved that of the aphasics.     

Agrammatism in a case-inflected language: Comprehension of agent-object relations

Yugoslav agrammatic aphasics and normal control subjects were tested for comprehension of agent-object relations in a series of simple Serbo-Croatian sentences consisting of two nouns (N) and a transitive action verb (V). The availability of nominative and accusative case inflections and a semantic contrast was systematically varied across sentences. Sentences were also varied with respect to the two sequences NVN and VNN. An analysis of subjects' agent-object assignments yielded the following results: While Broca's aphasics did show some sensitivity to case inflections, their ability to process such cues was greatly impaired relative to normal subjects, for whom morphological cues were almost completely deterministic. To a lesser degree, Broca's aphasics were impaired in their ability to employ a strategy of “choose the first noun as agent” when case inflections and semantic contrasts were not available. While Broca's aphasics showed no impairment in their ability to exploit semantic contrasts for agent-object assignment, there was no absolute compensatory increase in the degree to which they relied on semantic cues. Differences in word sequence had no effect on agent-object assignment in Broca's aphasics. Finally, Broca's aphasics frequently responded unsystematically when cues to agent-object relations occurred in isolation or in competition with one another, but when there was a convergence of cues their performance approached that of normal subjects. This result was interpreted in terms of an accessing hypothesis.     

Speech production mechanisms in aphasia: A delayed auditory feedback study

Data collected from a delayed auditory feedback (DAF) study conducted by F. Boller, P. B. Vrtunski, Y. Kim, and J. L. Mack (1978, Cortex, 14, 212–226) were reanalyzed to determine if speech quality measures which were significantly affected during DAF could be operationalized and to ascertain which type of errors are responsible for the judgement. A second goal of this study was to determine if Conduction aphasics were relatively spared under conditions of DAF, as has been shown in previous studies. Twenty aphasic patients and ten controls were presented with several speech production tasks under two delay conditions and two simultaneous feedback conditions. Results indicated that only the category of vowel length produced a significant number of errors, suggesting that DAF affects articulatory implementation. Conduction aphasics showed the least effect of all the groups. These results support Wernicke's and Geschwind's model, in which Conduction aphasics have a disconnection between the sensory and motor images of words. In contrast, Broca's aphasics were the most affected group under DAF, suggesting that a major component of their disorder is phonetic in nature.     

Sequences of phonemic approximations in aphasia

The trends of sequences of phonemic approximations to a single target were studied in three types of aphasia (Broca's, conduction, and Wernicke's), as gathered in five tasks (spontaneous speech, repetition of meaningful words, repetition of nonsense words, reading aloud, and automatized sequences). A phonemic error ratio was defined in order to quantify the distance between each approximation of a given sequence and its target. The results of a computer analysis based on this ratio were analyzed according to three parameters. A study of three types of patients revealed that conduction aphasics exhibited the most regular trend toward the target in sequences of phonemic approximations; the analysis of the various tasks indicated that sequences produced in repetition by conduction aphasics form an exception to the regularity of this trend, and an examination of the various lengths of sequences indicated that longer sequences showed a less decisive trend toward the target than shorter sequences. The discussion bears on some theoretical aspects of the phonological production mechanism and its control: the initial strength and permanence of the internal representation of the target emerge as important factors required for the good functioning of this mechanism.     

Communicative gestures in aphasia

Gestural communications of 10 mild and moderate aphasics and five controls were examined in two conditions: Face-to-face informal dyadic conversation and restricted visual access between speaker and listener. Gestural production was significantly reduced with restriction of visual access, supporting the posited communicative function of the hand and arm gestures investigated in this study. No differences were found between aphasic and control subjects in the rate of gestural communication in the natural condition of face-to-face interaction. Moderate aphasics, however, were found to produce proportionally fewer of the complex semantic modifying and relational communicative gestures and more nonspecific, nonconsensually shared, unclear gestures. Gestural complexity was significantly negatively correlated with measures of linguistic impairment for the aphasics. The relationship between the frequency and complexity of communicative gestures and concurrent verbalizations was also examined. The findings of this study provide confirmation for the view that there is an identifiable class of gestures utilized by aphasics for communication, aphasics are impaired in their gestural communicative competence in natural conditions of communication, and the quality of aphasics' gestural communications parallels changes in their verbal communication patterns.     

