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Biomedical subjects

D W Kee

Publications and source records attributed to D W Kee.

15 recordsLinked to original sources
PubMed1995

Lateralized dual task interference in left-handers: initial value differences do not affect the outcome.

The study was conducted to clarify factors involved in dual-task finger-tapping interference. Left-handers, as assessed by hand-writing preference and left-hand baseline tapping advantage, tapped both alone and while solving anagrams. Even though the left-hand baseline tapping advantage was experimentally removed on some (adjusted) trials, greater left- than right-hand tapping interference was observed during concurrent task performance. This result coupled with previous findings for right-handed subjects [Kee and Cherry, Neuropsychologia, Vol. 28, pp. 313-316, 1990] indicates that lateralized interference effects are not merely due to initial baseline tapping differences as proposed by Willis and Goodwin [Neuropsychologia, Vol. 25, pp. 719-724, 1987].

Brain↗
PubMed1994

Finger-tapping interference as produced by concurrent verbal and nonverbal tasks: an analysis of individual differences in left-handers.

Verbal cerebral asymmetry was examined in 96 right- and left-handed college students using dual-task methods. The manual task was finger-tapping; verbal tasks were anagram-solution in silent and aloud conditions; nonverbal tasks were solution of Raven's Progressive Matrices and forms memory. Both handedness groups were sensitive to the task manipulation, i.e., verbal tasks produced a significant change in tapping rate from a no-change rate of zero; nonverbal tasks produced no significant change in tapping rate. Right-handers experienced the expected asymmetric manual performance indicative of left-hemisphere language laterality. Left-handers as a group experienced no asymmetric pattern but rather a percentage decrease in both hands which suggested bilateralization of language functions. Only when examining manual performance patterns within specific left-handed subpopulations (composed of a complete crossing of handwriting posture, familial sinistrality, and sex) did laterality patterns emerge. Specifically, asymmetric manual performance was found only in familial sinistral inverted posture females. Results demonstrate the advantage of controlling for subject characteristics when assessing cerebral laterality in left-handers.

Adult↗
PubMed1994

Development differences in associative memory: strategy use, mental effort, and knowledge access interactions.

The deployment of memory strategies is resource demanding and more so for younger children than for older children and adults. The associative memory studies reviewed show that accessibility to relevant event knowledge is directly related to the resource demands of using an elaboration strategy. The greater efficiency of strategy use by older children and adults permits the use of available mental resources to support additional task-relevant processing of to-be-learned items. This additional processing might include alternate or more durable encodings of pair relationships, creation of retrieval opportunities (strategies), and effective strategy monitoring. The additional processing enabled by the freeing of information-processing resources is hypothesized to be responsible for the developmental increase in the efficacy of elaboration and other associative strategies. Knowledge access also affects the nature of the relational strategy selected and the recall benefits observed. Although increases in "elaboration" were hypothesized to account for developmental differences in associative memory, the evidence clearly shows that other associative strategies are also involved. Although these other associative strategies involve elaboration in a nontechnical sense, the observed dissociations between them and the elaboration strategy argue for maintaining the distinction. Moreover, further analysis is needed to understand the interactions between strategy selection and knowledge access. In this regard, the initial strategy deployed by a learner is dependent on his or her knowledge about the relative effectiveness of various relational associations and interactions with knowledge access. For example, a younger subject might forgo "elaboration" if the items are "captured" by an "other associative" relationship activated during strategy deployment (particularly if the initial search for an elaboration is very effortful). In contrast, an older subject might persevere at retrieving a relevant event because of his or her knowledge about the benefits of encoding "direct" interactions for pair members. The learner's subsequent strategy selection, either for additional processing or encoding of new pairs, is undoubtedly more complex because of increases in the learner's knowledge about the relationships between strategy use, knowledge access, and resource demands. In conclusion, research examined in this chapter verified relationships between strategy use, mental effort, and knowledge access. Moreover, interactions between strategy use and knowledge access were exposed. These relationships are presumed to underlie developmental differences in the efficacy of memory strategies.

