The use of experimenter-given cues by South African fur seals (<Emphasis Type="Italic">Arctocephalus pusillus</Emphasis>)

Dogs can use a variety of experimenter-given cues such as pointing, head direction, and eye direction to locate food hidden under one of several containers. Some authors have proposed that this is a result of the domestication process. In this study we tested four captive fur seals in a two alternative object choice task in which subjects had to use one of the following experimenter-given cues to locate the food: (1) the experimenter pointed and gazed at one of the objects, (2) the experimenter pointed at only one of the objects, (3) the experimenter gazed at only one of the objects, (4) the experimenter glanced at only one of the objects, (5) the experimenter pointed and gazed at one of the objects but was sitting closer to one object than to the other, (6) the experimenter pointed only with the index finger at one of the objects, (7) the experimenter presented a replica of one of the objects. The fur seals were able to use cues which involved a fully exposed arm or a head direction, but failed to use glance only, the index finger pointing and the object replica cues. The results showed that a domestication process was not necessary to develop receptive skills to cues given by an experimenter. Instead, we hypothesize that close interactions with humans prior to testing enabled fur seals to use some gestural cues without formal training. We also analyzed the behavior of the seals depending on the level of difficulty of the task. Behavioral signs of hesitation increased with task difficulty. This suggests that the fur seals were sensitive to task difficulty.     

Timing accuracy in motion extrapolation: reverse effects of target size and visible extent of motion at low and high speeds

By varying target size, speed, and extent of visible motion we examined the timing accuracy in motion extrapolation. Small or large targets (0.2 or 0.8 deg) moved at either 2.5, 5, or 10 deg s(-1) across a horizontal path (2.5 or 10 deg) and then vanished behind an occluder. Observers responded when they judged that the target had reached a randomly specified position between 0 and 12 deg. With higher speeds, the timing accuracy (the reverse of absolute error) was better for small than for large targets, and for long than for short visible extents. With low speed, these effects were reversed. In addition, while long visible extents yielded a greater accuracy at high than at low speeds, for short extents the accuracy was much better with the low speed. The findings suggest that, when extrapolating motion with targets and visible extents of different sizes, the visual system implements different scaling algorithms depending on target speed. At higher speeds, processing of visible and occluded motion is likely to share a common scaling mechanism based on velocity transposition. Reverse effects for target size and extent of visible motion at low and high speeds converge with the assumption of two distinct speed-tuned motion-processing mechanisms in human vision.     

“I don't know but I know who to ask”: 12‐month‐olds actively seek information from knowledgeable adults

Active social communication is an effective way for infants to learn about the world. Do pre‐verbal and pre‐pointing infants seek epistemic information from their social partners when motivated to obtain information they cannot discover independently? The present study investigated whether 12‐month‐olds (N = 30) selectively seek information from knowledgeable adults in situations of referential uncertainty. In a live experiment, infants were introduced to two unfamiliar adults, an Informant (reliably labeling objects) and a Non‐Informant (equally socially engaging, but ignorant about object labels). At test, infants were asked to make an impossible choice—locate a novel referent among two novel objects. When facing epistemic uncertainty—but not at other phases of the procedure—infants selectively referred to the Informant rather than the Non‐Informant. These results show that pre‐verbal infants use social referencing to actively and selectively seek information from social partners as part of their interrogative communicative toolkit. A video abstract of this article can be viewed at https://youtu.be/23dLPsa-fAY     

Maternal perinatal representations and their associations with mother–infant interaction and attachment: A longitudinal comparison of Portuguese and Brazilian dyads

