Sleep disruption and motor development: Does pulling-to-stand impacts sleep–wake regulation?

During the second half of the 1st year, periods of increased sleep disruption have been documented alongside overall improvement in sleep–wake regulation. The objective of the present research was to test if pulling-to-stand (PTS), a milestone typically achieved during the latter part of the 1st year, co-occurs with a period of disrupted sleep. In a longitudinal design, 20 healthy infants were followed-up, from 7 to 11–12 months, at 3-week intervals. Each measurement consisted of filmed motor observations and sleep recordings (actigraphy), both conducted at home. It was found that among early achievers of PTS (by 8 months), the milestone was time-linked to a period of disrupted sleep. The results point to the significance of timing in the interplay between domains of development, and highlight the importance of considering both chronological and developmental metrics in studying changes in sleep–wake regulation.     

The relative importance of different perceptual-cognitive skills during anticipation

We examined whether anticipation is underpinned by perceiving structured patterns or postural cues and whether the relative importance of these processes varied as a function of task constraints. Skilled and less-skilled soccer players completed anticipation paradigms in video-film and point light display (PLD) format. Skilled players anticipated more accurately regardless of display condition, indicating that both perception of structured patterns between players and postural cues contribute to anticipation. However, the Skill × Display interaction showed skilled players’ advantage was enhanced in the video-film condition, suggesting that they make better use of postural cues when available during anticipation. We also examined anticipation as a function of proximity to the ball. When participants were near the ball, anticipation was more accurate for video-film than PLD clips, whereas when the ball was far away there was no difference between viewing conditions. Perceiving advance postural cues appears more important than structured patterns when the ball is closer to the observer, whereas the reverse is true when the ball is far away. Various perceptual-cognitive skills contribute to anticipation with the relative importance of perceiving structured patterns and advance postural cues being determined by task constraints and the availability of perceptual information.     

Temporal generalization gradients following an interdimensional discrimination protocol

We investigated the effects of interdimensional discrimination training in the temporal generalization gradient. In a matching-to-sample task, pigeons learned to choose key S after a T–s houselight sample and key NS in the absence of the houselight sample. For one group of pigeons, T?=?20?s; for another, T?=?10?s. Subsequently, houselight duration was varied to obtain temporal generalization gradients. Results showed that (a) proportion S increased as houselight duration ranged from 0?s to T?s and then remained high for houselight durations longer than T; (b) the gradients were well described by negative-exponential functions; (c) these non-flat gradients were present from the beginning of testing, and; (d) the average gradients obtained with T?=?20?s and T?=?10?s overlapped when plotted in relative time. We conclude that temporal control does not require explicit discrimination training along the temporal dimension, and that temporal generalization gradients obtained with an interdimensional protocol show the scalar property of timing. We discuss how these findings challenge current models of timing.     

婴幼儿词语习得中的社会性认知加工过程

有关婴幼儿词语习得的研究主要有三种理论假设:联想学习理论、制约限制理论和社会语用理论.本文将从以下四个方面着重介绍社会语用理论的相关研究:婴幼儿词语习得过程涉及哪些社会性认知加工过程,社会语用理论如何应对来自前两种理论的质疑和挑战,社会性认知加工过程的相对权重如何以及自闲症儿童词语习得存在怎样的社会性认知加工障碍.相关研究结果表明社会性认知加工过程在婴幼儿词语习得中具有基础性作用.最后对今后在该领域的研究中需要进一步深入探讨的问题提出了一些思考.     

A non-linear utility theory with multiple objectives

The aim of this paper is to make optimum several objectives at the same time which would enable a measurement of utility for several possible alternatives. The problem is solved if a strong or weak dominance exists between the alternatives, otherwise a set of incomparable alternatives would be present. Therefore, indifference curve analysis offers the outcome but as these indifference loci are difficult to determine only the characteristics of this analysis are maintained viz. decreasing marginal utility, non-linearity and even non-convexity. Indifference and reference point theory with the Minkowski min–max-metric only respond to these characteristics. Also the problem of generating alternatives during the process is taken into consideration. © 1998 John Wiley & Sons, Ltd.     

