An exploratory study of the relationship between face recognition memory and the volume of medial temporal lobe structures in healthy young males

A rigorous new methodology was applied to the study of structure function relationships in the living human brain. Face recognition memory (FRM) and other cognitive measures were made in 29 healthy young male subjects (mean age = 21.7 years) and related to volumetric measurements of their cerebral hemispheres and of structures in their medial temporal lobes, obtained using the Cavalieri method in combination with high resolution Magnetic Resonance Imaging (MRI. Greatest proportional variability in volumes was found for the lateral ventricles (57%) for the cerebral hemispheres (8%) in the mean volumes of the hippocampus, parahippocampal gyrus, amygdala, caudate nucleus, temporal pole and temporal lobe on the right and left sides of the brain. The volumes of the right and left parahippocampal gyrus, temporal pole, temporal lobe, and left hippocampus were, prior to application of the Bonferroni correction to take account of 12 multiple comparisons, significantly correlated with the volume of the corresponding hemisphere(p < 0.05). The volumes of all structures were highly correlated (p < 0.0002 for all comparisons) between the two cerebral hemispheres. There were no positive relationships between structure volumes and FRM score. However, the volume of the right amygdala was, prior to application of the Bonferroni correction to take account of 38~multiple comparisons, found to be significantly smaller in the five most consistent high scorers compared to the five most consistent low scorers (t = 2.77,p = 0.025). The implications for possible relationships between healthy medial temporal lobe structures and memory are discussed.     

Evidence for a boundary effect in roll vection

Large circular displays rotating around the line of sight produce an illusion in which the seen orientation of the true vertical is shifted in a direction opposite to the display’s motion. Two experiments were performed to determine whether the magnitude of this illusory tilt is a function of the area of display elements, of their boundary length, or of their spatial frequency. In Experiment 1, 12 subjects viewed each of nine displays across which the number and area of the circular elements were independently varied. Three of the displays were equated for the area of their elements. The results suggested that tilt magnitude and onset latency could be explained by a boundary length effect. A second experiment tested eight subjects on two displays, equated for element boundary length but differing in the spatial frequency of the elements. The displays produced closely similar illusory trite corroborating the view that, within broad limits, element boundary length—and not spatial frequency or area—determines the size and onset latency of illusory tilt. A third experiment confirmed previous research in finding greater tilt and more rapid onset with more peripherally projected displays.     

Chicks' responses to familiar stimuli in unfamiliar environments

The aim of the present experiments was to find out how imprinted chicks respond to familiar figures in unfamiliar settings. Experiment I showed that chicks individually imprinted with a coloured stationary disc did not readily approach it when later confronted with it in a larger pen—a confirmation of an earlier finding. Experiment II showed a similar disruptive effect when the chicks were individually presented with a stationary object (a ball) in a pen differing in colour from the original one. Experiment III, however, in which chicks were imprinted to a moving ball, showed unattenuated imprinting when testing took place in a strange environment. It was concluded that the disruptive effect of neophobia can be overcome when a high degree of figure salience ensures powerful imprinting.     

On the fragility of medical virtue in a neoliberal context: the case of commercial conflicts of interest in reproductive medicine

Social, political, and economic environments play an active role in nurturing professional virtue. Yet, these environments can also lead to the erosion of virtue. As such, professional virtue is fragile and vulnerable to environmental shifts. While physicians are often considered to be among the most virtuous of professional groups, concern has also always existed about the impact of commercial arrangements on physicians’ willingness and capacity to enact their professional virtues. This article examines the ways in which commercial arrangements have been negotiated to secure medical virtue from real or perceived threats of erosion. In particular, we focus on the concern surrounding conflicts of interest arising from commercial arrangements that have developed as a result of neoliberal economic and social policies. The deregulation of medical markets and privatization of services have produced new commercial relationships that are often misunderstood by patients, publics, and physicians themselves. ‘Conflicts of interest’ policies have been introduced in an attempt to safeguard ethical conduct and medical practice. However, a number of virtue ethicists have critiqued these policies as inadequate for securing virtue. We examine the ways in which commercial arrangements have been seen to impact upon medical virtue, both historically and in the context of modern medicine (using the example of fertility services in Australia). We then describe and critique current efforts to restore clinical virtue through both conflict of interest policies and through virtue ethics. Finally, we suggest some possible ways of addressing the corrosive effects of neoliberalism on medical virtue.     

