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Biomedical subjects

K Mackie

Publications and source records attributed to K Mackie.

58 records · Page 4Linked to original sources
PubMed1983

Dichotic listening in good and poor readers.

Dichotic listening performance using CV pairs was investigated in a group of 30 children, 15 good readers and 15 poor readers, aged 10-13 years. The results indicate that the poor readers did not demonstrate atypical laterality or phonetic processing effects, although there was a significant difference in their ability to identify both items on dichotic trials correctly. However, when the same stimuli were presented monotically, there was no difference in the performance of the groups. Additional testing indicated that the poor performance for the double-correct response class was also demonstrated in conditions where the dichotic stimuli were separated by as much as 500 and 1000 msec. These results support previous findings that reading-disabled children exhibit a deficit in their capacity to process two items on dichotic tasks. The implications of these results are discussed in terms of both neurological and auditory processing interpretations, and it is suggested that dichotic tasks are useful for investigating auditory processing problems in reading-disabled children.

Child↗
PubMed1983

Control of extracellular ions in skate brain during osmotic disturbances.

Regulation of brain water and osmolytes in osmotic disturbances has been studied in the little skate, Raja erinacea. Free-swimming fish were subjected to seawater plus 125 mM NaCl (hyperosmotic; these also received 10 ml/kg body wt im 4.19 M NaCl in elasmobranch Ringer) or to 50% seawater (hyposmotic). At a set time, fish were killed, and blood and brain (telencephalon and medulla) were analyzed. Brain water was divided into a Cl- and a non-Cl- space. Responses of water and osmolytes to osmotic disturbances were mutually consistent. In telencephalon, there was good regulation of Cl- space, based on Na+ and Cl- shifts in hypo- and hyperosmolality. This control was near perfect at 2- and 4-h hyperosmolality. Regulation of non-Cl- space was minimal at 24-h hyperosmolality, with small K+ uptake. In medulla, Cl- space and ions were unregulated, whereas non-Cl- space was partly controlled in hyposmolality in relation to amino acid loss. Thus in this elasmobranch, regulation of Cl- space and of Na+ and Cl- is effective in telencephalon but is nonexistent in medulla oblongata.

Amino Acids↗
PubMedDate not supplied

Auditory processing limitations in low verbal children: evidence from a two-response dichotic listening task.

Evidence for auditory processing limitations based on the use of two-response consonant-vowel (CV) dichotic listening tasks is reviewed. These studies show that low verbal children obtain fewer trials on which both items are correctly identified (double correct responses). A study is reported comparing a group of good and poor readers on the dichotic CV task. These data are then analyzed in terms of a normative model which attempts to show the effects of overall performance and guessing on double correct responses. It is concluded, in terms of the model, that the poor double correct performance of the poor readers is the direct result of poor auditory processing capacity.

Auditory Perception↗