Comparison of native and non-native phone imitation by English and Spanish speakers

Experiments investigating phonetic convergence in conversation often focus on interlocutors with similar phonetic inventories. Extending these experiments to those with dissimilar inventories requires understanding the capacity of speakers to imitate native and non-native phones. In the present study, we tested native Spanish and native English speakers to determine whether imitation of non-native tokens differs qualitatively from imitation of native tokens. Participants imitated a [ba]–[pa] continuum that varied in VOT from −60 ms (prevoiced, Spanish [b]) to +60 ms (long lag, English [p]) such that the continuum consisted of some tokens that were native to Spanish speakers and some that were native to English speakers. Analysis of the imitations showed two critical results. First, both groups of speakers demonstrated sensitivity to VOT differences in tokens that fell within their native regions of the VOT continuum (prevoiced region for Spanish and long lag region for English). Secondly, neither group of speakers demonstrated such sensitivity to VOT differences among tokens that fell in their non-native regions of the continuum. These results show that, even in an intentional imitation task, speakers cannot accurately imitate non-native tokens, but are clearly flexible in producing native tokens. Implications of these findings are discussed with reference to the constraints on convergence in interlocutors from different linguistic backgrounds

Achievement of the recommendations of intake of vitamin D and calcium in patients with osteoporosis

Objetivos: - Conocer los aportes diarios de vitamina D y calcio (suplementos farmacológicos y dieta) en mujeres mayores de 65 años. - Conocer si existe relación entre el consumo diario de vitamina D y las variables clínicas y sociodemográficas

Avoiding moving obstacles

To successfully move our hand to a target, we must consider how to get there without hitting surrounding objects. In a dynamic environment this involves being able to respond quickly when our relationship with surrounding objects changes. People adjust their hand movements with a latency of about 120 ms when the visually perceived position of their hand or of the target suddenly changes. It is not known whether people can react as quickly when the position of an obstacle changes. Here we show that quick responses of the hand to changes in obstacle position are possible, but that these responses are direct reactions to the motion in the surrounding. True adjustments to the changed position of the obstacle appeared at much longer latencies (about 200 ms). This is even so when the possible change is predictable. Apparently, our brain uses certain information exceptionally quickly for guiding our movements, at the expense of not always responding adequately. For reaching a target that changes position, one must at some time move in the same direction as the target did. For avoiding obstacles that change position, moving in the same direction as the obstacle is not always an adequate response, not only because it may be easier to avoid the obstacle by moving the other way, but also because one wants to hit the target after passing the obstacle. Perhaps subjects nevertheless quickly respond in the direction of motion because this helps avoid collisions when pressed for time. © 2008 Springer-Verlag

Kv7 Channels Can Function without Constitutive Calmodulin Tethering

M-channels are voltage-gated potassium channels composed of Kv7.2-7.5 subunits that serve as important regulators of neuronal excitability. Calmodulin binding is required for Kv7 channel function and mutations in Kv7.2 that disrupt calmodulin binding cause Benign Familial Neonatal Convulsions (BFNC), a dominantly inherited human epilepsy. On the basis that Kv7.2 mutants deficient in calmodulin binding are not functional, calmodulin has been defined as an auxiliary subunit of Kv7 channels. However, we have identified a presumably phosphomimetic mutation S511D that permits calmodulin-independent function. Thus, our data reveal that constitutive tethering of calmodulin is not required for Kv7 channel function

Memory shapes visual search strategies in large-scale environments

Abstract Search is a central visual function. Most of what is known about search derives from experiments where subjects view 2D displays on computer monitors. In the natural world, however, search involves movement of the body in large-scale spatial contexts, and it is unclear how this might affect search strategies. In this experiment, we explore the nature of memory representations developed when searching in an immersive virtual environment. By manipulating target location, we demonstrate that search depends on episodic spatial memory as well as learnt spatial priors. Subjects rapidly learned the large-scale structure of the space, with shorter paths and less head rotation to find targets. These results suggest that spatial memory of the global structure allows a search strategy that involves efficient attention allocation based on the relevance of scene regions. Thus spatial memory may allow less energetically costly search strategies

Vision in Natural and Virtual Environments

Our knowledge of the way that the visual system operates in everyday behavior has, until recently, been very limited. This information is critical not only for understanding visual function, but also for understanding the consequences of various kinds of visual impairment, and for the development of interfaces between human and artificial systems. The development of eye trackers that can be mounted on the head now allows monitoring of gaze without restricting the observer's movements. Observations of natural behavior have demonstrated the highly task-specific and directed nature of fixation patterns, and reveal considerable regularity between observers. Eye, head, and hand coordination also reveals much greater flexibility and task-specificity than previously supposed. Experimental examination of the issues raised by observations of natural behavior requires the development of complex virtual environments that can be manipulated by the experimenter at critical points during task performance. Experiments where we monitored gaze in a simulated driving environment demonstrate that visibility of task relevant information depends critically on active search initiated by the observer according to an internally generated schedule, and this schedule depends on learnt regularities in the environment. In another virtual environment where observers copied toy models we showed that regularities in the spatial structure are used by observers to control eye movement targeting. Other experiments in a virtual environment with haptic feedback show that even simple visual properties like size are not continuously available or processed automatically by the visual system, but are dynamically acquired and discarded according to the momentary task demands

Cumplimiento de las recomendaciones de aportes de vitamina D y calcio en pacientes con osteoporosis

Objetivos: - Conocer los aportes diarios de vitamina D y calcio (suplementos farmacológicos y dieta) en mujeres mayores de 65 años. - Conocer si existe relación entre el consumo diario de vitamina D y las variables clínicas y sociodemográficas