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PubMed1983

Age, presentation rate, and the effectiveness of structural and semantic recall cues.

To replicate the results of research on age-related differences in the effectiveness of structural and semantic memory cues, 18 young, 18 middle-aged, and 18 elderly adults recalled three 20-item lists aided by category labels, or the initial two letters of each word, or no cues. Lists were presented at 1.5 or 4 sec presentation rates to evaluate the effects of changes in processing speed on age-related trends in cue effectiveness. Semantic cues were most effective in improving recall at all three age levels; structural cues produced intermediate levels of recall facilitation. There was no indication of reduced effectiveness of semantic cues with increases in age and presentation rate, suggesting factors other than age-related changes in the depth of processing are responsible for developmental differences in memory.

Adult↗

PubMed2001

The selective preservation of colour naming in semantic dementia.

This paper documents a series of seven patients with semantic dementia who showed a selective preservation in colour naming. This was in the context of a pervasive impairment in naming nouns across a wide range of other semantic categories. To our knowledge, this is the first series of patients with semantic dementia documenting a selective preservation of colour naming. These findings are discussed in the light of current theoretical accounts of category-specific effects and the possible contribution of imageability to this selective preservation of colours.

Aged↗

PubMed2001

The hemispheric difference of semantic processing of Chinese characters in two dimensions as revealed by ERPs.

An experiment was conducted to examine the hemispheric dominance in semantic processing of Chinese characters. Results showed that N1 is the earliest component that reflects the semantic processing of Chinese characters. Although N1 of the left hemisphere is larger in amplitude, that of the right hemisphere is shorter in latency. Based on these findings, the authors propose that the left hemisphere does not start processing until the necessary information has been transferred from the right hemisphere. Once the left hemisphere starts processing, its intensity is stronger. Thus, it is more appropriate to differentiate hemispheric processing dominance into two dimensions: speed and intensity. Moreover, the semantic cognition onset of Chinese characters occurs from 100 ms to 160 ms in the posterior perceptual processing area of brain.

Adult↗

PubMedDate not supplied

What does the word "psychosomatic" really mean? A historical and semantic inquiry.

Semantics and history of psychosomatic medicine are not popular topics nowadays, if they ever were; yet both of them constitute indispensable facets of any discipline that lays claim to a separate identity, as psychosomatics does. The latter, being an inchoate and inherently complex field of study, is especially in need of repeated efforts to clarify the meaning of its key terms, to delineate its scope, and to chart its development over time. Such efforts should pay off in improved teaching of this subject and in more effective communication with workers in other disciplines and with the general public. I have tried in this paper to sketch the historic development of psychosomatic conceptions and address some relevant semantic issues. It appears that early in this century, the convergence of two ancient conceptions, the holistic and the psychogenic, prepared the ground for the emergence in the 1930s of psychosomatic medicine as an organized scientific discipline and a counterreformation against the mechanistic view of man and medicine. Those two conceptions came to be subsumed by the word "psychosomatic" and thus contributed its two distinct connotations. The latter have not usually been clearly distinguished; hence, the ambiguity of the term. I have argued that only the holistic connotation should be retained, as it properly conveys the contemporary viewpoint. It is unfortunate that the word "holistic" has been appropriated recently by an anti-scientific and antiintellectual so-called "holistic health movement" (67), with resulting increment in semantic confusion and, in the eyes of many, loss of credibility for the misappropriated term. However, to retain it has merit as it is short, simple, and derived from the Greek - as were the very conceptions it has come to connote. Moreover, "holistic" has been part of the basic vocabulary of psychosomatic medicine from the beginning and conveys its core premises and purpose faithfully. As a historian aptly put it, the historic function of the psychosomatic movement has been to "vitalize the whole of medicine, psychiatry no less . . . with the holistic and ecologic viewpoint" (59, p. 9).(ABSTRACT TRUNCATED AT 400 WORDS)

History, 17th Century↗

PubMed2003

Histological image retrieval based on semantic content analysis.

The demand for automatically recognizing and retrieving medical images for screening, reference, and management is growing faster than ever. In this paper, we present an intelligent content-based image retrieval system called I-Browse, which integrates both iconic and semantic content for histological image analysis. The I-Browse system combines low-level image processing technology with high-level semantic analysis of medical image content through different processing modules in the proposed system architecture. Similarity measures are proposed and their performance is evaluated. Furthermore, as a byproduct of semantic analysis, I-Browse allows textual annotations to be generated for unknown images. As an image browser, apart from retrieving images by image example, it also supports query by natural language.

