Task-related factors in oral motor control: speech and oral diadochokinesis in dysarthria and apraxia of speech

This study was focused on the potential influence of task-related factors on oral motor performance in patients with speech disorders. Sentence production was compared with a nonspeech oral motor task, i.e., oral diadochokinesis. Perceptual and acoustic measures of speech impairment were used as dependent variables. Between-task comparisons were made for subsamples of a population of 140 patients with different motor speech syndromes, including apraxia of speech and cerebellar dysarthria. In a further analysis subgroups were matched for speaking rate. Overall, dysdiadochokinesis was correlated with the degree of speech impairment, but there was a strong interaction between task type and motor speech syndrome. In particular, cerebellar pathology affected DDK to a relatively greater extent than sentence production, while apraxic pathology spared the ability of repeating syllables at maximum speed.     

The relationship between buccofacial and limb apraxia

There are at least two possible models depicting the relationship between buccofacial and limb apraxia. First, apraxia can be viewed as a unitary motor disorder which transcends the output modalities of both buccofacial and limb output. A high degree of similarity between the two types of apraxia would support this model. Alternatively, the relationship between buccofacial and limb apraxia may not include a unitary mechanism. The presence of quantitative and qualitative differences between buccofacial and limb performance would support this nonunitary model. The results of the present study support the nonunitary model.     

on the acoustic analysis of primate vocalizations

The acoustic theory of speech production relates articulatory maneuvers to acoustic attributes of speech. Some procedures are discussed that make use of this theory to analyze the vocalizations of nonhuman primates. These procedures make use of sound spectrograms, oscillograms, and computer-implemented analogs of the primate vocal apparatus as well as anatomical measurements. The use of these techniques in recent studies of nonhuman primate vocalizations is reviewed. These studies show that nonhuman primates lack the anatomical apparatus that is necessary for the production of the full range of human speech. Some unresolved questions concerning the structure of nonhuman primate utterances are discussed with regard to human linguistic ability.     

The relationship between limb apraxia and the spontaneous use of communicative gesture in aphasia

This study investigated the relationship between limb apraxia, as assessed by a formal clinical test, and the production of spontaneous communicative gesture, as measured by a newly designed rating scale--the Nonvocal Communication Scale (NCS). Subjects were aphasic adult males with cerebrovascular lesions of the left hemisphere. The performance of aphasic patients on the praxis test and the NCS was independent of demographic, neuroanatomic, linguistic, or cognitive variables, except for global aphasics who were low-scoring across the board. There was a significant positive correlation, however, between praxis ability and spontaneous gestural communication. Clinical implications of these findings are discussed.     

Cognitive mechanisms of visuomotor transformation in movement imitation: Examining predictions based on models of apraxia and motor control

When we observe a movement and then reproduce it, how is this visual input transformed into motor output? Studies on stroke patients with apraxia suggest that there may be two distinct routes used for gesture imitation; an indirect route that recruits stored movement memories (motor programs) and a direct route that bypasses them. The present study examined 30 healthy adults ages 18–80 (mean age = 44.0 years, SD = 19.5) to learn how motor programs are recruited or bypassed in movement imitation depending upon task conditions (whether familiar letters or novel shapes are imitated) and perceptual factors (whether shapes or letters are perceived). Subjects were asked to imitate the movements of a model who formed shapes and letters on a sheer mesh screen, and to report whether they perceived the task as a shape or a letter. Movements were recorded using a Vicon motion analysis system, and subsequently analyzed to determine the degree of difference between the demonstrated and produced movements. As predicted, letter perception on the letter tasks resulted in increased temporal error when the demonstrated stroke order conflicted with subjects’ habitual pattern of letter formation. No such interference effects were observed when the letter tasks were perceived as shapes. These findings are discussed in the context of current theories on imitation, and implications for rehabilitation and motor re-learning are presented.     

Differential diagnosis of cluttering and stuttering in Bulgaria

Fifteen stutterers, primarily children, who visited the Medical Pedagogical Department at the University of Blagoevgrad were evaluated for a variety of criteria used in Bulgaria to differentiate cluttering, stuttering, and mixed cluttering and stuttering. The same battery of tests was administered to all subjects. Based on these criteria, five subjects were diagnosed as clutterers, six as stutterers, and four as mixed. Daly's (1992–1993) Checklist for Possible Cluttering, Experimental Edition was also utilized to classify the subjects. Differences between the differential diagnostic criteria used by Bulgarian logopedists and other authors are discussed.     

