A generalized visual latency explanation of the Pulfrich phenomenon.

The classical visual latency explanation of the Pulfrich phenomenon is generalized to allow for the possibility that the visual system uses velocity information from motion detectors to compensate for spatial lag due to time lag, in identifying the instantaneous position of a moving object. The results of the reported experiment verify one consequence of the generalized version: the elliptical apparent path is skewed away from the filtered eye. The results suggest also that the extrapolation factor increases with visual latency and that there is a different extrapolation factor for each eye when the eyes are illuminated unequally.     

Incorporating prior theory in covariance structure analysis: A bayesian approach

A Bayesian approach to the testing of competing covariance structures is developed. The method provides approximate posterior probablities for each model under consideration without prior specification of individual parameter distributions. The method is based on ayesian updating using cross-validated pseudo-likelihoods. Given that the observed variables are the samefor all competing models, the approximate posterior probabilities may be obtained easily from the chi square values and other known constants, using only a hand calculator. The approach is illustrated using and example which illustrates how the prior probabilities can alter the results concerning which model specification is preferred.     

NEWSART: Negative binomial weighted spectral analysis in real time

In this paper, digital filters are described for concurrent adaptive estimation of the spectral powers at several target frequencies. Least-squares estimation is used, with a tapered weight function that discounts time-series data according to age. Frequency selectivity and reliability of spectral estimates are controlled by different parameters. The spectral windows are closely approximated by Student’st distribution, which is useful in the planning of experiments.     

FORTRAN subroutine for an EEG feedback digital filter

A method of constructing digital filters is outlined and illustrated in an application for research uses of EEG feedback. The method is based on least squares estimation with geometric weighting. Old data in the time series are discounted according to age, as new data arrive. Recurrence relations are used, allowing the computations to be performed in real time. A FORTRAN digital filter is formulated that simultaneously estimates (1) the spectral power in a band centered at a target frequency, (2) the total spectral power, and (3) the dominant frequency.     

Patterns of practice with the TAT in juvenile forensic settings

Psychologists in juvenile forensic psychological clinics were surveyed about usage of the TAT. A clear majority uses the TAT as part of their assessment battery, the majority using between six and ten cards. Administration and scoring methods were examined. Selection of cards was harmonious with prior research on theme productivity. Many respondents were found not to use the TAT because of time constraints, a finding discussed in terms of appropriate standards of care. Additional research needs to establish representative as well as expected standards of ethical practice for the TAT among general clinical groups, both adult and adolescent.     

The logical status of metacognitive training

It is argued that knowing-how (to perform) is not dependent on knowing that (knowing propositions about performance). Existing evidence allows any benefits from metacognitive training to be attributed to generalization training, not to the announcement of rules. Rules may encourage the subject to learn new tasks, but these tasks must be learned in the contexts of eventual application.     

Playing it by ear: Overcoming the limitations of speech synthesizers

Inexpensive speech synthesizers are now available that either plug into the card slots on computers or connect to their serial ports. With some practice in listening, the speech produced by these synthesizers is quite intelligible, and because they present information that appears on the screen of the monitor, they make it possible for blind persons to interact with computers. However, they provide only a partial solution. In too many instances, some of the text appearing on the monitor screen cannot be directed to the synthesizer, and the missing information is often crucial. This happens because the writers of application programs sometimes modify the computer’s disk operating system. This limitation can be overcome by using special hardware that reads the screen buffer directly and creates a virtual image of the screen in memory external to the computer. Because the image is updated continually, it is always an accurate representation of whatever appears on the screen. The characters contained in the external buffer can be sent to a speech synthesizer, and can be examined selectively by means of a small keyboard. Several successful hardware solutions have been demonstrated, and one of these solutions is described here in detail.