Development of binocular fixation in human infants

Two experiments measured changes in binocular eye alignment from 1- to 6-month-old human infants. In Experiment 1 changes in binocular eye alignment were recorded from 1, 2, and 3 month olds using corneal photography. A luminous target was moved along the infant's midline at one of two constant speeds. Infants at all three ages showed some evidence of appropriate changes in binocular eye alignment (convergence as the target approached and divergence as the target receded). The likelihood of appropriate convergence and divergence increased with age, as did the ability to respond appropriately to the faster target motion. A measure of convergence lag (further decrease in interpupillary distance after target motion had ended) was obtained for trials on which the target approached the infant. Convergence lag decreased with age and was greater on trials at the faster target speed until 3 months of age. Experiment 2 measured the responses of 3, $\text{4}\text{1}\text{2}$, and 6 month olds as a wedge prism was placed alternately in front of each eye. The prism displaced the image nasally (either 2.5° or 5°), creating inappropriate binocular eye alignment. A refixation eye movement in response to the prism was not present consistently until 6 months of age. Hypotheses as to the mechanism controlling infant binocular eye alignment are discussed with respect both to the present findings and to findings from human adults and animals.     

The emergence of functional play in infants: Evidence for a major cognitive transition

Sixty-four infants, eight boys and eight girls at each of four ages, $\text{9}\text{1}\text{2}\text{, 11}\text{1}\text{2}\text{, 13}\text{1}\text{2}\text{,}\text{and}\text{15}\text{1}\text{2}$ months, were observed during a 15-minute free play session. Three types of play (stereotypical, relational, and functional) and the number of appropriate uses for specific realistic toys were recorded. Stereotypical play (87% of total active play at $\text{9}\text{1}\text{2}$ months) gave way to relational (35% at $\text{13}\text{1}\text{2}$ months) and functional play (52% at $\text{15}\text{1}\text{2}$ months) as the dominant activity. Both functional play and the number of different appropriate uses of toys were rare at $\text{9}\text{1}\text{2}$ months, appeared reliably at $\text{11}\text{1}\text{2}$ months and increased lineraly through $\text{15}\text{1}\text{2}$ months. A change in the quality of play from indiscriminate mouthing, waving, banging, and fingering of objects to the matching of appropriate uses for a large array of toys indicates that the child's manipulations become more object specific and functional over this 6-month age span. Among possible explanations for the linear increase in the frequency and diversity of appropriate toy uses is the suggestion that an important cognitive change occurs toward the end of the first year of life. A case study is presented to illustrate the application of the play procedure for both assessment and treatment.     

Propositional self-control in children

The scope of Dulany's (1968) Theory of Propositional Control was examined using 54 $\text{11}\text{1}\text{2}\text{-, 8}\text{1}\text{2}\text{-,}\text{and 4}\text{1}\text{2}\text{-year-olds}$. Significance of the reinforcer was manipulated orthogonally to value of the reinforcer. With a six attribute concept attainment task $\text{4}\text{1}\text{2}\text{-}\text{year-olds}$ did not learn in either of two significant ways: a performance change over blocks, nor the acquisition of a rule of reinforcement. Children of $\text{8}\text{1}\text{2}$ and $\text{11}\text{1}\text{2}$ learned in both of the above senses. In addition, for the latter subjects the central equations of the theory held with strength and subjects' intentions accounted for more variance in performance than did the experimental manipulations. In supplementary experiments using a simplified task some $\text{4}\text{1}\text{2}\text{-}\text{year-olds}$ learned. When only the $\text{4}\text{1}\text{2}\text{-}\text{year-olds}$ who learned to a criterion were examined the central equations of the theory were nearly as strong as for subjects at ages $\text{8}\text{1}\text{2}$ and $\text{11}\text{1}\text{2}$. There was no evidence for learning without awareness at any age level.     

