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W F McKeever

Publications and source records attributed to W F McKeever.

16 recordsLinked to original sources
PubMed1990

Cross-modal correlation of dichotic and tachistoscopic language laterality tasks: the importance of familial sinistrality.

Previous studies have found little if any correlation between dichotic and tachistoscopic language laterality task performance asymmetries. Problems with these studies have been that quite dissimilar auditory and visual tasks have often been used, and the reliability of the asymmetry measures has generally been unknown or, when known, relatively poor. We assessed the cross-modal correlation for two tasks, the Bilateral Object Naming Latency Task (BONLT) and the Dichotic Object Naming Latency Task (DONLT). These tasks are highly similar and have demonstrated high reliabilities. A significant, though rather small, cross-modal correlation was found (r = +.28). When cross-modal correlations were computed for FS- and FS+ subjects separately, no correlation was found for FS+ subjects (r = +.02), but the correlation for FS- subjects was highly significant (r = +.54, p less than .004). This led us to reexamine some previously collected data (P.L. Van Eys and W. F. McKeever, 1988, Brain and Cognition, 4, 413-429) which had administered two highly reliable language laterality tasks (the BONLT and the Dichotic Consonant Vowel Task), but had not assessed cross-modal correlation. A significant cross-modal correlation was found for FS- but not for FS+ subjects. The results are consistent with the hypothesis of H. Hecaen, M. De Agnostini, and A. Monzon-Montes (1981, Brain and Language, 12, 261-284) which suggests that one effect of FS+ is to induce a greater heterogeneity of localizations of different language processes.

Adult↗
PubMed1990

An investigation of immune system disorder as a "marker" for anomalous dominance.

Geschwind and Galaburda (1987) proposed that immune disorder (ID) susceptibility, along with left handedness and familial sinistrality (FS), is a "marker" for anomalous dominance. The theory predicts lesser left lateralization for language processes, lessened left hemisphere abilities, and enhanced right hemisphere abilities. We assessed language laterality (dichotic consonant vowel task) and performances on spatial and verbal tasks. Subjects were 128 college students. The factors of handedness, sex, FS, and immune disorder history (negative or positive) were perfectly counterbalanced. Left-handers were significantly less lateralized for language and scored lower than right-handers on the spatial tasks. Females scored lower on mental rotation than males, but performed comparably to males on the spatial relations task. The only effect of ID was by way of interaction with FS on both spatial tasks--subjects who were either negative or positive on both FS and ID status factors scored significantly higher than subjects negative for one but positive for the other factor. A speculative explanatory model for this interaction was proposed. The model incorporates the notion that FS and ID factors are comparably correlated, but in opposite directions, with hormonal factors implicated by other research as relevant for spatial ability differences. Finally, no support for the "anomalous dominance" hypothesis predictions was found.

Adult↗
PubMed1990

Left handedness and immune disorders.

The Geschwind-Behan hypothesis that immune disorder (IMD) is more common among left than among right handed persons was tested in a sample of 3080 college students. Subjects indicated, for each of a list of IMDs, whether they: (1) had no reason to believe they had the disorder; (2) thought they might have the disorder; (3) had the disorder diagnosed by a physician; or (4) had had a disorder diagnosed and treated by a physician. Females reported significantly more IMDs than did males. Among females, the distribution of responses across the four response categories was not different for left and right handers, but IMD was significantly higher among left handed females when only the extreme categories were considered. Among males, no handedness effect was seen across the four categories, nor when only the extreme categories were considered. Laterality quotients, from the Edinburgh Handedness Inventory, were unrelated to IMD reports in both sexes. Results provide no real support for the Geschwind-Behan hypothesis. Even in the case of the extreme categories of IMD reports of females, the association of left handedness (for writing) and IMD accounts for only three-tenths of one percent of the variance.

Female↗
PubMed1989

Language laterality in Navajo reservation children: dichotic test results depend on the language context of the testing.

Language lateralization in 40 Navajo and 20 Anglo fifth graders was assessed via the Dichotic Consonant-Vowel Task (DCVT). One group of Navajo children was tested by an experimenter who spoke only Navajo with them. The other Navajo group and the Anglo group were tested by an experimenter who spoke only English to them. Strong right ear advantages (REAs) were obtained for the Anglo group and for the Navajo group tested by the Navajo-speaking experimenter. The Navajo group tested by the English-speaking experimenter showed minimal, nonsignificant REAs. Previous findings of an absence of REAs in Native American children failed to consider the possibility that this might occur only when the experimenter does not speak the dominant language of the children. Our results are not consistent with the view that Native Americans are more right hemisphere dominant as a function of an "appositional" mode of language and thought.

Arizona↗
PubMed1989

Inverted handwriting posture in left handers is related to familial sinistrality incidence.