The appreciation of antonymic contrasts in aphasia

To secure information on the ability of aphasic patients to comprehend antonymic relations, the kinds of confusions typically made, and the extent to which antonymic sensitivity depends upon mode of presentation and task demands, three linguistic and nonlinguistic tests were administered to aphasic patients, right hemisphere-damaged patients, and non-neurological controls. Although difficulty with antonymous relations was found among all the organic patients, the kinds of problems evidenced and the relative profile of difficulties differed across populations. Among the principal findings were the generally preserved sensitivity to antonymy found among anterior (particularly Broca's) aphasics; a surprising insensitivity to antonymy and a preference for synonyms, found among right hemisphere patients, particularly on the nonlinguistic tasks; a relative preservation of sensitivity to antonymy on nonlinguistic tasks, coupled with a loss of such sensitivity on linguistic tasks, found among posterior (particularly Wernicke's) aphasics; a proclivity toward stereotypical correct responses among the organic patients; and an absolutely worse performance by right hemisphere patients on tasks involving antonymic relations in pictures and abstract designs.     

Active selection of items to be remembered: The role of timing

A series of experiments was carried out in which Ss were required to extract critical stimuli from a stream of nine spoken inputs, presented at various rates, and report on these after the presentation of each list. The critical items were normally digits at positions 2, 4, 6, and 8 in the input sequence. Subjects were required to employ either an “active” extraction strategy, aimed at achieving temporary storage only of items to be remembered, or a “passive” strategy, involving storage of all inputs with subsequent extraction of critical items. The initial experiment showed that the active strategy markedly improved performance efficiency as the presentation rate decreased; passive performance remained relatively stable. Experiments 2 and 3 indicated that the level of active performance was higher when critical items were categorically different from unwanted items. There were indications that this effect was independent of the effect of changes in the presentation rate.The final experiments in the series showed that when Ss were denied the opportunity of predicting the time of arrival of critical items active performance hardly benefitted from a reduction in rate.A “controlled activation” process is proposed as a basis for S's ability to modulate his state of alertness, so as to maximize receptivity for critical stimuli arriving at well-defined points in time.     

Perceiving versus inferring movements to understand dynamic events: The influence of content complexity

ObjectivesWhat type of visual presentation is best in helping learners to understand the functioning of a dynamic system and under what conditions? This study investigated the effect of content complexity on perceived cognitive load and performance resulting from studying depicted movements of team play either in an explicit manner (animation) or via arrow symbols (static diagram).DesignA 2 (treatment: diagram vs. animation) × 2 (content complexity: low vs. high) between subjects design was adopted in the experiment.MethodsForty-eight university students were randomly assigned to the four study conditions and required to perform a reconstruction test and rate their perceived cognitive load following the study phase.ResultsData analyses revealed that for low-complexity content, participants exposed to the animation treatment learned more efficiently – based on the combination of learning and cognitive load scores – than those exposed to the diagram treatment. On the other hand, for high-complexity content, participants exposed to the diagram treatment learned more efficiently than those exposed to the animation treatment.ConclusionThe findings stress the importance of considering the task complexity factor when designing and presenting instructional materials to learners.     

Lexical and semantic factors influencing picture naming in aphasia

Picture naming requires early visual analysis, accessing stored structural knowledge, semantic activation, and lexical retrieval. We tested the effect of perceptual, lexical, and semantic variables on the performance of aphasics in picture naming and assessed prevalence of natural categories vs artifact dissociations. Forty-nine aphasics were asked to name 60 pictures, from three natural (animals, fruits, and vegetables) and three artificial categories (tools, furniture, and vehicles). For each item visual (drawing complexity, image agreement), semantic (prototypicality, concept familiarity) and lexical variables (word frequency, name agreement) were available. The effect of these variables showed individual differences; altogether, visual complexity had little influence, whereas lexical and semantic variables were more influential. Name agreement was most important, followed by word frequency. On a multiple single case analysis 10 patients (20%) showed a natural/artificial category dissociation. Five of the six subjects faring better with artifacts were males, and all of four patients faring better with natural categories were females. Interpretations of this finding are discussed.     