Correlations between speakers' body size and acoustic parameters of voice

Generally, there is a significant relationship between some acoustic measures (F0 and formant parameters) and the body size of speakers; however, data become less clear when age and sex variables are controlled. To date, no other vocal parameter apart from F0 has been studied in relation to body size. In the present study, correlations between a set of 27 parameters of the Multi-dimensional Voice Program (Kay Elemetrics Corp.) and 4 body measures were obtained from 134 speakers of both sexes belonging to one age group (20-29 years). Correlations within sex groups were null or very weak, and all significant coefficients were below .35.     

Differential diagnosis of malingering and factitious disorder with physical symptoms

The present article attempts to clarify the difficult diagnostic discrimination between malingering and factitious disorder with physical symptoms. It is proposed that diagnostic evaluations focusing on the patient's observed symptomatology will be limited in their accuracy and utility. Instead, a longitudinal approach is needed to include the course of the disorder over time, its response to treatment, and the proposed etiology of the disorder. It is hoped that with a better understanding of these two disorders, prompt and accurate diagnosis can lay the foundation for effective management of both malingering and factitious disorders.     

Differential diagnosis and different etiologies of monopolar and bipolar phasic psychoses

Monopolar and bipolar phasic psychoses can be differentiated not only on the course but also on the symptom pattern. This applies also to the euphoric forms which usually are still assigned to Manic-depressive illness. The differential diagnosis is presented. Aetiology is completely different in the monopolar and the bipolar phasic psychoses. Manic-depressive illness has a hereditary basic, whereas in the monopolar ("pure") forms loading is very low. Particularly few psychoses among the relatives have been found in the euphoric forms which demonstrates their independency for if they would belong to Manic-depressive illness they necessarily would show the heavy genetic loading of this bipolar illness. In the pure phasic psychoses external causes were detected when we focused on the sibships in which the probands had grown up. The euphoric patients had relatively many older siblings, the depressive ones relatively few older siblings. A similar difference was found in two cycloid psychoses. Transcultural observations as well as shifts in the incidence rate of the psychoses in our times confirmed our results. Prophylactic measures can be derived.     

Response interference between functional and structural object‐related actions is increased in patients with ideomotor apraxia

We report data from two left hemisphere stroke patients with moderate‐to‐severe ideomotor apraxia who exhibited deficits in positioning their hands to use ‘conflict’ objects (objects grasped and used with different hand postures) relative to controls and patients with mild apraxia. These novel data support the claim that actions to common objects are subject to interference between multiple responses, and suggest that errors in apraxia may be attributed to deficient resolution of competition between appropriate and inappropriate actions.     

Differential context effects between sweet tastes and smells

"Sweet" smells and tastes are perceptually similar, and physiological data indicate some commonality of central processing. However, sweet tastes and sweet smells do not provide interchangeable contexts in psychophysical experiments. The same sweet tastes are perceived as less intense when stronger sweet tastes are present, and they are perceived as more intense when weaker sweet tastes are present, as with sweet smells. However, complementary sets of sweet tastes and smells (e.g., weak sweet tastes, strong sweet smells) do not eliminate these differential context effects (DCEs). The present experiments examined, first, whether DCEs between sweet tastes and smells arise because of differences between odors and tastes in the way that sweetness scales with intensity as concentration rises, and, second, whether DCEs may be smaller for sweet tastes and smells, when contrasted with sweet tastes and nonsweet smells. The findings were clear: DCEs were consistently present, suggesting they are independent of perceptual similarity. These results imply that DCEs are probably not psychological in origin or centrally based; rather, they may have a subcortical locus.     

Verisimilitude based on concept analysis

In the paper ordering relations for comparison of verisimilitude of theories are introduced and discussed. The relations refer to semantic analysis of the results of theories, in particular to analysis of concepts the theories deal with.     

