The effects of stressor predictability on lymphocyte proliferation in humans

Abstract

To demonstrate the effects of predictable and unpredictable stressors on immune function, 36 male subjects were randomly assigned to complete ten trials of either a predictable or unpredictable cold pressor task or a non-stressful warm pressor control task. The predictable and no-stressor groups were given information about the duration of each pressor trial and a countdown of seconds passed from beginning to end of each trial. The unpredictable stressor group received no information. Self-report, cardiovascular, and biochemical measures were taken throughout the tasks in order to ascertain the effectiveness of the predictability and stressor manipulations. Lymphocyte proliferation to concanavalin A (Con A) and pokeweed mitogen (PWM) were measured before, during and after the tasks. Lymphocyte proliferation to Con A (10/μg/ml) was significantly reduced only in response to the unpredictable stressor suggesting that predictability buffered the effect of the stressor on immune function. Proliferation to PWM followed a similar pattern but was not statistically significant. Blood pressure responses were negatively correlated with proliferation values suggesting that stressor predictability may attenuate stress-associated immune decreases by reducing sympathetic arousal.     

Effects of crystallization on corrosion resistance and electron work function of Zr65Al7.5Cu17.5Ni10 amorphous alloys

The effects of crystallization on the electron work function and corrosion resistance of Zr₆₅Al_7.5Cu_17.5Ni₁₀ amorphous alloys have been studied. The single-phase amorphous alloy exhibits a better corrosion resistance and has a higher work function than the partially and fully crystallized alloys with the same composition. The close relationship between corrosion resistance and work function indicates that the Kelvin probe technique can be a powerful tool for characterizing the corrosion behaviour of amorphous alloy on an electronic level.     

The Acquisition and Function of Religious Beliefs: A Review and Synthesis of Proximate and Ultimate Perspectives

ABSTRACT

Two main scientific approaches have renewed in the last decade the scientific study of religion: the cognitive and the adaptationist. The former is focused on proximate causes, the latter is looking for ultimate causes of religious beliefs and behaviours. Both approaches are useful and promising. However, in both cases, various important aspects and contexts associated with the origin, acquisition, and transmission of religious beliefs have been neglected. The present paper offers an approach that conjoins both models after reviewing several critical issues, to highlight a distinction between cognitive conditions and structures, on one side; and developments or applications, on the other. As a result greater attention needs to be paid to religious functions and their cultural framework to better understand religion and to explain some current processes, like massive secularization in several areas.     

The present and absent object—on thinking and the capacity to symbolize

In this paper, Bion's different theories on the development of thinking will be introduced: on the one hand, his theory of thoughts as resulting from tolerance for the absence of the object, and on the other hand, dream thoughts and thoughts as resulting from the presence of the object, originally through the mother's containing function. The effects of failures in this development will be discussed; among other things, a hypertrophy of the apparatus of projective identification at the expense of thinking capacities. Briefly, a comparison will be made between a facilitating relation between container and contained and the oscillation between the paranoid-schizoid and depressive position, which Bion describes as a prerequisite for open symbolizing processes. Bion's theories and concepts will be supplemented by Winnicott's theories on the “creative illusion” and the breast/the mother as a “subjective object” as a precondition for the symbolizing capacity that later develops in the “potential space”. Very briefly, a comparison is made between Winnicott's term “the subjective object” and Segal's term “symbolic equation”. Clinical vignettes are interpolated.     

Executive function outcomes of children with traumatic brain injury sustained before three years

Traumatic brain injury (TBI) is a common cause of disability in childhood. While the outcomes of TBI sustained in school years has been heavily researched, very little is known about the impact of TBI in infants and young children. The aim of this study was to investigate the impact of TBI on executive function (EF) in children who sustained a TBI before 3 years of age. A group of 55 children, 19 with a mild TBI, 16 children with a moderate-severe TBI, and 20 uninjured comparison children participated. The EF of children aged 3 to 6 years were compared using child-based measures of attentional control and information processing. Parents completed questionnaires rating their child's EF. Severity groups differed on the child-based EF measure of attentional control with children with TBI performing below the control group. There were no significant group differences for information processing or parent-rated EF. It appears that children who sustain a TBI before the age of 3 years display impairments in some areas of attentional control 3–4 years postinjury. The findings fit with the existing EF literature for older children.     

Neuropsychological impairments on the NEPSY-II among children with FASD

Background: We examined the pattern of neuropsychological impairments of children with FASD (compared to controls) on NEPSY-II measures of attention and executive functioning, language, memory, visuospatial processing, and social perception.

