Choosing and using tools: capuchins (Cebus apella) use a different metric than tamarins (Saguinus oedipus)

Cotton-top tamarins (Saguinus oedipus) selected canes positioned so that a straight inward pull brought food within reach (M. D. Hauser, 1997; see also record 1997-41347-003). Tamarins failed to retrieve food with canes in other positions, and they did not reposition these canes. In this study, tufted capuchin monkeys (Cebus apella) preferred canes they could pull straight in when these were present, but they also repositioned canes in individually variable ways, and their success at obtaining food with repositioned canes improved with practice. In accord with predictions drawn from ecological psychology, capuchins discovered affordances of canes through exploratory actions with these objects, whereas tamarins did not. Ecological theory predicts these differences on the basis of species-typical manipulative activity, and it provides a useful approach for the study of species differences in tool-using behavior.     

The influence of parafoveal word length and contextual constraint on fixation durations and word skipping in reading

The present study examined the relationship between the predictability of words within a sentence and the availability of parafoveal word length information, on when and where the eyes move in reading. Predictability influenced first-pass reading times when parafoveal word length preview information was correct, but not when it was incorrect. Similarly, for saccades launched from near the target word (wordn), predictability influenced the probability with which it was skipped only when the word length preview was correct. By contrast, for saccades launched farther away from wordn, predictability influenced word skipping regardless of the parafoveal word length preview. Taken together, the data suggest that parafoveal word length preview and predictability can act as a joint constraint on the decision of when and where to move the eyes.     

Enhanced priming for trauma-related material in posttraumatic stress disorder

Intrusive reexperiencing in posttraumatic stress disorder (PTSD) has been linked to perceptual priming for trauma-related material. A prospective longitudinal study (N = 69) investigated perceptual priming for trauma-related, general threat, and neutral words in assault survivors with and without PTSD, using a new version of the word-stem completion task. Survivors with PTSD showed enhanced priming for trauma-related words. Furthermore, priming for trauma-related words measured soon after the trauma was associated with subsequent PTSD severity at 3, 6, and 9 months. The enhanced priming effect was specific to trauma-related words. Enhanced perceptual priming for traumatic material appears to be one of the cognitive processes operating in PTSD.     

The relationship of body image dissatisfaction to cigarette smoking in college students

This study examined the association of cigarette smoking status and body image dissatisfaction as measured by the Multidimensional Body-Self Relations Questionnaire (MBSRQ), in 1575 young adult college students, 18–24 years of age. Respondents were current cigarette smokers (N = 482) or never tobacco users (N = 1093). Smoking status was found to be significantly associated with 5 of the 10 MBSRQ subscales, with current smokers having lower scores on Fitness Orientation, Health Evaluation and Health Orientation (all p < 0.001) and higher scores on Appearance Orientation (p = 0.01) and Overweight Preoccupation (p = 0.03) compared with never tobacco users. Furthermore, among current smokers, a higher number of days smoked in the last 30 days were associated with lower scores on all MBSRQ subscales, except Self-Classified Weight. In terms of clinical implications, interventions for smoking cessation among college students might benefit from inclusion of components for addressing body image dissatisfaction and improving health beliefs.     

Something from nothing: exploring dimensions of children's knowing through the repeated reading of favourite books

Witte‐Townsend and DiGiulio explore some of the dimensions of knowing that children, teachers and parents may engage together during story‐time. They reflect on some of their own long‐term relationships with children and children's books, especially Phoebe Gilman's Gilman P 1992 Something from nothing (New York, NY, Scholastic Inc)  [Google Scholar] Something from nothing (published in 1992) and Simms Taback's Taback S 1999 Joseph had a little overcoat (New York, NY, Viking‐Penguin)  [Google Scholar] Joseph had a little overcoat, published in 1999. The authors probe issues such as why children ask to hear a favourite story over and over and why they suddenly abandon all interest and move on to a new book. They explore the meaning of the silences that sometimes arise during story‐time, pooling around the young listeners as the last words of the book are read. Witte‐Townsend and DiGiulio remind us of the value of literature in the lives of children and they affirm that the reading and re‐reading of favourite stories enables the understanding of complex human issues and contributes significantly to social, emotional and spiritual growth.     

The associative memory deficit of older adults: further support using face-name associations

Previous studies have established an associative deficit hypothesis (Naveh-Benjamin, 2000), which attributes part of older adults' deficient episodic memory performance to their difficulty in creating cohesive episodes. In this article, the authors further evaluate this hypothesis, using ecologically relevant materials. Young and old participants studied name-face pairs and were then tested on their recognition memory for the names, faces, and the name-face pairs. The results extend the conditions under which older adults exhibit an associative deficit. They also show that reduced attentional resources are not the sole mediator of this deficit.     

Partition-edit-count: naive extensional reasoning in judgment of conditional probability

The authors provide evidence that people typically evaluate conditional probabilities by subjectively partitioning the sample space into n interchangeable events, editing out events that can be eliminated on the basis of conditioning information, counting remaining events, then reporting probabilities as a ratio of the number of focal to total events. Participants' responses to conditional probability problems were influenced by irrelevant information (Study 1), small variations in problem wording (Study 2), and grouping of events (Study 3), as predicted by the partition-edit-count model. Informal protocol analysis also supports the authors' interpretation. A 4th study extends this account from situations where events are treated as interchangeable (chance and ignorance) to situations where participants have information they can use to distinguish among events (uncertainty).     

Stabilization and destabilization of perception--action patterns influence the self-organized recruitment of degrees of freedom

The recruitment of an additional biomechanical degree of freedom in a unimanual rhythmic task was explored. Subjects were asked to synchronize adduction or abduction of their right index finger with a metronome, the frequency of which was increased systematically. In addition, haptic contact on or off the metronome beat was provided. Results showed that the pattern exhibiting the highest intrinsic stability recruited the vertical plane more than did the less stable one. Moreover, presence and location of haptic contact modulated coordination stability and therefore induced changes in the recruitment of the vertical plane. Thus, a trade-off was shown between coordination stability on the horizontal plane and recruitment of the vertical one. These findings suggest that recruitment of degrees of freedom is governed by general principles of coordination dynamics.     

Distant melodies: statistical learning of nonadjacent dependencies in tone sequences

Human listeners can keep track of statistical regularities among temporally adjacent elements in both speech and musical streams. However, for speech streams, when statistical regularities occur among nonadjacent elements, only certain types of patterns are acquired. Here, using musical tone sequences, the authors investigate nonadjacent learning. When the elements were all similar in pitch range and timbre, learners acquired moderate regularities among adjacent tones but did not acquire highly consistent regularities among nonadjacent tones. However, when elements differed in pitch range or timbre, learners acquired statistical regularities among the similar, but temporally nonadjacent, elements. Finally, with a moderate grouping cue, both adjacent and nonadjacent statistics were learned, indicating that statistical learning is governed not only by temporal adjacency but also by Gestalt principles of similarity.