Adult age differences in the rate of learning serial patterns: Evidence from direct and indirect tests.

Ss performed a serial reaction time (RT) task (adopted from M. J. Nissen and P. Bullemer, 1987) that contained a repeating pattern of spatial locations. In Exp 1, following 20 repetitions of a 10- or 16-element pattern, RT was equally disrupted for both younger and older people when the sequence became random. In Exp 2, the response times for Ss encountering the 10-element pattern were compared with those of Ss encountering a random sequence. These response time functions diverged at the same point in training for the 2 age groups. Thus, on this indirect measure of response time facilitation, both experiments revealed age similarity in the rate of pattern learning. In contrast, on a subsequent direct test of pattern learning that required prediction, the younger people earned a higher percentage correct score than the older in both experiments. Age-related dissociations between direct and indirect measures of learning and comparisons with memory-impaired populations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characterization of PC12 cell proliferation and differentiation-stimulated by ECM adhesion proteins and neurotrophic factors

Among the various elements which influence axonal outgrowth in vivo is the physicochemical interaction of actively outgrowing nerve fibers with the various substrata they encounter during differentiation. Several experiments have explored the role of the extracellular matrix (ECM) in the control of neuronal differentiation. The nature, however, of the interactions between neurons and components of the ECM during regeneration and development are largely a matter of speculation. Although previous studies have already explored the influence of a number of ECM adhesion proteins and neurotrophic factors on neurite outgrowth, none have been carried in a systematic approach that allows for the simultaneous comparison of different surface conditions in relation to different neurotrophic factors. Motivated by the necessity of establishing controlled environments that allow for the rational design of stable neuronal/biomaterial interfaces, the long-term effects of NGF and FGF-2 on the behavior of PC12 cells plated on collagen and laminin modified surfaces were evaluated. A pheochromocytoma cell line derived from transplantable rat adrenal medulla, PC12 cells have been commonly employed as an instructive model for studying the underlying mechanisms of neuronal differentiation. Long-term characterization of PC12 proliferation and neuronal differentiation for an experimental duration of 7–22 days was achieved by both qualitatively and quantitatively assaying for cell count, neurite number, neurite mean length, and neurite stability. Neurite stability was determined in terms of resistance to loss after neurotrophic factor (NGF/FGF-2) withdrawal. The present findings demonstrate that ECM adhesion proteins collagen and laminin are equally effective in promoting PC12 proliferation. It was noted as well that NGF supplemented collagen cultures are significantly more efficient in providing long-term support to PC12 differentiation in terms of neurite number, mean length, and stability.     

Review of Learning and behavior: A contemporary synthesis.

Reviews the book, Learning and behavior: A contemporary synthesis by Mark E. Bouton (see record 2006-21409-000). The reviewer praises the author for creating a student-friendly textbook for an undergraduate course in animal learning that is both comprehensive and current. Bouton presents the major theoretical issues and findings in their historical context. Chapter topics include: (1) adaptation; (2) Pavlovian conditioning; (3) operant conditioning; (4) choice behavior; (5) theories of reinforcement; (6) motivation; (7) cognition; (8) spatial learning; (9) learned helplessness; and (10) superstitious behavior. Bouton comes full circle in the final section, "A cognitive analysis of instrumental action," by describing experimental evidence for the existence of various types of associations (i.e., S-S*, R-S*) that were introduced in the first chapter. The reviewer believes students and instructors alike will enjoy this very readable book. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Interpersonal Process Model of Intimacy: The Role of Self-Disclosure, Partner Disclosure, and Partner Responsiveness in Interactions Between Breast Cancer Patients and Their Partners.

