The location and interpretation of the bisection point

In atemporal bisectiontask with humans, the observer is required to decide whether a probe duration ( t ) is more similar to the short referent (S), an R S response, or to the long referent (L), an R L response. Temporal bisection yields a psychometric function relating the proportion of long responses, P(R L ), to probe duration t . The value of t at which R S and R L occur with equal frequency, P(RL) = .5, is referred to as the bisection point, T 1/2 . Bisection models usually interpret T 1/2 as identifying the value of t that is equally confusable with S and L, but they differ in their predictions for the location of T 1/2 . The present paper presents new data relevant to the location and interpretation of T 1/2 . The data indicate that the empirical values usually are biased, the biases being influenced by duration range, L:S ratio, and probe spacing. Moreover, the biases often are not consistent across observers. It is concluded that empirical values of T 1/2 should not be interpreted as indicating the value of t that is equally confusable with S and L.     

Stability over age and sex of children's responses to embedded figures test

240 children in Grades K to 4 were administered the entire Children's Embedded Figures Test to determine whether similar factor structures are obtained from samples of different sex and age as well as when the population is randomly split. Data were analyzed by principal axis factor analysis and relevant factor structures were compared using Veldman's 1967 program "Relate". There was one stable factor which was consistent across sex and accounted for about 19% of the variance. Results were inconsistent across grades and indicated a possible lack of agreement of factor structures.     

Alternate forms of the matching familiar figures test: a critical note

Criticism is leveled at attempts to develop alternative forms of the Matching Familiar Figures test when the literature suggests that what is required is a more reliable test, not simply an alternate version.     

The Gollin incomplete figures test: a flexible, computerised version

The Gollin incomplete figures test has been used as a measure of visual development, as a clinical test for parietal cortex dysfunction, and to examine long-term memory in amnesic patients. It has traditionally been administered by using a series of three or five stimulus cards, successive cards containing progressively more information. A study is reported in which digitised outline drawings of familiar objects were presented via a computer, the percentage of the figure on the screen slowly increasing from 0 to 100. The original findings of Gollin were successfully replicated; children's performance on the task improved markedly over the age range 2-5 years, and performance improved dramatically over three tests in all subjects. Computerisation of the Gollin task provides a precise and versatile alternative to the original card version.     

A test for children's goal-directed behavior: a pilot study

A test for children's goal-directed behavior was developed, based on neuropsychological executive function research of Vilkki and Holst and on the framework of Lewin's level-of-aspiration research. 46 12-yr.-old children were participants. Fluid Intelligence was expected to be linked to goal-directed behavior and a commonly used executive function task, the Wisconsin Card-sorting Test. A child was asked to set personal goals in a short-term memory task without prior knowledge about performance. Four different task versions were developed employing both verbal (memorizing series of words) and visuospatial (memorizing block sequences) material. The child set an individual goal for each memory trial. Goal-setting after successful and failed trials was investigated. Usually, the children lowered their goals after failures and set their goals higher or did not change them after successful trials. Compared to goal on a previous trial, Inadequate Responses included setting a goal higher after a failed trial and setting it lower after success. Fluid Intelligence was related to goal-directed behavior, viz., Inadequate Responses. It also correlated with scores on the Wisconsin Card-sorting Test. The results are in concordance with previous research. In addition to experimental executive function research, the novel test might be useful in research concerning children's motivation, self-efficacy, and self-regulated learning.     

Some experiments on spacial position as a factor in children's perception and reproduction of simple figures

Summary It has appeared in our experiments that certain absolute spacial directions play a dominant r?le in the drawings even of young children, but that frequently the dominant directions are not determined by absolute position but by their significance in a given form.

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Zusammenfassung In unseren Versuchen hat sich ergeben, da? gewisse absolute Raumrichtungen schon bei jungen Kindern ausgezeichnet sind, da? aber andererseits die Bestimmung der Hauptrichtung oft nicht absolut, sondern durch ihre Rolle innerhalb einer gegebenen Form gegeben ist.

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From the Research Laboratory of Smith College

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With 10 Figures     

A computer-controlled administration of the matching familiar figures test

The Kagan Matching Familiar Figures Test of Impulsivity/Reflectivity was modified to allow computer control of stimulus presentation and data acquisition via IBM-compatible systems. The comparability of computer administration and traditional hand administration was examined in a split-half study with a sample of 58 students (ages, 18–39 years). Analyses of variance revealed no significant differences between the administration techniques for latency and a small but significant difference for accuracy. Correlations between the two administration techniques were .61 for latency and .40 for error scores. Internal consistency coefficients for computer administration exceeded those for hand administration on both latency and accuracy. These data compare favorably with results reported by others and suggest that computer administration offers a viable alternative to traditional hand administration of the MFFT in research applications.     

