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PubMedDate not supplied

Visual word perception and semantic processing: an electrophysiological perspective.

This paper reports data from three experiments in which semantic priming effects were investigated using the event-related potentials (ERP) technique. In the first experiment, a specific electrophysiological manifestation of semantic priming was demonstrated, and it was related to a previously reported negative component--N400. In the second experiment, it was suggested that the N400 wave does not directly reflect disconfirmation of subjects' expectations, but that it is related to semantic activation and is affected by the amount of lexical processing. In the third experiment, it was demonstrated that priming effects are also evident in natural reading, without any time constraints imposed by the task. It is concluded that the ERP technique provides an important tool in cognitive research in general, and language processing in particular.

Brain↗
PubMed1977

[In the boundaries of aphasia].

The anatomical boundaries of those structures whose lesion leads to the disturbances of language are indistintic and largely exceed the classical "areas of language", including subcortical structures as the thalamus and the non-dominant hemisphere. It is equally indistinct the possibility of definition of aphasic disturbances. On one hand aphasia can be seen within the realm of decodification, as a failure of a mental rather than of a verbal process, close to dementia, while among the codification mechanisms motor aphasia can appear a syndrome of phonetic desintegration with component of apraxic, dystonic and paretic nature. Esquizophasia and agrammatism are two examples of those peculiar disturbances of language. The correlation between disturbances of language and of intelligence is another frontier of aphasies where a causal relationship appears to be well established. Aphasias, interpreted in the beginnings as anatomically localized well defined disturbances of function, are now seen both anatomically and functionally, as a process with indistinct and mixed boundarie related to other equally illimited and indistinct functions.

Aphasia↗
PubMed1992

Delay versus deviance in the language acquisition of language-impaired children.

To investigate the issue of delay versus deviance in the language acquisition of language-impaired (LI) children, the order of acquisition of a set of linguistic structures and the relationship obtaining between one structure and another were examined in comprehension and production over a 5-year period in a group of LI and language-matched normal children. The results demonstrated a marked similarity between groups, both in the point at which mastery of individual structures was achieved and in the overall patterns of acquisition demonstrated. These data suggest that LI children are constructing grammars based on the same rules and principles as those of linguistically normal control subjects, and that their linguistic impairments may be principally processing, not representational, in nature.

Child, Preschool↗
PubMedDate not supplied

Adaptive communication systems for patients with mobility disorders.

An adaptive communication system has been developed for individuals with mobility disorders. It uses specialized computer software and hardware that compensate for this disability. For an individual with a motor-control impairment who is not able to use a keyboard effectively, a computer voice-recognition technology now removes this communication barrier. Speech-recognition systems consist of three basic components: speech processing, speech recognition, and speech understanding. The new Dragon Dictate (Dragon Systems, Inc., Newton, Mass.) is the first large-vocabulary speech recognition system in the personal computer industry that interactively learns a user's vocabulary and mode of speaking and responds to natural language rather than to limited sets of words. This speech-recognition system requires a microprocessor, a display monitor, a printer, and specific software packages, including word-processing and enhanced memory-management software. Important considerations in the use of this speech-recognition system include microphone positioning and training of the system. With the advent of this new voice-recognition computer system, another communication barrier between the disabled and society has been overcome.

Communication Devices for People with Disabilities↗
PubMed1989

Dimensional thinking in language impaired children.

This study investigated the dimensional knowledge evidenced by language impaired (LI) preschoolers. Ten LI and 10 language normal (LN) children, aged 3:6 to 5:9, were asked to solve verbal and nonverbal problems requiring color and size judgments. There were no group differences on the verbal task, but the LI children performed less well than the LN children on the nonverbal task. Much of this difference stemmed from their difficulty with size items. The ordinal nature of the size dimension implies greater cognitive processing demands than are inherent in nominal dimensions such as color. Given the known processing limitations of language impaired children, this complexity apparently can lead to erroneous judgment even when requisite knowledge is present. It may also contribute to delays in the initial construction of dimensional knowledge.

Child, Preschool↗
PubMed1986

An ultimate view of reading ability.

Research on reading and developmental reading disorders has almost exclusively questioned the immediate or proximate basis of these skills and deficits. A supplementary view is offered that considers reading ability from an evolutionary vantage. It is argued that in contrast to language, which has a long natural history in man and which has risen from a widespread biological adaptation in our species, reading has not, until very recently, exerted ecological pressure on humans and therefore no specific biological adaptations have occurred for these skills. It follows that developmental reading disorders may be due to genetically based, naturally occurring variants in neurological traits and not the result of pathological processes.

Animals↗
PubMed1990

Associative agnosias and the functions of the left hemisphere.