Diagnostic Imaging↗

PubMed2004

Partial awareness creates the "illusion" of subliminal semantic priming.

We argue that the lack of consensus regarding the existence of subliminal semantic processing arises from not taking into account the fact that linguistic stimuli are represented across several processing levels (features, letters, word form) that can independently reach or not reach awareness. Using masked words, we constructed conditions in which participants were aware of some letters or fragments of a word, while remaining unaware of the whole word. Three experiments using the Stroop priming paradigm show that when the stimulus set is reduced and participants are encouraged to guess the identity of the prime, such partially perceived stimuli can nonetheless give rise to "semantic" processing. We provide evidence that this effect is due to illusory reconstruction of the incompletely perceived stimulus, followed by usual semantic processing of the result. We conclude that previously reported unconscious Stroop priming is in fact a conscious effect, but applied to a perceptual illusion.

Attention↗

PubMed1995

Variation in the latencies and amplitudes of N400 and NA as a function of semantic priming.

The purpose of this study was to determine whether the latencies of two event-related potential (ERP) components, the NA and N400, were sensitive to semantic priming. Subjects performed a semantic judgment task, which was designed in such a way that the N400 could be examined without overlap from the P3. Priming effects on the latencies of both NA and N400 were most apparent at frontocentral sites. The amplitude of NA was not significantly affected by priming. The amplitude of N400 was smaller for primed than for unprimed words, but the effect was significant only at centroposterior sites. Current source density (CSD) analyses performed on the ERP data suggested the activation of multiple generators in the N400 time region. The ERP and CSD data were consistent with the existence of two types of N400, a frontal N400 that varies in latency as a function of semantic priming, and a posterior N400 that varies in amplitude.

Adult↗

PubMed1998

Semantic mediation of age-related deficits in episodic recognition of common odors.

In the present research, the relationship between various semantic memory functions and episodic odor memory across the adult life span is addressed. In contrast to earlier evidence that odors may be encoded and stored as unique, nonlinguistic whole percepts, the present work suggests that episodic odor information is mediated by factors that can be subsumed under the rubric of semantic memory. Specific olfactory knowledge, such as perceived familiarity and identifiability, is strongly and positively related to episodic odor memory performance. In contrast to research using verbal and visual stimuli, proficiency in complex verbal intellectual abilities, such as vocabulary and fluency, seems to be of minor importance in memory for olfactory information. In agreement with earlier findings, this research indicates that episodic odor memory deteriorates across the adult life span. A similar negative age trend was observed for odor naming. Most importantly, statistical control of odor naming resulted in the elimination of age-related odor memory deficits. These results suggest that age-related failures in accessing specific semantic information of odors determine largely age-related deficits in episodic odor recognition.

Adult↗

PubMed1999

Semantic dysfunction in frontotemporal lobar degeneration.

Semantic dementia, characterized by loss of word meaning and impaired face and object recognition, is one of the clinical manifestations of frontotemporal lobar degeneration and is associated with atrophy of the inferior and middle temporal gyri. Patients may present predominantly with problems in naming and understanding words, or in face and object recognition, the verbal or nonverbal predominance reflecting the accent of atrophy on the left or right temporal lobe. Behavioural changes may occur, although these have a more obsessional quality than is typically seen in frontotemporal dementia (FTD). However, overlap in clinical symptomatology of semantic dementia and FTD may occur with disease progression reinforcing the link between these clinical syndromes. Semantic dysfunction is poorly recognized and may be mistaken for the amnesia of Alzheimer's disease, yet may be important in explaining some of the behavioural characteristics seen in focal cerebral degeneration.

Dementia↗

PubMed2001

Perceptual and semantic components of memory for objects and faces: a pet study.

Previous studies have suggested differences in the neural substrates of recognition memory when the contributions of perceptual and semantic information are manipulated. In a within-subjects design PET study, we investigated the neural correlates of the following factors: material type (objects or faces), semantic knowledge (familiar or unfamiliar items), and perceptual similarity at study and test (identical or different pictures). There was consistent material-specific lateralization in frontal and temporal lobe regions when the retrieval of different types of nonverbal stimuli was compared, with objects activating bilateral areas and faces preferentially activating the right hemisphere. Retrieval of memories for nameable, familiar items was associated with increased activation in the left ventrolateral prefrontal cortex, while memory for unfamiliar items involved occipital regions. Recognition memory for different pictures of the same item at study and test produced blood flow increase in left inferior temporal cortex. These results have implications for our understanding of the neural correlates of perceptual and semantic contributions to recognition memory.

