Structure Of Semantic Knowledge Research Articles

Promoting pre-service teachers’ knowledge integration from multiple text sources across domains with instructional prompts

AbstractMultiple document comprehension and knowledge integration across domains are particularly important for pre-service teachers, as integrated professional knowledge forms the basis for teaching expertise and competence. This study examines the effects of instructional prompts and relevance prompts embedded in pre-service teachers’ learning processes on the quality their knowledge integration in multiple document comprehension across domains. 109 pre-service teachers participated in an experimental study. They read four texts on “competencies” from different knowledge domains and wrote a text on a given scenario. Experimental group 1 was aided with instructional and relevance prompts, while experimental group 2 received only relevance prompts. The control group received no prompting. Perceived relevance of knowledge integration was assessed in a pre-post-test. Pre-service teachers’ separative and integrative learning, epistemological beliefs, metacognition, study-specific self-concept, and post-experimental motivation were assessed as control variables. Participants’ texts were analyzed concerning knowledge integration by raters and with computer linguistic measures. A key finding is that combined complex prompting enhances pre-service teachers perceived relevance of knowledge integration. This study found effects of prompting types on the pre-service teachers’ semantic knowledge structures. Implications for transfer are discussed.

Local but not global graph theoretic measures of semantic networks generalize across tasks.

"Dogs" are connected to "cats" in our minds, and "backyard" to "outdoors." Does the structure of this semantic knowledge differ across people? Network-based approaches are a popular representational scheme for thinking about how relations between different concepts are organized. Recent research uses graph theoretic analyses to examine individual differences in semantic networks for simple concepts and how they relate to other higher-level cognitive processes, such as creativity. However, it remains ambiguous whether individual differences captured via network analyses reflect true differences in measures of the structure of semantic knowledge, or differences in how people strategically approach semantic relatedness tasks. To test this, we examine the reliability of local and global metrics of semantic networks for simple concepts across different semantic relatedness tasks. In four experiments, we find that both weighted and unweighted graph theoretic representations reliably capture individual differences in local measures of semantic networks (e.g., how related pot is to pan versus lion). In contrast, we find that metrics of global structural properties of semantic networks, such as the average clustering coefficient and shortest path length, are less robust across tasks and may not provide reliable individual difference measures of how people represent simple concepts. We discuss the implications of these results and offer recommendations for researchers who seek to apply graph theoretic analyses in the study of individual differences in semantic memory.

Category Exemplar Production Norms for Hong Kong Cantonese: Instance Probabilities and Word Familiarity.

The lexical system of Hong Kong Cantonese has been heavily shaped by the local trilingual environment. The development of cultural- and language-specific norms for Hong Kong Cantonese is fundamental for understanding how the speaker population organize semantic memory, how they utilize their semantic resources, and what information processing strategies they use for the retrieval of semantic knowledge. This study presents a normative database of 72 lexical categories in Hong Kong Cantonese produced by native speakers in a category exemplar production task. Exemplars are enlisted under a category label, along with the instance probabilities and word familiarity scores. Possible English equivalents are given to the exemplars for the convenience of non-HKC speaker researchers. Statistics on categories were further extracted to capture the heterogeneity of the categories: the total number of valid exemplars, the number of exemplars covering 90% of the occurrence and the probabilities of the most frequent exemplars in each category. The database offers a direct lexical sketch of the vocabulary of modern Hong Kong Cantonese in a categorical structure. The category-exemplar lists and the comparative statistics together lay the foundations for further investigations on the Hong Kong Cantonese speaking population from multiple disciplines, such as the structure of semantic knowledge, the time-course of knowledge access, and the processing strategies of young adults. Results of this norm can be also used as a benchmark for other age groups. The database can serve as a crucial resource for establishing initial screening tests to assess the cognitive and psychological functioning of the Cantonese-speaking Hong Kong population in both educational and clinical settings. In sum, this normative study provides a fundamental resource for future studies on language processing mechanisms of Hong Kong Cantonese speaking population, as well as language studies and other cross-language/culture studies on Hong Kong Cantonese.

