Automaintenance,contrast, and contingencies: Effects of local vs. overall and prior vs. impending reinforcement context

The pigeon's keypeck was investigated in a variety of multiple schedules of response-independent or -dependent reinforcement. Experiments 1 and 2 found that keypecking developed to a reinforcement-associated cue that signaled an increase in local rate of reinforcement, but signaled either no change or a decrease in the overall rate of reinforcement, defined as that prevailing in the cue's absence. In Experiment 3 a greater rate of responding to a target stimulus was observed when it was preceded by a second signal—associated with the same, or a lower, rate of reinforcement—and followed by extinction than when this temporal sequence was reversed. In Experiment 4 responding to a target cue increased when either a temporally prior or a subsequent reinforcement-associated cue was changed to signal extinction. Experiment 5 examined the conditioned reinforcing effectiveness of target cues in two types of situations varying the local context of reinforcement. Stimuli associated with selected target components of a response-dependent multiple schedule of reinforcement could appear as the terminal-link consequences in a two-link chain schedule. Enhanced responding during a target cue which accompanied the introduction of an extinction period following this cue was paralleled by an increase in the conditioned reinforcement effects of this cue. No such increase was found for target cues in which an enhancement of responding had been produced by the interposition of an extinction period prior to the cue.     

Children's comprehension of presupposed information: Logical and pragmatic inferences to speaker belief

This study explored the ability of young children (5 and 8 years old) to make presuppositional inferences to a speaker's belief in uttering a sentence. Presuppositional information is the information a speaker believes to be common between himself and the hearer. The information is cued by a speaker either logically, by the use of specific lexical items, or pragmatically, by the use of an utterance in violation of conventional rules of conversation. Comprehension of the information may require a reading of the context of utterance. Kindergarten and thirdgrade children and adults were read paragraphs containing both logical and pragmatic presuppositional information, as well as a sentence that could be treated in a logical or a pragmatic manner depending on the context of utterance. The results showed that both groups of children and the adults could make presuppositional inferences to a speaker's belief, and that the responses of the children and adults were context sensitive.     

The development of complex sentence processing strategies

Children aged 3, 4, and 5 years and adults heard sentences with clauses connected by after, and, or before, saw a picture, and indicated whether or not the picture matched one of the events of the sentence. Response times were taken as a measure of immediate accessibility to the meaning of the clause that the picture was about. Temporal organization of sentence meanings was dominant in 3-year-olds and adults, but not in 4- or 5-year-olds. The 3-year-olds and especially the adults processed and-sentences as implicitly temporal. The results for 4- and 5-year-olds are interpreted as indicating experimentation with alternate strategies for organizing sentences based on the structural/presuppositional properties of clauses.     

A developmental study of choice reaction time: the effect of two forms of stimulus degradation on encoding.

To assess the effects of environmental enrichment, 156 normal, full-term institutionalized infants were randomly assigned to Group I (30 min per day of supplementary vestibular stimulation), Group II (30 min per day of supplementary vestibular-plus-verbal stimulation), or Group III (untreated controls). Stimulation began at about the age of 12 days and continued until the children were adopted, approximately 6 weeks later. Children were assessed at regular intervals on the Gesell Developmental Schedules, until the age of 27 months. Group comparisons revealed no significant treatment effects.     

The mental effort requirement of cumulative rehearsal: A developmental study

Three experiments were conducted examining the relationship between the mental effort requirement of cumulative rehearsal and spontaneous utilization of the strategy by children. Mental effort was assessed by measuring the interference produced by cumulative rehearsal with a simultaneously performed secondary task (finger-tapping). It was found in Experiment 1 that second- and third-grade children experienced significantly more finger-tapping interference during instructed cumulative rehearsal than did sixth-grade children, an effect which, Experiment 2 demonstrated, could not be attributed simply to developmental differences in time-sharing performance. In Experiment 3 it was found that, for children in grades 2 through 5, rehearsal set size during spontaneous rehearsal was negatively correlated with amount of finger-tapping interference during instructed cumulative rehearsal, suggesting that spontaneous use of a cumulative rehearsal strategy was negatively correlated with the mental effort requirement of strategy use. These findings support the view that the mental effort requirement of strategy use may influence children's strategy selection on memory tasks.     