Influence of aging on recovery from aphasia in polyglots

We analyzed patterns of recovery, according to the rules of Pitres [1895, Revue de Medecine (Paris), 15, 873–899] and Ribot (1881, Les Maladies de la Memoire, Paris: Libraire Germer Baillere et Cie, pp. 146–147), in polyglot aphasics divided into subgroups by age. The rule of Ribot did not apply predictably for any age group. Pitres' rule clearly applied, but only for the nonelderly groups. Aging and its concomitant deterioration of recent memory seem to influence patterns of recovery from aphasia in polyglots.     

Influence of linguistic complexity,rate of presentation,and interphrase pause time on auditory-verbal comprehension of adult aphasic patients

Among the variables affecting comprehension of linguistic stimuli by aphasic subjects are syntactic complexity and processing time. Comprehension performance of 15 aphasic adults was studied while altering the rate of speech presentation and varying the pause time between the major phrases within sentences of increasing grammatical complexity.Simple Active Affirmative Declarative Sentences, Negative, and Passive sentences were presented (1) at the rate of 150 words per minute (wpm) with 1-sec interphrase pause time (IPT); (2) 150 wpm with no pauses; (3) 120 wpm with 1-sec IPT; (4) 120 wpm with no pauses added.Performance was seen to vary with increasing syntactical complexity and as a function of processing time. Greater comprehension was seen with active affirmative than negative; greater with passive affirmative than with active negative. Clinical implications are discussed. Subjects demonstrated greater comprehension when sentences were presented at slower than normal rate; addition of interphrase pause time intervals aided comprehension. Combining slower rate of presentation and IPT intervals provided greatest increase in auditory processing time and showed concomitant increase in comprehension performance.     

Perception of rate-altered sentential approximations by normal and aphasic children.

25 4-word, first, and second-order sentential approximations were presented to 18 aphasic and 18 normal children. The material was taped and altered to represent 5 speaking rates: 140 (normal); 75 and 105 (expanded); and 180 and 205 (compressed) words per minute. Order of presentation was randomized. The major difference between the children was that the second-order material was perceived best by normals regardless of rate, while the aphasics showed this preference only at the normal rate.     

Responding in the squirrel monkey under fixed-ratio schedules of stimulus termination

Key pressing was maintained under a fixed-ratio schedule in which electric shock was scheduled for delivery at a fixed time (t seconds) after each stimulus onset, and every n^th response terminated the stimulus and initiated a timeout from shock. Under this procedure, the higher the rate of responding, the briefer the duration of the stimulus presentation and the lower the frequency of shock delivery. The effects of several schedule parameters were studied to determine whether the maintenance of responding was dependent on an inverse relation between response rate and shock frequency. Shock rate and shock frequency were made independent of response rate by decreasing the value of t to 0.5 second and delivering shock only during the first presentation of the stimulus after a fixed time, including stimulus and timeout durations, had elapsed since the previous shock. The experiments showed that shock frequency and response rate are inversely related when t is of relatively long duration compared to the value of the fixed-ratio parameter, but that a decrease in shock rate or frequency due to a high rate of responding is not necessary for the maintenance of responding under a fixed-ratio schedule of stimulus termination.     

Mental rotation of random two-dimensional shapes

Two experiments are reported in which Ss were required to determine whether a random, angular form, presented at any of a number of picture-plane orientations, was a “standard” or “reflected” version. Average time required to make this determination increased linearly with the angular departure of the form from a previously learned orientation. The slope and intercept of the reaction-time (RT) function were virtually constant, regardless of the perceptual complexity of the test form and the orientation selected for initial learning.When Ss were informed in advance as to the identity and the orientation of the upcoming test form and, further, were permitted to indicate when they were prepared for its external presentation, RT for determining the version of the form was constant for all test-form orientations. However, the time needed to prepare for the test-form presentation increased linearly with the angular departure of the form from the learned orientation.It is argued that the processes both of preparing for and of responding to a disoriented test form consist of the mental rotation of an image, and that both sorts of mental rotation (pre-stimulus and post-stimulus) are carried out at essentially the same constant rate.