Discrimination of spatially confusable letters by young children

A study of the ability of young children to discriminate spatially confusable letters using four different methods of discrimination (matching, copying, naming, and writing to dictation) was carried out. The subjects were 31 English children whose ages ranged from 5 years 6 months to 6 years 10 months. The test material consisted of 10 spatially confusable letters, i.e., letters whose differential features depend upon their spatial orientation: p, q, d, b, u, and n, and to a lesser extent h and y and w and m. The results show that the accuracy of discrimination of spatially confusable letters is dependent upon the method of assessment employed. The highest accuracy is achieved when the method requires copying confusable letters from a given sample, followed by the method that requires matching a given letter with other possible alternatives. Naming the confusable letters and writing them in response to dictation are the most difficult tasks to perform. The results also indicate that there is a significant correlation between individual performances in the matching, naming, and writing to dictation tests; but in the copying task individual performances varied independently of the performances in the other tests. Some theoretical implications of the findings are discussed.     

Discrimination of small shapes by the rat

Three experiments on small shape discrimination are described. The first investigates the discrimination of square from circle, a discrimination claimed by Lashley to be extremely difficult for the rat and which has since become a matter of theoretical interest. The second and third test a prediction from the writer's theory of shape recognition; the prediction is refuted.     

Discrimination of faces by young infants

An experiment was conducted to obtain normative data concerning discrimination between human faces by infants under 6 months of age and to determine the information base required for this performance. Infants were habituated to a specific face and recovery of attention was monitored to a novel face, where one or more features was common to both faces. Results suggested that discrimination between photographs of adult, female faces is possible from 5 weeks of age, with critical information probably lying in the hair-face outline while internal features were relatively unimportant until the 19th week.     

Discrimination by young infants of stimuli presented discontinuously

Four experiments are reported showing that young infants can pick up visual information from very brief displays. Pattern, edge orientation, and form can be discriminated when stimuli are presented for repeated exposures of only 300 ms.     

Discrimination of picture requests for missing items among young children with developmental disabilities

Two experiments were conducted to assess discrimination of picture requests for missing items among young children with developmental disabilities. In Experiment 1, three children were first taught to request one object when it was missing from a set of two related leisure items. In Experiment 2, two children were taught to request one object belonging to a set of three leisure items. In both studies the requesting response consisted of pointing to a photograph of the missing item. After acquisition of the initial request, discrimination of picture requests was assessed when the second item (Experiment 1) and second or third item (Experiment 2) was missing. Requests for the untrained items emerged in the presence of natural maintaining contingencies and in the absence of instructional prompts for all but the third child in Experiment 1. This child required continued intervention on the initial request. The results suggest that for some children a sequence of intervention and the programming of natural maintaining contingencies may prove effective in promoting the discrimination of picture requests for missing items among young children with developmental disabilities.     

Intermanual transfer of mirror-image discrimination by monkeys

Mirror image equivalence has been studied in four monkeys during inter-manual transfer of tactile discrimination learning. The tasks were designed to progressively reduce the possibility that discrimination would be based on use of the thumb. On three of the four tasks there were consistently significant mirror reversals. The findings support the supposition that mirror inversion occurs during the formation of memory traces, and specifically when the trace is laid down in a second cerebral hemisphere.     

Discrimination training of mirror-image stimuli with a delayed-prompt technique: some critical dimensions of extra-stimulus prompts

Research on fading and delay procedures has shown that extra-stimulus prompts frequently fail to help children learn difficult discriminations. The present study analyzed two delay conditions for an extra-stimulus prompt to help preschoolers discriminate mirror-image stimuli as a function of the configurations and locations of the prompts. All subjects were selected on their ability to discriminate the task stimuli in the presence of a third stimulus, a replica of the S+ and an arrow pointing to that stimulus; and on their inability to do so without these stimuli. Experiments 1 and 2 compared these prompt configurations (S+ replica, arrow) when presented equidistant from the task stimuli. Experiment 3 analyzed the contribution of the replica configuration in terms of its location, in between stimuli or immediately above the S+. Experiment 4 investigated the extent to which the results of the previous experiments could be influenced by the methodology for the assessment of prompt control. The results consistently demonstrated that most subjects did not learn the task unless the extra-stimulus prompt had the same configuration as the S+ and was located equidistant from both task stimuli.     