Semantic Knowledge Structure of Normal Elderly in Concrete Words Definition

Semantic Knowledge Structure of Normal Elderly in Concrete Words Definition

Nanotechnology Ontology: Semantic Access to Information in the Nano World

Scientific progress in a domain depends greatly on making use of results of previous research activities. Like human beings, it is difficult for computers to encode and retrieve the unsupervised Web information. The basic answer to this problem is to describe the information explicitly and semantically with ontology. The article presents a brief discussion of the study undertaken to design an ontology for Nanotechnology field.Scientific progress in a domain depends greatly on making use of results of previous research activities. Like human beings, it is difficult for computers to encode and retrieve the expanding web information. The basic answer to this problem is to describe the information explicitly and semantically with ontology. The article presents a brief discussion of the study undertaken to design an ontology for Nanotechnology, which was developed by using the Resource Description Framework (RDF).  This paper further describes methodology opted to develop the Nanotechnology ontology, where a semantic structure of Nanotechnology thesaurus was utilised for its creation. The study has further presented the features of nMap software, which was developed specifically for the study by using VB.net as front-end tool and MS-access as back-end tool. Outcome of the study offers a semantic knowledge structure to Nanotechnology researchers in machine readable environment. Further, development of ontology in RDF format serves interoperability and will further support semantic interpretation by machines to facilitate human understanding.  dx.doi.org/10.14429/djlit.36.1.9198

Modeling semantic knowledge structures for creative problem solving: Studies on expressing concepts, categories, associations, goals and context

This paper presents a model for semantic network representation. According to the model, the main purpose of a semantic network is to help to correctly and quickly understand the features and structure of the solutions, and then make reliable predictions about their outcomes and rewards. These objectives are achieved under constrains like limited resources (e.g., memory size and access), time limitations, and variations of solution characteristics. The paper summarizes the elements of the model and presents a set of properties that describe the effectiveness of semantic networks in creative problem solving, including design. Six examples (based on three case studies from the related literature and three experimental studies conducted by the authors) discuss the model elements, characteristics, and properties.

Familiarity and recall memory for environments: A comparison of children and adults

To date, very little research has examined developmental reversals in false memory outside of the word list paradigm. The purpose of this study was to investigate whether knowledge of, and familiarity with types of environments influenced the quantity, accuracy, and errors recalled by children (4- to 6- year-olds) and adults. Using images and open recall questions, the findings of the present study support the predicted reversal in false memories (i.e., developmental variability), supporting a cross-over effect of age and false memories. Children performed better than adults through providing less relevant errors (i.e., commission or semantic-based errors) about environments that were more familiar to adults. These findings support the predicted developmental reversal in false memories. The findings are discussed within the context of fuzzy trace theory and semantic knowledge structures. Implications for the applied eyewitness context are examined.

Walking across Wikipedia: a scale-free network model of semantic memory retrieval.

Semantic knowledge has been investigated using both online and offline methods. One common online method is category recall, in which members of a semantic category like “animals” are retrieved in a given period of time. The order, timing, and number of retrievals are used as assays of semantic memory processes. One common offline method is corpus analysis, in which the structure of semantic knowledge is extracted from texts using co-occurrence or encyclopedic methods. Online measures of semantic processing, as well as offline measures of semantic structure, have yielded data resembling inverse power law distributions. The aim of the present study is to investigate whether these patterns in data might be related. A semantic network model of animal knowledge is formulated on the basis of Wikipedia pages and their overlap in word probability distributions. The network is scale-free, in that node degree is related to node frequency as an inverse power law. A random walk over this network is shown to simulate a number of results from a category recall experiment, including power law-like distributions of inter-response intervals. Results are discussed in terms of theories of semantic structure and processing.

The developmental process of semantic knowledge structure in false memory.

The developmental process of semantic knowledge structure in false memory.

Toddlers Activate Lexical Semantic Knowledge in the Absence of Visual Referents: Evidence from Auditory Priming.

Language learners rapidly acquire extensive semantic knowledge, but the development of this knowledge is difficult to study, in part because it is difficult to assess young children's lexical semantic representations. In our studies, we solved this problem by investigating lexical semantic knowledge in 24-month-olds using the Head-turn Preference Procedure. In Experiment 1, looking times to a repeating spoken word stimulus (e.g., kitty-kitty-kitty) were shorter for trials preceded by a semantically related word (e.g., dog-dog-dog) than trials preceded by an unrelated word (e.g., juice-juice-juice). Experiment 2 yielded similar results using a method in which pairs of words were presented on the same trial. The studies provide evidence that young children activate of lexical semantic knowledge, and critically, that they do so in the absence of visual referents or sentence contexts. Auditory lexical priming is a promising technique for studying the development and structure of semantic knowledge in young children.

The structure of semantic knowledge in young children's false memory.

The structure of semantic knowledge in young children's false memory.

Action verb understanding in first-episode schizophrenia: Is there evidence for a simulation deficit?

