Three-dimensional spatial cognition: information in the vertical dimension overrides information from the horizontal

Fish live in three-dimensional environments, through which they swim with three translational and three rotational degrees of freedom. Navigating through such environments is recognised as a difficult problem, yet fish, and other animals that swim and fly, achieve this regularly. Despite this, the vast majority of research has considered how animals navigate horizontally from place to place and has ignored the vertical component. Here, we test the importance of the vertical axis of space for fish solving a three-dimensional spatial cognition task. We trained banded tetras (Astyanax fasciatus) to learn the route towards a goal in a rotating Y-maze in which the arms led either up and left or down and right in an environment that allowed access to visual landmarks providing horizontal and vertical information. Our results revealed that the landmarks increased navigational efficiency during training. However, these landmarks were ignored when the horizontal and vertical components were placed in conflict with each other by rotating the maze 90° during testing. From this surprising result, we conclude that the cues that are present in the vertical axis (presumably hydrostatic pressure) override landmark cues that have been shown to be salient in experiments that only consider the horizontal component of space.     

Shock,Adjust, Decide: Reproductive Decision Making in Cystic Fibrosis (CF) Carrier Couples—A Qualitative Study

Cystic fibrosis (CF) is the most common recessive condition affecting the White British population. Facilitating reproductive decision making for couples at genetic risk for CF is an important aspect of genetic counseling practice in the UK. The purpose of this study was to explore the reproductive decision making process for 31 members of CF carrier couples (15 men and 16 women) with or without an affected child. The design involved a qualitative approach consisting of semi-structured interviews and data analysis informed by grounded theory methodology. Sex and personal experience of CF were identified as factors that may influence reproductive decision making. Findings suggest these hypotheses: (1) CF carrier couples who have an affected child/pregnancy, are more likely to embark on another pregnancy than couples who have a healthy child from an at-risk pregnancy, and (2) men and women play different roles in the reproductive decision making process. Data analysis resulted in development of a structured framework modeling the reproductive decision making process, which may be helpful in guiding genetic counseling with CF carrier couples and other at risk couples making reproductive decisions.     

Nonaddictive instrumental drug use: Theoretical strengths and weaknesses

The potential to instrumentalize drug use based upon the detection of very many different drug states undoubtedly exists, and such states may play a role in psychiatric and many other drug uses. Nevertheless, nonaddictive drug use is potentially more parsimoniously explained in terms of sensation seeking/impulsivity and drug expectations. Cultural factors also play a major role in nonaddictive drug use.     

The 2nd to 4th digit ratio (2D:4D) and eating disorder diagnosis in women

Eating disorders are more common in females than in males and are believed to be caused, in part, by biological and hormonal factors. Digit ratio or 2D:4D (the ratio of the 2nd to the 4th digit) is considered to be a proxy for prenatal testosterone (PT) and prenatal oestrogen (PE) exposure. However, how 2D:4D may be related to type of eating pathology is unknown. The relationship between 2D:4D and eating disorder diagnosis was investigated in recovered and currently eating disordered (n = 31) and control (n = 99) women. Mean 2D:4D ratio was significantly lower (indicating higher levels of PT and lower levels of PE) in anorexic (AN) compared to bulimic (BN) women, with controls intermediary. In eating disordered women, 2D:4D was positively and significantly related to current weight, lowest weight and current BMI, with strongest associations for right 2D:4D. Among women, low 2D:4D is related to AN and high 2D:4D to BN, suggesting a differential causal influence of prenatal sex hormones on later eating pathology.     

Girls�� and Boys�� Disclosure about Problems as a Predictor of Changes in Depressive Symptoms Over Time

Gender differences consistently emerge in adolescents?? friendships, with girls disclosing to friends about troubles and concerns more than boys. Although theories regarding possible emotional benefits of catharsis, as well as everyday assumptions, suggest that talking about problems makes people feel better, research regarding the impact of disclosure about problems on depressive symptoms has not been conclusive. In the current study, 79 early adolescent high school students residing in the Southeastern United States (73% European American) were observed talking about problems with a friend. Of primary interest was whether disclosure to friends predicted changes in self-reported depression over 6 months for girls and boys. Although girls disclosed to friends about problems (especially interpersonal problems) more than did boys, disclosure did not buffer girls from the development of depressive symptoms over time. In contrast, boys?? disclosure predicted their experiencing fewer depressive symptoms 6 months later. Results suggest that talking to friends may not be an especially effective method of coping with problems for girls.     

