Visual tracking in young infants: Evidence for object identity or object permanence?

Previous research has shown that 5-month-old infants visually anticipate a moving object's appearance after it disappears behind a screen. This experiment assesses the underlying basis for such anticipatory tracking. Three tracking tasks were presented to 5- and 9-month-old infants. In the Permanence task, the object's continuous existence was apparently violated while it was behind a screen. In the Feature and Trajectory tasks, the object's features or trajectory changed while behind the screen. Disruptions in the infant's smooth visual pursuit of the object were recorded. Five-mont-olds showed disruptions of visual tracking in the Feature and Trajectory tasks, but not in the Permanence task. The tracking of the 9-month-olds was disrupted in all three tasks. We conclude that both 5- and 9-month-olds possess rules specifying the identity of a moving object which is occluded. For 5-month-olds these rules are based upon the object's features and trajectory, but not upon a concept of object permanence. For 9-month-olds all three rules—feature, trajectory, and permanence—are utilized in visual tracking.     

Infant responses of ocular fixation to moving visual stimuli

Infants of 1, 2, and 3 months of age were presented with two checkerboard patterns, one stationary and the other moving in a horizontal oscillatory motion at one of eight rates. An observer who could see only the infant's head and eyes recorded, for each 30-sec trial, (a) the position of first fixation, (b) position of fixation at the end of each 5-sec interval, and (c) a final forced-choice judgment of the position of the moving stimulus. Results showed reliable differences in ocular behavior as a function of rate of stimulus motion for all three groups of infants.     

Attention of 4-month infants to discrepancy and babyishness

A set of four facial stimuli derived from the Bolton standards of craniofacial development representing a human male at 6 months, 3, 8, and 18 years of age were used in a test of Lorenz's concept of babyishness and of the discrepancy hypothesis. Each 4-month-old subject was habituated to a criterion with one of the four stimuli and then presented with one of the four as a new stimulus. The design and analysis permitted the response to a new stimulus to be broken down into a component attributable to the physical characteristics of the new stimulus and a part attributable to its discrepancy from the familiar standard. The data revealed longer looking at the infant facial stimulus, but no difference in a rating of affect accompanying fixation. This lent partial support to the babyishness concept for infant subjects. Both fixation and affect increased monotonically with magnitude of discrepancy. The increasing rather than curvilinear result presumably derived from the failure of these stimuli (which were common to the infant's experience) to generate extreme levels of subjective uncertainty.     

Effects of sound frequency on behavioral and cardiac orienting in newborn and five-month-old infants

Alert newborn and 5-month-old infants' responsivity to variations in spectral composition of a rattle sound was examined. Each child received four stimulus conditions: low-, mid-, and high-frequency bandpass-filtered rattles and an unfiltered broadband rattle. Stimuli were played through a single loudspeaker laterally positioned, and head orientation and cardiac responses to sound were recorded. Compared to other stimuli, the low-frequency sound elicted less head turning in both age groups, with this effect exaggerated in younger infants. Head orientation toward the mid-frequency, high-frequency, and broadband stimuli did not differ with age. For all conditions, latency and duration of newborns' head turning was longer than that of 5-month-olds. Newborns responded with cardiac deceleration only on trials when they failed to turn. When head turns occurred, an acceleratory cardiac response was obtained. Five-month-olds responded with reliable cardiac deceleration irrespective of head turning toward the sound. Heart rate change did not vary as a function of frequency at either age, suggesting that all stimuli were equally effective in eliciting the infant's attention.     

Trait attributions and defense against insult from a dissimilar other

It was hypothesized that subjects would prefer to blame a character assault on negative ability characteristics of a dissimilar attacker as opposed to negative motivational characteristics in order to escape responsibility for the attack. It was reasoned that because we generally think of ourselves as having less potential influence over the abilities as opposed to the motivations of another person, it might be possible to diminish one's responsibility for another's behavior by attributing that behavior to that person's ability characteristics. Subjects in this experiment responded either to an insulting or noninsulting stimulus person who was either similar or dissimilar by selecting from a list of both motivational and ability bipolar trait dimensions, those dimensions they would most prefer to use in rating the stimulus person. As predicted, subjects responding to an insulting and dissimilar stimulus person showed a significantly greater preference for ability trait dimensions than subjects in the other conditions combined and also disliked the stimulus person more. The significance of these results for defensive attribution processes and phenomena such as racism and sexism are discussed.     

