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PubMedDate not supplied

Semantic memory in DAT, MID and parkinsonism.

Previous studies found the semantic system particularly affected in Dementia of Alzheimer's Type (DAT), which would have important implications for the clinical diagnosis of this disease. We compared 14 non-demented parkinsonian patients and 14 controls on one hand and demented patients suffering from multi-infarct dementia (n = 17), DAT (n = 18) and Parkinsonism + dementia (n = 7) on the other. Demented groups were well matched regarding severity of dementia. Two tasks of semantic memory (naming, word fluency) did not differentiate within demented groups, but were correlated with severity of dementia.

Aged↗

PubMed1988

Semantically assisted medical bibliographic retrieval: an experimental computer system.

An experimental computer-based bibliographic retrieval system has been implemented to explore how semantic (conceptual) relationships between MeSH terms might assist the retrieval process. To construct the experimental system's database, lists of abstracts were produced using MEDLINE. Each list contained papers discussing a specified pair of terms. Each abstract was then analyzed to determine the specific relationship(s) between the two terms discussed in that paper. The project then explored how these semantic relationships could be incorporated into the computer to enhance bibliographic retrieval.

Information Systems↗

PubMed1987

[Semantic scales for noise evaluation. Third stage: subjective characterization of sound stimuli].

This is the third step of a research for which Osgood's Differential Semantic Technique was resorted to in order to get suitable scales on a subjective evaluation of sound stimuli. Thus, a three-stage work was fulfilled. The first one dealt with the construction of seven-point bipolar scales starting from experimentally selected adjectives. The second one succeeded in finding the subjacent dimensions of the said scales by means of Factorial Analysis Method. The present stage aims at characterizing 40 sound stimuli through the discovered dimensions most representative scales. A special Semantic Differential Program was used to getting the following Index: Scalar Scores, Polarity, Familiarity and Interconcept Distances. The interpretation of the Index showed the best characterized stimuli altogether with their affective meanings and their similarities and differences as well.

Acoustic Stimulation↗

PubMed1987

Toward the problem of physical and semantic component of the form during eye scanning.

In subjects inspecting random polygonal shapes eye movements were recorded by means of a corneal reflection technique and computer processed. Eye fixations were mostly located around angles. Distribution of fixations over different angles was unhomogenous. Angular rotation changed both semantic meaning of the shapes and the eye fixation distribution. Sequential Markov dependence was found only in cases when semantic interpretation of the shapes was reported by the subjects and was absent when the shapes were perceived as meaning-less geometrical patterns.

Eye Movements↗

PubMed1985

Semantic processing and serial learning by EMR adolescents.

In a previous study we found that providing the semantic strategy of stories linking to-be-remembered items facilitated free-recall in original learning and in retention after 2 months (Glidden & Warner, 1983). The present study replicated the previous study but with a serial-recall requirement. A story linking items within blocks of a to-be-recalled list was provided for EMR subjects. In comparison to control subjects, they recalled more in the early trials of original learning, but retention after 8 months was comparable for the two conditions. Future investigators should focus on how to train retarded subjects to generate their own semantic strategies for serial learning.

Adolescent↗

PubMed1985

Associative strength level and retrieval inhibition in semantic memory.

In a series of investigations, E. F. Loftus (1973; G. R. Loftus & E. F. Loftus, 1974; E. F. Loftus, Senders, & Turkletaub, 1974) discovered that the latency of item retrieval from a semantic category was reduced if it immediately followed an earlier retrieval from the same category, a phenomenon attributed to spreading activation. Subsequently, Brown (1981) discovered an increase in latency across extended retrievals from a single semantic category. The present investigation followed up this finding by comparing exemplars that varied in strength of association to the category name. The probability of obtaining inhibition (longer latencies and increased errors) was inversely related to the associative strength of the exemplars. The results suggest that low-strength category associates build up inhibition more rapidly because they accrue situational strength relatively more rapidly than high-strength associates.

Association↗

PubMed1984

[The effect of script frequency on semantic processing of Kanji and Kana words].

To examine the effect of script type and/or script frequency on the semantic access to words, 34 undergraduates were required to category decision for each word presented tachistoscopically. Three classes of words were used as stimuli; Kana words with low Kana script frequency (Kana-Low), Kana words with high Kana script frequency (Kana-High), and Kanji words with high Kanji script frequency (Kanji). Mean decision latency for Kana-High was shorter than that for Kana-Low, while there was no difference of latency between Kana-High and Kanji. These results show that the speed of semantic access depends on script frequency rather than script type.