Positive and negative conditioned suppression in the pigeon: Effects of the locus and modality of the CS

In Experiment I, four pigeons were exposed to trials in which a 12-sec key light illumination was followed by free food. These trials were superimposed upon a baseline of key pecking for food reinforcement on a variable-interval schedule. When the signal for food was on the operant key, response rate was substantially higher during the signal than during the baseline procedure. When the signal was on a second, signal key, operant responding was suppressed during the signal and substantial pecking of the signal key occurred. The sum of signal key and operant key pecks far exceeded the operant baseline rate of responding. An explanation of opposite results obtained with rats and pigeons as subjects in experiments of this type was suggested in terms of the spatial relation between the signal for free food and the operant target which usually characterizes these experiments. Experiment II assessed the importance of signal location when shock rather than food was the US. Suppression of operant key pecking was unaffected by signal location. Experiment III assessed the relative effectiveness of visual and auditory stimuli (clicks) as signals for food and shock, and found that all combinations of signal and US were equally effective in suppressing operant key responding. The three experiments together suggested that the identification of important effects of species—typical behavior in one experimental situation does not imply that there will be like effects in similar situations.     

A developmental study of attention to auditory and visual signals

Three experiments tested for developmental changes in attention to simple auditory and visual signals. Subject pressed a single button in response to the onset (Experiment 1) or offset (Experiment 2) of either a tone or a light. During one block of trials subjects knew which stimulus would come on or go off on each trial (precue condition) whereas during the other block of trials no precue was provided. In both experiments subjects as young as 4 years old responded more rapidly with precues, indicating that they were able to allocate their attention to the indicated modality. Experiment 3 utilized a choice reaction paradigm (in which subjects pressed different buttons in response to the onset of the light and the tone) in order to examine their attention allocation when no precues were provided. It was found that the adults and 7-year-olds tended to allocate their attention to vision rather than audition when no precue was provided. The results with the 4-year-olds were not entirely consistent, but suggested a similar biasing of attention to vision on their part as well.     

Poison-enhanced neophobia: Effects of CS-UCSUCS-CS procedures and long-delay training

Experiment 1 (n = 110 male rats) showed that pairing sucrose with toxicosis under forward or backward conditioning procedures yielded reliable poison-enhanced neophobia toward casein hydrolysate. Forward procedures produced reliably greater and more persistent enhancement of neophobia. Experiment 2 (n = 160 male rats) showed that interpolating 10 min, or 1, 4, 8, or 12 hr between sucrose and toxicosis yielded reliable aversion effects to sucrose and poison-enhanced neophobia to casein at each interval except 8 and 12 hr. Generally speaking, the effects of training interval were similar for conditioned aversion and enhanced neophobia but conditioned aversion effects were more enduring.     

The use of natural consequences and a make-up period to eliminate school phobic behavior: A case study

The school-phobic behavior of a seven-year-old male was modified through implementing a program characterized by maximum parental involvement, restructing of natural consequences, and the use of a make-up period. Full-time school attendance was achieved on the sixteenth day of the program. The advantages of using school personnel as monitors and not as disciplinarians of the school-phobic child's behavior are discussed.     

Children's beliefs about adoption: A developmental study

Attributions about adoption were examined in adopted and nonadopted children between the ages of 6 and 13 years. Results indicated that nonadopted children had a more negative view of adoption than their adopted age-mates, at least during the early to middle childhood years. By 10–11 years, however, no group difference was noted in adoption beliefs. In addition, with increasing age nonadopted children became less negative about adoption whereas adopted children became more negative about adoption. These results are discussed in the context of differential socialization for adopted and nonadopted children. Implications of adoption beliefs for children's adoption adjustment also are raised.     