Ambiguous-cue learning in preschool children: A test of the dimensional characteristics of task stimuli

Sixteen preschool children were administered a two-choice discrimination problem consisting of three stimulus compounds: the consistently rewarded stimulus, the consistently nonrewarded stimulus, and the ambiguous stimulus which was nonrewarded when paired with the positive, but rewarded when paired with the negative. When both pair of stimuli, positive-ambiguous and negative-ambiguous, were presented together the subject was required either to choose or to avoid the ambiguous stimulus depending upon the stimulus with which it was paired. In Experiment 1, when each of three stimuli (positive, negative, ambiguous) varied along one nonspatial cue dimension (color), performance was better on negative-ambiguous trials than positive-ambiguous trials. In Experiment 2, when the positive and negative stimuli varied along three nonspatial cue dimensions (colors and form) and the ambiguous stimulus varied along one of these dimensions (color), superior positive-ambiguous over negative-ambiguous performance was obtained. These findings complement those reported for other subjects and confirm Berch's (D. B. Berch, Learning and Motivation, 1974, 5, 135–148) predictions regarding use of differential numbers of cue dimensions.     

The effects of onset and offset warning and post-target stimuli on the saccade latency of children and adults

Two studies, involving children (mean age = 10 years) and adults, investigated the effects of visual stimulus onsets and offsets on the latency of saccades to peripheral targets. Saccade latency was reduced when foveal stimulus onsets or offsets preceded the target. When stimulus onset occurred 100 msec after target onset, the stimulus interfered with responding, with this interference effect significantly greater for children than for adults. When stimuli were presented in the peripheral visual field facilitation and interference effects were similar for children and adults. These results were interpreted as indicating that oculomotor processes are similar in children and adults while the stimulus intake processes that follow stimulus onset at the point of fixation have a greater interference effect on children's than on adults' eye movements.     

Stimulus selection with duration as a relevant cue

To date, research has not explicitly examined how duration competes with other stimulus dimensions for control over responding. The present study investigated some familiar selective mechanisms of stimulus control over key pecking in pigeons, with duration and line tilt as discriminative stimuli in successive discrimination procedures. Specifically, pigeon's key pecking was reinforced with food or extinguished following compound stimuli comprising one of two line orientation stimuli presented for one of two different durations. Traditional experimental designs explored stimulus additivity, overshadowing, blocking, and learned irrelevance. Although stimulus additivity was observed, control by duration was masked by line tilt in extinction testing that followed facilitated acquisition with redundant, relevant cues. In addition, although prior training with duration relevant partially blocked subsequent acquisition of control by line tilt when both stimulus dimensions were relevant, there was a tendency for control by duration to decrease with continued compound training. It was suggested that the greater time required to distinguish duration on a trial—compared to more commonly studied stimulus dimensions, which can be distinguished almost immediately—puts duration at a competitive disadvantage in situations where other relevant dimensions are also available.     

The effects of self-monitoring and self-reported consistency on the consistency of personality judgments made by strangers and intimates

How consistent are strangers' and intimates' judgments of stimulus people's personalities, and how is this interjudge consistency affected by stimulus persons' assessed self-monitoring and self-reported behavioral consistency? To answer these questions, 38 stimulus subjects rated themselves on the personality dimensions of extraversion and anxiety and also rated their cross-situational consistency on these dimensions. Strangers, friends, mothers, and fathers of stimulus persons also rated them on extraversion and anxiety. The results indicated that: For judgments of anxiety there was lower interjudge consistency for high than for low self-monitoring stimulus subjects. For judgments of extraversion there was no difference in interjudge consistency for low and high self-monitoring stimulus subjects. The results also showed that anxiety was a more “private” trait in that intimates' but not strangers' judgments correlated with stimulus subjects' self-reported anxiety (r = .50 and r = .11, respectively), while extraversion was a more “public” trait in that both intimates' and strangers' judgments correlated with stimulus subjects' self-reported extraversion (r = .42 and r = .51, respectively). These results suggest that self-monitoring of stimulus persons affects interjudge consistency of peroonality judgments particularly for “private” traits such as anxiety, which are most subject to expressive control and inhibition.     

