A new processing model for predicting performance on Pascual-Leone's test of M-space

A new model is proposed for explaining children's performance on Pascual-Leone's test of M-space. The model differs from Pascual-Leone's in three regards. (1) It assumes that children do not stop sampling a compound stimulus until every simple stimulus in their field of attention has already been noticed and responded to. (2) It assumes that the probability of sampling different combinations of simple stimuli conforms to the laws of Maxwell-Boltzman statistics rather than Bose-Einstein statistics. (3) It assumes that children's ability to detect all the simple stimuli in a compound stimulus is highly dependent both on the relative saliencies of the simple stimuli and on the length of time for which the compound stimulus is exposed. Using the developmental values of M hypothesized by Pascual-Leone, and standard techniques of computer simulation, the new model is used to generate theoretical performance curves for children at four different age levels and seven different levels of stimulus complexity. It is shown that the predicted performance curves for an exposure time of 5 sec provide a reasonable fit to the data originally reported by Pascual-Leone (1970), and that the predicted performance curves for an exposure time of 10 sec provide a reasonable fit to data obtained more recently by Parkinson (1976). Finally, it is shown that the order of children's responses as well as the number of their responses can be predicted. Two conclusions are drawn. (1) The new processing model offers a viable alternative to the model originally proposed by Pascual-Leone. (2) Regardless of which processing model is employed, the M-values originally postulated by Pascual-Leone are valid.     

Resolution time and the coding of arithmetic relations on supraliminally different visual extents

Comparison time for pairs of vertical-line stimuli, sufficiently different that they can be errorlessly discriminated with respect to visual extent, was examined as a function of arithmetic relations (physical ratio and difference) on members of the pair. Arithmetic relations are coded very precisely by judgment time: Responses slow as stimulus ratios approach one with difference fixed, and as stimulus differences approach zero with ratio fixed. Most models which assume a simple (Difference or Ratio) resolution rule operating on independent sensations require judgment time to depend on either ratios or on differences but not on both. Further tests showed both an index based on median judgment times and a confusion index based on pairs of observed judgment times, satisfied the requirements for a Positive Difference Structure. One representation of these data, which remains acceptable through all analyses, is a Difference resolution rule operating on sensations determined by a power psychophysical function with β < 1. Specifically, L(x, y) = F{ψ(x) ? ψ(y)} + R, where L(x, y) is the judgment time with the stimulus pair x and y, ψ(x) = Ax^β + C, R is a positive constant, and F is a continuous monotone decreasing function.     

Consistency of the labial temperature change measure of human female eroticism

Six adult, human female volunteers participated in a study to determine the consistency of their pattern of sexual arousal to two erotic films over two experimental sessions. Sexual arousal was assessed objectively by means of continuous measurement of temperature changes of the labia minora and subjectively by periodic self-ratings. Each subject developed increases in labial temperature to both film presentations that ranged from about 0.10°C to 1.36°C above basal levels. The amount of temperature change in a subject's labia minora during the first film presentation was significantly correlated with that during the second film, and there was a reasonable degree of consistency across the two sessions with regard to the rate at which the subject's labial temperature subsided towards basal levels after the cessation of erotic stimulation. Labial temperature changes and subjective ratings were also significantly correlated during each of the two film presentations.     

Less is not more: Further observations on nonlinguistic strategies

In an attempt to clarify the role of nonlinguistic preferences in children's responses to the words more and less, children 3–4 years of age were administered three tasks. Two of these required the child to indicate which of two arrays had more or less items, as instructed; the third task required the child to point to any one of two arrays. Children consistently selected the arrays with more items on all three tasks. The present finding of a response bias necessitates a reinterpretation of earlier studies of more and less. The results are discussed in terms of the full and partial semantics hypotheses as articulated by E. Clark.     

Modeling spatial knowledge

A person's cognitive map, or knowledge of large-scale space, is built up from observations gathered as he travels through the environment. It acts as a problem solver to find routes and relative positions, as well as describing the current location. The TOUR model captures the multiple representations that make up the cognitive map, the problem-solving strategies it uses, and the mechanisms for assimilating new information. The representations have rich collections of states of partial knowledge, which support many of the performance characteristics of common-sense knowledge.     

Cluster analysis in school psychology: An example

This investigation demonstrates the use of Ward's method of cluster analysis to uncover the underlying classification structure in a group of children (N = 200) referred for psychological evaluations by their public school teachers. Data were acquired on children's intellectual development, academic achievement, and social adjustment. The cluster solution identifies six groups of children which are statistically distinct. All three measurement areas are important in distinguishing among the different groups. The six-group solution accounted for appreciable amounts (95%) of the variability in the three measurement areas. Implications for psychologists working in the schools are discussed.     

An experimental analysis of social traps

Social traps, such as the overgrazing of pasturelands, overpopulation, and the extinction of species, are situations where individuals in a group respond for their own advantage in a manner damaging to the group. A laboratory analog was devised to simulate conditions that produce social traps. The traps were constructed by superimposing schedules of reinforcement. Single responses were followed by multiple consequences which were opposite in valence, with the negative consequence delayed. Subjects in groups of three could respond individually for points that applied toward class credit. Each ten presses of a button added one point to the subject's total and subtracted one point from a common pool. The pool was replenished with points at fixed rates. If subjects responded for points faster than the replenishment rates, the pool would empty and the experiment would terminate before subjects could accumulate maximum credit. In addition, the maximum pool size and the ability to communicate were varied. Main effects were found for both, which indicated the least effective resource management occurred when the pool was small and no communication allowed. An analysis of cumulative records showed differing response patterns across conditions.     

Differential acquisition of conditioned suppression in rats with increased and decreased luminance levels as CS + s

Using a conditioned suppression procedure, it was demonstrated that suppression of responding was substantially enhanced when the CS signaling the occurrence of shock was an increment in luminance level (bright CS), relative to an equivalent decrement in luminance level serving as a signal for shock (dim CS). The results of a pseudoconditioning control procedure illustrated that the differential effectiveness of the bright and dim CSs was dependent upon explicit CS-US pairings. The bright and dim stimuli were found to produce equivalent rates of conditioning when they were used to signal the availability of reinforcing stimuli in an appetitive discrimination procedure. The interpretation considered to be most consistent with the data is associative in nature; rats may be brought into the experimental setting prepared to associate bright light with danger and contraprepared to associate dim light with danger.     

Fisher transformations for correlations corrected for selection and missing data

The validity of a test is often estimated in a nonrandom sample of selected individuals. To accurately estimate the relation between the predictor and the criterion we correct this correlation for range restriction. Unfortunately, this corrected correlation cannot be transformed using Fisher'sZ transformation, and asymptotic tests of hypotheses based on small or moderate samples are not accurate. We developed a Fisherr toZ transformation for the corrected correlation for each of two conditions: (a) the criterion data were missing due to selection on the predictor (the missing data were MAR); and (b) the criterion was missing at random, not due to selection (the missing data were MCAR). The twoZ transformations were evaluated in a computer simulation. The transformations were accurate, and tests of hypotheses and confidence intervals based on the transformations were superior to those that were not based on the transformations.