Assessment of infant cry: acoustic cry analysis and parental perception

Infant crying signals distress to potential caretakers who can alleviate the aversive conditions that gave rise to the cry. The cry signal results from coordination among several brain regions that control respiration and vocal cord vibration from which the cry sounds are produced. Previous work has shown a relationship between acoustic characteristics of the cry and diagnoses related to neurological damage, SIDS, prematurity, medical conditions, and substance exposure during pregnancy. Thus, assessment of infant cry provides a window into the neurological and medical status of the infant. Assessment of infant cry is brief and noninvasive and requires recording equipment and a standardized stimulus to elicit a pain cry. The typical protocol involves 30 seconds of crying from a single application of the stimulus. The recorded cry is submitted to an automated computer analysis system that digitizes the cry and either presents a digital spectrogram of the cry or calculates measures of cry characteristics. The most common interpretation of cry measures is based on deviations from typical cry characteristics. Another approach evaluates the pattern across cry characteristics suggesting arousal or under-arousal or difficult temperament. Infants with abnormal cries should be referred for a full neurological evaluation. The second function of crying--to elicit caretaking--involves parent perception of the infant's needs. Typically, parents are sensitive to deviations in cry characteristics, but their perception can be altered by factors in themselves (e.g., depression) or in the context (e.g., culture). The potential for cry assessment is largely untapped. Infant crying and parental response is the first language of the new dyadic relationship. Deviations in the signal and/or misunderstanding the message can compromise infant care, parental effectiveness, and undermine the budding relationship. (c) 2005 Wiley-Liss, Inc. MRDD Research Reviews 2005;11:83-93.     

Interactions between perceptual organization based on Gestalt laws and those based on hierarchical processing

Our recent research with compound stimuli (Han, Humphreys, & Chen, 1999a) suggests that grouping between local elements facilitates the perception of global structure, whereas encoding closure in local elements enhances their segmentation. The present study presents further evidence supporting this assertion. Experiment 1 first developed a new paradigm in which grouping between local elements was manipulated. Subjects responded to the orientations of perceptual groups consisting of local arrows or triangles embedded in background crosses. Responses to the orientations of the groups were slowed as a function of the increased contrast of the crosses, indicating that the strength of grouping between local arrows or triangles was gradually weakened by increasing the contrast of the crosses. Using a similar paradigm, Experiments 2 and 3 investigated the role of Gestalt factors in hierarchical analysis. Global arrows or triangles made up of local arrows, or triangles were embedded in background crosses. Subjects responded to global or local stimuli in terms of orientation or closure. Increasing the contrast of the background crosses produced stronger effects on global responses than on local responses and resulted in elimination of the global precedence effect and emerging of a local precedence effect, which was stronger for closure discrimination than for orientation discrimination. These results provide new evidence supporting our previous claim about the role of Gestalt factors in hierarchical analysis.     

Differential incidence of procrastination between blue and white-collar workers

The present study compared chronic procrastination tendencies claimed by “whitecollar” working adults (n = 141) with rates reported by Harriott and Ferrari ( 1996) of “blue-collar” working adults (n - 211). Participants completed reliable and valid measures of everyday procrastination tendencies (decisional, arousal, and avoidant), and socio-demographic items at one of several public forums. Results showed no significant difference between classes of working adults on age, gender, marital status, or the number of children, although “white-collar” workers claimed higher levels of education than “blue-collar” workers. “White-collar” workers also reported significantly higher scores on all three forms of chronic procrastination than “blue-collar” workers. It seems that professional employees report procrastination more frequently than unskilled workers. Further research is needed to explore the causes and consequences associated with differences in chronic procrastination by occupational group.     

Differential incidence of procrastination between blue and white-collar workers

The present study compared chronic procrastination tendencies claimed by “whitecollar” working adults (n = 141) with rates reported by Harriott and Ferrari ( 1996) of “blue-collar” working adults (n - 211). Participants completed reliable and valid measures of everyday procrastination tendencies (decisional, arousal, and avoidant), and socio-demographic items at one of several public forums. Results showed no significant difference between classes of working adults on age, gender, marital status, or the number of children, although “white-collar” workers claimed higher levels of education than “blue-collar” workers. “White-collar” workers also reported significantly higher scores on all three forms of chronic procrastination than “blue-collar” workers. It seems that professional employees report procrastination more frequently than unskilled workers. Further research is needed to explore the causes and consequences associated with differences in chronic procrastination by occupational group.