Associative agnosias are traditionally regarded as perceptual, and ideational apraxia as motor, deficits, but they can be understood as amnesias for generic knowledge, caused by bilateral or unilateral left-hemispheric cortical lesions. Current theories of hemispheric specialization explain these syndromes' mandatory link with left-hemispheric damage, and are validated by this link. This link reflects the multiple nature of generic, categorical representational systems, not all reducible to natural language, and the left hemisphere's principal role as their substrate, regardless of their dependence on language. The distinction between processing novel information, and processing based on well-established, routinized representations, captures a fundamental difference between the functions of the right and left hemispheres. The complementary link of apperceptive agnosias with right-and associative agnosias with left-hemisphere lesions is an expression of this general principle in the posterior cortex. Future studies of the neuroanatomy of agnosias in animals may offer insights into the evolutionary continuities of hemispheric specialization.

Agnosia↗
PubMed1990

[Test method for pre-speech language: I. Outline of test].

The purpose of this study is to determine infants' preliminary linguistic ability. For this a pre-speech language test method has been developed. The test method is as follows. First, a definition of language is given. Then the development process in infancy is explained according to the definition. Subsequently, the test items are decided according to the above process. (1) Definition of language: It is difficult to define language because of its many aspects. Here, for the language definition, the aspects are restricted to the following based on the properties of natural language. Section-1 Situation of language i) Formation of communication ii) Understanding and grasping of situation circumstance Section-2 Development of symbolizing function Section-3 Representing the function of language (generally, articulation of babbling and functional change) (2) Development of language: the above three aspects develop and change from preterm infancy to late infancy. The development process is as follows. Section-1 i) The formation of communication is confirmed by action situations between baby and mother. The actions include a steady gaze in the early stage and talking baby talk later. Requests for instruction assistance and emotional communication appear with gradual differentiation of communication. Section-1 ii) Understanding and grasping of the situation circumstance is confirmed with response to action from mother to baby in the early stage. These are then confirmed with the ability to understand the action and situation of surroundings as time and space extensity, and to give appropriate appeal to the surroundings. Subsequently, understanding with language only is acquired by daily experience, including language and understanding of the surrounding.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1989

Neuropsychological differences between the dementias of Alzheimer's and Parkinson's diseases.

The question of whether dementia of the Alzheimer type and dementia associated with Parkinson's disease are clinically separable is controversial. We examined possible neuropsychological differences in these two patient groups matched for overall severity of dementia. Patients with dementia of the Alzheimer type had more severe impairment on measurements of memory, language, and orientation, and, unlike patients with Parkinson's disease, there was evidence of apraxia. Patients with Parkinson's disease had more severe impairment related to speed of information processing, and, unlike patients with dementia of the Alzheimer type, they also had disturbance of mood. The nature of visuospatial abnormalities also differentiated the two groups. The pattern of neuropsychological differences is consistent with the cortical-subcortical hypothesis.

Affect↗
PubMed1984

Non-speech communication symbols and systems: where have we been and where are we going?

During the past quarter century, and especially during the past decade, we have seen the emergence of various non-speech communication symbols and systems as viable means of communication by and with severely handicapped individuals. A brief overview of the full range of both aided (static or graphic) and unaided (dynamic or manual) non-speech symbols and systems is presented. A hierarchy of difficulty, cognitive requisites, approximation to English (or other natural languages), abstraction, acceptance, etc. is considered. Advantages of non-speech communication are related to general input simplification, response production, receptive language/auditory processing, stimulus processing/stimulus association, and symbolic representation. The advantages of vocabulary limits and attentional facilitation for intervention with severely handicapped individuals are discussed. Major research issues are also explored.

Attention↗
PubMed1983

Visual problem solving in the absence of lexical semantics: evidence from dementia.

A case of dissociation between visual and praxic skills and linguistic, referential, and semantic skills is described in a case of dementia. Testing revealed that her visual processing was intact and that she was capable of a wide range of visually based tasks. These included copying geometric figures and block designs; matching items on the basis of number, color, or relative size, matching upper and lower case letters, sequencing numerals, orienting pictures, coins, and letters appropriately, and solving problems based on the identification of geometric patterns or on the identification of logical sequences based on pattern alternation, number, and size increases. In contrast, she was completely incapable of matching pictures on the basis of their semantic or referential meaning; similarly she had lost all comprehension of language. It was argued that this case demonstrates the capacities of a visual system cut off from all symbolic and semantic processes. When examined with other case studies this case provides information about the nature of and interaction between modality-specific perceptual processing and semantic processing, and information about the various cognitive factors involved in visual gnosis. The CT scan indicated frontal atrophy and marked anterior temporal atrophy, a pattern that is consistent with Pick's disease. The case was discussed in terms of the correlation between the pattern of observed strengths and deficits and the neurological pattern of atrophy.