Methods: Participants included 32 children with FASD and 30 typically developing control children, ranging in age from 6 to 16 years. Children were tested on the following subtests of the NEPSY-II: Attention and Executive Functioning (animal sorting, auditory attention/response set, and inhibition), Language (comprehension of instructions and speeded naming), Memory (memory for names/delayed memory for names), Visual-Spatial Processing (arrows), and Social Perception (theory of mind). Groups were compared using MANOVA.

Results: Children with FASD were impaired relative to controls on the following subtests: animal sorting, response set, inhibition (naming and switching conditions), comprehension of instructions, speeded naming, and memory for names total and delayed, but group differences were not significant on auditory attention, inhibition (inhibition condition), arrows, and theory of mind. Among the FASD group, IQ scores were not correlated with performance on the NEPSY-II subtests, and there were no significant differences between those with and without comorbid ADHD.

Conclusions: The NEPSY-II is an effective and useful tool for measuring a variety of neuropsychological impairments among children with FASD. Children with FASD displayed a pattern of results with impairments (relative to controls) on measures of executive functioning (set shifting, concept formation, and inhibition), language, and memory, and relative strengths on measures of basic attention, visual spatial processing, and social perception.     

Interference control in adolescents with Mild-to-Borderline Intellectual Disabilities and/or behavior disorders

The aim of this study was to investigate interference control in adolescents with Mild to Borderline Intellectual Disability (MBID) by addressing two key questions. First, as MBID is often associated with comorbid behavior disorders (BD), we investigated whether MBID and BD both affect interference control. Second, we studied whether interference control deficits are associated to problems in everyday executive functioning. Four groups of adolescents with and without MBID and/or BD performed the Eriksen flanker task, requiring participants to respond to a central target while ignoring interfering flanking stimuli. Their teachers rated behavior on the Behavior Rating Inventory Executive Function (BRIEF). We found pronounced effects of MBID but not BD on flanker interference control. In contrast, we observed pronounced effects of BD, but not MBID, on the BRIEF. In addition, flanker interference scores and BRIEF scores did not correlate. These results are taken to suggest that adolescents with MBID are characterized by deficits in interference control that do not become manifest in ratings of everyday executive functioning. In contrast, adolescents with BD are not characterized by deficits in interference control but do show elevated ratings of deficits in everyday executive function.     

Characterization of Children's Decision Making: Sensitivity to Punishment Frequency,Not Task Complexity

On a gambling task that models real-life decision making, children between ages 7 and 12 perform like patients with bilateral lesions of the ventromedial prefrontal cortex (VMPFC), opting for choices that yield high immediate gains in spite of higher future losses (Crone &; Van der Molen, 2004 Crone, E. A. and Van der Molen, M. W. 2004. Developmental changes in decision-making: Performance on a gambling task previously shown to rely on ventromedial prefrontal cortex. Developmental Neuropsychology, 25(3): 251–279. [PUBMED][INFOTRIEVE][CROSSREF][Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]). The current study set out to characterize developmental changes in decision making by varying task complexity and punishment frequency. Three age groups (7–9 years, 10–12 years, 13–15 years) performed two versions of a computerized variant of the original Iowa gambling task. Task complexity was manipulated by varying the number of choices participants could make. Punishment frequency was manipulated by varying the frequency of delayed punishment. Results showed a developmental increase in the sensitivity to future consequences, which was present only when the punishment was presented infrequently. These results could not be explained by differential sensitivity to task complexity, hypersensitivity to reward, or failure to switch response set after receiving punishment. There was a general pattern of boys outperforming girls by making more advantageous choices over the course of the task. In conclusion, 7–12-year-old children—like VMPFC patients—appear myopic about the future except when the potential for future punishment is high.     

Executive Function in Young Children and Chimpanzees (Pan troglodytes): Evidence From a Nonverbal Dimensional Change Card Sort Task

In this article the authors compared chimpanzees’ executive function with that of children. They developed a nonverbal dimensional change card sorting task, which indexed the development of executive function. Three pairs of mother and offspring chimpanzees and 30 typically developed 5-year-old children were presented with 2 target stimuli and a test stimulus comprising 2 dimensions (size and shape) on a display; they were required to sort the test stimulus according to 1 dimension (e.g., shape). After 5 consecutive correct trials, the participants had to sort the test stimulus according to the other dimension (e.g., size). The results showed that the chimpanzees often failed to sort the test stimuli according to the first and reversed dimensions. On the other hand, the children were correctly able to use both dimensions. These results indicate that chimpanzees may have less developed executive skills than children.