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Biomedical subjects

T Wilcox

Publications and source records attributed to T Wilcox.

10 recordsLinked to original sources
PubMed1999

Object individuation: infants' use of shape, size, pattern, and color.

Recent research indicates that when an event-monitoring paradigm is used, infants as young as 4.5 months of age demonstrate the ability to use featural information to individuate objects involved in occlusion events (Wilcox & Baillargeon, 1998a, Object individuation in infancy: The use of featural information in reasoning about occlusion events. Cognitive Psychology 37, 97-155; Wilcox & Baillargeon, 1998b, Object individuation in young infants: Further evidence with an event monitoring task. Developmental Science 1, 127-142). For example, in one experiment (Wilcox & Baillargeon, 1998b, Object individuation in young infants: Further evidence with an event monitoring task. Developmental Science 1, 127-142) 4.5-month-old infants saw a test event in which a green ball with colored dots disappeared behind one edge of a narrow or wide screen, and a red box with silver thumbtacks appeared at the other edge; the narrow screen was too narrow to hide both objects simultaneously, whereas the wide screen was sufficiently wide to hide both objects at the same time. The infants looked reliably longer at the narrow- than at the wide-screen test event. These and control results suggested that the infants had: (a) used the featural differences between the ball and box to conclude that two objects were involved in the event; (b) judged that both objects could fit simultaneously behind the wide but not the narrow screen; and hence (c) were surprised by the narrow-screen event. The present experiments build on these initial findings by investigating the features to which infants are most sensitive. Four experiments were conducted with infants 4.5-11.5 months of age using the same procedure, except that only one feature was manipulated at a time: shape, size, pattern, or color. The results indicated that 4.5-month-olds use both shape and size features to individuate objects involved in occlusion events. However, it is not until 7.5 months that infants use pattern, and 11.5 months that infants use color, to reason about object identity. It is suggested that these results reflect biases in the kind of information that infants attend to when reasoning about occlusion events. Possible sources of bias are discussed.

Child Development↗
PubMed1998

Object individuation in infancy: the use of featural information in reasoning about occlusion events.

Recent findings by Xu and Carey (1996) indicate that, after seeing two distinct objects (e.g., a duck and a ball) emerge on the opposite sides of a screen, 10-month-olds show no surprise when the screen is removed to reveal one (e.g., a duck) as opposed to two objects (e.g., a duck and a ball). The authors took their results to mean that 10-month-olds are unable to use featural information to individuate objects. The present research examined a different interpretation of the results. This interpretation was based on a distinction between event mapping, in which infants see a sequence of two distinct events and judge whether the two are consistent, and event monitoring, in which infants see a single event and judge whether successive portions of the event are consistent. The present research contrasted infants' performances in event-mapping tasks in which they saw first an occlusion and then a no-occlusion situation (as in Xu & Carey) and in event-monitoring tasks in which they saw only an occlusion situation. It was hypothesized that infants would be more likely to give evidence of correct individuation when tested with the event-monitoring as opposed to the event-mapping tasks. Eight experiments were conducted with infants ages 7.5 to 11.5 months. These experiments yielded two main findings. First, when tested with an event-monitoring task, even 7.5-month-olds give evidence that they can use featural information to individuate the objects involved in an occlusion event. Second, when tested with an event-mapping task, even 9.5-month-olds give evidence that they can use featural information to interpret an occlusion event as long as the event is made extremely simple. These findings give weight to the distinction between event mapping and monitoring and more generally begin to shed light on the fundamental processes involved in infants' formation and use of event representations.

Analysis of Variance↗
PubMed1998

The relationship between symptoms and IgG and IgE antibodies in an office environment.

Airborne fungi have been postulated as a cause of symptoms among office workers. Using the MAST chemiluminescent system, this study evaluated 36 IgG and 36 IgE antibody levels in 47 office workers from an area with elevated airborne fungal concentrations and 44 office workers from an otherwise similar area with lower airborne fungal exposure. No difference was found in IgG antibody to fungi between the lower and higher exposure areas, but high IgG antibody to one or more of the fungi studied was detected in 67% of all the workers tested. IgE antibody to one or more antigens was detected in 40% of the participants. Workers who reported atopic symptoms (sneezing, runny nose, and itchy eyes) or "sick building" symptoms (any three of the following temporally related to work: headache, fatigue, stuffy nose, irritated eyes, or sore throat) were more likely to have one positive IgE antibody test. Type I hypersensitivity to aeroallergens besides fungi may play a role in some symptoms reported by some participants in this office building.

Adult↗
PubMed1996

Raw shellfish consumption and warning labels: results from the 1993 Texas Behavioral Risk Factor Surveillance System (BRFSS) survey.

We used the 1993 Texas Behavioral Risk Factor Surveillance System survey to assess the prevalence of raw shellfish consumption and to find the demographic and behavioral characteristics of raw shellfish consumers. We studied the general impact of warning labels reported by survey respondents. Data were analyzed using univariate and multiple logistic regression methods. Fourteen percent of the Texas surveyed reported consuming raw shellfish. Respondents with incomes greater than or equal to $25,000 and with education beyond high school were more likely to report consuming raw shellfish than were those with incomes less than $25,000 and with high school diplomas or less. Respondents at risk for acute and chronic drinking, driving while intoxicated, and driving without a seat belt were more likely than those not at risk of these behaviors to report consumption of raw shellfish. We did not find a significant difference between eaters and noneaters of raw shellfish regarding the impact of warning labels: however, among eaters of raw shellfish, older respondents were more likely than younger respondents to report that warning labels had no effect on them.

