Dichotic interactions of speech sounds and phonetic feature processing

Identification of CV syllables was studied in a backward masking paradigm in order to examine two types of interactions observed between dichotically presented speech sounds: the feature sharing effect and the lag effect. Pairs of syllables differed in the consonant, the vowel, and their relative times of onset. Interference between the two dichotic inputs was observed primarily for pairs which contrasted on voicing. Performance on pairs that shared voicing remained excellent under all three conditions. The results suggest that the interference underlying the lag effect and the feature sharing effect for voicing occur before phonetic analysis where both auditory inputs interact.     

FOCAL,FORTRAN, and BASIC programs for reformatting and analyzing data collected by the SKED program

Several programs have been written in the FOCAL, FORTRAN, and BASIC languages for reformatting and analyzing SKED data. These programs include selection and explicit labeling of sets of recording counters representing distributions and/or total counts of events, several general manipulations of distributional data, and standard statistical treatment of distributions.     

Visual proprioceptive control of standing in human infants

Human infants learning to stand use visual proprioceptive information about body sway in order to maintain stable posture. Moreover, the visual proprioceptive information is more potent than the nonvisual. This is shown by an experiment in which infants were caused to sway and even fall forward or backward in response to appropriate visual stimulation.     

Second-order schedules with fixed-ratio components: variation of component size

Key pecking by pigeons was reinforced with food under second-order schedules with fixed-ratio units. A constant total number of key pecks was required for reinforcement under each condition, but the size and, inversely, number of fixed-ratio components were varied. The total response requirement of 256 pecks was divided into fixed-ratio units of 128, 64, 32, 8, and 2 responses. A brief stimulus, which always preceded food reinforcement, was presented upon completion of each fixed-ratio unit. Under most conditions, the pattern of within-unit responding was typical of that under simple fixed-ratio schedules. Overall response rate was an inverted U-shaped function of component size. That is, response rates were highest under moderate sized units (fixed ratio 128 and 64). This relationship is consistent with previous determinations of rate as a function of fixed-ratio value for simple fixed-ratio schedules.     

Binocular stereopsis without spatial disparity

Binocular stereopsis has traditionally been studied mainly under static viewing conditions. There has consequently been the tendency to view binocular stereopsis only in terms of the pickup of purely spatial (time-frozen) disparity. However, whenever there is movement of objects or the 0, the structure of the light entering each eye undergoes continuous change, and so a different type of disparity—kinetic disparity—is made potentially available to the binocular system. That kinetic disparity can, in fact, be picked up is shown by the present experiment, in which there was no spatial disparity information available about the three-dimensional motion path of an object; only kinetic disparity information was available. This suggests that a clear distinction should be made between binocular-static and binocular-kinetic space perception.     

Optimal choice of rater teams II: Applications

In a previous paper [Elashoff 1969], we derived optimal rater teams for a particular formulation of the dichotomous rater problem. Here, we describe a computer-based procedure for selecting good rater teams in practice; we apply the procedure to the selection of items for a psychological inventory. This research was supported in part by the author's predoctoral fellowship from the National Institutes of Health and by National Science Foundation Grant GS-341, and National Institutes of Health Grants FR-3 and FR-122.     

Factorial effects in the categorization of externally distributed stimulus samples

On each trial a sample point randomly drawn from one of two normal probability distributions was exhibited to S, who had to guess whether the sample was a “1” or a “2.” He was then given feedback, which was determined by which of the two distributions the sample point derived from. Two continua were employed: dot position on a file card, and groyness of square in. patches. Three levels of d’ were employed. The function giving the probability of a response “1” for different sample values was sharper for the higher d’ conditions, and for the dot position continuum. Cessation of feedback resulted in improved performance for the low d’ condition. Incentive payoff, confidence ratings, and experimenter had virtually no effects on task performance.     

Changes in the visual threshold as a function of subception

In a previous paper (Dixon, 1958b) one of the authors reported an experiment which suggested that apparent changes in the threshold for one eye occur as a function of the emotionality of stimulus material presented below threshold to the other eye. The following experiment describes an attempt to investigate further the validity of this conclusion. The results are consistent with those from the previous research.