Molecular Mechanisms Associated with the Benefits of Variable Practice in Motor Learning

Abstract

Variable practice promotes a higher level of motor learning than constant practice. The glutamate receptors, n-methyl-d-aspartate (NMDA) and alfa-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA), have been associated with the changes in motor cortex that occur throughout the process of motor learning. Considering that, it is possible that variable practice is more associated with the NMDA and AMPA receptors than constant practice. This study aimed ao investigating the association between the glutamate receptors, NMDA and AMPA, and constant and variable practice schedules. Seventy-eight male mice practiced the rotarod task in a constant or variable scheduling, in two consecutive days (acquisition phase). Learning tests were performed 24?h and 10?days after the end of the acquisition phase. Variable practice was more associated with the NMDA receptor and had a greater AMPA receptor expression than constant practice. The results suggest that the benefits of variable practice are result of both the greater dependency on the NMDA receptor and the greater AMPA receptor expression.     

Investigating the latent dimensions of posttraumatic stress disorder and the role of anxiety sensitivity in combat-exposed Filipino soldiers

ABSTRACT

Identifying the optimal factor structure of posttraumatic stress disorder (PTSD) has recently been reinvigorated in literature due to the substantial changes to its diagnostic criteria in the fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Currently, six models of PTSD are supported in literature, but there is no consensus on the best-fitting factor structure. Additionally, the extant literature examining the relationship between PTSD symptom-grouping and AS in the latent level has been scarce. The present study’s objectives are two-fold: first, we aimed to identify the best-fitted model of PTSD by comparing the six empirically-supported models, and; second, we examined the relationship between the best-fitting model with anxiety sensitivity (AS). Utilizing a sample of 476 combat-exposed soldiers, the results suggest that both the anhedonia and hybrid models provide the best fit to the data, with the anhedonia model achieving slightly better fit indices. Further, the examination on the influence of AS to PTSD reveal that while there is a pattern of decreasing factor loadings and factor correlations when accounting for AS, the changes are not significant to alter the PTSD symptom-structure. Based on these results, our findings suggest further investigation on the possible mediating or moderating mechanisms by which AS may influence PTSD.     

Spaceship Archeology: Methodological Experiments in NSF Counter-Insurgency at the 2017 Oregon Eclipse Festival

Abstract

This article examines several aspects of knowledge production among practitioners of 21st century capitalism, critiquing the motivations, funding, methods, and dissemination of today’s politically and economically dominant epistemology. We document a methodological experiment undertaken during the Oregon Eclipse Festival—a week-long event coinciding with the solar eclipse that crossed the United States on August 21, 2017. As commissioned participants in the festival’s Art & Science exhibit, we designed an interactive archeological excavation that sought to produce material evidence corroborating the (un)reality of UFO activity in Oregon. From this performance, we highlight four insights into the relationship between science, evidence, and responsibility.     

Social Responsiveness and Objectification: The Moderating Roles of Serotonin Transporter and Serotonin Receptor 2A Genotypes in an Objectification Theory Model of Disordered Eating

Feminist scholars have called for gender researchers to consider gene-environment interactions for gender-imbalanced disorders (Salk and Hyde Psychology of Women Quarterly, 36, 395–411, 2012). Responding to these calls, the present study integrates objectification theory (Fredrickson and Roberts Psychology of Women Quarterly, 21, 173–206, 1997) and genetic research. In the tested model, objectification experiences are associated with disordered eating through body surveillance and body shame, and serotonin transporter (SLC6A4) genotypes (5-HTTLPR and rs25531), serotonin 2A receptor SNP genotypes (HTR2A rs6311), and the epistatic interaction between those genotypes function as moderators. U.S. undergraduate women (n?=?526) completed self-reports of objectification, body surveillance, body shame, and disordered eating and donated buccal cells for genetic analyses. The association between objectification and disordered eating was mediated by body shame, but not body surveillance. The paths from objectification to both body surveillance and body shame were moderated by genotypes. The indirect effect of objectification on disordered eating through body shame was only present for SLC6A4 L′ and rs6311 G homozygotes. Our results are consistent with previous evidence that serotonin system genetic variation is associated with disordered eating risk. They provide evidence of a non-deterministic genetic effect that is context-dependent and subtle. These findings also reinforce efforts to develop personalized prevention and treatment approaches for eating disorders.

     

A Machine Learning Approach to Identifying the Thought Markers of Suicidal Subjects: A Prospective Multicenter Trial

Death by suicide demonstrates profound personal suffering and societal failure. While basic sciences provide the opportunity to understand biological markers related to suicide, computer science provides opportunities to understand suicide thought markers. In this novel prospective, multimodal, multicenter, mixed demographic study, we used machine learning to measure and fuse two classes of suicidal thought markers: verbal and nonverbal. Machine learning algorithms were used with the subjects’ words and vocal characteristics to classify 379 subjects recruited from two academic medical centers and a rural community hospital into one of three groups: suicidal, mentally ill but not suicidal, or controls. By combining linguistic and acoustic characteristics, subjects could be classified into one of the three groups with up to 85% accuracy. The results provide insight into how advanced technology can be used for suicide assessment and prevention.     

Attenuation of change blindness in children with autism spectrum disorders

Change blindness refers to the difficulty most people find in detecting a difference between two pictures when these are presented successively, with a brief interruption between. Attention at the site of the change is required for detection. A number of studies have investigated change blindness in adults and children with autism spectrum disorders (ASD). Some have produced evidence that people with ASD find changes to social stimuli harder to detect and changes to non‐social stimuli easier to detect, relative to comparison participants. However, other studies have produced entirely contradictory findings. There is a need for consistency in methodology to aid understanding of change blindness and attentional processes in ASD. Here, we replicate a change blindness study previously carried out with typically developing (TD) children and adults and with adults with ASD. Results reveal attenuated change blindness for non‐social stimuli in children with ASD relative to TD norms. Our results are interpreted, alongside others' findings, as potentially indicative of a complex relationship between different influences on attention over time.     

The effect of visual frame of reference on a judgement of plane stimulus orientation by children

Three studies are reported with children aged 4 1/2 to 9 1/2 years and also with educationally subnormal children, in which it was found that up to about 7 years children's selection of one of a pair of line stimuli as 'falling over' is affected by the nature of the visual surround contours provided. Both the form of the stimulus surround and the presence or absence of a baseline tilted 45 degrees relative to the horizontal were found to affect the children's judgements. The plane (horizontal or vertical) in which the stimuli were presented had no effect on the results. It is argued that while the results show the influence of the visual surround on children's comprehension of 'falling over', this may not be wholly explicable in terms of surround contour matching, as conventionally correct judgements were obtained in the absence of all straight line contours in the immediate surround.     

Women in the Middle Years: A Critique of Research and Theory

Research and theory on women in the middle years reflect assumptions and biases that limit our understanding and impair our ability to resolve conflicting findings about women's well-being. Such theorists as Erikson and Levinson focus on chronological age and assume an inappropriate sequence of stages and events. In most research, the centrality of women's reproductive role is assumed and the importance of their work role pattern is ignored. Thus menopause and the "empty nest" receive disproportionate attention. Too little attention is given to stage of the family life cycle and the conditions and status of work. Two active research areas that appear promising for understanding adult women are also discussed: locus of control and attributions; and social networks and support systems.