Lightness differences and the perceived segregation of regions and populations

A striking finding reported by Beck, Sutter, and Ivry (1987) was that, in textures composed of regions differentiated by the arrangement (checks and stripes) of two texture elements (light and dark squares), a large lightness difference between the squares could fail to yield segregation between the regions, whereas a smaller lightness difference could sometimes yield strong segregation. In the experiments reported here, we compared the segregation of striped and checked arrangements of light and dark squares into regions with the segregation of two randomly interspersed populations of light and dark squares into subpopuiations. Perceived lightnesses are the same for a given set of squares, whether they are arranged in regions or in intermixed populations. Perceived population segregation is approximately a single-valued function of the lightness differences of the squares, but perceived region segregation is not. The reason for the difference between population segregation and region segregation may be that region segregation is mediated by detectors’ having large oriented receptive fields (large bar detectors) that are sensitive to the fundamental spatial frequency and orientation of the texture region as defined by the arrangement of the squares (Beck et al., 1987; Sutter, Beck, & Graham, 1989). These detectors cannot be responsible for population segregation, because the light and dark squares are distributed randomly throughout these patterns and therefore do not define a consistent arrangement of any particular spatial frequency or orientation. The light and dark squares in the population patterns fall equally on excitatory and inhibitory regions of large bar detectors. A plausible explanation for population segregation is to suppose that the segregation is the result of similarity grouping of the light and dark squares.     

The development of complex sentence processing strategies

Children aged 3, 4, and 5 years and adults heard sentences with clauses connected by after, and, or before, saw a picture, and indicated whether or not the picture matched one of the events of the sentence. Response times were taken as a measure of immediate accessibility to the meaning of the clause that the picture was about. Temporal organization of sentence meanings was dominant in 3-year-olds and adults, but not in 4- or 5-year-olds. The 3-year-olds and especially the adults processed and-sentences as implicitly temporal. The results for 4- and 5-year-olds are interpreted as indicating experimentation with alternate strategies for organizing sentences based on the structural/presuppositional properties of clauses.     

Elementary School Attendance as an Index of Guidance Needs

The attendance records of 235 second-grade students were studied. Each child was classified by his teacher either into one of two problem groups (Learning-Educational or Personal-Social) or into one of two non-problem groups (Enrichment or Average-Normal). The teachers are represented in one of four groups: either being from a school serving a higher or a lower economic area and as having extended or limited classroom experience. Three types of absences were studied: single day, multiple day, and total days absent. Single day absences were expected to be most closely related to guidance needs. Multiple classification analysis of variance revealed no significant differences in the average number of days absent among the four pupil groups, and the four teacher groups or among their interactions, regardless of whether the data were single day, multiple day, or total days absent. Whether the data were studied in terms of pupil or teacher groups, the average number of days absent was never significantly different from zero. No support was found for the idea that school attendance is an index of pupil achievement or adjustment.     

Lactation deficit in OFA hr/hr rats may be caused by differential sensitivity to stress compared with Wistar and Sprague Dawley rats

OFA hr/hr (OFA) rats present a major lactation deficit that impairs offspring survival. To explore whether abnormal stress responsiveness causes this deficit, we compared their hormonal (prolactin, progesterone, and corticosterone) responses to stress (room change and 2-min ether exposure) with those of Wistar and Sprague Dawley (SD) rats. We tested responses during the estrous cycle, pregnancy, lactation, after ovariectomy, and ovarian steroid hormone priming, and responses to suckling. We evaluated hypothalamic expression of receptors for prolactin (PRLRlong) and the isoforms of receptors for progesterone (PRA and B) and estrogen (ERα and β) in late pregnancy. We tested whether administration of an anxiolytic (diazepam) improved lactation. Ether exposure increased circulating levels of the three hormones in the three strains of rats, cycling and ovariectomized, but was less effective in pregnancy and lactation. Elevated estrogen level (estrus and estradiol-treated ovariectomized rats) potentiated the prolactin response more in SD and OFA rats than in Wistar rats. Elevated progesterone level (late pregnancy, lactation, progesterone-treated ovariectomized rats) inhibited the prolactin response less in OFA than in SD or Wistar rats. Ether exposure inhibited the prolactin and oxytocin responses to suckling only in OFA rats. Diazepam treatment increased pup survival rate and the prolactin response to suckling. Hypothalamic total PR mRNA content, assayed by RT-PCR, was higher in pregnant OFA rats compared with SD and Wistar rats, but the PRB/PRA protein ratio determined by Western blot was lowest in Wistar rats, intermediate in OFA rats, and highest in SD rats. The heightened sensitivity to stress of lactating OFA rats may contribute to their lactational deficit and be caused by a combination of hypoprolactinemia and reduced inhibitory capacity of progesterone.     