Psychological reactivity to discrepant events: Support for the curvilinear hypothesis

80 male and 60 female infants were observed under 5 a priori judged levels of discrepancy to assess whether sustained attention was linearly or curvilinearly related to degree of discrepancy from an experimental standard. Following habituation, $\text{7}\text{1}\text{2}$-month-old infants were exposed to either the repetition of the standard, a minimal, first- or second-level moderate discrepancy, or a novel stimulus having no relation to the standard. The related stimuli, varying in elongation, were sphere, pear, club, and cylinder-shaped objects; the novel stimulus was a different colored, tooth-like object. 80 infants observed the sphere as the standard and the cylinder as the second-level moderate discrepancy; 60 infants were exposed to the reverse order with the cylinder as the standard. The use of different stimuli at each discrepancy level controlled for specific stimulus effects. Habituation and recovery of responding were observed in an operant paradigm. Lever pressing, fixation, and vocalization increased most to the second-level moderate stimuli and decreased most to the familiar and novel objects; fretting was highest to the redundant stimuli and lowest to the moderate objects. There were no stimulus main effects or interactions. The results support the hypothesis of a curvilinear relation between stimulus discrepancy and sustained attention, excitement, and preference.     

Selective information use and perseveration in the search behavior of infants and young children

Two experiments examined the early development of selective information use in search. The first experiment tested 9- and 16-month-olds on a modification of Piaget's Stage IV object permanence task. It examined infants' use of information from previous experiences with an object (prior information) and from the most recent hiding (current information) to locate a hidden object. In the second experiment, 2-, $\text{2}\text{1}\text{2}$-, and 4-year-old children received these same sources of information along with new forms of prior and current information: information about the typical locations of objects (location specificity) and verbal information. No systematic perseveration was observed at 9 months, although previous findings related to perseveration were replicated. Perseveration was found at 16 months, but there was also evidence of selectivity at that age. When errors occurred, they tended to be to the prior location, but they were infrequent in comparison to correct searches at the current location. The preschoolers, while continuing to show perseveration, were more consistently selective than the infants. They also showed considerable generality in extending their selectivity to new sources of information.     

Correlational reasoning in an everyday context

In the context of everyday reasoning, individuals inferring a causal relation between an antecedent (A) and event (E) rarely have available as evidence for their inferences frequencies of all the four possible occurences, AE, A$\text{E}$, $\text{A}$E, and $\text{AE}$. The present study investigated the willingness of subjects in fourth, seventh, and tenth grades, and college to infer such a relation under the more typical condition of incomplete frequency data. There was some improvement with age, but even college subjects were remarkably willing to infer a relationship based on minimal data, notably the presence of cases in the AE cell. No subjects indicated the need for information regarding the remaining cells. Subsequent presentations of datafor the A$\text{E}$ cell did not substantially alter subjects' willingness to infer a relation, nor did subsequent presentation of data for the remaining two cells, despite the fact that complete frequency data indicated independence of A and E. A comparison group of subjects presented with all four cells at once showed somewhat more frequent application of quantitative reasoning strategies, but their willingness to infer a relationship between A and E was not notably less than that of subjects to whom the data were presented sequentially.     

Black-white differences at ages 212−812 on the McCarthy scales of children's abilities

Comparisons were made between matched groups of black and white children on the new McCarthy Scales of Children's Abilities. Using the standardization sample as the data source, 148 matched pairs were obtained. These were grouped as follows: ages $\text{2}\text{1}\text{2}\text{?3}\text{1}\text{2}\text{(}\text{N}\text{= 60), 6}\text{1}\text{2}\text{8}\text{1}\text{2}\text{(}\text{N}\text{= 45)}$. The blacks and whites did not differ significantly on any of the cognitive scales at ages $\text{2}\text{1}\text{2}\text{?3}\text{1}\text{2}\text{and}\text{4?5}\text{1}\text{2}$, although at ages $\text{6}\text{1}\text{2}\text{-8}\text{1}\text{2}$ the whites scored about $\text{1}\text{2}\text{SD}$ higher. The blacks scored significantly higher on the Motor Scale at ages $\text{4?5}\text{1}\text{2}$ but there were no differences at other ages. The implications of these findings are discussed.     

