Comorbidity of Asperger syndrome and gender identity disorder

The case of a 35-yearold biological woman with Asperger syndrome (AS) and gender identity disorder (GID) fulfilling DSM-IV criteria is reported. Against the background of recently emerging theories of cognitive male pattern underlying autism we present additional psychological assessments in order to discuss any possible interaction or discrimination between AS and GID. Whilst we explain GID as a secondary feature of AS, we examine the assumption of the necessity of treating GID in AS as a primary GID in accordance with international standards. We consider the treatment of GID as compelling, particularly because curative therapy for AS is lacking and with GID treatment in this vein, the patient gains psychosocial improvemen

Finger Length Ratio (2D:4D) in Adults with Gender Identity Disorder

From early childhood, gender identity and the 2nd to 4th finger length ratio (2D:4D) are discriminative characteristics between sexes. Both the human brain and 2D:4D may be influenced by prenatal testosterone levels. This calls for an examination of 2D:4D in patients with gender identity disorder (GID) to study the possible influence of prenatal testosterone on gender identity. Until now, the only study carried out on this issue suggests lower prenatal testosterone levels in right-handed male-to-female GID patients (MtF). We compared 2D:4D of 56 GID patients (39MtF; 17 female-to-male GID patients, FtM) with data from a control sample of 176 men and 190 women. Bivariate group comparisons showed that right hand 2D:4D in MtF was significantly higher (feminized) than in male controls, but similar to female controls. The comparison of 2D:4D ratios of biological women revealed significantly higher (feminized) values for right hands of right handed FtM. Analysis of variance confirmed significant effects for sex and for gender identity on 2D:4D ratios but not for sexual orientation or for the interaction among variables. Our results indirectly point to the possibility of a weak influence of reduced prenatal testosterone as an etiological factor in the multifactorially influenced development of MtF GID. The development of FtM GID seems even more unlikely to be notably influenced by prenatal testosteron

The desire for healthy limb amputation: structural brain correlates and clinical features of xenomelia

Xenomelia is the oppressive feeling that one or more limbs of one's body do not belong to one's self. We present the results of a thorough examination of the characteristics of the disorder in 15 males with a strong desire for amputation of one or both legs. The feeling of estrangement had been present since early childhood and was limited to a precisely demarcated part of the leg in all individuals. Neurological status examination and neuropsychological testing were normal in all participants, and psychiatric evaluation ruled out the presence of a psychotic disorder. In 13 individuals and in 13 pair-matched control participants, magnetic resonance imaging was performed, and surface-based morphometry revealed significant group differences in cortical architecture. In the right hemisphere, participants with xenomelia showed reduced cortical thickness in the superior parietal lobule and reduced cortical surface area in the primary and secondary somatosensory cortices, in the inferior parietal lobule, as well as in the anterior insular cortex. A cluster of increased thickness was located in the central sulcus. In the left hemisphere, affected individuals evinced a larger cortical surface area in the inferior parietal lobule and secondary somatosensory cortex. Although of modest size, these structural correlates of xenomelia appear meaningful when discussed against the background of some key clinical features of the disorder. Thus, the predominantly right-sided cortical abnormalities are in line with a strong bias for left-sided limbs as the target of the amputation desire, evident both in our sample and in previously described populations with xenomelia. We also propose that the higher incidence of lower compared with upper limbs (∼80% according to previous investigations) may explain the erotic connotations typically associated with xenomelia, also in the present sample. These may have their roots in the proximity of primary somatosensory cortex for leg representation, whose surface area was reduced in the participants with xenomelia, with that of the genitals. Alternatively, the spatial adjacency of secondary somatosensory cortex for leg representation and the anterior insula, the latter known to mediate sexual arousal beyond that induced by direct tactile stimulation of the genital area, might play a role. Although the right hemisphere regions of significant neuroarchitectural correlates of xenomelia are part of a network reportedly subserving body ownership, it remains unclear whether the structural alterations are the cause or rather the consequence of the long-standing and pervasive mismatch between body and sel

Return on IT Investments in Two-Sided Markets

In two-sided markets an intermediary brings together two distinct customer populations, such as buyers and sellers on an e-commerce platform. In these markets the growth process of customer populations depends on network effects both within and between buyers and sellers. Thus, assigning IT investments to customer populations and quantifying the monetary value of these investments is complex. We show that measuring the intermediary’ s platform value may provide a remedy, and make IT investments in two-sided markets accountable. Thereby, we develop a model for the platform value and the growth process of customer populations accounting for network effects in two-sided market. We apply our model to an e-commerce platform. Our results highlight a significant contribution of buyers to the platform value. Analysing former IT investments we find further evidence to rather invest in buyers than sellers, and to promote investments that increase buyers’ trust in products, intermediary and trading partners (sellers)

UtiliGEM: Energy Management Guided by Learned Application Utility

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Satisficing Response Behavior Across Time: Assessing Negative Panel Conditioning Using an Experimental Design with Six Repetitions