Children's judgments of numerical quantity: A new view of early quantification

Three experiments investigated the role of length, density, and number dimensions in children's numerosity judgments of linear arrays of beads. The number dimension is physically defined by a length × density rule. Judgments based, even in part, on the number dimension would show signs of a length × density rule. Experiment 1 examined numerosity judgments of large arrays. Results showed that judgments by 3- and 4-year-olds obeyed a length + density rule, providing cogent evidence for a general adding strategy in young children's judgments of quantity. The physical length × density rule emerged gradually with increasing age. Experiment 2 showed that numerosity judgments of small arrays by 3- and 4-year-olds obeyed a length × density rule, indicating response to the number dimension. This result was expected and thereby validated the linearity of the response scale at the youngest ages. Experiment 3 verified the integration rules for individual 3- and 4-year-olds. The integration rules were interpreted in terms of Piaget's stages of the development of quantification. No evidence for Piaget's initial stage was found. This leads to a new view of early quantification which grants young children the ability to integrate stimulus dimensions.     

Reinforcement magnitude effects in first- and second-order conditioning of directed action

Three experiments investigated the effects of reinforcement magnitude on conditioned key pecking in pigeons. Experiment 1, which included between-groups and within-subject designs, yielded significant effects of unconditioned stimulus (US) magnitude on the within-conditioned stimulus (CS) distribution of key pecks and on choice behavior, but no effect on the overall rate of key pecking. Experiment 2 employed a larger US-magnitude difference in a within-subject design. This manipulation resulted in differential rates of key pecking as well as a significant choice effect and differential within-CS key-peck distributions. A second-order conditioning procedure was used in Experiment 3, in which diffuse, visual stimuli (S1's) served as Pavlovian reinforcers for two key-light S2's. The S1 previously paired with a large US was more effective in conditioning second-order key-peck behavior to an S2 than was the S1 paired with a small US. The results of these experiments demonstrate that the associative effects of US magnitude can be expressed in the strength of CS-directed motor responding. The distinctive within-CS key-peck distributions in first-order conditioning suggests an interaction between CS- and US-directed responses.     

Perspective role-taking in young children

Children between the ages of 4 and 7 years were asked to select a photograph depicting the visual perspective of a puppet which was placed at various locations around a dollhouse in a modified version of Piaget and Inhelder's three-mountain task. A shielded condition was used for half of the children. Three types of errors were examined in relation to the shield condition, age, and type of vantage point (views from the corners and from the sides). Shielding of the stimulus array reduced egocentric errors among 4-year-olds, producing a pattern of responses more typical of that observed among older children. Increasing specificity in perspective role-taking with age was indicated by changes in error patterns. Finally, the task was more difficult on trials with corner views, particularly when the child's own view included some of the cues present in the puppet's perspective.     

Effects of positive and negative adult-child interactions on children's social preference

The effects of positive and negative interactions on children's performance and preferences for the adults associated with each type of interaction were studied. Five children served as subjects during daily sessions in which each of three adults followed prescribed patterns of social interaction. One adult (positive) dispensed positive comments contingent upon either color-sorting or completion of arithmetic problems; a second adult (negative) mildly reprimanded the child for off-task behavior; and the third adult (extinction or nonreactive) said nothing to the child when he was present. Following each session the three adults reentered and the child chose one of them for an additional period of interaction. Three response measures (frequency, latency, and percent of time on-task) and children's adult preferences were obtained daily. The negative adult affected the most task behavior and had strongest stimulus control; the positive adult, though exerting little control over children's behavior, was the most preferred. Children's adult preferences were not specific to the task setting, but were observed across a variety of contexts.     

Social episodes and social structure in an academic setting: The social environment of an intact group

The social environment of an intact academic group, composed of faculty members, research students, and staff, was studied using a multidimensional scaling (MDS) procedure. The perceived group structure and the perception of social episodes were represented, and the relationship between these two aspects of the social environment was analyzed. Results indicated that (a) the perceived group structure could be adequately represented in three dimensions with group members differentiated along dimensions of sociability, creativity, and competence, (b) an individuals' perception of the group and his position within it were significantly related, (c) group members perceived the social episodes of the group in terms of attribute dimensions such as anxiety, involvement, evaluation, and socioemotional vs task orientation, and (d) an individual's formal status and perceived position within the group were significantly related to his perception of the group's episodes. The results are discussed in terms of the factors influencing episode perception, and the symbolic processes mediating between social position and perception. The utility of social episodes in describing a social environment is considered.     

The acquisition of abstract letter codes

A modification of Posner's letter-matching paradigm proposed by Beller (1971) was employed to study the development of abstract visual and name codes for letters. Second-, fourth-, and sixth-grade students (ages 8, 10, and 12 years, respectively) were presented in advance one of a pair of to-be-matched letters. Case agreement (upper- and lowercase) between the prime letter and the letter pair was manipulated to differentiate facilitation based on concrete features of the stimulus letter from that based on the letter's abstract visual code. For physical matches second graders showed greater facilitation from same-case primes than from different-case primes, whereas sixth graders benefited equally from both types of prime. For same-name and different conditions, no qualitative developmental differences were revealed as all subjects benefited from letter primes irrespective of case agreement. The acquisition and utilization of abstract visual codes for letters are a later acquisition than name codes, which were clearly operative at the lowest grade level in the present experiment.     

