Origins of submovements during pointing movements

Submovements that are frequently observed in the final portion of pointing movements have traditionally been viewed as pointing accuracy adjustments. Here we re-examine this long-lasting interpretation by developing evidence that many of submovements may be non-corrective fluctuations arising from various sources of motor output variability. In particular, non-corrective submovements may emerge during motion termination and during motion of low speed. The contribution of these factors and the factor of accuracy regulation in submovement production is investigated here by manipulating movement mode (discrete, reciprocal, and passing) and target size (small and large). The three modes provided different temporal combinations of accuracy regulation and motion termination, thus allowing us to disentangle submovements associated with each factor. The target size manipulations further emphasized the role of accuracy regulation and provided variations in movement speed. Gross and fine submovements were distinguished based on the degree of perturbation of smooth motion. It was found that gross submovements were predominantly related to motion termination and not to pointing accuracy regulation. Although fine submovements were more frequent during movements to small than to large targets, other results show that they may also be not corrective submovements but rather motion fluctuations attributed to decreases in movement speed accompanying decreases in target size. Together, the findings challenge the traditional interpretation, suggesting that the majority of submovements are fluctuations emerging from mechanical and neural sources of motion variability. The implications of the findings for the mechanisms responsible for accurate target achievement are discussed.     

Parallel averaging of size is possible but range-limited: A reply to Marchant,Simons, and De Fockert

In their recent paper, Marchant, Simons, and De Fockert (2013) claimed that the ability to average between multiple items of different sizes is limited by small samples of arbitrarily attended members of a set. This claim is based on a finding that observers are good at representing the average when an ensemble includes only two sizes distributed among all items (regular sets), but their performance gets worse when the number of sizes increases with the number of items (irregular sets). We argue that an important factor not considered by Marchant et al. (2013) is the range of size variation that was much bigger in their irregular sets. We manipulated this factor across our experiments and found almost the same efficiency of averaging for both regular and irregular sets when the range was stabilized. Moreover, highly regular sets consisting only of small and large items (two-peaks distributions) were averaged with greater error than sets with small, large, and intermediate items, suggesting a segmentation threshold determining whether all variable items are perceived as a single ensemble or distinct subsets. Our results demonstrate that averaging can actually be parallel but the visual system has some difficulties with it when some items differ too much from others.     

Construction of a depression scale with the Rasch model

This study examines the psychometric properties of a depression questionnaire. The goal was to improve the technical quality of traditional measures of depression in Spanish youth. 310 participants, aged 18-24 years, filled in the self-report questionnaire. The data were analyzed by means of the Rasch model. Results show that model fit, average item reliability (.97), and average person reliability (.88) are high. After deleting four indicators showing misfit and 12 showing sex bias, the resulting scale measures clinical depression objectively. Using this scale, the expected sex-related differences are found.     

Integrative neuropsychological characteristics of subcortical-frontal brain regions as a schizophrenia liability factor

In order to study neuropsychological characteristics of subcortical-frontal brain regions function and assessment of their relation with vulnerability to schizophrenia 59 patients and 23 controls were investigated using Luria's neuropsychological methods. The analysis established bilateral abnormalities of the function of prefrontal and profound frontal lobe zones in patients as compared with controls. These abnormalities were more predominate in the left hemisphere. Point biserial correlation coefficients of determined integrative neuropsychological indicators with liability to schizophrenia were 0.39 +/- 0.11 and 0.28 +/- 0.09, for the left and right brain zones respectively. The obtained data permits discussion of the integrative neuropsychological indicators of subcortical-frontal brain regions as potential markers of liability to schizophrenia and confirms the role of structural and functional brain asymmetry in the pathogenesis of schizophrenia.     

