Amount of reward has opposite effects on the discounting of delayed and probabilistic outcomes

Previous research has shown that the value of large future rewards is discounted less steeply than is the value of small future rewards. These experiments extended this line of research to probabilistic rewards. Two experiments replicated the standard findings for delayed rewards but demonstrated that amount has an opposite effect on the discounting of probabilistic rewards. That is, large probabilistic amounts were discounted at the same or higher rates than small amounts. Although amount had opposite effects on the discounting of delayed and probabilistic rewards, nevertheless, the same form of mathematical function accurately described discounting of both types of reward. The findings suggest that fundamentally similar, but not identical, processes are involved in decision making regarding delayed and probabilistic rewards. The implications of these findings for impulsivity and self-control are discussed.     

Impact of Hyperbaric Oxygen Therapy on Cognitive Functions: a Systematic Review

Neuropsychology Review - Hyperbaric oxygen therapy (HBOT) is a modality of treatment in which patients inhale 100% oxygen inside a hyperbaric chamber pressurised to greater than 1...     

Depression and appearance-related distress in functioning with lipedema

Lipedema is a chronic, progressive adipose tissue disorder that may impact the quality of life of women who suffer from it. The main aim of this study was to asses the role of perceived symptom severity, physical and psychological functioning with the disease in predicting quality of life in patients with lipedema. We conducted an online study with 329 participants who responded to five questionnaires measuring quality of life (World Health Organization Quality of Life BREF), lipedema symptom severity, mobility (Lower Extremity Functional Scale), depression (Patients Health Questionnaire-9), and appearance-related distress (Derriford Appearance Scale 24). Multiple hierarchical regression analyses showed that appearance-related distress and depression explained significantly more variance in quality of life when added to the symptom severity and mobility. Lower quality of life was predicted by higher symptom severity, lower mobility, higher appearance-related distress and higher depression severity. Appearance-related distress and depression constitute important aspects of psychological functioning in women with lipedema. Considering their relationship with quality of life, their assessment should be included in lipedema treatment with appropriate interventions aimed at decreasing appearance-related distress, as well as preventing and addressing depression.     

The effects of ingroup and outgroup homogeneity on ingroup favouritism,stereotyping and overestimation of relative ingroup size

An experiment (n = 61) investigated the effects of ingroup and outgroup homogeneity on ingroup favouritism, stereotyping and the overestimation of relative ingroup size. As predicted, outgroup homogeneity was conducive to ingroup favouritism. Ingroup homogeneity, however, failed to influence ingroup favouritism. Also unexpectedly, asymmetry in group homogeneity — irrespective of whether the ingroup or the outgroup was the more homogeneous group — led to pronounced stereotyping of both groups and to the overestimation of relative ingroup size.     

Motivated learning for the development of autonomous systems

A new machine learning approach known as motivated learning (ML) is presented in this work. Motivated learning drives a machine to develop abstract motivations and choose its own goals. ML also provides a self-organizing system that controls a machine’s behavior based on competition between dynamically-changing pain signals. This provides an interplay of externally driven and internally generated control signals. It is demonstrated that ML not only yields a more sophisticated learning mechanism and system of values than reinforcement learning (RL), but is also more efficient in learning complex relations and delivers better performance than RL in dynamically-changing environments. In addition, this paper shows the basic neural network structures used to create abstract motivations, higher level goals, and subgoals. Finally, simulation results show comparisons between ML and RL in environments of gradually increasing sophistication and levels of difficulty.     

Association between tryptophan hydroxylase 2 gene polymorphism and completed suicide

The association between suicide and a single nucleotide polymorphism (rs1386483) was examined in the recently identified tryptophan hydroxylase 2 (TPH2) gene. Blood samples of 143 suicide victims and 162 age- and sex-matched controls were examined. The frequency of the TT genotype in the TPH2 polymorphism was higher in suicide victims than in controls (17.5% vs. 8.6%; p = 0.02), particularly in those with a history of repeated suicide attempts (53.3% vs. 8.6%; p < 0.0001). The examined TPH2 polymorphism was found to be associated with suicide. This genetic marker may be particularly important in understanding risk of multiple suicide attempts. Further analyses are needed to confirm these results.     

Birth order and person perception dispositions

The early social experiences of firstborn, laterborn, and only children were analyzed from the viewpoint of how those experiences influence the child's general image of human nature. It was hypothesized that there are some differences in the centrality of an evaluative dimension, that are related to birth order. Subjects in Poland and in the United States rated 20 known stimulus persons on 25 trait dimensions. The results supported the hypotheses and seem to point to some origins of individual differences in certain person perception processes.     

Individual differences in FFA activity suggest independent processing at different spatial scales

The brain processes images at different spatial scales, but it is unclear how far into the visual stream different scales remain segregated. Using functional magnetic resonance imaging, we found evidence that BOLD activity in the fusiform face area (FFA) reflects computations based on separate spatial frequency inputs. When subjects perform different tasks (attend location vs. identity; attend whole vs. parts) or the same task with different stimuli (upright or inverted) with high- and low-pass images of cars and faces, individual differences in the FFA in one condition are correlated with those in the other condition. However, FFA activity in response to low-pass stimuli is independent of its response to highpass stimuli. These results suggest that spatial scales are not integrated before the FFA and that processing in this area could support the flexible use of different sources of information present in broad-pass images.