Hypothalamic-pituitary-adrenal axis reactivity in the preschool-age offspring of depressed parents: moderation by early parenting

The hypothalamic-pituitary-adrenal axis is thought to play a role in the pathogenesis of depression. In the study reported here, we tested the hypothesis that parenting behavior moderates the relation between parents' lifetime history of depression and their offspring's cortisol reactivity to a psychosocial stressor. We exposed 160 preschool-age children to stress-inducing laboratory tasks, during which we obtained four salivary cortisol samples. Parents completed clinical interviews and an observational parent-child interaction task. The results confirmed our hypothesis: The offspring who evidenced high and increasing cortisol levels were those whose parents had a history of depression and demonstrated hostility toward their child. This moderating effect was specific to offspring who were exposed to maternal depression during the first few years of life. As do findings in animals, results of this study underscore the importance of the early rearing environment in the intergenerational transmission of stress sensitivity.     

Unequal motor durations under simple-, go/no-go, and choice-RT tasks: extension of Miller and Low (2001)

The logic of the Subtraction Method is used implicitly or explicitly in a variety of work, ranging from traditional response-time research to functional neuroimaging. One assumption of all forms of the Subtraction Method is that components may be inserted (or deleted) without causing changes in the remaining components. We tested this assumption as it applies to the duration of late motor processing using the lag between the onset of lateralized readiness potential (LRP) and the production of the required response as the measure of late motor processing. In contrast to a similar, previous study that used this approach (Miller & Low, 2001), we found differences in the LRP lags across the types of task that are used in the Subtraction Method. The LRP lag for simple-RT was shorter than the lags for either go/no-go or choice-RT. This finding constitutes evidence against an assumption required by the Subtraction Method, at least as applied to component durations, but can be explained in terms of a supplementary (non-subtractive) inhibitory component that is only employed in the go/no-go task.     

Recombinative reading derived from pseudoword instruction in a miniature linguistic system

A miniature linguistic system was used to study acquisition of recombinative symbolic behavior. Three studies evaluated the teaching conditions of conditional discriminations with printed and spoken pseudowords that could potentially generate recombinative reading. Fifty-four college students across all studies learned to match 12 printed pseudowords to 12 spoken pseudowords. Some also matched pictures to the same spoken words. Each two-syllable pseudoword was formed by symbols from an arbitrarily created alphabet composed of four vowels and four consonants. Letters had univocal correspondence with phonemes. Recombinative receptive reading, comprehensive reading, and textual responding to pseudowords were periodically assessed. Experiment 1 (n = 20) showed that recombinative reading increased as the number of trained words composed of the same symbols increased. Experiment 2 (n = 14) showed that overtraining the same two words did not produce recombinative reading for most participants. Experiment 3 (n = 20), in which training with pictures was omitted, showed that elemental control by within-syllable units can develop even when the trained pseudowords are meaningless (not related to pictures). The present results support the utility of the miniature linguistic system methodology for identifying and controlling environmental determinants of rudimentary reading skills.     

The "cost of caring" in youths' friendships: considering associations among social perspective taking, co-rumination, and empathetic distress

The current research considered the costs of caring in youths' friendships. The development of a new construct, empathetic distress, allowed for a direct test of the commonly held belief that females suffer greater vicarious distress in response to close others' stressors and problems than do males. Empathetic distress refers to one's strongly sharing a relationship partner's distress over problems to the point of taking on the partner's distress and experiencing it as one's own. This new construct was examined in an ethnically diverse sample of early adolescents who responded to a series of questionnaires in their classrooms. Results indicated that girls did experience greater empathetic distress in friendships than did boys. In addition, the current research revealed that social perspective taking in friendships (i.e., the social-cognitive ability to infer and understand the friend's perspective) had adjustment trade-offs in that it predicted greater positive friendship quality but also greater empathetic distress in the friendship. Interestingly, the associations of social perspective taking with both positive friendship quality and empathetic distress were partially mediated by co-rumination or excessive discussion of problems. Applied implications of the findings that girls' greater social perspective taking and associated co-rumination contributed both to their greater positive friendship quality but also to greater costs of caring in the form of empathetic distress are discussed.     

2.5-year-olds use cross-situational consistency to learn verbs under referential uncertainty

Recent evidence shows that children can use cross-situational statistics to learn new object labels under referential ambiguity (e.g., Smith & Yu, 2008). Such evidence has been interpreted as support for proposals that statistical information about word-referent co-occurrence plays a powerful role in word learning. But object labels represent only a fraction of the vocabulary children acquire, and arguably represent the simplest case of word learning based on observations of world scenes. Here we extended the study of cross-situational word learning to a new segment of the vocabulary, action verbs, to permit a stronger test of the role of statistical information in word learning. In two experiments, on each trial 2.5-year-olds encountered two novel intransitive (e.g., "She's pimming!"; Experiment 1) or transitive verbs (e.g., "She's pimming her toy!"; Experiment 2) while viewing two action events. The consistency with which each verb accompanied each action provided the only source of information about the intended referent of each verb. The 2.5-year-olds used cross-situational consistency in verb learning, but also showed significant limits on their ability to do so as the sentences and scenes became slightly more complex. These findings help to define the role of cross-situational observation in word learning.