Satisficing response behavior can be a threat to the quality of survey responses. Past research has provided broad empirical evidence on the existence of satisficing and its consequences on data quality, however, relatively little is known about the extent of satisficing over the course of a panel study and its impact on response quality in later waves. Drawing on panel conditioning research, we use question design experiments to investigate whether learning effects across waves of a panel study cause changes in the extent of satisficing and if so, whether general survey experience (process learning) or familiarity with specific question content (content learning) accounts for those changes. We use data from a longitudinal survey experiment comprising six panel waves administered within a German non-probability online access panel. To investigate the underlying mechanism of possible learning effects, the experimental study randomly assigned respondents to different frequencies of receiving identical question content over the six panel waves. Our results show the existence of satisficing in every panel wave, which is in its magnitude similar to the extent of satisficing in the probability-based GESIS Panel that we use as a benchmark study. However, we did not find changes in the extent of satisficing across panel waves, nor did we find moderation effects of the interval between the waves, respondents' cognitive ability, or motivation. Additional validity analyses showed that satisficing does not only affect the distribution of individual estimates by 15 percent or more but also can have an effect on associations between variables

Human subcortical brain asymmetries in 15,847 people worldwide reveal effects of age and sex

The two hemispheres of the human brain differ functionally and structurally. Despite over a century of research, the extent to which brain asymmetry is influenced by sex, handedness, age, and genetic factors is still controversial. Here we present the largest ever analysis of subcortical brain asymmetries, in a harmonized multi-site study using meta-analysis methods. Volumetric asymmetry of seven subcortical structures was assessed in 15,847 MRI scans from 52 datasets worldwide. There were sex differences in the asymmetry of the globus pallidus and putamen. Heritability estimates, derived from 1170 subjects belonging to 71 extended pedigrees, revealed that additive genetic factors influenced the asymmetry of these two structures and that of the hippocampus and thalamus. Handedness had no detectable effect on subcortical asymmetries, even in this unprecedented sample size, but the asymmetry of the putamen varied with age. Genetic drivers of asymmetry in the hippocampus, thalamus and basal ganglia may affect variability in human cognition, including susceptibility to psychiatric disorders

Satisficing Response Behavior Across Time: Assessing Negative Panel Conditioning Using an Experimental Design with Six Repetitions

Satisficing response behavior can be a threat to the quality of survey responses. Past research has provided broad empirical evidence on the existence of satisficing and its consequences on data quality, however, relatively little is known about the extent of satisficing over the course of a panel study and its impact on response quality in later waves. Drawing on panel conditioning research, we use question design experiments to investigate whether learning effects across waves of a panel study cause changes in the extent of satisficing and if so, whether general survey experience (process learning) or familiarity with specific question content (content learning) accounts for those changes. We use data from a longitudinal survey experiment comprising six panel waves administered within a German non-probability online access panel. To investigate the underlying mechanism of possible learning effects, the experimental study randomly assigned respondents to different frequencies of receiving identical question content over the six panel waves. Our results show the existence of satisficing in every panel wave, which is in its magnitude similar to the extent of satisficing in the probability-based GESIS Panel that we use as a benchmark study. However, we did not find changes in the extent of satisficing across panel waves, nor did we find moderation effects of the interval between the waves, respondents’ cognitive ability, or motivation. Additional validity analyses showed that satisficing does not only affect the distribution of individual estimates by 15 percent or more but also can have an effect on associations between variables

Panel Conditioning in A Probability-based Longitudinal study: A Comparison of Respondents with Different Levels of Survey Experience

Learning effects due to repeated interviewing, also known as panel conditioning, are a major threat to response quality in later waves of a panel study. To date, research has not provided a clear picture regarding the circumstances, mechanisms, and dimensions of potential panel conditioning effects. In particular, the effects of conditioning frequency, that is, different levels of experience within a panel, on response quality are underexplored. Against this background, we investigated the effects of panel conditioning by using data from the GESIS Panel, a German mixed-mode probability-based panel study. Using two refreshment samples, we compared three panel cohorts with differing levels of experience on several response quality indicators related to the mechanisms of reflection, satisficing, and social desirability. Overall, we find evidence for both negative (i.e., disadvantageous for response quality) and positive (i.e., advantageous for response quality) panel conditioning. Highly experienced respondents were more likely to satisfice by speeding through the questionnaire. They also had a higher probability of refusing to answer sensitive questions than less experienced panel members. However, more experienced respondents were also more likely to optimize the response process by needing less time compared to panelists with lower experience levels (when controlling for speeding). In contrast, we did not find significant differences with respect to the number of “don’t know” responses, nondifferentiation, the selection of first response categories and mid-responses, and the number of nontriggered filter questions. Of the observed differences, speeding showed the highest magnitude with an average increase of 6.0 percentage points for highly experienced panel members compared to low experienced panelists

Novel genetic loci associated with hippocampal volume

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness