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PubMed1991

Errors resembling semantic paralexias in Spanish-speaking aphasics.

Forty-one Spanish-speaking left-hemisphere-damaged patients were selected and divided into seven groups (transcortical, Broca's aphasia, conduction aphasia, Wernicke's aphasia, anomic aphasia, alexia without agraphia, and global aphasia). A reading battery composed of eight different subtests was given to each patient (reading of letters, reading of syllables, reading of pseudowords, reading of words, reading of sentences, understanding commands, reading and comprehension of texts, and logographic reading). Different types of reading errors were analyzed. Only in the logographic reading subtest were some word-recognition errors found, resembling semantic paralexias. It is proposed that semantic paralexias in English (and other languages) depend upon the partial logographic nature of the reading system. The importance of cross-linguistic analysis of reading errors, taking into account reading system idiosyncracies, is emphasized.

Adult↗

PubMed1992

The processing of negative sentences in fluent aphasics: semantic and pragmatic aspects.

This paper examines the processing of negative sentences with respect to their truth value in fluent aphasic subjects. Three groups of 25 subjects each (men and women) were studied: the first group consisted of fluent aphasics, the second consisted of right temporal lobe-damaged subjects, and the third of normal subjects. An experiment of sentence verification was carried out. A quantitative study of reaction time (RT) and a qualitative study of the types of answers were carried out. The results show that the fluent aphasics were impaired in their logical-semantic processing of negative sentences and showed a predilection for the affirmative in answering strategies. The right temporal lobe-damaged subjects showed differences only in respect to the normal subjects in the RT, but not in answering strategies. The results suggest that in Wernicke's Aphasics there is a tendency to substitute a type of contextual-pragmatic processing for the logical-semantic processing.

Adult↗

PubMed1987

Effects of spontaneous cortical slow potentials on semantic information processing.

Adult subjects were tested on a choice reaction time (RT) task for decisions of word pairs as synonyms or unrelated. For each trial the word stimuli were presented contingent upon computer-detection of a predetermined negative or positive EEG baseline shift, recorded from either parietal or frontal midline electrodes. With parietal slow potential (SP) shifts, RTs were significantly faster and less variable under negative than positive polarity conditions. No appreciable RT differences were found between negative and positive SP shifts from frontal electrodes or for control subjects. The parietal negative SP shifts are considered to reflect enhanced semantic processing. The present findings in combination with previous results (Born et al., 1982, Electroencephalogr. Clin. Neurophysiol., 54: 668-676) demonstrate a double dissociation between the functional properties of negative SP shifts from parietal and frontal cortical areas, with respective involvements in semantic processing and response selection and execution.

Adolescent↗

PubMedDate not supplied

Modulation of semantic processing by spatial selective attention.

The effects of spatial selective attention upon ERPs associated with the processing of word stimuli were investigated. While subjects maintained central eye fixation, ERPs were recorded to words presented to the left and right visual fields. In each of 6 runs, subjects focussed attention to alternate fields to perform a category-detection task. Pairs of semantically related and repeated words were embedded in the word lists presented to the attended and unattended visual fields. Consistent with prior studies, the P1-N1 visual ERP was larger when elicited by words in attended spatial locations. A large negative slow wave identified as N400 was elicited by attended, but not unattended, words. For attended words, N400 was smaller for semantically primed or repeated words. We concluded that spatial selective attention can modulate the degree to which words are processed, and that the cognitive processes associated with N400 are not automatic.

Adolescent↗

PubMedDate not supplied

Capturing the semantic relationship between clinical terms with current MeSH bibliographic coding.

This paper compares bibliographic retrieval using current MeSH (Medical Subject Headings) to bibliographic retrieval using explicitly coded semantic relationships between index terms. In a previous study, ten lists of abstracts, each list containing 20-40 papers discussing a specific pair of terms, were analyzed to identify the specific relationship(s) between those terms discussed in each paper. In the present study, we analyze how well current MeSH coding using topical subheadings and check tags, can selectively retrieve those papers discussing each semantic relationship.

Abstracting and Indexing↗

PubMed1994

Illness semantics and international health: the weak lungs/TB complex in the Philippines.

