12‐Month‐Old Infants' Perception of Attention Direction in Static Video Images

Twelve‐month‐old infants' ability to perceive gaze direction in static video images was investigated. The images showed a woman who performed attention‐directing actions by looking or pointing toward 1 of 4 objects positioned in front of her (2 on each side). When the model just pointed at the objects, she looked straight ahead, and when she just looked, her hands were hidden below the tabletop. An eye movement system (TOBII) was used to register the gaze of the participants. We found that the infants clearly discriminated the gaze directions to the objects. There was no tendency to mix up the 2 object positions, located 10° apart, on the same side of the model. The infants spent more time looking at the attended objects than the unattended ones and they shifted gaze more often from the face of the model to the attended object than to the unattended objects. Pointing did not significantly increase the infants' tendency to move gaze to the attended object, irrespective of whether the pointing gesture was accompanied by looking or not. In all conditions the infants spent most of the time looking at the model's face. This tendency was especially noticeable in the pointing‐only condition and the condition where the model just looked straight ahead.     

Approximating hidden Gaussian Markov random fields

Summary.  Gaussian Markov random-field (GMRF) models are frequently used in a wide variety of applications. In most cases parts of the GMRF are observed through mutually independent data; hence the full conditional of the GMRF, a hidden GMRF (HGMRF), is of interest. We are concerned with the case where the likelihood is non-Gaussian, leading to non-Gaussian HGMRF models. Several researchers have constructed block sampling Markov chain Monte Carlo schemes based on approximations of the HGMRF by a GMRF, using a second-order expansion of the log-density at or near the mode. This is possible as the GMRF approximation can be sampled exactly with a known normalizing constant. The Markov property of the GMRF approximation yields computational efficiency.The main contribution in the paper is to go beyond the GMRF approximation and to construct a class of non-Gaussian approximations which adapt automatically to the particular HGMRF that is under study. The accuracy can be tuned by intuitive parameters to nearly any precision. These non-Gaussian approximations share the same computational complexity as those which are based on GMRFs and can be sampled exactly with computable normalizing constants. We apply our approximations in spatial disease mapping and model-based geostatistical models with different likelihoods, obtain procedures for block updating and construct Metropolized independence samplers.     

Birth variations in populations which practise family planning

In the first section it is demonstrated that permanent periodicities may appear in populations, in which fertility occurs at two or more ages, separated by ages, in which there is no fertility at all. It is also shown that where periodicity does disappear, this may take much longer than is usually assumed, before the stable age distribution is attained.

The last section of the paper is based on Swedish data relating to female fertility for single-year cohorts and for periods. It is demonstrated that fertility behaviour of cohorts from different decades has varied considerably, not least as regards birth timing. This explains why the period fertility rate has varied in such an irregular fashion, whereas the rate for cohorts has moved much more regularly; after the original decline to an all-time low for the cohorts born around 1905, there has been a slow, and on the whole, regular increase. This increase is largely explained by a rise in nuptiality. If the total fertility rate required for reproduction is computed, it is seen that no cohorts born after about 1885 have reproduced themselves, and that for the cohorts born between 1895 and 1920 the gap was considerable.     

Birth variations in populations which practise family planning

Abstract In the first section it is demonstrated that permanent periodicities may appear in populations, in which fertility occurs at two or more ages, separated by ages, in which there is no fertility at all. It is also shown that where periodicity does disappear, this may take much longer than is usually assumed, before the stable age distribution is attained. The last section of the paper is based on Swedish data relating to female fertility for single-year cohorts and for periods. It is demonstrated that fertility behaviour of cohorts from different decades has varied considerably, not least as regards birth timing. This explains why the period fertility rate has varied in such an irregular fashion, whereas the rate for cohorts has moved much more regularly; after the original decline to an all-time low for the cohorts born around 1905, there has been a slow, and on the whole, regular increase. This increase is largely explained by a rise in nuptiality. If the total fertility rate required for reproduction is computed, it is seen that no cohorts born after about 1885 have reproduced themselves, and that for the cohorts born between 1895 and 1920 the gap was considerable.     

