Biomedical subjects

Jeffrey Coney

Publications and source records attributed to Jeffrey Coney.

7 recordsLinked to original sources

PubMed2005

Word frequency and the lateralization of lexical processes.

Despite the extensive clinical and neuropsychological evidence for major differences in language function between the left and right hemispheres, it has proven difficult to demonstrate reliable differences in lexical processing. It is particularly surprising that frequency has been found to have no differential effects upon word recognition in the hemispheres, in view of the evidence that this variable has significant effects upon lexical processing. It is possible, however, that any interaction between word frequency and hemispheric processes is too subtle or too complex to be revealed by the simple dichotomous studies previously attempted. This study manipulated word frequency across seven levels in an effort to provide a fine-grained insight into the relationship between word frequency and lexical processing in the hemispheres. The results revealed a clear additivity between visual field and word frequency across all levels of frequency, for both RT and errors. Such findings create difficulties for the interpretation of studies of lateralized lexical access in general, and are particularly hard to reconcile with lateral asymmetries revealed in other aspects of lexical processing. It is proposed that a resolution of this problem may depend upon the development of theories that emphasise the notion of laterally distributed word representations, rather than discrete lexical structures on each side of the brain.

Adolescent↗

PubMed2005

Hemispheric asymmetry in the processing of Japanese script.

The Japanese written language comprises both a logographic (kanji) and a phonetic (kana) script. Patterns of hemispheric asymmetry in the encoding of these scripts have been found to differ. The present study examined the way in which hemispheric differences at the level of orthographic encoding impact at the level of lexical access. A total of 32 participants performed a lexical decision task within an associative priming paradigm across both scripts. The results showed a right visual field advantage for the processing of kana, but no lateralised advantage for kanji stimuli. Patterns of facilitation also differed, with kanji stimuli eliciting a late-developing and eventually stronger priming effect in the left visual field. The results are discussed with reference to the recognition-with-phonology model in the processing of logographic script.

Adolescent↗

PubMed2004

Simple arithmetic processing: the question of automaticity.

In adult simple arithmetic performance, it is commonly held that retrieval of solutions occurs automatically from a network of stored facts in memory. However, such an account of performance necessarily predicts a uniform reaction time for solution retrieval and is therefore not consistent with the robust finding that reaction time increases with problem size and difficulty. Additionally, past research into arithmetic performance has relied on tasks that may have actually induced and measured attentional processing, thereby possibly confounding previous results and conclusions pertaining to automaticity. The present study therefore, attempted to more reliably assess the influence of automatic processing in arithmetic performance by utilizing a variant of the well-established semantic word-priming procedure with a target-naming task. The overall results revealed significant facilitation in naming times at SOAs of 240 and 1000 ms for congruent targets i.e., targets that represented the correct solutions to problems presented as primes (e.g., 6+8 and 14). Significant inhibition in comparison to a neutral condition (0+0 and 17) was also observed at 120 and 240 ms SOAs in naming incongruent targets (e.g., 6+8 and 17). Furthermore, response times were found to vary as a function of both arithmetic fluency and problem size. Differences in performance to addition and multiplication operations and implications for cognitive research and education are considered.

Adolescent↗

PubMed2004

Right hemisphere superiority for subitising.

Lateral differences in the enumeration of small sets of items (i.e., between two and five) were investigated in a normal adult sample. Confounds due to stimulus repetition, which have characterised previous subitising research, were eliminated in a task involving the presentation of purely random item arrays to the left and right visual fields. The results indicated a clear left visual field advantage for the enumeration of arrays containing three to four items. This finding is consistent with the widely held view that the subitising process is used to enumerate arrays of up to four items, and calls into question Butterworth's (1999) recent claim that subitising is a left hemisphere process. The implications for previous pattern recognition and visual process accounts of this ability are considered.

Adult↗

PubMed2002

Probing hemispheric processes in an on-line reading task.

Coney (1998) used a priming procedure to obtain evidence that the left and right hemispheres contributed equally to lexical processing of concrete nouns in a continuous reading task. In that study, however, there was no direct validation of the involvement of the right hemisphere in the task, and the possibility of left hemisphere processing of left visual field target stimuli could not be ruled out. The present study was designed to obtain validating evidence by using abstract and concrete noun primes in a similar reading task on the assumption that if the right hemisphere was contributing to the task there would be demonstrable differences between the visual fields in processing targets primed by abstract nouns. The results supported this expectation. While concrete targets projected to each visual field were primed by concrete nouns, there was significant priming by abstract nouns only in respect of targets presented to the right visual field. It is argued that this finding supports the involvement of the right hemisphere in continuous reading and further delimits the scope of its contribution to this process. Somewhat unexpectedly, the results also revealed that absolute response times were faster to left visual field targets when they were preceded by abstract nouns, even when there was no semantic relationship between the two words. It was suggested that this effect derives from the inability of the right hemisphere to process abstract nouns in that the failure of abstract nouns to engage lexical processing mechanisms leaves the right hemisphere relatively unencumbered when required to process a subsequent target.

Adult↗

PubMed2002

Lateral asymmetry in phonological processing: relating behavioral measures to neuroimaged structures.

Recent neuroimaging studies have revealed neuroanatomical centers of activation that appear to be linked specifically to phonological processes. Furthermore, there is evidence that these centers of activation are more likely to be bilaterally represented in women than in men. However, behavioral evidence of such hemispheric asymmetries or of related sex differences is somewhat inconsistent. Two experiments were carried out to determine whether behavioral correlates of the neuroimaging findings could be demonstrated. The first experiment employed a rhyme-matching task used in a recent neuroimaging study, in which two nonsense words were projected successively to the left or right sides of the visual field. The results indicated that the left hemisphere was superior for this task. An analysis of gender effects, however, revealed that the asymmetry was restricted to men. The second experiment employed a lateralized pseudohomophone detection task that was designed to determine whether the results of the first experiment could be confirmed in the context of a phonological task with a simpler structure. This experiment broadly supported the findings of the first experiment. The results support the specialization of the left hemisphere for phonological processing, and the existence of gender differences with respect to these processes.

Adult↗

PubMed2002

The effect of associative strength on priming in the cerebral hemispheres.

Recent studies have suggested that semantic memory is more diffusely organized in the right hemisphere of the brain and that words directed to this hemisphere are more likely to activate meanings distantly related to the input. It is argued that this model of language processes predicts that variations in the associative strength of word pairs should give rise to different patterns of priming in each hemisphere. Specifically, the right hemisphere should exhibit relatively more facilitation than the left in response to weaker associative relationships, whereas the left hemisphere should exhibit relatively more facilitation than the right in the context of stronger relationships. This study varied the strength of the semantic association between prime and target in a divided visual field priming procedure. The results were unequivocal in demonstrating similar associative strength functions in each hemisphere, under conditions that encouraged either automatic or controlled processing. Visual field differences in absolute RTs to words and in magnitude of facilitation effects support the claim that the data collected in this study are veridical with respect to priming processes in the hemispheres. It is suggested that current models of hemispheric language processes require further refinement.

Adult↗