A Multiobjective Diet Planning Support System Using the Satisficing Trade-off Method

This paper shows that the satisficing trade-off method (STOM), one of the interactive multiobjective programming techniques, can be applied effectively to the formulation of livestock rations. Nutrient requirements are considered as soft constraints whose right-hand sides are flexible to some extent. This is easily done by regarding the values of the right-hand sides of the constraints as aspiration levels of the decision maker for objective functions. In this way a well-balanced solution can be obtained by STOM with automatic trade-off analysis. In STOM, moreover, because the objective functions and the constraint functions are interchangeable, decision makers are not required to consider the role of objective and constraint as fixed from the beginning. The authors’ experience is that the method makes ration formulation very easy, rapid and flexible. In addition, this paper shows how effectively STOM can be applied not only to diet planning but also to nutritional diagnosis. © 1997 by John Wiley & Sons, Ltd. J. Multi-Crit. Decis. Anal. 6 : 131–139 (1997) No. of Figures: 1. No. of Tables: 3. No. of References: 28.     

Constraints for Input/Output Logics

In a previous paper we developed a general theory of input/output logics. These are operations resembling inference, but where inputs need not be included among outputs, and outputs need not be reusable as inputs. In the present paper we study what happens when they are constrained to render output consistent with input. This is of interest for deontic logic, where it provides a manner of handling contrary-to-duty obligations. Our procedure is to constrain the set of generators of the input/output system, considering only the maximal subsets that do not yield output conflicting with a given input. When inputs are authorised to reappear as outputs, both maxichoice revision in the sense of Alchourrón/Makinson and the default logic of Poole emerge as special cases, and there is a close relation with Reiter default logic. However, our focus is on the general case where inputs need not be outputs. We show in what contexts the consistency of input with output may be reduced to its consistency with a truth-functional combination of components of generators, and under what conditions constrained output may be obtained by a derivation that is constrained at every step.     

The effect of Parkinson's disease on time estimation as a function of stimulus duration range and modality

The present research sought to investigate the role of the basal ganglia in timing of sub- and supra-second intervals via an examination of the ability of people with Parkinson's disease (PD) to make temporal judgments in two ranges, 100-500 ms, and 1-5 s. Eighteen non-demented medicated patients with PD were compared with 14 matched controls on a duration-bisection task in which participants were required to discriminate auditory and visual signal durations within each time range. Results showed that patients with PD exhibited more variable duration judgments across both signal modality and duration range than controls, although closer analyses confirmed a timing deficit in the longer duration range only. The findings presented here suggest the bisection procedure may be a useful tool in identifying timing impairments in PD and, more generally, reaffirm the hypothesised role of the basal ganglia in temporal perception at the level of the attentionally mediated internal clock as well as memory retrieval and/or decision-making processes.     

Information–movement coupling in developing cricketers under changing ecological practice constraints

Changing informational constraints of practice, such as when using ball projection machines, has been shown to significantly affect movement coordination of skilled cricketers. To date, there has been no similar research on movement responses of developing batters, an important issue since ball projection machines are used heavily in cricket development programmes. Timing and coordination of young cricketers (n = 12, age = 15.6 ± 0.7 years) were analyzed during the forward defensive and forward drive strokes when facing a bowling machine and bowler (both with a delivery velocity of 28.14 ± 0.56 m s⁻¹). Significant group performance differences were observed between the practice task constraints, with earlier initiation of the backswing, front foot movement, downswing, and front foot placement when facing the bowler compared to the bowling machine. Peak height of the backswing was higher when facing the bowler, along with a significantly larger step length. Altering the informational constraints of practice caused major changes to the information–movement couplings of developing cricketers. Data from this study were interpreted to emanate from differences in available specifying variables under the distinct practice task constraints. Considered with previous findings, results confirmed the need to ensure representative batting task constraints in practice, cautioning against an over-reliance on ball projection machines in cricket development programmes.     

Erroneous choice and foregone gains in hoarding gray jays (Perisoreus canadensis)

Under the conventional assumption that natural selection favors choice behavior that maximizes some fitness-related currency, a forager making repeated binary choices should consistently choose the more valuable option. Under the alternative assumption that natural selection favors choice behavior that minimizes costly errors, erroneous choice is not only expected but is expected to be common when the cost of errors is low. This cost depends on the potential rate of return: the higher this rate, the smaller the cost of choosing the less valuable option. When this rate is very high, a forager may err frequently and yet forego no appreciable fitness gain. Errors should thus be more common when interruptions to foraging are shorter. Our experimental results supported this prediction: gray jays chose the less valuable option more frequently when subjected to shorter interruptions (experimentally imposed delays to access to food rewards). This tendency is consistent with the idea that an adaptive decision-making process may routinely produce errors, not because errors are in some way adaptive but because their fitness cost is minimal, particularly when delays are short. From a proximate perspective, this tendency to commit errors more frequently following shorter delays may be due to constraints on the jays’ information-processing capacity. In general, choice behavior should be viewed as the joint byproduct of adaptive decision making and cognitive constraints. Received: 8 June 2000 / Accepted after revision: 21 October 2000