Adult↗

PubMed2004

Dissociation of numbers and objects in corticobasal degeneration and semantic dementia.

BACKGROUND: Semantic memory is thought to consist of category-specific representations of knowledge that may be selectively compromised in patients with neurodegenerative diseases, but this has been difficult to demonstrate reliably across object categories. METHODS: The authors evaluated performance on several simple measures requiring number representations (including addition and magnitude judgments of single digits), and on a task that requires object representations (an object naming task) in patients with corticobasal degeneration (CBD; n = 13) and semantic dementia (SD; n = 15). They also examined regional cortical atrophy using voxel-based morphometric analyses of high resolution structural MRI in subgroups of five CBD patients and three SD patients. RESULTS: CBD patients were consistently more impaired on simple addition and magnitude judgment tasks requiring number representations compared to object representations. Impaired performance with numbers in CBD was associated with cortical atrophy in right parietal cortex. By comparison, SD patients demonstrated a greater impairment on a naming task requiring object representations relative to their performance on measures involving number representations. This was associated with left anterior temporal cortical atrophy. CONCLUSION: The cognitive and neuroanatomic dissociations between CBD and SD are consistent with the hypothesis that number and object representations constitute distinct domains in semantic memory, and these domains appear to be associated with distinct neural substrates.

Aged↗

PubMed2005

Event related potentials (ERPs) and behavioral responses: comparison of tonal stimuli to speech stimuli in phonological and semantic tasks.

Event related potentials (ERPs) were recorded from 20 young subjects to auditory target stimuli while they were performing three different tasks, using an oddball paradigm: 1. Tones: Subjects were instructed to respond to a 1 kHz tone, and ignore a 2 kHz tone; 2. Phonological: Subjects were instructed to respond only to pseudowords that had a specific ending ('f"); 3. Semantic: Subjects were instructed to respond to words that belonged to a specific category (animals). EEGs were recorded from 19 electrode sites. Peak amplitude of the early component (N100) did not differ significantly across the three tasks, although N100 peak latency differed significantly across tasks. In contrast, the later endogenous component (P300) was stimulus- and task-dependent. P300 latency differed significantly across stimuli and tasks: 336 ms to target tones; 682 ms to the phonological targets; and 727 ms to target words in the semantic task. P300 amplitude was significantly larger to tones than to speech stimuli. P300 peak amplitude recorded from electrode sites over the left hemisphere to the tonal target stimuli did not differ significantly from that recorded over the right hemisphere. In contrast, P300 amplitude recorded to both the phonological and semantic targets was significantly larger over the left hemisphere than over the right hemisphere at the parietal electrodes. The present results can contribute to our understanding of how humans process linguistic stimuli. These findings emphasize the importance of using similar experimental protocols when conducting broad comparisons of ERPs to a variety of stimuli and tasks.

Acoustic Stimulation↗

PubMed1991

Semantic-pragmatic disorder: a right hemisphere syndrome?

Following right hemisphere lesions, adults' speech can become copious and inappropriate, with abnormal prosody, and they may be unable to comprehend metaphor or humour. Their symptoms resemble those of children with semantic-pragmatic language disorder, who use fluent, grammatically complex language, but with poor sensitivity to the communicative situation. The hyperlexia found in some of these children reflects an underlying cognitive problem in integrating semantic information with knowledge of the world. Both groups of patients fail comprehend inferential meaning or to make use of paralinguistic features. It is hypothesised that the disorders of communication and cognition found in semantic-pragmatic language disorder may be linked to right hemisphere dysfunction, but this has yet to be confirmed by research.

Autistic Disorder↗

PubMed1995

Lexical-semantic deficits following right hemisphere damage: evidence from verbal fluency tasks.

