PubMed Health⌕ Search

Biomedical subjects

J Coney

Publications and source records attributed to J Coney.

6 recordsLinked to original sources
PubMed1996

Semantic category priming in the left cerebral hemisphere.

The representation of semantic codes in the cerebral hemispheres and the interhemispheric communication of these codes, was investigated in two priming experiments where prime and target words were independently projected to the left or right visual fields (LVF or RVF). Nonassociated category exemplars were employed as related pairs in a lexical decision task and separated by a stimulus onset asynchrony of 250 msec in Experiment 1 and 450 msec in Experiment 2. Both experiments obtained priming effects when primes and targets were both projected to the RVF, but not the LVF. Semantic category primes projected to the RVF also facilitated responses to LVF targets, but no LVF-RVF priming was obtained. This suggests that semantic category information is relayed from left to right hemisphere, but not vice versa. The results are consistent with the view that semantic categories are represented in the left hemisphere.

Adult↗
PubMed1994

Picture-name priming in the cerebral hemispheres.

In a lexical decision task, pictures and names of common objects were presented in succession to the left or right visual fields in an investigation of the relationship between visual and verbal representations within and between the hemispheres. On each trial, a picture was projected to the left or right side of the visual field, followed by a string of letters to the same or different side. The letter string could be the name of the object in the picture, an unrelated word, or a nonword. Although a strong priming effect was observed when the name of an object followed its picture, this did not depend on which visual fields had registered the stimuli. Activation of name codes was apparently independent of visual field of presentation of picture and word. This result was consistent with the view that representational systems for pictures and their names are not differentially specialized across the hemispheres. A further finding was that absolute response time to words was shorter when stimuli were divided between the visual fields, even at an SOA of 1000 msec. It is suggested that this result is due to the activation of picture-processing mechanisms within a hemisphere by the first (pictorial) stimulus, which causes a delay in processing the subsequent verbal stimulus in that hemisphere.

Adult↗
PubMed1993

Associative priming in the hemispheres as a function of SOA.

The representation of associative codes in the cerebral hemisphere was investigated in two priming experiments where associated prime and target words were independently projected to the left or right visual fields. The first experiment, using a stimulus onset asynchrony of 250 msec, found priming in all visual field conditions, except that in which both prime and target were projected to the right hemisphere. A second experiment was conducted to determine whether this absence of right hemisphere priming was due to an inadequate interval of time between prime and target. In this experiment, a stimulus onset asynchrony of 450 msec revealed significant priming in all visual field conditions. The results suggest that lexical representations are activated more slowly in the right hemisphere than in the left.

Adult↗
PubMed1990

Semantic and phonemic priming in the cerebral hemispheres.

Representation of semantic and phonemic codes in the cerebral hemispheres was investigated in two priming experiments where prime and target words were independently projected to the left or right visual fields. The first experiment, using phonemic primes, confirmed the view that phonological information is not accessible to the right hemisphere. Priming effects were obtained only when the prime and target were both projected to the right visual field. The second experiment, employing category exemplars as primes, again found the left hemisphere to be the principal locus of the priming effects. The right hemisphere was unable, by itself, to activate words related to the exemplar prime. However, projection of the prime to the right visual field significantly facilitated responses to left visual field targets. The present findings support the view advanced by Drews (Neuropsychologia 25, 419-427, 1987) and Levy and Trevarthen (J. exp. Psychol., Hum. Percep. Perform. 2,299-312, 1976) that the left lexicon is structured in accordance with an hierarchy of logical semantic relationships, while the right lexicon is organized on the basis of simple associations between concepts. It is suggested, furthermore, that the patterns of semantic, but not phonological, activation invoked by a prime may be relayed between the two lexicons.

Adult↗
PubMed1988

The effect of retention interval upon hemispheric processes in recognition memory.

Simple concrete nouns were presented unilaterally in a continuous recognition memory procedure. Each word was presented twice in a session, and subjects were required to signal the second occurrence of a word. Retention interval was manipulated by varying the lag separating word presentations, and lags of 1, 4, 8, and 32 items were employed in the design. Words were projected, on first and second presentations respectively, to the following visual fields: LL, LR, RR, and RL. No visual field effects were observed at lag 1, but an advantage for RVF probes was evident from lag 4 onwards. At lag 8, a relative superiority emerged from uncrossed versus crossed presentation. The results support the idea that lateral asymmetries develop as processing engages deeper and more complex levels of representation. There was also evidence that memory representations are more salient following direct, rather than transcallosal, stimulation of a hemisphere.

Adult↗