Adult↗

PubMed1984

[Semantic scales for the evaluation of noise (II). Subjacent dimensions in subjective judgments of sound stimuli].

Second stage of a research in which Osgood's Diferential Semantic Technique was used in two experiments with the following aims: a) to find out the subyacent dimensions of subjective evaluation of sound stimuli; b) to know if Osgood's Evaluation, Potency and Activity dimensions appear when sound stimuli are judged; c) to obtain a group of semantic scales that represent the found dimensions, which can be used in other researches in the same field. In the first experiment 37 scales were used by 98 Ss for judging 10 sound stimuli. In the second, 120 Ss performed the same task through 46 scales and 40 sound stimuli. Data of both experiments were processed by factor analysis method and a Varimax rotation was done. Having obtained 12 similar factors in both experiments the results were analized in a comparative way. Eight dimensions that explain the subject-sound stimuli relation were found. The other dimensions deal with the stimulis control, cognitive experience and structural caracteristics of sound stimuli, being the affective component also present in some of their scales. In the third stage the sound stimuli used will be analized through the found dimensions.

Acoustic Stimulation↗

PubMed1983

[Construction of semantic scales for the subjective evaluation of noise].

This is the first stage of a research the aim of which is to construct proper scales for the subjective evaluation of noise, using Osgood's Differential Semantic Technique. 137 adjectives were selected using two criteria. For the first criterium a method based on Gougenheim's and Hogenraad's researches was used. 200 subjects were asked to write 30 adjectives that could be used for qualifying sonorous stimuli. The frequencies of the adjectives given by the subjects were calculated and 25 of them were selected for being under the 10% limit of the probability, arbitrarily chosen as a criterium for the selection. For the second criterium 10 acoustic researchers were asked to write all those adjectives they considered important for noise evaluation. Thus, 112 adjectives were selected. The 137 adjectives got by the two criteria were judged by 15 university professors of different careers, for getting their opposites. A level of agreement of at least 6 of 15 judges was considered. 62 adjectives with their opposites were got and using other two criteria they were reduced to 37. A hypothesis was formulated grouping the adjectives into 8 factors taking into account the three universal factors: Evaluation (E), Potency (P) and Activity (A) according to the Differential Semantic Technique. Seven point scales were constructed with the adjectives. The construction of the scales, the selection of concepts, the application of them to a sample of subjects and data analysis will be the second stage of this research.

Acoustic Stimulation↗

PubMed1984

Unconstrained retrieval from semantic memory.

The present study was designed to examine developmental change in the processes used to retrieve lexical information from semantic memory. We asked 8-, 12-, and 21-year-olds to name as many animals and pieces of furniture as they could, in separate 7-min intervals. The principal results were the following: (1) the number of items retrieved increased with age, but at all ages retrieval declined hyperbolically over the 7-min interval; (2) analysis of the time between retrieval of successive items indicated that older individuals retrieved larger clusters of items, but that the number of clusters retrieved did not vary with age; and (3) at all ages prototypic category members were retrieved first, followed by typical (but not prototypic) and atypical category members. The results are explained in terms of a model in which the information in semantic memory changes with age, but the processes used to retrieve that information do not.

Adult↗

PubMed1982

A differential semantic assay in order to measure aggressiveness.

The Semantic Differential test for aggressiveness consists of 45 phrases depicting situations which may provoke aggression. They are semantically grouped in two categories of covert and of overt aggressiveness. The reliability of the test was verified in a preliminary study, using one group of patients clinically diagnosed as aggressive, and one group of non-aggressive subjects. The means of the two groups' scores were significantly different, 95% of aggressive subjects having greater than 8 unit and only 21% of non-aggressive ones. After the final validation of the test it can be used to diagnose the aggressiveness in Type A behaviour pattern.

Aggression↗

PubMed1980

Retrieval speed, age-of-acquisition estimates, uncertainty, and semantic-dimension comparisons with mentally retarded persons.

Age-of-acquisition estimates and ratings on seven semantic dimensions by nonretarded adults were compared with the codability and retrieval speed of those items by retarded individuals. Correlational analyses indicated that age-of-acquisition estimates, codability, and retrieval speed were highly related to each other and significantly related to most of the semantic dimensions. Regression analyses revealed that codability, meaningfulness, and imagery each contributed significantly to the variance of retrieval speed. These results were compared with those of similar studies in which the lexical retrieval speed of nonretarded persons was investigated.