Object‐Label‐Order Effect When Learning From an Inconsistent Source

Learning in natural environments is often characterized by a degree of inconsistency from an input. These inconsistencies occur, for example, when learning from more than one source, or when the presence of environmental noise distorts incoming information; as a result, the task faced by the learner becomes ambiguous. In this study, we investigate how learners handle such situations. We focus on the setting where a learner receives and processes a sequence of utterances to master associations between objects and their labels, where the source is inconsistent by design: It uses both “correct” and “incorrect” object‐label pairings. We hypothesize that depending on the order of presentation, the result of the learning may be different. To this end, we consider two types of symbolic learning procedures: the Object‐Label (OL) and the Label‐Object (LO) process. In the OL process, the learner is first exposed to the object, and then the label. In the LO process, this order is reversed. We perform experiments with human subjects, and also construct a computational model that is based on a nonlinear stochastic reinforcement learning algorithm. It is observed experimentally that OL learners are generally better at processing inconsistent input compared to LO learners. We show that the patterns observed in the learning experiments can be reproduced in the simulations if the model includes (a) an ability to regularize the input (and also to do the opposite, i.e., undermatch) and (b) an ability to take account of implicit negative evidence (i.e., interactions among different objects/labels). The model suggests that while both types of learners utilize implicit negative evidence in a similar way, there is a difference in regularization patterns: OL learners regularize the input, whereas LO learners undermatch. As a result, OL learners are able to form a more consistent system of image‐utterance associations, despite the ambiguous learning task.     

Bad,Pathetic and Greedy Women: Expressions of Surrogate Motherhood Stigma in a Russian Online Forum

Gestational surrogacy, in which the surrogate mother is not biologically related to the child she is carrying, is the most common type of surrogacy today. Although technologically well-developed and legal in many countries, it is stigmatized socially because it provokes and even contradicts basic traditional concepts of family, motherhood, and gender roles. The present study examines the types and expressions of the surrogacy stigma in Russia, applying a dual-pathway stigma model to a qualitative content analysis of 15,602 posts on a Russian-language online forum for surrogate mothers. Our findings reveal that the women’s choice to become surrogate mothers initiated a social process in which these women experienced four types of stigma: Bad mothers, bad wives, pathetic losers, and greedy women. Surrogate mothers described the experience and internalization of stigma as threatening their social roles in the traditional family and financial realm alike. Our study places surrogacy stigma in the context of the post-Soviet financial and social climate as experienced and expressed by participants. Furthermore, understandings of the essence of perceived surrogacy stigma may help professionals develop a more nuanced and accurate approach for psychological and social care and may lead to increased accuracy in media, law, and political representation of members of this vulnerable group.

     

Coping with dialects from birth: Role of variability on infants’ early language development. Insights from Norwegian dialects

Previous research suggests that exposure to accent variability can affect toddlers’ familiar word recognition and word comprehension. The current preregistered study addressed the gap in knowledge on early language development in infants exposed to two dialects from birth and assessed the role of dialect similarity in infants’ word recognition and comprehension. A 12-month-old Norwegian-learning infants, exposed to native Norwegian parents speaking the same or two Norwegian dialects, took part in two eye-tracking tasks, assessing familiar word form recognition and word comprehension. Their parents’ speech was assessed for similarity by native Norwegian speakers. First, in contrast to previous research, our results revealed no listening preference for words over nonwords in both monodialectal and bidialectal infants, suggesting potential language-specific differences in the onset of word recognition. Second, the results showed evidence for word comprehension in monodialectal infants, but not in bidialectal infants, suggesting that exposure to dialectal variability impacts early word acquisition. Third, perceptual similarity between parental dialects tendentially facilitated bidialectal infants’ word recognition and comprehension. Forth, the results revealed a strong correlation between the raters and parents’ assessment of similarity between dialects, indicating that parental estimations can be reliably used to assess infants’ speech variability at home. Finally, our results revealed a strong relationship between word recognition and comprehension in monodialectal infants and the absence of such a relationship in bidialectal infants, suggesting that either these two skills do not necessarily align in infants exposed to more variable input, or that the alignment might occur at a later stage.     

Lost in the Moment? An Investigation of Procrastination, Mindfulness, and Well-being

In this study, we extend previous work documenting links between procrastination, stress, and physical health by examining the potential role of mindfulness in explaining the high stress and poor health reported by procrastinators. A sample of 339 students (81% female) completed an on-line survey that included measures of trait procrastination, mindfulness, perceived stress, and perceived health. Univariate analyses revealed that procrastination was associated with low mindfulness, high stress, and poor perceived health. Structural equation modelling was used to test the role of mindfulness in explaining the links between procrastination and stress, and between procrastination and perceived health. The overall measurement model indicated a good fit to the data. Tests of the nested mediation models revealed that the effects of procrastination on stress and health were mediated by mindfulness, and bootstrapping analyses confirmed the significance of these effects. Our findings are consistent with previous research and theory on the salutatory effects of mindfulness for health and well-being and indicate that for procrastinators, low mindfulness may be a risk factor for poor emotional and physical well-being.