Investigating the relationship between working memory and emotion regulation in mothers

Recent work suggests that executive functions, specifically working memory, may facilitate emotion regulation (ER). Here we examined whether measures of visuospatial working memory and verbal working memory relate to ER in a group of recent mothers. We found that while visuospatial working memory was associated with, and predictive of, self-reported measures of ER and emotion dysregulation—verbal working memory was correlated to only one dimension of emotion dysregulation. These findings suggest that working memory may play a unique role in everyday regulatory functioning. We frame our results in terms of the broader implications they may have for the potential role of executive functioning in parenting.     

Preliminary exploration of secondhand smoke exposure in youth with Sickle Cell Disease: biochemical verification,pulmonary functioning,and health care utilization

Exposure to secondhand smoke (SHSe) can compound an already challenging set of health problems for youth with Sickle Cell Disease (SCD). Exposure to electronic cigarettes may also impact SCD symptomology and respiratory functioning. This study built on these previous findings by a) utilizing two objective measures of SHSe, salivary cotinine and exhaled carbon monoxide and b) examining the association of SHSe with emergency department utilization, physician-reported sickle cell crises, and pulmonary functioning. Caregivers (N = 31 dyads; M_age = 37.6 years; SD = 8.5 years) of youth with SCD (M_age = 9.0 years; SD = 4.5 years) completed self-report measures of tobacco/nicotine use. Youth provided a saliva sample to assess cotinine levels, and performed pulmonary function tests. Dyads provided breath samples for measurement of eCO. A chart review was conducted to obtain medical history and utilization. Majority of youth (88%) were exposed to SHS via salivary cotinine. Interestingly, no significant associations were observed between youth cotinine levels and emergency department utilization, physician-reported sickle cell crises, or pulmonary functioning. Present findings indicate a need to assess for SHSe using objective assessment measures. Future research should investigate which specific factors contribute to increase SHSe/SHVe in youth with SCD.     

Visuospatial working memory in school-aged children exposed in utero to cocaine.

OBJECTIVE: Among the neurocognitive impairments reported as associated with prenatal cocaine exposure, slower response time, and less efficient learning in school-aged children are common to findings from several laboratories. This study presents performance data on a spatial working memory task in 75 prenatally cocaine exposed (CE) and 55 nondrug-exposed (NDE) 8- to 10-year-old children. METHODS: Children were administered a novel neuropsychological measure of immediate- and short-term memory for visuospatial information, the Groton Maze Learning Test (GMLT), a computer-based hidden maze learning test that consists of a "timed chase test" (a simple measure of visuomotor speed), eight learning trials followed by a delayed recall trial after an 8-minute delay and a reverse learning trial. Performance is expressed as correct moves per second and number of errors per trial. RESULTS: Across all trials, the cocaine-exposed group showed significantly slower correct moves per second and made significantly more errors. There were no significant main effects for amounts of alcohol, tobacco, or marijuana exposure. After an 8-minute delay and compared to the eighth trial, cocaine-exposed children showed less consolidation in learning compared to nonexposed children. When asked to complete the maze in reverse, cocaine-exposed children showed a greater decrement in performance (decreased correct moves per second and increased errors) compared to the eighth learning trial. CONCLUSIONS: Children exposed in utero to cocaine exhibit a possible impairment in procedural learning and diminished efficiency in creating and accessing an internal spatial map to master the hidden maze.     

Neurobiology of prenatal cocaine exposure effect on developing monoamine systems

Cocaine and crack belong to a broad category of agents that act primarily as central nervous system stimulants at the level of the monoaminergic neurotransmitter system (dopamine, norepinephrine, and serotonin). These neurotransmitters are involved in the regulation of a number of basic psychological functions including attention and arousal and play a crucial role in the defining of brain structure and neuronal formation. This paper outlines what is currently known about the direct effects of cocaine on the mature and developing central nervous system. Three general points are reviewed: (1) Cocaine has differing effects on structural and functional brain development throughout gestation (e.g., there is not a single, all or none effect); (2) No one area of the brain is singularly affected. Areas related by the monoaminergic system are differentially influenced and affecting one area may result in a functional change in another; and (3) Because substantial brain growth, synaptic formation, and remodeling occur in the first months after birth, ongoing postnatal exposure to cocaine also carries risk for direct effects on brain function. Understanding the developmental neurobiological effects of cocaine provides data to guide studies in infants and young children of how prenatal cocaine exposure may contribute to specific, biologically based areas of neurological vulnerability that will be expressed behaviorally and developmentally in the first 3 to 5 years of life.