Collaborative Home-Based Therapy (CHBT): A Culturally Responsive Model for Treating Children and Adolescents Involved in Child Protective Service Systems

Mental Health professionals are challenged with utilizing innovative treatment models to meet the needs of diverse communities. Enhancements in interventions have led to a reconceptualization of the role of mental health professionals, specifically, family therapists. This paper presents a collaborative, home-based model for working with children and adolescents involved in foster care. We begin by examining literature on home-based therapy. This review provides a framework to understand the need for a culturally responsive approach. A collaborative, home-based approach is presented along with unique issues and guidelines for practice. A clinical case is presented to illustrate implications for treatment.     

Clinical Commentary

Abstract

This paper is the narrative of a first-time father with a son born seven weeks early by Caesarean section. Against the anxiety and trauma of his infant's birth and his wife's illness, another inner darker drama is being relived. Michael shows all the wounds of a battered child. He asks two awesome questions - Will I be to my son as my father was to me? Will my son be to me as I was to my father? Fearful and at first unvoiced questions, the developing interviews gave them a voice. We respected Michael's sharing of the early and fearful days and nights when his infant first came home. We sometimes found it hard to empathize with his running away to hide in work, until we understood what he was hiding from. Most poignant was his struggle with his anger and hurt with his father and his desire to understand, ‘Why?’, so that he would not be like this to his son. We saw a sensitive revelation of life being born inside him anew, as he made contact with his real infant and his psychic infant within. Of particular interest was the therapeutic use of the research interview space and the interviewer.     

The use of indigenous interviewers in a study of latino men who have sex with men: A research note

The use of indigenous researchers has long been practiced in ethnographic research; a similar use of indigenous personnel has not been as commonly undertaken in interview studies of men who have sex with men (MSM). This research note reports on the use of indigenous interviewers in a study of Latino MSM’s perceptions about sexual relationships and behaviors. The full study explores sexual relationships among Latino MSM, and HIV risk behaviors undertaken by a population of MSM residing in a community in southern California. This research note describes both the strengths and limitations that arise from employing indigenous interviewers for improving the overall quality of sensitive data. Benefits discussed include improved access to an otherwise highly restricted group, enhanced rapport-building capabilities, and greater understanding of language unique to the study population. Limitations discussed include the use of previously untrained interview personnel and age and gender issues.     

Effects of occlusion on pigeons' visual object recognition

Casual observation suggests that pigeons and other animals can recognize occluded objects; yet laboratory research has thus far failed to show that pigeons can do so. In a series of experiments, we investigated pigeons' ability to 'name' shaded, textured stimuli by associating each with a different response. After first learning to recognize four unoccluded objects, pigeons had to recognize the objects when they were partially occluded by another surface or when they were placed on top of another surface; in each case, recognition was weak. Following training with the unoccluded stimuli and with the stimuli placed on top of the occluder, pigeons' recognition of occluded objects dramatically improved. Pigeons' improved recognition of occluded objects was not limited to the trained objects but transferred to novel objects as well. Evidently, the recognition of occluded objects requires pigeons to learn to discriminate the object from the occluder; once this discrimination is mastered, occluded objects can be better recognized.