Prior research in Western countries (mostly the US, Canada and northern Europe) indicates that mothers' representations are associated with mother–infant interaction quality and their child's attachment security later in the first year. Fewer studies, however, have evaluated whether these associations hold for mother–infant dyads in other countries, such as Brazil and Portugal. Although these countries share a similar language and culture, they differ on societal dimensions that may affect parenting attitudes and mother–infant relationships, such as economic stress, social organisation, social policy, and the availability of services for young families. In this longitudinal study, we followed two independent samples of Brazilian and Portuguese mother–infant dyads from the perinatal period to 12 months post-partum. We assessed mothers' perinatal representations using semi-structured interviews in the first 48 hours after the infant's birth, and evaluated the associations of these representations with mother interaction quality at 9 months and infant attachment at 12 months. Results were similar in each country, corroborating prior research in single Western countries: Mothers with more positive perinatal representations were more sensitive to their infants during free play at 9 months and were more likely to have infants classified as securely attached at 12 months.     

Validation of a shortened assessment of physical self in adults

The purpose was to adapt a brief tool, the Physical Self Inventory-Version b, for the assessment of physical self in adults. The inventory is a refined version of the previously validated version, which was derived from the Physical Self Inventory (25 items). This French validation of the Physical Self-Perception Profile of Fox and Corbin includes a global self-esteem scale. As in the earlier version the current one has 6 single items to assess dimensions of global self-esteem, physical selfworth, sport competence, physical condition, attractive body, and physical strength. Rating is performed on a visual analog scale. Items in the new inventory were stated in the first person and in more general terms to be acceptable to a wider range of subjects. An item of measurement error was added. Analysis of responses of 185 men and 148 women to the new version supported the hierarchical structure. Significant correlations between the scores and constructs like masculinity, neuroticism, and depression indicated external validity. The new inventory showed acceptable psychometric properties for use in idiographic studies.     

Response scale transfer for visual speed

By reversing the presentation order and frequency of stimuli between two series of trials, we studied how the category scale for visual speed is transferred across stimulus contexts. Participants judged five stimulus speeds, using three categories (slow, moderate, and fast). In Experiment 1, mainly frequent speeds (either low or high) occurred on the initial trials. This manipulation produced divergent preshift ratings for identical stimuli. Although subsequent reversal of stimulus context resulted in a reversal of scales, the adjustment was incomplete: The postshift ratings did not match the comparable preshift ones. In Experiment 2, mainly infrequent speeds were presented initially. Now the preshift ratings coincided, but higher postshift ratings occurred with the frequent high-speed rather than with the frequent low-speed stimuli. We conclude that with transfer into a new context, the spontaneous adjustment of response scale is determined (1) by the preshift primacy and the postshift frequency effects and (2) by the preshift frequency effect extended to the postshift trials.     

Tense and syntactic processes in agrammatic speech

This study focuses on inflectional errors in a group of eight, English-speaking people with agrammatism. Subjects were required to provide inflected verbs in declarative sentences and construct negative sentences. The errors made by these speakers are considered in terms of whether they resemble the errors made by children at the Optional Infinitive Stage. Results confirm that the errors differ from those made by children and that a different explanation is required. Explanations offered by Borer and Rohrbacher (1997) and by Friedmann and Grodzinsky (2000) are discussed but are considered inadequate to deal with our data. It is proposed that agrammatic speakers have problems with the implementation of grammar and particularly with syntactic processes such as feature-checking.     

German Unification as a Turning Point in East German Women's Life Course: Biographical Changes in Work and Family Roles

In order to explore the effects of German unification on the life course of East German women of three age cohorts, 36 biographical interviews were conducted. The purpose of the research was to examine whether unification meant a complete break with the German Democratic Republic's (GDR) standard biography in terms of a voluntary acceptance of West German patterns, or a modification of old patterns based on necessity. Results demonstrate that the historical moment of 1989/90 (the Wende or turning point) has changed the life plans of the three cohorts of women in East Germany in different ways, depending on its timing in their life course. The life patterns of the youngest cohort differ most significantly from the standard biography of the GDR woman in that family formation is postponed and employment prioritized over family. Rather than being a complete break with tradition and a voluntary adoption of Western norms, this means a modification of the life course, because the desire to combine work and family continues to dominate.