Attention is drawn to illness semantics and the need to move beyond health social science research on discrete diseases to sets of illnesses perceived to be interrelated within popular health culture. Considered is the weak lungs/TB complex as it is conceptualized in relation to other types of lung disease as well as predisposing factors which influence the moral identity of the afflicted and the social relations of illness. The illness category weak lungs is broad and covers a variety of symptom states inclusive of TB. While some people equate weak lungs with TB, many others think of weak lungs as a condition which may develop into TB over time. TB is recognized to be contagious, but many people do not perceive weak lungs to be contagious. Treatment practice is discussed in relation to perceptions of illness severity, economics, expectations from medicines and coexisting health concerns. Faith in biomedicine is strong. Broad usage of the term weak lungs affects self-treatment practices and over-the-counter purchase of TB medications. Several TB medicines are labeled in such a way as to give the impression that they are vitamins for the lungs. This association leads people to think that the medication is useful for all illnesses which weaken the lungs, even if taken for a short duration. Attention is drawn to the manner in which inappropriate use of TB medication increases the chances of drug resistance. Data presented on TB drug resistance in the Philippines suggests why a consideration of illness semantics is important.

Antitubercular Agents↗

PubMed1981

Brain potentials, perceptual mechanisms and semantic categorisation.

The behaviour of intermediate and long-latency evoked potential (EP) components were investigated in a semantic categorisation task. Visually presented 'narrow' and 'wide' priming category questions, intended to vary processing load, were followed, after 1.5 sec by a 100 msec presentation of a positive or negative instance for decision. Neither behavioural response latencies nor amplitudes of N1-P2 (130 and 212 msec mean latencies) differentiated between 'narrow' and 'wide' category decisions. However, response latencies were faster and N1-P2 amplitudes greater for positive than for negative instances of primed categories. This result is attributed to the priming effect, by 'spreading activation, of prior category questions on 'logogen-like' pre-conscious word detecting devices within the brain. Semantic discrimination by N1-P2 contradicts previous assertions that intermediate components only reflect selection based on crude stimulus characteristics. Comparison of N1-P2 amplitudes at lateral electrodes offered no evidence of hemispheric lateralisation of language function in the experimental task. There was no late wave unequivocally identifiable as P300 on morphological and scalp distribution criteria. A positive peak at mean latency 327 msec (called P3) was of low amplitude and stable latency and did not appear to index processing load as defined by the experimenters. However, the amplitude of N2-P3 was larger to positive instances of narrow categories than any of the other three conditions. This could be the sort of probability effect seen in P300 behaviour if it is assumed that the brain can discriminate between stimuli on the basis of the size of the subset from which they come.

Adult↗

PubMed1985

Saccade-related brain potentials in semantic categorization tasks.

Saccade-related brain potentials (SRPs) were recorded in word categorization tasks in which subjects had to perform a saccade in order to perceive the stimulus. For all three conditions representing different degrees of complexity of semantic categorization, the stimuli belonged to one of two categories which appeared with the respective probabilities of either 0.20 or 0.80. The late positivity (P4) of the SRPs to infrequent stimuli appeared systematically later as the complexity of stimulus evaluation increased: The easiest categorization was accompanied by a P4 at 400 msec, in the more complex condition it peaked at 600 msec, and in the most difficult semantic categorization the P4 peaked even later, at 680 msec. This shift in peak latency with increasing complexity of categorization is in agreement with the results for traditional ERPs (e.g. Kutas and Donchin, 1978). The possible overlap of the late components was investigated by applying Principal Component-Varimax Analysis to the SRPs.

Adult↗

PubMed1978

Relationship of patient semantic pain descriptions to physician diagnostic judgments, activity level measures and MMPI.

A consecutive sample of chronic pain patients presenting themselves for evaluation was studied. A set of 25 bi-polar adjectives was developed from medical records of previous pain patients' descriptions of their pain. Using the Semantic Differential (S-D) method, each patient rated the extent to which his/her pain was best described by either of the adjective pairs. The S-D findings were then compared with three other data sets and those data sets were compared with each other. First, six physicians classified each patient along an "organic"--"non-organic" continuum based on ratings derived from the full set of medical diagnostic labels each patient had accrued. Secondly, each patient, prior to examination, had completed up to two weeks of diary forms at home on which were recorded amount and distribution of time among sitting, standing/walking, and reclining. Finally, each patient completed a Minnesota Multiphasic Personality Inventory (MMPI). Few and only marginally significant relationships between patient semantic descriptions of their pain and the other measures were found. Secondly, physician agreement ot the "organic"--"non-organic" criterion, using diagnostic labels as their data, was statistically significant but clinically modest. The most substantial findings were between walking hours per week recorded on diary forms and five MMPI scales. Patients who walked more were less depressed, had fewer diffuse somatic complaints, and described themselves as less frustrated or angry and as less hypersensitive in interpersonal situations. The major conclusion of the study is that chronic pain patients present sets of interrelated problems too complex to be discriminated reliably by a single set of measures; particularly, by simple word sets.

