Rearing practices and impulsivity/hyperactivity symptoms in relation to inflated responsibility and obsessive‐compulsive symptoms

Smári, J., Rúrik Martinsson, D., & Einarsson, H. (2010). Rearing practices and impulsivity/hyperactivity symptoms in relation to inflated responsibility and obsessive‐compulsive symptoms. Scandinavian Journal of Psychology, 51, 392–397. The aim of the study was to investigate potential precursors of inflated responsibility (responsibility attitudes) and obsessive‐compulsive (OCD) symptoms. It was argued that both parental overprotection and impulsivity, separately and in interaction with each other, contribute to inflated responsibility and OCD symptoms. In a large sample of young adults (N = 570), self‐report measures of OCD symptoms (OCI‐R), responsibility attitudes (RAS), anxiety/depression (HADS), rearing practices (EMBU), present and past impulsivity/hyperactivity symptoms (IMP/HY) were administered. Overprotection as well as IMP/HY were found to predict OCD symptoms as well as inflated responsibility. Finally, a significant interaction was found between IMP/HY and overprotection with regard to both OCD symptoms and inflated responsibility. This effect reflected that IMP/HY was more strongly related to OCD symptoms and responsibility in people who had not been overprotected than in people who had been. Conversely overprotection was related to OCD symptoms and responsibility in people low but not in people high in IMP/HY. The results seem to indicate that the inadequacy between offer and need for parental control may play a role in the development of OCD symptoms.     

Parity still isn't a generalisation problem

Clark & Thornton take issue with my claim that parity is not a generalisation problem, and that nothing can be inferred about back-propagation in particular, or learning in general, from failures of parity generalisation. They advance arguments to support their contention that generalisation is a relevant issue. In this continuing commentary, I examine generalisation more closely in order to refute these arguments. Different learning algorithms will have different patterns of failure: back-propagation has no special status in this respect. This is not to deny that a particular algorithm might fortuitously happen to produce the "intended" function in an (oxymoronic) parity-generalisation task.     

Human and machine perception of biological motion

More than 30 years ago, Johansson was the first to show that humans are capable of recovering information about the identity and activity of animate creatures rapidly and reliably from very sparse visual inputs – the phenomenon of biological motion. He filmed human actors in a dark setting with just a few strategic points on the body marked by lights – so-called moving light displays (MLDs). Subjects viewing the MLDs reported a vivid impression of moving human forms, and were even able to tell the activity in which the perceived humans were engaged. Subsequently, the phenomenon has been widely studied and many attempts have been made to model and to understand it. Typical questions that arise are: How precisely is the sparse low-level information integrated over space and time to produce the global percept, and how important is world knowledge (e.g., about animal form, locomotion, gravity, etc.)? In an attempt to answer such questions, we have implemented a machine-perception model of biological motion. If the computational model can replicate human data then it might offer clues as to how humans achieve the task. In particular, if it can do so with no or minimal world knowledge then this knowledge cannot be essential to the perception of biological motion. To provide human data for training and against which to assess the model, an extensive psychophysical experiment was undertaken in which 93 subjects were shown 12 categories of MLDs (e.g., normal, walking backwards, inverted, random dots, etc.) and were asked to indicate the presence or absence of natural human motion. Machine perception models were then trained on normal sequences as positive data and random sequences as negative data. Two models were used: a k-nearest neighbour (k-NN) classifier as an exemplar of ‘lazy’ learning and a back-propagation neural network as an exemplar of ‘eager’ learning. We find that the k-NN classifier is better able to model the human data but it still fails to represent aspects of knowledge about body shape (especially how relative joint positions change under rotation) that appear to be important to human judgements.     

Neural network models of categorical perception

Studies of the categorical perception (CP) of sensory continua have a long and rich history in psychophysics. In 1977, Macmillan, Kaplan, and Creelman introduced the use of signal detection theory to CP studies. Anderson and colleagues simultaneously proposed the first neural model for CP, yet this line of research has been less well explored. In this paper, we assess the ability of neural-network models of CP to predict the psychophysical performance of real observers with speech sounds and artificial/novel stimuli. We show that a variety of neural mechanisms are capable of generating the characteristics of CP. Hence, CP may not be a special model of perception but an emergent property of any sufficiently powerful general learning system.     

Adult attachment styles,self‐esteem,and depressive symptoms: A comparison between postpartum and nonpostpartum women in Korea

Life stress related to child bearing has been suggested to increase the risk of maternal depression in vulnerable women who have an insecure relationship. This study examined the relationship between adult attachment security and maternal depression in postpartum women as compared to nonpostpartum women. A total of 254 Korean women were recruited from pediatric hospitals, of whom 119 were in the postpartum period. Participants completed the Relationship Questionnaire, the Beck Depression Inventory, and the Rosenberg Self‐Esteem Scale. Both preoccupied and fearful attachment styles were associated with low self‐esteem and higher levels of depressive symptoms, but a dismissing attachment style was not related to self‐esteem and depression severity. Low self‐esteem was found to mediate the relation between insecure attachment and depression severity; however, this mediating effect differed depending on the insecure attachment style. For preoccupied attachment, the role of self‐esteem as a mediator was observed only in postpartum women, not in nonpostpartum women (moderated mediation). In contrast, for fearful attachment, the mediating effects emerged in both groups. The results highlight the fact that there is a complex mechanism behind the link between interpersonal relationships and risk of maternal depression.