Schizophrenia is often associated with deficits in the domain of language, which are thought to be closely related to deficits in the structure of semantic knowledge. The main aim of the present study was to behaviorally investigate whether semantic impairments in schizophrenia are present also at the very basic level of action verb processing, in particular at the level of motor simulation. We used a go-no go paradigm both for a semantic decision task (with either an early, EGD, or a delayed go-signal delivery, DGD) and for a lexical decision task (control task). Only the first task requires motor simulation to be solved. We found that first-episode schizophrenia (FES) patients, like healthy control (HC) participants, use motor simulation as a basic strategy to semantically judge action verbs. In the EGD condition, both motor simulation and action verb understanding seem to be preserved in FES. However, differently from HC participants, FES patients kept on using the simulation strategy also with the DGD condition, whereas, simultaneously, task performance during this condition appeared to be less efficient and sensitive. Voxel-based morphometry analysis suggested that this altered performance in FES patients could be related to structural brain abnormalities in the right dorsolateral prefrontal cortex. We propose that a prolonged motor simulation in FES may serve as a compensatory strategy for impairments in the selection of action representation and/or for memory deficits disclosed by the DGD condition during the semantic decision task investigated in the present study.

Semantic networks for odors and colors in Alzheimer's disease.

Impairment in odor-naming ability and in verbal and visual semantic networks raised the hypothesis of a breakdown in the semantic network for odors in Alzheimer's disease (AD). The current study addressed this hypothesis. Twenty-four individuals, half patients with probable AD and half control participants, performed triadic-similarity judgments for odors and colors, separately, which, utilizing the multidimensional scaling (MDS) technique of individual difference scaling analysis (INDSCAL), generated two-dimensional configurations of similarity. The abilities to match odors and colors with written name labels were assessed to investigate disease-related differences in ability to identify and conceptualize the stimuli. In addition, responses on attribute-sorting tasks, requiring the odor and color perceptions to be categorized as one polarity of a certain dimension, were obtained to allow for objective interpretation of the MDS spatial maps. Whereas comparison subjects generated spatial maps based predominantly on relatively abstract characteristics, patients with AD classified odors on perceptual characteristics. The maps for patients with AD also showed disorganized groupings and loose associations between odors. Their normal configurations for colors imply that the patients were able to comprehend the task per se. The data for label matching and for attribute sorting provide further evidence for a disturbance in semantic odor memory in AD. The patients performed poorer than controls on both these odor tasks, implying that the ability to identify and/or conceptualize odors is impaired in AD. The results provide clear evidence for deterioration of the structure of semantic knowledge for odors in AD.

The categorical structure of knowledge for famous people (and a novel application of Centre-Surround theory)

Knowledge of familiar people is essential to guide social interaction, yet there is uncertainty about whether semantic knowledge for people is stored in a categorical structure as for objects. Four priming experiments using hard-to-perceive primes investigated whether occupation forms a category connecting famous persons in semantic memory. Primes were famous faces exposed for 17 ms with masking, resulting in severely restricted awareness and thus precluding expectancy-based priming effects. Targets were consciously perceptible famous faces (Experiments 1–3), famous names (Experiment 3), or occupations (Experiment 4) representing either the same or different occupation to the prime. Significant priming demonstrated the operation of automatic processes, including spreading activation, among persons sharing a common occupation; this supports the categorical view. The direction of priming (faster/slower responses to same-occupation than different-occupation targets) was dependent on prime-target stimulus onset asynchrony (Experiments 1–3) and type of target (Experiment 4). This pattern of results is attributed to the Centre-Surround mechanism proposed by Carr and Dagenbach [Carr, T. H., & Dagenbach, D. (1990). Semantic priming and repetition priming from masked words: evidence for a centre-surround attentional mechanism in perceptual recognition. Journal of Experimental Psychology: Learning, Memory and Cognition, 16, 341–350]. These results support (a) the categorical structure of semantic knowledge for famous people and (b) the application of the Centre-Surround mechanism to the domain of person recognition.

Word retrieval following mild TBI: Implications for categorical deficits

Background: Theories on the organisation and structure of semantic knowledge of nouns and verbs have been based on findings with aphasic patients with focal lesions. Populations with diffuse lesions, such as mild traumatic brain injury (MTBI), may offer additional information relative to lexical access of nouns and verbs. Aims: The purpose of this study was to investigate possible dissociation between noun and verb retrieval after MTBI using the Test of Adolescent Adult Word Finding (TAWF). Methods & Procedures: Two groups, 10 MTBI and 10 non‐brain‐damaged (NBD) persons, who had normal vision and hearing, and no history of developmental disabilities, previous head injury, or substance abuse, were participants. Criteria for MTBI included: loss of consciousness <30 minutes and/or PTA<24 hours, GCS 13–15, and negative CT scan. The experimental task was the TAWF, focusing on differences in accuracy and response time for noun and verb naming. Outcomes & Results: Paired sample t‐tests comparing nouns and verbs on accuracy and response time revealed no significant differences for the MTBI group; for the NBD group, there were significant differences for response time only. One‐tailed independent sample t‐tests revealed significant group differences for accuracy and response time on combined nouns and only response time for verbs. Paired sample t‐tests revealed significant differences for naming living and nonliving items only for the MTBI group. Conclusions: No significant accuracy differences were found for either group between nouns and verbs. However, the NBD group named nouns significantly faster than verbs, whereas the MTBI group showed no significant difference. The MTBI group was significantly slower and less accurate than the NBD group for noun naming but only significantly slower for verbs. The MTBI group exhibited higher accuracy in naming living items as compared to nonliving. Therefore, response times appeared to be more sensitive than accuracy in identifying group differences.