This study evaluated H. Reis and P. Shaver's (1988) interpersonal process model of intimacy in a sample of 98 women with breast cancer and their partners. Couples engaged in two discussions and rated self- and partner disclosure, perceived partner responsiveness, and intimacy experienced. A mediational model was tested in which partner responsiveness mediated the association between disclosure and intimacy. For patients, perceived responsiveness partially mediated the association between partner disclosure and intimacy, but self-disclosure was not significantly associated with responsiveness or intimacy. For partners, perceived responsiveness mediated the association between self-disclosure and perceived partner disclosure and intimacy. For breast cancer patients, partner disclosure predicted patient feelings of intimacy, because this type of disclosure was associated with greater feelings of acceptance, understanding, and caring. These findings may have implications for interventions to improve relationship closeness among couples coping with breast cancer. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and the priming of newly learned associations.

In each of 2 experiments, 32 young (aged 18–25 yrs) and 32 elderly (aged 63–79 yrs) adults studied 36 sentences of the form NOUN1-VERB-NOUN2. They then made item-recognition judgments regarding whether single nouns had occurred in the sentences. After 2 or more presentations of each sentence, both young and elderly Ss showed equivalent priming between the nouns within the sentences; a noun was recognized faster when it was tested immediately after the other noun from the same sentence than when it was tested following a noun from a different sentence. After only 1 presentation of each sentence, young Ss showed priming but elderly Ss did not. Under all study conditions, young Ss were superior to the elderly in cued recall of the same sentences. It is argued that priming provides a sensitive measure of what is stored in memory and so will be useful for studies of aging. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Coherent orbital waves in the photo-induced insulator-metal dynamics of a magnetoresistive manganite

Photo-excitation can drive strongly correlated electron insulators into competing conducting phases, resulting in giant and ultrafast changes of their electronic and magnetic properties. The underlying non-equilibrium dynamics involve many degrees of freedom at once, whereby sufficiently short optical pulses can trigger the corresponding collective modes of the solid along temporally coherent pathways. The characteristic frequencies of these modes range between the few GHz of acoustic vibrations to the tens or even hundreds of THz for purely electronic excitations. Virtually all experiments so far have used 100 fs or longer pulses, detecting only comparatively slow lattice dynamics. Here, we use sub-10-fs optical pulses to study the photo-induced insulator-metal transition in the magnetoresistive manganite Pr(0.7)Ca(0.3)MnO(3). At room temperature, we find that the time-dependent pathway towards the metallic phase is accompanied by coherent 31 THz oscillations of the optical reflectivity, significantly faster than all lattice vibrations. These high-frequency oscillations are suggestive of coherent orbital waves, crystal-field excitations triggered here by impulsive stimulated Raman scattering. Orbital waves are likely to be initially localized to the small polarons of this room-temperature manganite, coupling to other degrees of freedom at longer times, as photo-domains coalesce into a metallic phase.     

What is next for the Dietary Reference Intakes for bone metabolism related nutrients beyond calcium: phosphorus, magnesium, vitamin D, and fluoride?

The science supporting the Dietary Reference Intakes (DRI) for phosphorus, magnesium, vitamin D, and fluoride was examined in this review. Along with the previous article on calcium in this series both of these reviews represent all the DRI for nutrients considered essential for bone metabolism and health, as reported in the Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride (Institute of Medicine, Food and Nutrition Board (FNB), 1997). The Recomended Dietary Allowances (RDA) or adequate intake (AI), and the tolerable upper intake level (UL) were recommended for each of these essential nutrients. For adults and in the case of fluoride, for infants as well, UL were calculated since all of these nutrients have the potential for mild to detrimental side effects. Dietary intake data and controversies regarding the role these nutrients may play in other chronic diseases have also been discussed. Advances and controversies reported since the publication of the DRI for these nutrients were also addressed in this review. A recent Dietary Reference Intake Research Synthesis Workshop report identified an extensive range of suggested future research directions needed to improve our understanding of these bone-related nutrients and their contributions to human health.     

Dynamic approach for real-time skin detection

Journal of Real-Time Image Processing - Human face and hand detection, recognition and tracking are important research areas for many computer interaction applications. Face and hand are considered...