Adolescent↗
PubMed1991

Dual-task interference in left-handed subjects: hemispheric specialization vs manual dominance.

Thirty-six left-handed subjects performed a dichotic listening task and two concurrent (verbal plus finger-tapping) tasks. Baseline tapping scores revealed both left- and right-hand dominance within left-handed subjects. Moreover when subjects were categorized as consistent or inconsistent for 'sidedness advantage' (e.g. consistent = same side for dominant hand and ear advantage), it was shown that the dual-task interference effects found on the concurrent tapping tasks were due to both hemispheric specialization and manual dominance.

Adult↗
PubMed1991

Consistency of hand preference: predictions to intelligence and school achievement.

Gottfried and Bathurst (1983) reported that hand preference consistency measured over time during infancy and early childhood predicts intellectual precocity for females, but not for males. In the present study longitudinal assessments of children previously classified by Gottfried and Bathurst as consistent or nonconsistent in cross-time hand preference were conducted during middle childhood (ages 5 to 9). Findings show that (a) early measurement of hand preference consistency for females predicts school-age intellectual precocity, (b) the locus of the difference between consistent vs. nonconsistent females is in verbal intelligence, and (c) the precocity of the consistent females was also revealed on tests of school achievement, particularly tests of reading and mathematics.

Child↗
PubMed1990

Mental effort and elaboration: effects of accessibility and instruction.

The present study examined the effects of accessibility to relevant schematic knowledge for elaboration in the associative learning of noun pairs. Fifth-grade participants performed two simultaneous tasks--associative learning and finger tapping--so that the mental effort demands of elaborating pairs that varied in accessibility could be estimated. The mental effort expended during the creation of sentence elaborations was greater for inaccessible pairs than accessible pairs. This accessibility difference was not observed when subjects were provided with the pair members in sentences. These findings confirm information-processing analyses of the elaboration process and support a knowledge-base interpretation of developmental differences in elaboration effort.

Attention↗
PubMed1990

Lateralized interference in finger tapping: initial value differences do not affect the outcome.

Willis and Goodwin, Neuropsychologia 25, 719-724, 1987, have suggested that asymmetric interference observed in dual-task/time-sharing studies may be a statistical artifact of "initial-values" differences and not hemispheric lateralization. In the present study lateralized finger-tapping interference produced by concurrent anagram solution was observed even after the initial right-hand advantage in baseline tapping performance was removed experimentally.

Adult↗
PubMed1989

Lateralized finger-tapping interference produced by block design activities.

Dual task procedures were used to examine hemispheric specialization for nonmanual block design activities. College subjects performed a finger-tapping task with each hand; on some trials concurrent WISC block design solutions were required. Patterns of lateralized interference in tapping under dual-task conditions indicated more left- than right-hemispheric involvement for males, while more bilateral involvement was shown for females.

Adult↗
PubMed1989

The triple option choice: self-selection bias in traditional coverage, HMOs, and PPOs.

Health care costs and utilization by salaried employees and their dependents at a large self-insured midwestern industrial manufacturing corporation were analyzed for the year before employees were first offered a triple option choice. Members had the option of retaining traditional Blue Cross and Blue Shield of Michigan (BCBSM) coverage or switching to either a number of health maintenance organizations (HMOs) or a number of preferred provider organizations (PPOs). Members who switched to HMOs or PPOs were generally younger and had lower average expenses and utilization rates than those who retained the traditional BCBSM plan. The results suggest that a selection bias does occur in this population, as lower cost members were more attracted to the HMOs and PPOs than were more expensive members. Implications for the corporation as well as for the drive toward managed care alternatives are discussed.

Age Factors↗
PubMed1986

Lateralized interference in finger tapping: comparisons of rate and variability measures under speed and consistency tapping instructions.

