Vocal congruence in mother-infant play

Turn-taking is the fundamental temporal structure of adult dialogue. This structure defines two types of joint silence: intrapersonal pause (silence bounded by the vocalizations of a single speaker) and switching pause (silence bounded by the vocalizations of different speakers). Switching pauses mark the boundaries of the turn exchange. In adult conversation the mean durations of both types of pause are characteristically matched between partners. This matching, termed vocal congruence, occurs developmentally earlier in the case of switching pauses. We hypothesized and confirmed that mothers and infants match switching pauses but not intrapersonal pauses at 4 months, even though the infants' vocalizations are prelinguistic. Second, since there are known affective correlates of vocal congruence in adult conversation, we hypothesized a similar affective correlate for mother-infant vocal congruence. We found, for the intrapersonal pause only, that the degree of matching within a dyad correlated with infant affective engagement. We conclude, from switching pause congruence, that a turntaking dialogic structure is being regulated in the mother-infant pair at 4 months in the same way as seen in adult conversation. Thus, both the temporal structure of adult dialogue and its affective correlate are prelinguistic.Supported in part by NIMH grant No. 41675.     

Running laboratory experiments using the RSX operating system and FORTRAN on the PDP-11

A system of FORTRAN-callable subroutines designed to facilitate running laboratories with the RSX operating system on a PDP-11 computer is presented. The subroutines include ones to give the FORTRAN programmer timing capability, better control of CRT input and output, control of a parallel-bit input and output interface, control of an analog-to-digital interface, and control of a digital-to-analog interface.     

An Excel macro for transformed and weighted averaging

An Excel macro is presented for averaging spreadsheet data. The macro has several special features: (1) The data are weighted by the inverse variance of each datum to decrease the contribution-of noisy outliers. (2) There is a provision for a power or a log transform of the data before averaging. The rationale for transforming the data before averaging is discussed (3) The output includes the average value, its standard error, and the reduced chi-square that measures the goodness of fit (4) The standard error is corrected by a heterogeneity factor based on the reduced chi-square The averaging of data is rarely done properly, and the intent of this article is to clarify the issues and provide a tool that allows researchers to improve their averaging techniques.     

Persons and their Properties

According to what I call 'the asymmetry thesis', persons, though they are the direct bearers of the properties expressed by mental predicates, are not the direct bearers of properties such as those expressed by 'weighs 135 pounds' or 'has crossed legs'. A number of different views about persons entail the asymmetry thesis. I first argue that the asymmetry thesis entails an error theory about our discourse involving person-referring terms. I then argue that it is further threatened by consideration of the grounds we have for self-ascribing mental and physical predicates.     

Discriminative activation and maintenance of contingent self-reinforcement

The present experiment studied the process by which environmental events come to exercise some degree of control over the activation of contingent self-reinforcement. Through differential training, animals learned to impose performance requirements for self-reward in certain environmental contexts but not in others. Both contextual influences and periodic negative consequences for noncontingent self-reward increased adherence to response requisites for self-reinforcement.     

A high-speed computer-coinpatible event recorder

Design considerations, construction information, and programming considerations of a high-speed event recorder are presented. The device records discrete events on magnetic tape for later processing by a large computer. Although the design information is general, the instrument has 120 event channels, a time resolution of up to 100 microsec, and can record 60 or more events per second.     

Differentiation and decrement in the Mueller-Lyer illusion

Two experiments were conducted to test the hypothesis that decrement of the Mueller-Lyer illusion with inspection is due to learning to differentiate the test element from the accessory lines. In one experiment, the test element is predifferentiated for the observer by means of configurational variations and in the other by restriction of attention. Although the initial magnitude of the illusion is found to be inversely proportional to the amount of predifferentiation, the slopes of the decrement curves are not affected.     

The influence of optical aberrations on the magnitude of the Poggendorff illusion

The amount of blurring of the retinal image can be reduced by proper selection of an artificial pupil and a chromatic filter. Reduction of the amount of blurring due to optical aberrations by viewing through a 1-mm artificial pupil and an interference filter in the eye, results in a concomitant reduction in the magnitude of the Poggendorff illusion. The magnitude of the reduction is smaller, however, than would be expected if the illusion was predominantly determined by blur due to optical aberration.