Concepts and aims of functional interpretations: towards a functional interpretation of constructive set theory

The aim of this article is to give an introduction to functional interpretations of set theory given by the authorin Burr (2000a). The first part starts with some general remarks on Gödel's functional interpretation with a focus on aspects related to problems that arise in the context of set theory. The second part gives an insight in the techniques needed to perform a functional interpretation of systems of set theory. However, the first part of this article is not intended to be a complete survey of functional interpretations and here we recommend, for example, Avigad and Feferman (1998),Troelstra (1990) and Troelstra (1973).     

Factors affecting the social validity of a role-play test of children's social skills

The social validity of a role-play test of children's social skills, the Social Skills Test for Children (SST-C), was evaluated by 63 subjects (33 adults and 30 children) who subjectively judged the quality of three children's role-play performances. The three children were selected as having high, medium, or low social skill based upon their performance on the SST-C. Assessment of the effects of subject characteristics upon judgments of social skill suggested that similarities in age and race between the subjects and the three children tended to diminish perceived differences in social skill among the three children. It was concluded that the social validity of the role-play test was supported only if the persons evaluating social behavior were dissimilar in age and racial characteristics from the persons who were being evaluated.     

Achievement and adjustment correlates of the matching familiar figures test

To help clarify the relationship between the Matching Familiar Figures (MFF) Test and measures of school achievement and adjustment, 450 children from kindergarten, second, and fifth grades were tested and achievement scores and teacher's ratings of classroom and personal adjustment were obtained. Regardless of grades, MFF latency in most instances did not predict achievement or adjustment. At the kindergarten level the correlations between MFF errors and both achievement and adjustment were significant for most subscales but at second grade correlations were lower and generally nonsignificant except for a few adjustment items. At the fifth grade level the correlations were moderately high but when IQ was partialled out the correlations with achievement and school adjustment dropped to near zero; however, partialling out IQ did not affect the moderate correlations between errors and personal adjustment. The errors score evidencedmore important relationships than the latency scores. The relationship between the MFF and ratings of social and emotional adjustment was consistently higher than the correlations between the MFF and achievement. These results suggest that MFF errors are personalogically relevant and that MFF performance is generally more related to adjustment than achievement.     

The role of stimulus axis salience in children's ability to mentally rotate unfamiliar figures

A mental rotation task with unfamiliar stimuli was presented to 5-year-old (n = 36) and 8-year-old children (n = 36). The stimuli contained either an intrinsic salient axis (S +) or no salient axis (s-). Results showed that both 5-year-old and 8-year-old children were able to perform the mental rotation task with the S + stimulus. However, 5-year-old children had difficulties in performing the mental rotation task with the S- stimulus. These results suggest that there are limitations in mental rotation abilities of young children. The ability to encode and mentally rotate unfamiliar stimuli containing no salient axis seems to improve between the ages of 5 and 8.     

Amodal completion, depth stratification, and illusory figures: a test of Kanizsa's explanation.

Subjective contours have been explained by Kanizsa as being a consequence of amodal completion of incomplete figures. According to the theory of amodal completion, figural incompleteness triggers the emergence of an illusory object superimposed on the gaps in the inducers, which in turn hide parts of the pattern, thus suggesting that the plane of the illusory object must always be seen to be above the plane of the inducers. A figure was created in which subjective contours are seen despite the fact that the perceived depth relationships run counter to that required by the theory of amodal completion. In four experiments, this depth relationship is confirmed by using direct and indirect measures which assess both registered and apprehended depth. By emphasizing a logical inconsistency in the explanation based on amodal completion, the results show that amodal completion, at least in Kanizsa-like patterns, cannot be considered as a causal factor for subjective contour figures.     

The bisection of a spatial interval by the pigeon

Pigeons pecked two response keys to move a white dot until it was equidistant from two other dots on a screen. Continuous records of dot position showed the effects of reinforcement and stimulus parameters upon the accuracy with which the dot was positioned. The method may prove useful for studying the perception of distance in non-human organisms.