Discrimination of small numerosities in young chicks

Chicks were trained to discriminate small sets of identical elements. They were then tested for choices (unrewarded) between sets of similar numerosities, when continuous physical variables such as spatial distribution, contour length, and overall surface were equalized. In all conditions chicks discriminated one versus two and two versus three stimulus sets. Similar results were obtained when elements were presented under conditions of partial occlusion. In contrast, with sets of four versus five, four versus six, and three versus four elements chicks seemed unable to discriminate on the basis of number, although nonnumerical discrimination based on perceptual cues was observed. This adds to increasing evidence for discrimination of small numerosities of up to three elements in human infants and nonhuman animals.     

Deception by young children following noncompliance

A paradigm devised by M. Lewis, C. Stanger, and M. W. Sullivan (1989) was adapted to study deception and false-belief understanding. In Study 1, 3- and 5-year-olds were asked not to touch a toy in the experimenter's absence. Just over half of the children touched the toy, and of those children, the majority denied having done so. Of control children who were given permission to touch the toy, all touched it and admitted having done so. In Study 2, 3- and 5-year-olds were asked not to look in a box to identify its contents. Almost all children looked, most denied having looked, and a minority consistently feigned ignorance of the contents. False-belief understanding was linked to denial of looking but not to feigning ignorance. Of control children who were given permission to look, all acknowledged looking, and they almost always revealed their knowledge of the contents. The studies confirm that preschoolers deceive in the context of a minor misdemeanor but are less effective at feigning ignorance.     

Area-matching strategies used by young children

Across three studies, conditions were varied under which children aged 4–5 years matched the area of a rectangle with a given width (or height) to that of a square. In the first study, subjects observed the rectangle being changed in height from trial to trial and had access to their immediately preceding response. Under these conditions, rectangle width (the dimension under subject control) was a linear decreasing function of rectangle height. This function was interpreted as evidence for a hypothetical addition/subtraction strategy for maintaining equality in area between the comparison rectangle and the standard square. As a test of this hypothesis, in a second experiment the subjects were denied access to their immediately previous response, and in a third study they were also unable to observe the rectangle as it was altered by the experimenter between trials. The purpose of these changes was to remove the information necessary for readily implementing an addition/subtraction strategy. In both studies, area matches seemed to be based on a side-matching strategy, such that subjects matched one dimension of the rectangle to one side of the standard square. It was suggested that young children use different cues or strategies with different variants of the matching task because they do not possess a fixed, specific concept of area.     

Discrimination of English and French orthographic patterns by biliterate children

We investigated whether young English–French biliterate children can distinguish between English and French orthographic patterns. Children in French immersion programs were asked to play a dictionary game when they were in Grade 2 and again when they were in Grade 3. They were shown pseudowords that contained either an English spelling pattern or a French spelling pattern, and they were asked to decide whether each pseudoword should go in an English dictionary or a French dictionary if it became a real word. Comparison groups of monolingual English children, monolingual French children, and English–French bilingual university students were also tested on the task. French immersion students in both grades were above chance in discriminating between the two types of pseudowords but were well below adult performance on the task. Measures obtained in kindergarten showed that early print knowledge had some ability to predict later ability to discriminate between the orthographic patterns of the two languages. Further analyses indicated that exposure to print in each language in Grades 1 to 3 was strongly related to discrimination performance. The findings are interpreted as being consistent with the statistical learning hypothesis.     

The perception of incongruity by young children

Seventy-four children, four to seven years of age, were asked to describe what they saw in a photograph of a three-sided building taken so that it appeared, in contrast to the buildings surrounding it, to have only one wall, although at the same time it appeared to be, or to have been, inhabited. The readiness with which the awareness of this incongruity was expressed was found to be a positive monotonic function of both mental and chronological age. The most frequent rationalization offered for the incongruity was that the building had been damaged by some act of Nature. Only three children, two of whom had seen such buildings, offered the correct interpretation.