Development of depth perception mediated by motion parallax in unidimensional projections of rotation in depth.

Motion parallax is a composite of five transformations demonstrated to be effective in adult judgments of rotation direction in polar motion projections of a horizontal row of dots rotating in depth. The effectiveness of these transformations as a function of age was tested by presenting six such motion projections to first graders (age = 6 years), seventh graders (age = 13 years), and college students (age = 19 years). Identical age functions were obtained for judged rotation direction from the four motion projections representing (1) Velocity, corresponding to the traditional definition of motion parallax as differential velocity, (2) Velocity plus differences between ratios of instantaneous displacement to instantaneous acceleration for dots on the near and far sides of the rotation axis ($\text{D}\text{A}$ Difference), (3) Velocity, $\text{D}\text{A}$ Difference, and a gradient across the row of $\text{D}\text{A}$ ratios, and (4) all transformations. First graders, unable to use horizontal transformations, performed at chance on these four projections, while older students made correct judgments. Order, separated from Velocity for the first time, resulted in chance performance at all ages, while Direction, also separated from Velocity for the first time, resulted in veridical judgments in only 4 of 24 college students.     

Long-term predictive validity of the WPPSI: An 11-year follow-up study

As part of a longitudinal study, a control group of 85 children were tested on the WPPSI at 5$\text{1}\text{2}$ years and the WISC-R at 16$\text{1}\text{2}$ years. Educational attainment was also assessed in adolescence. Data are presented illustrating the long-term predictive validity of the WPPSI. The Full Scale IQs on the two tests intercorrelated +0.86.     

Fourteen‐month‐old infants track the language comprehension of communicative partners

Infants employ sophisticated mechanisms to acquire their first language, including some that rely on taking the perspective of adults as speakers or listeners. When do infants first show awareness of what other people understand? We tested 14‐month‐old infants in two experiments measuring event‐related potentials. In Experiment 1, we established that infants produce the N400 effect, a brain signature of semantic violations, in a live object naming paradigm in the presence of an adult observer. In Experiment 2, we induced false beliefs about the labeled objects in the adult observer to test whether infants keep track of the other person's comprehension. The results revealed that infants reacted to the semantic incongruity heard by the other as if they encountered it themselves: they exhibited an N400‐like response, even though labels were congruous from their perspective. This finding demonstrates that infants track the linguistic understanding of social partners. A video abstract of this article can be viewed at https://youtu.be/pQUv8yFhnbk .     

Developmental change in early representational intelligence: Evidence from spatial classification strategies and related verbal expressions

The procedures 1- to 3-year-old children use to group simple sets of objects are analyzed in an investigation of cognitive change in early representational intelligence. Forty children spontaneously manipulated two-class arrays and participated in two experimental probes of object grouping. Children 1 to 2 years of age group classes by looking for one kind of thing at a time. Consistent with this, they verbally mark single classes. Children from $\text{2}\text{1}\text{2}$ to 3 years old employ spatial grouping procedures that require simultaneous consideration of two classes, and they refer to relations between classes. Advances made during the second year are consistent with other initial signs of representational-symbolic intelligence. The advances in the third year are unaccounted for by traditional cognitive-developmental theories, but they are congruent with late-emerging patterns in natural representational systems such as language, suggesting the presence of broad changes in mental organization shortly after the onset of representational intelligence.     

