Neural and behavioral correlates of emotion recognition in children and adults.

Event-related potentials (ERPs), accuracy scores, and reaction times were used to examine the recognition of emotional expressions. Adults and 7-year-old children saw upright and inverted chromatic slides of the facial expressions of happiness, fear, surprise, and anger, and were asked to press a button for either "happy" or "angry" faces. A positive-going waveform (P300) was apparent at parietal scalp (Pz) and at left and right temporal scalp. Although the behavioral data were similar for both children and adults (e.g., both had more difficulty recognizing angry expressions than happy ones, and angry expressions were more difficult to recognize upside-down than were happy faces), the ERPs indicated that children responded differently than adults did to happy and angry expressions. Adults showed greater P300 amplitude to happy faces, while children showed greater P300 amplitude to angry faces. In addition, for adults, but not children, there were greater P300 amplitude responses at right vs. left temporal scalp.     

The effect of object alignment on the representation of depth in young children's drawings.

Light and Humphreys (1981, Journal of Experimental Child Psychology, 31, 521-530) provided evidence that young children's drawings, despite infrequently showing view-specific occlusion, do systematically reflect spatial relations within an array. The present research tested the hypothesis that young children's preferences for canonical "best views" interact with array-faithful tendencies to increase early uses of occlusion. Forty-three children between 4 and 7 years of age drew arrays like Light and Humphreys' end-to-end alignments, with end-on views of objects in depth, and arrays aligned side-to-side, with canonical side-views of objects in depth. Significantly fewer single-object, view-specific occlusions were produced for end-to-end than for side-to-side alignments. Nevertheless, the former reveal that more children are able to use the vertical dimension to depict multiple objects in depth. Other comparisons suggest an interaction in multiple-object depictions of canonicality with spatial dimension and graphic complexity.     

Difference and ratio information in children's and adults' memory representations.

A study was made of the choice reaction times of 8-, 10-, 12-year-olds and adults in order to investigate whether length information stored in memory was coded to preserve numerical relations between stimuli. Subjects learned unique line length-color associations and were later presented with pairs of colors and were instructed to choose the color that had been associated with the longer line. For all age groups, choice reaction times were related to both differences and ratios. These results were interpreted as supporting the analog theory of representation.     

Effect of a means-end contingency on young children's food preferences.

This study showed that a means-end relationship between two snacks exerts a negative influence on preference for the means snack in the contingency. Two snacks ranked of approximately equal medium appeal were individually chosen from an array by each of 86 children (ages 4 years, 4 months to 7 years, 2 months). Children were then assigned to a means-end condition (where one snack was eaten as a means of gaining the other), a temporal order control group (where one snack was presented and eaten before the other), or a mere exposure control group (where the children chose the order in which they ate the two snacks). Post-treatment rankings of the snacks showed that children in the means-end group came to devalue the means snack relative to the reward snack, despite the demonstrably equal prior appeal of the two snacks. Children in the temporal order and mere exposure control groups did not come to prefer the two snacks preferentially. Implications of the finding that adults can affect children's preferences by relatively minor variations in the manner of presentation are discussed.     

Conservation acquisition, maintenance, and generalization by mentally retarded children using equality-rule training.

To teach conservation to mildly retarded, preoperational preadolescents (9 to 12 years old), a number-representational system was used to mediate the invariance of quantity as part of "equality-rule" training. Before viewing a perceptually misleading configuration of either two equal quantities or two unequal quantities entailing the dimensions of number or length, participants learned that equality involved the assignment of two identical numbers and inequality the assignment of two different numbers. These numbers were then applied to the actual quantities and became the basis for rule statements that were rehearsed, memorized, and subject-generated each time the quantities were transformed into a new configuration. Following equality training, correct judgments and verbal justifications of conservation were high (M greater than or equal to 85%) during both immediate and delayed post-tests and for near-generalization (number and length) and far-generalization (weight, liquid substance, and solid substance) tasks. In contrast, the post-test levels of comparable participants given learning-set (LS) training, LS plus verbal-rule training (a combination of statements about identity, negation, and compensation), or no training at all were substantially and significantly lower. Equality training is of theoretical and practical interest because of its potential to teach a symbolic representational rule that directly and meaningfully articulates the quantitative properties of objects and counteracts the overreliance on task-specific and faulty perceptual cues inherent in the conservation task.     

Hypermnesia using auditory input.

The author investigated whether hypermnesia would occur with auditory input. In addition, the author examined the effects of subjects' knowledge that they would later be asked to recall the stimuli. Two groups of 26 subjects each were given three successive recall trials after they listened to an audiotape of 59 high-imagery nouns. The subjects in the uninformed group were not told that they would later be asked to remember the words; those in the informed group were. Hypermnesia was evident, but only in the uninformed group.