Dementia↗
PubMed1985

An interactive aid for expressive communication with pictographic symbols.

An individual who is unable to acquire skills in natural language communication may frequently find a pictographic symbolic language to be an appropriate alternative means of expression. This paper discusses some underlying features of the communication process and describes a computer-based augmentative aid for communication with pictographic linguistic units, which provides flexibility for user-definition of symbols, inter-symbol mapping and multi-mode expression. The system is consequently a potentially very powerful tool for the development and utilisation of communication processes among groups of users who do not necessarily share access to a common linguistic knowledge base.

Communication↗
PubMed1984

[Simulation modeling of the initiation of tumor growth in continually renewed cell systems].

A discrete stochastic model of simulation of a cell renewal system is discussed. The model is based on a functional approach to the present-day concepts on the nature of processes of cell proliferation and differentiation as well as mechanisms responsible for integration of these processes. Due to application of specialized programming means of simulation (language GPSS /360) a complete functional pattern of maintenance of cell-population homeostasis in tissue was reproduced. Disturbances in certain mechanisms of intra-tissue regulatory system accompanied by formation of tumor growth foci were simulated experimentally.

Animals↗
PubMed1990

SAPHIRE--an information retrieval system featuring concept matching, automatic indexing, probabilistic retrieval, and hierarchical relationships.

SAPHIRE (Semantic and Probabilistic Heuristic Information Retrieval Environment) is an experimental computer program designed to test new techniques in automated information retrieval in the biomedical domain. A main feature of the program is a concept-finding algorithm that processes free text to find canonical concepts. The algorithm is designed to handle a wide variety of synonyms and convert them to canonical form. This allows natural language to be used for query input and also serves as the basis for a new approach to automatic indexing based on a combination of probabilistic and linguistic methods.

Abstracting and Indexing↗
PubMed1985

The effects of slowed speech on auditory comprehension in aphasia.

The present study investigates the effects of slowed speech on auditory comprehension in aphasia. Specifically, an attempt was made to isolate the effects of added time on comprehension at the language processing stages of auditory perception, by increasing the duration of the vowel segments in each word; word recognition and semantic analysis, by adding silences between words; and syntactic analysis, by adding silences at constituent phrase boundaries. Sentences were also read at a slow rate to see the effects of naturally slowed speech on sentence comprehension. Test sentences consisted of simple active and passive declarative sentences, and complex sentences with embedded medial and final relative clauses. Sentences were either semantically reversible or nonreversible. Thirty-four aphasic patients who varied in both severity and type of aphasia were tested on a picture verification task. Results indicated that slowing facilitated language comprehension significantly only in the syntactic condition. Neither syntactic complexity nor semantic reversibility interacted with slowed speech to facilitate auditory language comprehension. Further, it was only the Wernicke's aphasics who showed significant improvement with time added at constituent boundaries. These results suggest that time alone does not facilitate language comprehension in aphasia, but that rather it is the interaction of time with syntactic processing which improves comprehension.

Aphasia↗
PubMed1979

Personal pronouns and the autistic child.

The long-recognized difficulties of the speaking autistic child with the use and nonuse of personal pronouns ["reversals" and "avoidance"] have been generally attributed either to the nondifferentiation of the self or to the frequently coexisting symptom of echolalia. These explanations are reconsidered in this eclectic analysis from the perspective of current theory and research in development of self and of language. Emphasis is on studies of normal development of personal pronouns and the roles played in that process by listening, echoic memory, mitigated echolalia [recoding], and person deixis. It is concluded that multiple developmental obstacles of a social, cognitive, and grammatical nature underlie the more obvious symptoms and militate against the child's resolution of labels and their referents. Treatment alternatives that de-emphasize the primacy of I are offered.

Autistic Disorder↗
PubMed1991

Standardized and flexible batteries in neuropsychology: an assessment update.

This article summarizes current literature relevant to commonly used tests and test batteries in clinical neuropsychology. The first section contains a discussion of the philosophy and relative advantages of standardized and flexible battery approaches in neuropsychology. The second contains historical background and a literature review of the two major standardized test batteries: the Halstead-Reitan and Luria-Nebraska. The third section includes reviews of tests that are frequently used in the flexible battery approach. Various tests of intellectual functioning, attention, memory, language, and spatial analyses are critiqued in this section. Contributions of the process approach are noted. The article ends by underscoring the need for continued research into the nature of neuropsychological measures and the abilities they assess.

Attention↗