The influence of incongruity and preexposure on the familiarity effect in visual selection of children

A consistent finding in the literature concerning visual selection is that Ss will spend more time viewing unfamiliar stimuli than stimuli with which they have been familiarized. In the present experiment, the relationship between the magnitude of this familiarity effect and the level of stimulus incongruity was examined and found to be monotonic and increasing. In addition, amount of stimulus preexposure had no significant effect on the magnitude of the familiarity effect. Furthermore, there was no overall difference in Ss' preference for familiar and unfamiliar stimuli. Results are interpreted as supporting a theory of visual selection based on information-conflict resolution.     

Exploring and reexploring issues of integrality,perceptual sensitivity,and dimensional salience

Some observations that can be described conveniently by investigators in terms of dimensional sensitivity and dimensional salience actually need not implicate the psychological reality of the dimensions for the subjects. The developmental hypothesis that stimuli are perceived often as integral in early childhood can account for such phenomena only with the assumption that young children often apprehend objects as global wholes, related to one another by overall similarity. Classification data, recently presented by J. R. Aschkenasy and R. D. Odom (Journal of Experimental Child Psychology, 1982, 34, 435–448) can be reinterpreted in this way. On this reinterpretation, Aschkenasy and Odom's findings are exactly what the developmental form of the integrality-separability hypothesis predicts. Moreover, a variety of other findings and lines of inference converge on the conclusion that, in young children, the use of overall similarity relations to organize perception and cognition predominates over the use of dimensional relations (and that the relative balance between these stimulus relations changes in development). Examples are selected from the literature on the natural development of word meanings, as well as from the literatures on children's and adults' classification.     

Beauty and the attributions of the beholder

Four studies used an attributional approach to examine interpersonal attraction. Underlying causal dimensions were predicted to influence differentially two components of attraction, dating and complimenting. In the first study, 24 subjects indicated whether they would date physically attractive stimulus persons. Complimenting was examined in the second and third studies, with 24 subjects rating the likelihood of complimenting attractive opposite-sex stimulus persons and 32 subjects rating the likelihood of complimenting same-sex stimulus persons. For these studies the reason for the stimulus person's attractiveness varied in controllability (volitional versus nonvolitional) and stability (temporary versus permanent). Consistent with predictions, controllability influenced likelihood of complimenting but not dating. In addition, compliments were more likely when the reason for attractiveness was unstable than when stable. Conversely, dating was more likely when attactiveness was stable than when unstable. However, stability had less influence on men responding to women than on either men responding to men or women responding to both sexes. Similar results were obtained in a fourth study in which 56 subjects recalled incidents where they complimented or dated others for their physical attractiveness.     

The effects of stimulus type,training, and chronological age on children's identification and recoding of multidimensional stimuli

Kindergarten and second-grade children (75 and 99 months of age, respectively) were first taught that the two stimuli within each of four pairs of multidimentional stimuli differed with respect to their values on every one of three bivalued dimensions: color, size, and form. Each of the eight stimuli was then presented twice, one at a time, and the child was asked either to find its duplicate (eight encoding trials) or to find its complementary mate (eight recoding trials) among the complete set of eight stimuli. Next, each of the eight stimulus compounds was presented twice as a display stimulus for 5 sec and, after a delay of 10 to 15 sec, the child was asked to find the display stimulus (eight trials of encoding plus memory) or its complement (eight trials of recoding plus memory) among the complete set. The stimuli for half the children in each age group were standard unitary compounds (e.g., a large red circle, a small blue square, etc.) and for the other half they were partitioned stimuli with their dimensional values spatially separated (e.g., large arrow, circle outline, and patch of color). Half of the children in each of these subgroups were given a basic pretraining, and the other half received extended pretraining, in recoding the stimulus attributes. The results indicated that unitary stimuli were easier to encode but the partitioned stimuli were easier to recode, that recoding was much more difficult than encoding, that extended training improved recoding performance, and that second graders were slightly better at encoding and much better at recoding than the kindergarten children. The patterns of performance on the tasks involving memory were similar to those just described. The results were discussed in terms of children's abilities to analyze multidimensional stimuli into their dimensional components.