Activities of Daily Living↗

PubMed1980

Cross-cultural pain semantics.

Cultures differ as to typical linguistic reports and classifications of pain. In some languages upwards of a dozen specific pain terms are in common use, each indicating a particular pain experience. In other languages a single inclusive term is the norm, perhaps with optional qualifiers added to make desired distinctions. Pain experience thus undergoes cognitive sorting of different types, and it is important to be aware of how obligatory or how optional imposed linguistic distinction may be. Cultural responses to pain, including local medical practices, may be linked to such cognitive sorting. A bolder speculation (in line with the Sapir-Whorf hypothesis) would be to think of cognitive categorizations as exerting controls on affective perception itself through some type of neo-cortical monitoring or filtering of incoming neural messages. Before turning to these questions, more technical aspects of pain-term semantics need to be studied and issues must be clearly formulated. The present paper examines in some detail a representative proliferated system (Thai) and then makes some comparisons with distinctions in other languages. Taxonomic and sequential contrast relationships are discussed and illustrated. In particular, it is proposed that varying types and degrees of looseness in semantic contrast cannot be ignored if revealing cross-cultural comparisons are to be made.

Cross-Cultural Comparison↗

PubMed1976

Addicts' attitudes toward drugs: a semantic-differential study.

The Drug Rating Scale, an adaptation of the Osgood semantic-differential technique, was devised to measure the connotative aspects of attitudes toward drugs. Sixty-two heroin-addict clients and fourteen staff members of the Haight-Ashbury Free Medical Clinic completed the Scale. The Addict group tended to regard heroin in a negative light, possibly consistent with their own lack of self-esteem. Amphetamines and LSD had the greatest distance from heroin in the addicts' "semantic space"; this was consistent with addicts' relative preference for alternative drugs to heroin. The evaluative and activity dimensions provided a plausible assignment of the eight drugs inquired about into four quadrants.

Adult↗

PubMed1993

Event-related brain potentials during natural speech processing: effects of semantic, morphological and syntactic violations.

The present study investigated different aspects of auditory language comprehension. The sentences which were presented as connected speech were either correct or incorrect including a semantic error (selectional restriction), a morphological error (verb inflection), or a syntactic error (phrase structure). After each sentence, a probe word was presented auditorily, and subjects had to decide whether this word was part of the preceding sentence or not. Event-related brain potentials (ERPs) were recorded from 7 scalp electrodes. The ERPs evoked by incorrect sentences differed significantly from the correct ones as a function of error type. Semantic anomalies evoked a 'classical' N400 pattern. Morphological errors elicited a pronounced negativity between 300 and 600 ms followed by a late positivity. Syntactic errors, in contrast, evoked an early negativity peaking around 180 ms followed by a negativity around 400 ms. The early negativity was only significant over the left anterior electrode. The present data demonstrate that linguistic errors of different categories evoke different ERP patterns. They indicate that with using connected speech as input, different aspects of language comprehension processes cannot only be described with respect to their temporal structure, but eventually also with respect to possible brain systems subserving these processes.

Adult↗

PubMed2005

A semantic verbal fluency test for English- and Spanish-speaking older Mexican-Americans.

Currently, there are few semantic verbal fluency tests available with appropriate and adequate normative data for older Latinos of Mexican ancestry. The purposes of this study were to examine the effects of language and socioeconomic variables on a semantic verbal fluency test, derive normative data and develop statistical corrections for the effects of significant variables. A large, community-dwelling sample of Latinos of primarily Mexican ancestry over age 60 was asked to name animals with four legs within 1 min in their preferred language of English or Spanish. The total sum of animals named was influenced by age, education, gender, and, to a much lesser extent, language of test administration. Regression coefficients derived from demographic variables were used to adjust raw scores in a general correction formula, and specific percentile cutoff values were identified for these adjusted scores. Normative data tables stratified on demographic variables are also presented.

Aged↗

PubMed2006

Age-of-acquisition differences in young and older adults affect latencies in lexical decision and semantic categorization.

