Comparing methods for measuring peak look duration: Are individual differences observed on screen-based tasks also found in more ecologically valid contexts?

Convergent research points to the importance of studying the ontogenesis of sustained attention during the early years of life, but little research hitherto has compared and contrasted different techniques available for measuring sustained attention. Here, we compare methods that have been used to assess one parameter of sustained attention, namely infants’ peak look duration to novel stimuli. Our focus was to assess whether individual differences in peak look duration are stable across different measurement techniques. In a single cohort of 42 typically developing 11-month-old infants we assessed peak look duration using six different measurement paradigms (four screen-based, two naturalistic). Zero-order correlations suggested that individual differences in peak look duration were stable across all four screen-based paradigms, but no correlations were found between peak look durations observed on the screen-based and the naturalistic paradigms. A factor analysis conducted on the dependent variable of peak look duration identified two factors. All four screen-based tasks loaded onto the first factor, but the two naturalistic tasks did not relate, and mapped onto a different factor. Our results question how individual differences observed on screen-based tasks manifest in more ecologically valid contexts.     

An investigation of phonology and orthography in spoken-word recognition.

The possible influence of initial phonological and/or orthographic information on spoken-word processing was examined in six experiments modelled after and extending the work Jakimik, Cole, and Rudnicky (1985). Following Jakimik et al., Experiment 1 used polysyllabic primes with monosyllabic targets (e.g., BUCKLE-BUCK/[symbol: see text]; MYSTERY-MISS,/[symbol: see text]). Experiments 2, 3, and 4 used polysyllabic primes and polysyllabic targets whose initial syllables shared phonological information (e.g., NUISANCE-NOODLE,/[symbol: see text]), orthographic information (e.g., RATIO-RATIFY,/[symbol: see text]), both (e.g., FUNNEL-FUNNY,/[symbol: see text]), or were unrelated (e.g., SERMON-NOODLE,/[symbol: see text]). Participants engaged in a lexical decision (Experiments 1, 3, and 4) or a shadowing (Experiment 2) task with a single-trial (Experiments 2 and 3) or subsequent-trial (Experiments 1 and 4) priming procedure. Experiment 5 tested primes and targets that varied in the number of shared graphemes while holding shared phonemes constant at one. Experiment 6 used the procedures of Experiment 2 but a low proportion of related trials. Results revealed that response times were facilitated for prime-target pairs that shared initial phonological and orthographic information. These results were confirmed under conditions when strategic processing was greatly reduced suggesting that phonological and orthographic information is automatically activated during spoken-word processing.     

Optimisation and mathematical explanation: doing the Lévy Walk

The indispensability argument seeks to establish the existence of mathematical objects. The success of the indispensability argument turns on finding cases of genuine extra-mathematical explanation (the explanation of physical facts by mathematical facts). In this paper, I identify a new case of extra-mathematical explanation, involving the search patterns of fully-aquatic marine predators. I go on to use this case to predict the prevalence of extra-mathematical explanation in science.     

Use of social network sites and instant messaging does not lead to increased offline social network size, or to emotionally closer relationships with offline network members

The effect of Internet use on social relationships is still a matter of intense debate. This study examined the relationships between use of social media (instant messaging and social network sites), network size, and emotional closeness in a sample of 117 individuals aged 18 to 63 years old. Time spent using social media was associated with a larger number of online social network "friends." However, time spent using social media was not associated with larger offline networks, or feeling emotionally closer to offline network members. Further, those that used social media, as compared to non-users of social media, did not have larger offline networks, and were not emotionally closer to offline network members. These results highlight the importance of considering potential time and cognitive constraints on offline social networks when examining the impact of social media use on social relationships.     

Reliability of upper extremity kinematics while performing different tasks in individuals with stroke

Assessments of upper extremity performance typically include qualitative rather than quantitative measures of functional ability. Kinematic analysis is an objective, discriminative measure that quantifies movement biomechanics; however, the use within the poststroke impaired upper extremity is not well established. The purpose of this study was to examine the reliability of upper extremity kinematics in 18 individuals with stroke and 9 healthy controls. Participants performed reaching and grasping tasks over 2 separate days and metrics included movement time, peak velocity, index of curvature, trunk displacement, maximum aperture, and percentage of the movement cycle where maximum aperture occurred. The results showed moderate to high intraclass correlation and low standard error of measurement values for most variables, demonstrating that kinematic analysis may be a feasible and useful tool to quantify upper extremity movement after stroke.     

Psychological Distress in a Sample of Teachers

This article describes a cross-sectional study of the links between job-related stressors and depressive and psychophysiologic symptoms and morale in 67 New York City teachers. The teachers' mean score on the Center for Epidemiologic Studies Depression Scale (CES-D; M = 13.03) was higher than might be expected from average community residents. The teachers also tended to express dissatisfaction with their jobs. The CES-D and the Psychophysiologic Symptom Scale were correlated as highly as their reliabilities would permit, a finding consistent with the view that the CES-D and the Psycho physiologic Symptom Scale measure the same construct, nonspecific psychological distress. The correlational findings suggest that distress is distinct from job-related morale, which was indexed by measures of motivation to continue teaching and job satisfaction. The results of regression analyses, which controlled for sociodemographic factors, indicated that the level of job strain (frequency of ongoing stressors) is more closely related to psychological distress and low morale than episodic stressors, including crimes in which the teacher was victim. The regression analyses also indicated that colleague support was related to lower symptom levels and higher morale.     

How to endure presentism

Presentism and endurantism are natural bedfellows: arguments have been mounted from endurantism to presentism and vice versa. I generalise an argument against the compatibility between presentism and endurantism offered recently by Tallant (forthcoming. “Presentism, Persistence and Trans-temporal Dependence.” Philosophical Studies). I then show how to reformulate endurantism so that it is compatible with presentism. I demonstrate that this reformulated version of endurantism can do the same work with respect to the problem of temporary intrinsics as can standard definitions.