A follow-up developmental study of hypothesis behavior among mentally retarded and nonretarded children

To clarify the roles of IQ and mental age (MA) in hypothesis behavior, MA-matched subjects at three levels of IQ (70, 100, and 130) and three levels of MA ($\text{5}\text{1}\text{2}\text{, 7}\text{1}\text{2}\text{,}\text{and}\text{9}\text{1}\text{2}\text{years}$) received blank-trial discrimination learning problems using procedures designed to discourage position-oriented responding. With position responding discouraged, earlier findings were contradicted in that no hypothesis measure showed a main effect of IQ. This suggest that previously reported IQ group differences in hypothesis behavior may not reflect cognitive deficits inherently linked to low IQ, but instead may reflect the influence of specific methodological factors. The finding and interpretation are consistent with Zigler's (American Journal of Mental Deficiency, 1969, 73, 536–556) “developmental” theory of retardation and inconsistent with the general “difference” position. In additional findings, the predictions that subjects at all three MA levels would use hypotheses, and that retarded children from special-education classes would use hypotheses more often than retarded children “mainstreamed” in classes for the nonretarded were confirmed.     

Cultural differences on WISC-R verbal items

The item difficulty patterns of four groups of nonreferred, average children— Anglos, Blacks, Chicanos and Bermudians—were compared on each of the verbal subtests of the Wechsler Intelligence Scale for Children-Revised. The analysis was done for $\text{7}\text{1}\text{2}$ years old and $\text{10}\text{1}\text{2}$ year olds separately. Although this procedure identified a small number of items differentially difficult for one group of children or another, the item difficulty curves for the four groups were remarkably parallel, considering the differences in the children's cultures.     

On the scales of measurement

Let $\text{X}$ = 〈X, ≧, R₁, R₂…〉 be a relational structure, 〈$\text{X, ≧}$〉 be a Dedekind complete, totally ordered set, and n be a nonnegative integer. $\text{X}$ is said to satisfy n-point homogeneity if and only if for each x₁,…, x_n, y₁,…, y_n such that x₁ ? x₂ ? … ? x_n and y₁ ? y₂ … ? y_n, there exists an automorphism α of $\text{X}$ such that α(x₁) = y_i. $\text{X}$ is said to satisfy n-point uniqueness if and only if for all automorphisms β and γ of $\text{X}$, if β and γ agree at n distinct points of $\text{X}$, then β and γ are identical. It is shown that if $\text{X}$ satisfies n-point homogeneity and n-point uniqueness, then n ≦ 2, and for the case n = 1, $\text{X}$ is ratio scalable, and for the case n = 2, interval scalable. This result is very general and may in part provide an explanation of why so few scale types have arisen in science. The cases of 0-point homogeneity and infinite point homogeneity are also discussed.     

Developmental changes in conditional reasoning: Linguistic or logical?

This study investigated reasoning with abstract conditional sentences as a function of age. Subjects from third-grade to eleventh-grade were required to evaluate the conclusion of several conditional arguments. The results confirmed the previously established finding that performance improves with age, particularly between 11 and 15 years. This finding could be interpreted to indicate that individuals become more logical as they get older. However, another possible interpretation is that the meaning of a conditional sentence like pthenq for naive Ss may not always be given by the truth function pq true, $\text{p}\text{q}$ false, $\text{p}\text{q}$ true, and $\text{p}\text{q}$ true. Further analysis suggested that at 9 years individuals treat the connective in the sentence, ifpthenq, as if it were either a conjunctive or a biconditional, that the conjunctive meaning disappears with increasing age and after 13 years is gradually superceded by the conditional.     

Improving visual acuity in a myopic child: Assessing compliance and effectiveness

Improvements in visual acuity following vision training were evaluated for an 11$\text{1}\text{2}$-yr-old myopic male. Initial increases in the distance at which the S could discriminate letters were found. However, performance began to deteriorate as training progressed. A negative-reinforcement procedure was employed in order to rule out motivational factors potentially related to this decreased performance. Using a changing criterion within an ABCBC reversal design, the distance at which the S correctly discriminated letters increased by more than $\text{4}\text{1}\text{2}$ times and was clearly related to the reinforcement procedure.