Adolescent↗
PubMed1995

Familial hemiplegic migraine and autosomal dominant arteriopathy with leukoencephalopathy (CADASIL).

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a recently described familial cerebrovascular disorder shown to map to chromosome 19q12. Familial hemiplegic migraine has also been shown in some families to map close to the CADASIL locus. The fully developed CADASIL phenotype consists of recurrent strokes developing in the fourth decade, progressing to a pseudobulbar palsy, spastic quadriparesis, and subcortical dementia. In an Irish family 15 members were fully investigated by magnetic resonance scanning; 10 had typical magnetic resonance features of CADASIL. Five members of this family had familial hemiplegic migraine and 4 of these had magnetic resonance evidence of CADASIL. Two other members had migraine with and without aura as a presenting clinical symptom of CADASIL. This disorder has been shown by linkage analysis to map to the CADASIL locus at chromosome 19. The phenotype at presentation of CADASIL in this family was variable and age related and included familial hemiplegic migraine, migraine with and without aura, transient ischemic attacks, strokes, and spinal cord infarction. This family study increases our understanding of the spectrum of clinical manifestations of this underrecognized familial cerebrovascular disorder.

Adult↗
PubMed1994

The relationship of age, gender, handedness, and sidedness to the size of the corpus callosum.

OBJECTIVES: We correlated the area and size of the corpus callosum, as measured by MR imaging, with the individual's handedness, sidedness, age, and gender. MATERIALS AND METHODS: A total of 117 patients (59 male, 58 female) aged 15-75 years were selected for this study. This included 12 persons who were either left-handed or ambidextrous. Each patient was tested extensively to determine handedness and sidedness. Callosal areas and thickness were measured and correlated with brain size. RESULTS: The body of the corpus callosum decreases in size with age and is larger in right-handed persons. The cross-sectional areas of the genu, splenium, and corpus callosum, overall, do not vary significantly with respect to age, gender, sidedness, or handedness. CONCLUSIONS: The size of the corpus callosum consistently decreases with age. Otherwise, few statistical differences in callosal size relate to gender, sidedness, or handedness.

Adolescent↗
PubMed1989

Lateral differences in schematic face encoding during dual-task performance with increasing levels of difficulty.

20 normal, right-handed, familial dextral men performed (a) unimanual finger tapping, (b) encoding of schematic faces at three levels of difficulty (3, 5, and 7 faces), (c) verbal production, (d) concurrent tapping and verbal production, and (e) concurrent tapping and face encoding. Subsequent recognition of faces was disrupted more by concurrent left-hand tapping than by concurrent right-hand tapping, supporting both the hypothesis that the right hemisphere mediates face encoding in adults and Kinsbourne and Hicks' (1978) "functional cerebral distance principle." Left- and right-hand tapping rate and variability were not asymmetrically affected by either verbal production or face encoding. While there was an increase in generalized interference effects on face encoding, the degree of asymmetry of the interference remained constant. In addition, as the difficulty of the memory task increased, variability of tapping rate decreased. This was discussed in terms of attention and automatic motor programming.

Adult↗
PubMed1983

The effects of increased information on intake decision making in a rural mental health center.

To increase the efficiency with which decisions were made in their agency, the staff of a rural mental health center developed a self-administered intake inventory to gather information more relevant to the available treatment alternatives. The new format sought to provide information relevant to marital and family, as well as individual, psychotherapy. An evaluation of the effects of the new format showed that it altered the percentages of clients in the various treatments, while heightened staff awareness of differential treatment did not. The results also suggested that, except for part-time psychiatrists, there was no association between the individual doing treatment and the intervention offered. This result was interpreted as being important in a rural setting where staff members must be generalists rather than specialists.

Community Mental Health Centers↗
PubMed1981

Maintained fertility in a patient with hyperprolactinemia due to big, big prolactin.

The heterogeneity of serum PRL in a hyperprolactinemic but fertile woman (Patient A) was studied by gel chromatography. Ninety percent of her PRL eluted with the void volume as "big, big" PRL and only 6% coincided with monomeric "little" PRL. Sera from a woman who had hyperprolactinemia associated with infertility (Patient B) and a normal woman (Patient C) exhibited the usual heterogeneous distribution, where 5% and 19%, respectively, eluted as big, big PRL and 76% and 65%, respectively, eluted as little PRL. Serial dilutions of the serum from Patient A displayed nonparallelism to the lines obtained from similar dilutions of both PRL standard and serum from a normal woman, suggesting possible immunological differences among the three forms of the circulating hormone. This finding, together with reports that suggest big, big PRL has a low receptor affinity, may account for the apparent lack of any biological effect upon Patient A from her sustained hyperprolactinemia.

Adult↗