An ongoing discussion about the role of age of acquisition (AoA) in word processing concerns the confound with word frequency. This study removed possible frequency confounds by comparing AoA and word familiarity differences in young (18-23 years) and older (52-56 years) adults. A first study investigated the differences in AoA and word familiarity ratings. The norms of AoA and familiarity were significantly different for young and older adults whereas these were previously considered equivalent [Morrison, C. M., Hirsh, K. W., Chappell, T., & Ellis, A. W. (2002). Age and age of acquisition: An evaluation of the cumulative frequency hypothesis. European Journal of Cognitive Psychology, 14, 435-459]. In the second study, AoA and familiarity effects were significantly different for the older and young adults in a lexical decision task. The third study replicated these findings in a semantic artifact/naturally occurring categorization experiment, thus providing further evidence for AoA-effects when word processing requires semantic mediation. Results from both studies were in line with the hypothesis that AoA effects on word processing cannot be accounted for by word frequency or other possible confounds.

Adolescent↗

PubMed2006

Semantic priming effects from single words in a lexical decision task.

The present research examines the semantic priming effects of a centrally presented single prime word to which participants were instructed to either "attend and remember" or "ignore". The prime word was followed by a central probe target on which the participants made a lexical decision task. The main variables manipulated across experiments were prime duration (50 or 100 ms), the presence or absence of a mask following the prime, and the presence (or absence) and type of distractor stimulus (random set of consonants or pseudowords) on the probe display. There was a consistent interaction between the instructions and the semantic priming effects. Relative to the "attend and remember" instruction, an "ignore" instruction produced reduced positive priming from single primes presented for 100 ms, irrespective of the presence or absence of a prime mask, and regardless of whether the probe target was presented with or without distractors. Additionally, reliable negative priming was found from ignored primes presented for briefer durations (50 ms) and immediately followed by a mask. Methodological and theoretical implications of the present findings for the extant negative priming literature are discussed.

Adolescent↗

PubMed2006

Brain activation during semantic processing in autism spectrum disorders via functional magnetic resonance imaging.

Language and communication deficits are core features of autism spectrum disorders (ASD), even in high-functioning adults with ASD. This study investigated brain activation patterns using functional magnetic resonance imaging in right-handed adult males with ASD and a control group, matched on age, handedness, and verbal IQ. Semantic processing in the controls produced robust activation in Broca's area (left inferior frontal gyrus) and in superior medial frontal gyrus and right cerebellum. The ASD group had substantially reduced Broca's activation, but increased left temporal (Wernicke's) activation. Furthermore, the ASD group showed diminished activation differences between concrete and abstract words, consistent with behavioral studies. The current study suggests Broca's area is a region of abnormal neurodevelopment in ASD, which may be linked with semantic and related language deficits frequently observed in ASD.

Adult↗

PubMed2007

Hemispheric differences in the time-course of semantic priming processes: evidence from event-related potentials (ERPs).

To investigate hemispheric differences in the timing of word priming, the modulation of event-related potentials by semantic word relationships was examined in each cerebral hemisphere. Primes and targets, either categorically (silk-wool) or associatively (needle-sewing) related, were presented to the left or right visual field in a go/no-go lexical decision task. The results revealed significant reaction-time and physiological differences in both visual fields only for associatively related word pairs, but an electrophysiological difference also tended to reach significance for categorically related words when presented in the left visual field. ERP waveforms showed a different time-course of associative priming effects according to the field of presentation. In the right visual field/left hemisphere, both N400 and Late Positive Component (LPC/P600) were modulated by semantic relatedness, while only a late effect was present in the left visual field/ right hemisphere.

Adult↗

PubMed2004

Semantic, lexical, and phonological influences on the production of verb inflections in agrammatic aphasia.

Verb inflection errors, often seen in agrammatic aphasic speech, have been attributed to either impaired encoding of diacritical features that specify tense and aspect, or to impaired affixation during phonological encoding. In this study we examined the effect of semantic markedness, word form frequency and affix frequency, as well as accuracy and error patterns, in an attempt to evaluate whether diacritical or affixation operations are impaired. Verb inflections (V + ing, V + ed, V + s, and V stem in present progressive, past, present 3rd person singular, and future tense contexts, respectively) were elicited in eight mild-moderate agrammatic aphasic individuals in a sentence context using a picture description task. Results revealed that the majority of verbs produced were affixed (75%) although accuracy was low (36%). Word form frequency was found to be a significant predictor of the accuracy with which verb inflections were produced; while affix frequency and semantic markedness were not found to influence accuracy. These results suggest that a diacritical deficit is more likely to undermine the production of verb inflections than a affixation deficit, and indicate that when diacritical processes are compromised, word form frequency is likely to influence production of verb inflections in agrammatic aphasia.

Adult↗