Discussing feedback system thinking in relation to scenario evaluation in a balanced scorecard setup

Since the emergence of the Balanced Scorecard (BSC) at the beginning of the 1990s, literature has intensively discussed the problems of the cause-and-effect relationships, the time-delay elements between measures and perspectives and the concepts of feedback loops. This article focuses on the use of the System Dynamics Modelling approach to deal with these three problems, an approach first suggested by Forrester back in 1958. The wide scope of application of BSC as a decision-supporting instrument continues to spur the interest in BSC. We have used an actual case as inspiration on which our model construction and our simulation scenarios are based. Our findings suggest that the idea of linking BSC and System Dynamics together based on properties of the systems dynamic nature seem to be both a natural and a relevant development. Furthermore, our simulations demonstrate the ability to: (1) provide a scheme for the translation of the strategy into operational terms and at the same time (2) offer possibilities for the decision maker to be able to evaluate the plan–do–review results based on the feedbacks, specifically in a risk evaluating context.     

The Development of Anticipatory Postural Adjustments in Infancy

Efficient voluntary action requires postural adjustments that compensate for potential balance disturbances before they occur. These anticipatory postural adjustments have been widely investigated in adults, but relatively little is known about their development, especially during infancy. This study examined the early development of anticipatory postural activity in support of pulling action while standing. A total of 34 infants between 10 and 17 months were tested. The task required infants to open a cabinet drawer to retrieve toys while a force resisting the pulling action was applied to the drawer. The experiment included between 9 and 13 pulling trials. The force resisting the pull was doubled after the first 4 initial trials and returned again to its original value after another 4 trials. Electromyographic activity from the gastrocnemius and biceps brachii muscles was recorded. The proportion of pulls involving anticipatory activity in the gastrocnemius muscles progressively increased between 10 and 17 months. In addition, infants with considerable experience in opening drawers learned to recruit greater strength of their anticipatory postural adjustments for heavier pulls. Implications for the role of motoric experience in anticipatory postural activity are discussed.     

Infants' Evolving Representations of Object Motion During Occlusion: A Longitudinal Study of 6‐ to 12‐Month‐Old Infants

Infants' ability to track temporarily occluded objects that moved on circular trajectories was investigated in 20 infants using a longitudinal design. They were first seen at 6 months and then every 2nd month until the end of their 1st year. Infants were presented with occlusion events covering 20% of the target's trajectory (effective occlusion interval ranged from 500–4,000 msec). Gaze was measured using an ASL 504 infrared eye‐tracking system. Results effectively demonstrate that infants from 6 months of age can represent the spatiotemporal dynamics of occluded objects. Infants at all ages tested were able to predict, under certain conditions, when and where the object would reappear after occlusion. They moved gaze accurately to the position where the object was going to reappear and scaled their timing to the current occlusion duration. The average rate of predictive gaze crossings increased with occlusion duration. These results are discussed as a 2‐factor process. Successful predictions are dependent on strong representations, themselves dependent on the richness of information available during encoding and graded representations.     

On the scaling of annoyance due to environmental factors

A recurrent problem in sociological annoyance surveys is to scale the environmental variables quantitatively as they are perceived. Data from two surveys on malodors and noise are discussed within a framework of scaling theory. A Thurstonian scaling technique was applied to the category annoyance data. In the investigation of malodors a rather stable picture of the results of the annoyance reports was obtained independently of the assumptions made in data treatment. On the other hand, the results of the noise investigation indicate that paired comparisons may furnish a better procedure than verbal category scaling for data collection in surveys. Scales of annoyance from different populations will give different units of measurement, and annoyance scales cannot be compared adequately unless the scales are calibrated. A possible calibration procedure is to introduce a defined psychological unit of measurement into the data.This study was supported by grants from the Swedish Environment Protection Board and the Swedish Council for Social Science Research. The authors wish to thank Anita and Peter Medlund for collecting parts of the data.