McKeever (1979) reported that left handers who wrote with an inverted handwriting posture (IHP) had a higher incidence of left handedness in their families than did left handers who wrote with a non-inverted handwriting posture (NHP). Parlow and Kinsbourne (1981), however, failed to find a relationship between handwriting posture (HWP) and positive familial sinistrality (FS+). McKeever had classified his left handed subjects according to whether they had several, one, or no left handers among their first degree relatives and biologically-related second degree relatives. Parlow and Kinsbourne classified subjects as FS- or FS+ on the basis of first degree relatives and did not inquire about the handedness of second degree relatives. In the present study, handedness for writing of all first and second degree relatives was recorded for 216 NIP and 255 IHP left handers. Results showed a significant association of HWP and FS factors when second degree relatives were considered, but not when second degree relative handedness was ignored. The relationship was strongest within the maternal family line, where the proportion of left handers was more than twice as high for the IHP as for the NHP group. These findings suggest that HWP may well be of some importance for a complete understanding of the cerebral organization of left handers.

Adult↗
PubMed1979

Material specific serial memory deficit in adolescent dyslexics.

The present experiment was concerned with an assessment of possible serial, as opposed to general, memory deficit in dyslexia. Previous studies had consistently confounded general and serial memory assessments. Fifteen specifically dyslexic adolescents and 15 normal-reading controls were administered four separate memory tasks. In the general memory for verbal material task they were shown 20 words, each for three seconds, and were then given a deck of 40 word cards and required to pick out the 20 words just seen. In the serial memory version of the verbal task they were again shown 20 words and subsequently required to reproduce the order in which they had been shown. Two comparable (general and serial) procedures were also administered using faces as the to-be-remembered materials. Results showed comparable performances of the dyslexics and controls on both versions of the face memory task and on the general memory version of the words task. On the serial reproduction version of the verbal task, however, dyslexics were found to be significantly impaired relative to controls. Thus, adolescent dyslexics appear to have a memory impairment which is specific for both type of material (verbal) and type of memory (serial). The results are compatible with Orton's (1937) speculation regarding "sequecing" and "memory" in dyslexia and with the view that the defect resides within the neuropsychological processes of the language-dominant hemisphere.

Adolescent↗
PubMed1977

Failure to confirm a spatial ability impairment in persons with evidence of right hemisphere speech capability.

Levy hypothesized that persons lacking strict left hemispheric dominance for language processing should be impaired in spatial processing ability. This leads to the expectation that left-handers, because they are more often not strictly left hemisphere dominant for language, would, as a group, be impaired in spatial ability relative to right-handers. Evidence regarding this hypothesis has been inconsistent. The present study systematically examined the effects of handedness, sex, and hemispheric language dominance on verbal and spatial ability in 80 right-handed and 71 left-handed university students. Males were found to be superior to females in all handedness-hemispheric language dominance groups on the spatial ability measure. No effects of handedness or hemispheric lanaguage dominance nor interactions of these factors obtained for either verbal or spatial ability measures. It was concluded that the hypothesis of verbal-spatial processing incompatibility within the same hemisphere was not supported.

Dominance, Cerebral↗
PubMed1977

Familial sinistrality and degree of left-handedness.

Hécaen & Sauguet (1970) reported that, according to a handedness inventory measure, familial sinistrality among left-handers (brain-damaged patients) was associated with weak left-handedness. We assessed the relationship of familial sinistrality and degree of left-handedness among 71 normal left-and 80 right-handed subjects. No general relationship of degree of left-handedness, defined by four handedness tasks, to familial sinistrality obtained. Only one of the tasks (finger tapping speed) significantly differed between familial and non-familial left-handers, the familial left-handers being more strongly left-handed on the task.

Culture↗
PubMed1975

Dyslexic adolescents: evidence of impaired visual and auditory language processing associated with normal lateralization and visual responsivity.

The questions of whether chronically dyslexic adolescent suffer any deficits of simple language stimulus processing or are less left hemisphere dominant than normal reading controls were addressed. The dyslexics were chosen for clarity of their specific reading problem and were older than dyslexics previously studied with lateralizing tests. Tasks administered in Experiment I were unilateral and bilateral tachistoscopic work recognitions and a tachistoscopic recognition report-time task for single lateralized letter stimuli. Experiment II, conducted a year later, readministered these tasks with modifications, and added dichotic digits and motor reaction time-stimulus detection tasks. It was concluded that right handed, chronic dyslexics: (1) possess left hemisphere language specialization; (2) show normal interhemispheric processing delays for single letter stimuli; (3) are, unlike nondyslexis but equally poor-reading Ss, clearly impaired in their efficiency of visual and auditory processing of simple language stimuli; (4) possess clear auditory memory deficits for verbal material; and (5) may possess an additional deficit of left hemisphere visual association area function.

Adolescent↗