The evidence of lexical-semantic deficits following right, non-language-dominant hemisphere injury was assessed using word (or verbal) fluency tests. Two groups of subjects (non-brain-damaged controls and right hemisphere-damaged patients) were indistinguishable in their performances on convergent lexical tasks. Subjects completed verbal fluency tasks by five semantic criteria. The brain-damaged subjects produced significantly fewer responses on two of the categories and demonstrated fewer lexical retrieval strategies. The results were interpreted as evidence that lexical-semantic knowledge is largely intact following right-hemisphere damage, and that apparent lexical deficits result from failure to use lexical knowledge flexibility, suggesting that right-hemisphere language disorders may stem from broader cognitive failures.

Aged↗

PubMed1998

Semantic pragmatic disorder with application of selected pragmatic concepts.

Children with semantic pragmatic disorder have been described as having difficulties in conversational interaction. The content of their conversations has been described as 'odd', 'loose', tangential', 'irrelevant' and 'inappropriate' (Stubbs 1986). A diagnosis of semantic pragmatic disorder is currently made based on whether or not a child displays certain surface characteristics. The present study attempts to apply precision to the intuitive terms which have been used to describe these children's conversations. To this end conversation samples from three children identified by speech and language therapists as fitting the clinical diagnosis of semantic pragmatic disorder were analysed. Aspects of pragmatic theory which best explained the strengths and weaknesses which emerged in the conversations are discussed. Therefore this represents an essentially data driven study.

Communication↗

PubMed2000

Electrophysiological estimates of the time course of semantic and phonological encoding during implicit picture naming.

Two different event-related potential (ERP) components were used to investigate the temporal processing of semantic and phonological encoding during implicit picture naming. Participants were shown pictures and carried out a dual choice go/nogo decision based on semantic information (i.e., whether the picture was of an object or an animal) and phonological information (i.e., whether the picture's name starts with a vowel or a consonant). In addition to the already established lateralized readiness potential (LRP; related to response preparation), we introduce the N200 (presumably related to response inhibition) as a tool for measuring online language processing. Both, the LRP and the N200 data indicated that semantic processing began earlier than phonological processing. The data are discussed in the context of language production models. Therein, the LRP and N200 results, taken together, favor a serial or cascaded processing model of language production in contrast to a parallel processing account.

Adult↗

PubMedDate not supplied

[Changes in episodic and semantic memory associated with temporal lobectomy].

INTRODUCTION: Temporal lobectomy (TL) is an effective treatment for drug refractory temporal lobe epilepsy. The main neuropsychological consequences of the intervention are changes in episodic and semantic memory. Aim. To study the consequences of right temporal lobectomy (RTL) and left temporal lobectomy (LTL) on episodic and semantic mnemonic functioning. PATIENTS AND METHOD: 27 patients who had undergone TL in the Hospital Universitario Virgen de las Nieves in Granada were submitted to pre and post surgical evaluation by means of a battery of neuropsychological tests that included episodic and semantic memory tests for both verbal and visual material. RESULTS AND CONCLUSIONS: ANOVA analysis was employed to analyse the pre and post surgical changes for the whole group of patients, and Student s t and Wilcoxon s non parametric test were used for each group of RTL and LTL. No deterioration was found in ipsilateral memory after the intervention, that is to say, in the verbal memory of the patients submitted to LTL and in the visual memory of RTL patients. With regard to contralateral memory, that is, the visual memory of patients submitted to LTL and the verbal memory of RTL patients, the ANOVA analyses of the whole group revealed a statistically significant improvement. The analyses performed for the whole group (LTL and RTL), however, did not reveal any statistically significant changes.

Adult↗

PubMed1987

A controlled study of processing of semantic and syntactic information in Alzheimer's disease.

Several previous studies have suggested a possible dissociation in the ability of patients with Alzheimer's Disease (AD) to utilize syntactic versus semantic information. This report describes a controlled experimental investigation of AD subjects' ability to process syntactic and semantic information. Thirteen mildly and moderately impaired AD patients were compared with 17 age- and education-matched elderly controls. Two tasks required subjects to identify and correct sentential errors; a third was a homophone spelling task. Results of the first task indicated that AD subjects were equivalent to controls in their ability to detect various types of sentential errors. When performing the second task, AD subjects were impaired in their ability to correct both types of errors, although there was a tendency for better performance with syntactically-based corrections. The third (homophone-spelling) task did not reveal a statistically significant differential sensitivity of AD subjects to syntactic versus semantic information. However, there was again a tendency for the former to be more easily processed. Results are discussed in terms of possible mechanisms which may underlie variations in the language-related performance of AD subjects.

Journal Article↗