Biomedical subjects

G Kellas

Publications and source records attributed to G Kellas.

At least 19 recordsLinked to original sources

PubMed1992

Influence of contextual features on the activation of ambiguous word meanings.

Three studies examined whether initial meaning activation is sensitive to context. Experiment 1 demonstrated that contextually appropriate targets were activated more than inappropriate targets. Experiment 2 evaluated activation across intervals of 0, 300, and 600 ms. Constraining sentences activated contextually appropriate meanings over inappropriate meanings. This was maintained across the intervals for highly salient targets. Less-salient targets, although initially activated, were no longer activated 300 ms following the homograph. Experiment 3 converged on context-sensitive activation following a 50-ms exposure of the sentence-final homograph. Conclusions are (a) initial meaning activation can be sensitive to context, (b) when a homograph is instantiated, it is congruent with a broad scope of targets, and (c) less-salient targets receive less activation over the time course.

Adult↗

PubMed1992

Age-related changes in the effects of target orientation on word recognition.

Twenty-four undergraduates and 24 retired faculty participated in an experiment involving semantic priming of lexical decisions. Age-related differences in the use of semantic information during visual word recognition were examined at varying orientations of the target word. Four main results were found: (1) larger rotation effects for elderly adults; (2) larger priming effects for elderly adults; (3) larger priming effects with increasing Target Orientation; and (4) larger priming effects for the elderly adults as Target Orientation increased. Results are interpreted within an interactive-compensatory framework.

Adult↗

PubMed1988

Lexical ambiguity and the timecourse of attentional allocation in word recognition.

In two experiments the allocation of attention during the recognition of ambiguous and unambiguous words was investigated. In Experiment 1, separate groups performed either lexical decision, auditory probe detection, or their combination. In the combined condition probes occurred 90, 180, or 270 ms following the onset of the lexical-decision target. Lexical decisions and probe responses were fastest for ambiguous words, followed by unambiguous words and pseudowords, respectively, which indicated that processing ambiguous words was less attention demanding than unambiguous words or pseudowords. Attention demands decreased across the timecourse of word recognition for all stimulus types. In Experiment 2, one group performed the lexical-decision task alone, whereas another group performed the lexical-decision task during the retention interval of a short-term memory task. The results were consistent with those from Experiment 1 and showed that word recognition is an attention-demanding process and that the demands are inversely related to the number of meanings of the stimulus. These results are discussed with regard to the structure of the mental lexicon (i.e., single vs. multiple lexical entries) and the effect of such a structure on attentional mechanisms.

Attention↗

PubMed1985

Semantic activation of noun concepts in context.

A modified Stoop procedure was used to examine the role that context plays in guiding semantic access of unambiguous nouns in sentence contexts. The sentences either emphasized a high- or a low-dominant property of a noun that was the last word in the sentence or were control sentences. Each sentence was followed by the relevant high- or low-dominant property either immediately or after a 300-or 600-ms delay. There was significant color-naming interference (relative to control) for high-dominant properties regardless of biasing context in the immediate and delayed conditions. There was also significant color-naming interference for low-dominant properties in the immediate condition regardless of context. However, in the delayed conditions, the low-dominant properties led to color-naming interference only when preceded by sentence contexts biasing interpretation toward the low-dominant property. It was concluded that high-dominant properties function as core, or invariant, aspects of meaning and that initial semantic access is context independent.

Attention↗

PubMed1984

Processing category terms in context: instantiation and the structure of semantic categories.

The present study sought to determine if semantic categories processed in context are encoded as particular exemplars. In Experiment 1 we replicated previous results on an extended and modified set of stimuli by showing that when subjects read sentences containing a category term in a context designed to bias encoding toward an atypical exemplar, the atypical exemplar serves as a better retrieval cue than a typical exemplar. In Experiment 2 we tested whether these cued-recall results were due to processes operating at encoding or retrieval. The pattern of semantic interference obtained in a modified Stroop paradigm clearly contradicted the position that readers routinely encode general terms as examples, or "instantiations." In particular, there was significant color-naming interference when typical exemplars served as targets even when preceded by sentences designed to bias encoding toward an atypical exemplar. No significant color-naming interference was generated to atypical exemplars. Experiment 3 ruled out the possibility that differences between the cued-recall and Stroop results in the first two experiments were due to encoding strategy differences. It was concluded that assigning a referent to a category term is not a routine activity in sentence encoding and that processing category terms entails activation of summary representations.

Adult↗

PubMed1981

False recognition of static and dynamic object properties by preschool children.

A false recognition task was used to compare preschool children's use of static and dynamic properties of objects in semantic processing. Four, five, and six year old children heard a list of object names, and then were tested for recognition of these words with a recognition test list that included distractor words that were static or dynamic properties of the objects on the first list. False recognition scores of dynamic properties were higher than those for static, for 4 and 5 year old children, with no differences for 6 year old children. The results argue for a functional basis for the encoding of referential terms in memory, and are discussed in terms of two models of semantic development.

Age Factors↗

PubMed1974