Episodic inhibition.

Six experiments examined the proposal that an item of long-term knowledge can be simultaneously inhibited and activated. In 2 directed forgetting experiments items to-be-forgotten were found to be inhibited in list-cued recall but activated in lexical decision tasks. In 3 retrieval practice experiments, unpracticed items from practiced categories were found to be inhibited in category-cued recall but were primed in lexical decision. If, however, the primes and targets in lexical decision were taken directly from the study list, inhibition was observed. Finally, it was found that when items highly associated with a study list were processed in between study and test, no inhibition in recall was present. These, and a broad range of other findings, can be explained by the concept of "episodic inhibition," which proposes that episodic memories retain copies of semantic knowledge structures that preserve patterns of activation/inhibition originally generated in those structures during encoding. ((c) 2006 APA, all rights reserved).

The Best Laid Plans ... : Beyond Scripts are Counterscripts

This study examined whether counterscripts (general, semantic knowledge structures for unexpected events exhibiting definable, common event structure) are part of our event knowledge. Classic among counterscript events are situationally ironic ones (e.g., an agent's goal-directed actions yield the opposite outcome or are superseded by fluke actions in securing a goal). In a category ratings task, adults rated 3 event kinds for ironic status: script (expected, routine events associated with general knowledge structures), counterscript ironic, and anomaly-unexpected (unexpected events with no common structure and not associated with general knowledge structures). The data indicate that general, semantic knowledge structures exist for counterscript ironic events. These events were rated in the ironic range and more ironic than script and anomaly-unexpected events. Script events were rated least ironic. Script and counterscript events emerged as independent event factors. Moreover, counterscript ironic events exhibited internal structure (degree of irony varied across event kinds), a component of conceptual coherence.

Implicit association measurement with the IAT: evidence for effects of executive control processes.

It is argued that a model of goal-independent spreading activation in a social or semantic knowledge structure is insufficient to explain implicit association effects in the IAT (Greenwald, McGhee, & Schwartz, 1998). An alternative account is proposed, which attributes IAT effects to differential costs for switching between task sets. Two experiments were conduced to test this account. In Experiment 1, specific task-set switching cost was a function of IAT condition: switching between tasks was associated with significantly more cost in the incompatible IAT phase. In a second experiment the magnitude of the IAT effect was reduced when task-set reconfiguration was possible in advance of or simultaneously with the upcoming stimulus. The results are discussed with respect to recently suggested accounts of the effect.

The deterioration of semantic memory in Alzheimer's disease.

Semantic memory impairment is a common feature of dementia of the Alzheimer type (DAT). Recent research has shown that patients with DAT are more impaired (relative to non-demented controls) in generating exemplars from a particular semantic category (e.g., animals) than words beginning with a particular letter, exhibit an altered temporal dynamic during the production of category exemplars, are impaired on confrontation naming tasks and make predominantly superordinate or semantically related errors, consistently misidentify the same objects across a variety of semantic tasks, and have alterations in multi-dimensional scaling models of their semantic network that are indicative of a loss of concepts and associations. These results are consistent with the view that Alzheimer's disease results in a breakdown in the organization and structure of semantic knowledge as neurodegeneration spreads to the association cortices that presumably store semantic representations.

Semantically-Triggered Reading Epilepsy: An Experimental Case Study

Primary reading epilepsy (PRE) is a rare syndrome in which epileptic seizures are electively provoked by reading. Cognitive neuropsychology has demonstrated the existence of at least two pathways for reading, the sublexical pathway involved in converting graphemes to phonemes, and the lexical pathway used when meaning is conveyed. Which of these specific pathways is relevant in triggering epileptic discharges remains largely unknown. We report the case of a patient suffering from PRE in which the two routes were distinguished on the basis of the reading material employed. Significantly less epileptic discharges were observed when the patient read non-words than words. In view of our findings, we tentatively contrast a lexical form of PRE, triggered by the activation of semantic knowledge structures, with a sublexical form, triggered by non-word reading. Evidence from the literature suggests that the former is characterized by bilateral EEG activating patterns, whereas the latter involves preferentially the left hemisphere.