Forty right-handed college subjects tapped with and without a verbal task under two instructional conditions (tap as quickly as possible vs. tap as consistently as possible) and two levels of verbal production (silent vs. aloud). The tapping task consisted of the alternate tapping of two keys with the index finger of the left vs. right hands, while the verbal task was anagram solution. Three rate and four variability measures of tapping performance were evaluated in the identification of lateralized interference. The results indicate that reliable lateralized interference, more right-hand than left-hand tapping disruption, was observed only for variability measures under instructions to tap as consistently as possible. Furthermore, only one of these variability measures was sensitive to an increase in lateralized interference produced by verbal production. Because of the limited demonstration of verbal laterality effects with the two-key tapping procedure in this study, conclusions suggest that the simpler manual task of repetitive tapping of one key should be viewed as the method of choice in future dual-task studies.

Female↗
PubMed1984

Lateralized interference in finger tapping: assessment of block design activities.

Dual task procedures were used to evaluate lateralized processing of block design solutions. Right-handed college students tapped a micro-key alone vs tapped while solving block design problems. Lateralized interference, implicating right-hemisphere processing, was observed when subjects manually completed block designs with their non-tapping band. When manual block manipulation was not required and subjects solved designs mentally, a different laterality pattern suggesting left-hand facilitation in conjunction with right-hand interference in tapping performance was observed. Only the facilitation effect, however, was reliably different from zero.

Brain↗
PubMed1983

Lateralized interference of repetitive finger tapping: influence of familial handedness, cognitive load and verbal production.

The repetitive finger tapping of 24 right-handed subjects from dextral and sinistral families was evaluated. Subjects tapped with and without concurrent verbal tasks which included reciting a nursery rhyme, reading words (silent vs aloud) and solving anagrams (silent vs aloud). Overall, results indicated that the concurrent verbal tasks interfered more with right-hand tapping than with left-hand tapping. This pattern was more pronounced for familial dextral subjects than familial sinistral subjects. This latter finding was most evident with the complex verbal task of solving anagrams.

Adult↗
PubMed1981

The development of organizational strategies in the storage and retrieval of categorical items in free-recall learning.

The present study examined the relative effectiveness of organization strategy use at study versus test in a single-trial, free-recall learning task, 90 subjects from each of 3 grade levels (second vs. sixth vs, college) were presented with 36 pictures selected equally from 6 different taxonomic categories. 3 levels of organizational strategy use were factorially crossed during study and test: Categorical cues were either (a) absent, (b) available, or (c) imposed. Developmental increases in performance were observed for the dependent measures of correct recall, study-trial organization, test-trial organization, frequency of cue use, and self-reported study activities. Generally speaking, imposed organization at study attenuated age differences in correct recall performance and study-trial organization, whereas imposed organization at test served to attenuate age differences in verbal clustering. Performance in the available cue condition at study or test was indistinguishable from performance in the control condition (i.e., cues absent). The results from the present study are generally consistent with previous assessments of organizational effects and provide new evidence concerning their independent and additive functions at study and test in developmental free-recall performance.

Adult↗
PubMed1980

Developmental differences in visual backward masking.

2 experiments were conducted to examine developmental differences in visual recognition masking when verbal encoding and response demands are minimized. Precautions were taken in the experiments to ensure the implication of the central visual system in the backward-masking component of each experiment. Sampling was conducted across the kindergarten, third-grade, sixth-grade, and college levels. In the first experiment, no-mask target recognition was set at 100% correct. The results indicated systematic grade differences in backward masking such that older children and adults showed more rapid recognition improvement across stimulus onset asynchronies (SOAs) than did young subjects (i.e., a grade x SOA interaction). Although this finding could be interpreted to suggest developmental differences in the rate of visual information processing, such an interpretation would be inappropriate. The problem is that the masking functions for all grade levels reach asymptote at 100% correct (i.e., a ceiling effect). Thus, the grade X SOA interaction could have been produced for reasons other than rate-of-processing differences (e.g., developmental differences in the quality of stimulus reception). Thus, experiment 2 was designed to assess this possibility by evaluating developmental differences in visual backward masking when no-mask target recognition was set at the 75% level for the grades sampled. The grade x SOA interaction observed in experiment 1 was not observed in experiment 2. The results from the studies indicate that, when the ceiling effects in no-mask target recognition are removed, the visual information processing rates for children and adults can be considered equivalent.

Adolescent↗