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.     

Mouthing and grasping in neonates: Evidence for the early detection of what hard or soft substances afford for action

Newborns and 2- and 3-month-old infants were presented for 3 min with a rigid or an elastic object either introduced into their mouths for mouthing or into their right hands for grasping. Each object was connected to an air pressure transducer allowing polygraphic recording of the positive pressure variations applied by the infant to the object. Results indicate that, from birth, infants haptically discriminate between the rigidity and elasticity of objects by generating different rates and patterns of responses. Furthermore, the differential haptic responding by the infant does not manifest itself in an analogous manner for the oral or the manual modality of response but is reversed relative to the two objects' properties. During the first 3 months, a developmental trend is observed wherein the infant's oral response rates and patterns begin to align themselves with her/his manual responding to either one of the two objects. Relative to a similar output of positive pressures generated orally or manually, these observations show that from birth the infant's response is both object-dependent (hard vs. soft substance) and modality-dependent (oral vs. manual condition). These results are interpreted as suggesting that early mouthing and grasping are not merely controlled by reflexive (automatic) mechanisms but rather are guided by what objects afford for functional actions.     

Ground reaction force adaptations during cross-slope walking and running

Though transversely inclined (cross-sloped) surfaces are prevalent, our understanding of the biomechanical adaptations required for cross-slope locomotion is limited. The purpose of this study was to examine ground reaction forces (GRF) in cross-sloped and level walking and running. Nine young adult males walked and ran barefoot along an inclinable walkway in both level (0°) and cross-slope (10°) configurations. The magnitude and time of occurrence of selected features of the GRF were extracted from the force plate data. GRF data were collected in level walking and running (LW and LR), inclined walking and running up-slope (IWU and IRU), and down-slope (IWD and IRD), respectively. The GRF data were then analyzed using repeated measures MANOVA. In the anteroposterior direction, the timing of the peak force values differed across conditions during walking (p=.041), while the magnitude of forces were modified across conditions for running (p=.047). Most significant differences were observed in the mediolateral direction, where generally force values were up to 390% and 530% (p<.001) larger during the cross-slope conditions compared to level for walking and running, respectively. The maximum force peak during running occurred earlier at IRU compared to the other conditions (p≤.031). For the normal axis a significant difference was observed in the first maximum force peak during walking (p=.049). The findings of this study showed that compared to level surfaces, functional adaptations are required to maintain forward progression and dynamic stability in stance during cross-slope walking and running.     

Carbon dioxide narcosis modifies the patch leaving decision of foraging parasitoids

Gleaning information is a way for foragers to adjust their behavior in order to maximize their fitness. Information decreases the uncertainty about the environment and could help foragers to accurately estimate environmental characteristics. In a patchy resource, information sampled during previous patch visits is efficient only if it is retained in the memory and retrieved upon arrival in a new patch. In this study, we tested whether the braconid Asobara tabida, a parasitoid of Drosophila larvae, retains information gleaned on patch quality in the memory and adjusts its foraging behavior accordingly. Females were anesthetized with CO₂ after leaving a first patch containing a different number of hosts and were allowed to visit a second patch containing only kairomones. CO₂ is known to erase unconsolidated information from the memory. We show that in the absence of a short CO₂ narcosis, females responded according to their previous experience, whereas anesthetized females did not. The anesthetized females stayed a given time in the second patch irrespective of what they encountered before. CO₂ narcosis had no effect on the residence time of the non-experienced females in a patch containing hosts or only kairomones in comparison with the non-anesthetized females that had a previous foraging experience. We conclude that CO₂ narcosis erases the effect of the previous patch quality, perhaps due to a memory disruption. Direct information processing is likely to be involved in parasitoid decision making through retention of the information on the previous patch quality into a CO₂ sensitive memory.     

Psychometric evaluation of the Fear of Positive Evaluation Scale in patients with social anxiety disorder

The Fear of Positive Evaluation Scale (FPES; J. W. Weeks, R. G. Heimberg, & T. L. Rodebaugh, 2008) was designed to assess fear of positive evaluation, a proposed cognitive component of social anxiety. Although previous findings on the psychometric properties of the FPES have been highly encouraging, only 1 previous study has examined the psychometric profile of the FPES in a sample of patients with social anxiety disorder (T. A. Fergus et al., 2009). The primary purpose of the present study was to conduct a large multisite examination of the psychometric profile of the FPES among patients with a principal diagnosis of social anxiety disorder (n = 226; generalized subtype = 97.8%). Responses of nonanxious control participants (n = 42) were also examined. The factorial validity, internal consistency, test-retest reliability, construct validity, and treatment sensitivity of the FPES were strongly supported by our findings. Furthermore, an FPES cutoff score was identified for distinguishing levels of fear of positive evaluation characteristic of patients with social anxiety disorder from those characteristic of the control group. Results provide additional support for the psychometric properties of the FPES in clinical samples.     

Social awareness and early self-recognition

Self-recognition by 86 children (14-52months) was assessed using the mirror mark test in two different social contexts. In the classic mirror task condition, only the child was marked prior to mirror exposure (Classic condition). In the social norm condition, the child, experimenter, and accompanying parent were marked prior to the child's mirror exposure (Norm condition). Results indicate that in both conditions children pass the test in comparable proportion, with the same increase as a function of age. However, in the Norm condition, children displayed significantly more hesitation while removing the mark, often touching it without removing it or, if so, promptly putting the mark back onto their forehead. In the Classic condition, only one child showed such hesitation. These results suggest that from the outset, mirror self-recognition can refer to social awareness. This link is interpreted as the trademark of human self-consciousness, a deeply rooted "looking glass" self-awareness.     

Information Related to Prenatal Genetic Counseling: Interpretation by Adolescents, Effects on Risk Perception and Ethical Implications

Being raised in the genomic era may not only increase knowledge of available genetic testing but may also have an impact on how genetic information is perceived. However, little is known about how current adolescents react to the language commonly used by health care professionals providing prenatal counseling. In addition, as risk communication is related to numbers and figures, having different educational backgrounds may be associated with variability in risk perceptions. In order to investigate these issues, a previously developed questionnaire studying different ways of being told about hypothetical anomalies in a baby and corresponding risks (Abramsky and Fletcher Prenatal Diagnosis 22(13):1188-1194, 2002) was administered to high-school students in Sweden. A total of 344 questionnaires were completed by students belonging to a natural science or a social science program. The data show that teenage participants found technical jargon and words such as rare and abnormal more worrying than the presented comparison terms. Negative framing effects and perception differences related to numeric risk formats were also present. Additionally, participants' gender and educational program did not seem to have an effect on risk assessment. In addition to reporting the questionnaire results, we discuss the ethical implications of the data based on the norm of non-directiveness and make some recommendations for practice. In general, genetic counselors should be aware that the language used within clinical services can be influential on this group of upcoming counselees.