Age Factors↗

PubMedDate not supplied

[The role of the first and second signal systems in the correlation of semantic and perceptive color spaces].

The first and the second signal systems were studied in computerized experiments using colour stimuli and colour names. Multidimensional graduation of subjective differences between monochromatic colours and colour names showed that perceptual colour space and semantic colour space were isomorphic and constituted hyperspheres in a four-dimensional space. The angles of the hypersphere corresponded to hue, lightness, and saturation of colours and ordered colour names with respect to these characteristics. The subjective differences between monochromatic colours and colour names made it possible to construct a common space where monochromatic colours and corresponding colour names were represented by the neighbouring points, thus supporting isomorphic relations between perceptual and semantic colour spaces.

Color Perception↗

PubMed1993

Semantic processing in information retrieval.

Intuition suggests that one way to enhance the information retrieval process would be the use of phrases to characterize the contents of text. A number of researchers, however, have noted that phrases alone do not improve retrieval effectiveness. In this paper we briefly review the use of phrases in information retrieval and then suggest extensions to this paradigm using semantic information. We claim that semantic processing, which can be viewed as expressing relations between the concepts represented by phrases, will in fact enhance retrieval effectiveness. The availability of the UMLS domain model, which we exploit extensively, significantly contributes to the feasibility of this processing.

Information Storage and Retrieval↗

PubMed1993

[Semantic activation phenomena in healthy probands and in schizophrenic patients. Analysis on the level of word pairs].

Semantic priming in normal controls and schizophrenic patients can be demonstrated in lexical decision tasks. Data from such a lexical decision task are analyzed with special respect to the question as to whether associative processes in schizophrenic patients are characterized by the occurrence of entirely new associations or by the intrusion of normal associations, i.e., associations which can be found in normal subjects. The analysis of the semantic priming effects of single word pairs demonstrates little qualitative differences between the associations of normals and of schizophrenic patients. This finding provides further support for Maher's hypothesis of activated normal associations in schizophrenic patients. From a methodological perspective, the item-by-item analysis of lexical decision task data can be used to optimize this method.

Adult↗

PubMedDate not supplied

[The perceptive, mnemonic and semantic levels of subjective reflection].

Comparison of different colour stimuli between each other has shown that the whole quantity of colours is projected onto the surface of a sphere in a four-dimensional space. Geometric distances between the points representing colours are directly proportional to subjective differences between the colours. Information on the perceptible colours is recorded in the long-term memory. Traces of the colour memory form a mnemic space isomorphous to a perceptive colour space. Traces of the colour memory are connected by means of two-way bonds with symbol representation of colours which form a semantic colour space. Analysis of subjective differences between the colour names has shown that the terms of colours are represented by points on the surface of a hypersphere in a four-dimensional space. Colour stimuli being reflected at the perceptive, mnemic and semantic levels become an act of consciousness with participation of the activating brain systems.

Color↗

PubMed1997

[A semantic-pragmatic learning disabled child who showed a discrepancy between the abilities of verbal and non-verbal comprehension].

A learning disabled (LD) child with disorder of verbal semantic comprehension was reported. This case showed normal ability of non-verbal semantic comprehension. He was not able to understand the meaning of what he read aloud and/or repeated, which he did well. The focus of his brain dysfunction in the left temporal lobe was revealed by SPECT in spite of MRI findings of no particular lesions. Neuropsychological and cognitive-psychological findings were similar to those reported of adult sensory aphasias with localized lesions.

Child↗

PubMed1998

The role of semantic context and memory in the acquisition of novel nouns.

Three studies assessed the ability of 2-year-olds to use semantic context to infer the meanings of novel nouns and to retain those meanings a day later. In the first experiment, 24 2-year-olds heard novel nouns in sentences that contained semantically constraining verbs (e.g., "Mommy feeds the ferret"). They chose from a set of four novel object pictures to indicate the referent. Children learned a majority of the novel words. However, they occasionally failed to choose the correct object even when they understood the verb. Experiment 2 examined whether this was due to an inability to identify some of the pictures of novel objects. Experiment 3 tested 24 2-year-olds' memory for the newly learned nouns following a 24 hr delay and found significant retention. Results are discussed in terms of learning mechanisms that facilitate vocabulary acquisition in young children.

Age Factors↗