Children's numerical skill and judgments of confidence in estimation

This study investigated how children's fluent use of a basic numerical skill is related to their perceptions of confidence on a task of quantitative estimation. One hundred four 10th graders (age 15.7 years) were categorized according to level of numerical fluency as assessed by timed tasks of counting in various nonunity increments. They then made estimates of large numbers of dots and rated how confident they were on each trial. The estimation task varied according to two within-subject factors of task difficulty. It was found that counting skill was related not only to accuracy in estimating, but also to the appropriateness of the children's confidence in their responses. Skillful children made judgments that corresponded with actual task difficulty. A derived calibration score corroborated ANOVA findings of the interaction of skill level and task difficulty on confidence ratings. It also revealed that while girls were less confident than boys, they were actually more realistic in their judgments. Findings are discussed in terms of (a) the effect of stimulus knowledge on awareness of task difficulty and (b) sex differences in achievement-related expectancies.     

Hemispheric asymmetry for alphabetic identification: Scaling analyses

In a test of the analytic-holistic theory of hemispheric asymmetry, 20 subjects saw brief presentations of upper-case letters in either the left or right visual half-field. A right half-field advantage was found for both accuracy of identification and vocal latency of erroneous responses. Multidimensional scaling, hierarchical clustering, and correlation analyses of the error patterns indicated similarities of processing between the hemispheres. The results were discussed in terms of loss of information from storage prior to processing.     

Stimulus factors and listening strategies in auditory memory: A theoretical analysis

A theory for the temporal course of perceptual coding during auditory short-term memory tasks is described. A low-level “sensor” and a high-level “identifier” process item and order information from stimulus word-strings. Both word durations and interword pauses are needed for this processing, and if adequate processing time is unavailable, perceptual delays will lead to degraded recall performance. Stimulus parameters and subject strategies interact to determine the quality and the order in which stimulus items are coded. These hypotheses are supported both by experiments using grammatical sentences and those using lists of unrelated words.     

Cognitive strategies for coping with uncertain outcomes

It was proposed that, when faced with highly desirable but uncertain outcomes, people may employ cognitive strategies in an attempt to influence their future affective responses to the outcomes in question. The present study attempted to demonstrate the use of two such strategies. First, it was hypothesized that when people are faced with a low probability of obtaining a highly desirable outcome, they tend to derogate that outcome by perceiving it as less attractive. Second, it was proposed that when people are faced with uncertainty regarding the occurrence of a highly desirable outcome, they tend to underestimate the likelihood of its occurrence, in an attempt to avoid future disappointment. These hypotheses were tested within the context of a lottery in which subjects were given a low, moderate, or high chance of winning a prize that was either high or low in attractiveness. As predicted, subjects viewed the highly attractive prize as less valuable and attractive when they had a low probability of winning than when the probability of winning was moderate or high. Subjects also perceived themselves as less likely to win when the prize was high in attractiveness than when it was low in attractiveness. The relationship of these findings to studies of self-handicapping and attribute ambiguity is discussed.     

Form and function in early communication: language and pointing gestures

Pointing gestures of verbally advanced 2-year-olds were contrasted with those of less advanced peers, in order to examine the relationships of gesture to language during the acquisition of each. Hypotheses regarding the replacement of gestural functions by speech as verbal skills improve, regarding developmental correspondences between the two communicative domains, and regarding the independence of language acquisition from nonverbal developments were drawn from evolutionary, structuralist, and nativist viewpoints, respectively. Both formal and functional aspects of each communicative skill were measured, and were shown to be largely unrelated, particularly in the gestural domain. No evidence that language replaced gesture for communication in ontogeny was obtained. Correspondences between gesture and language occurred only between functional aspects of each, and the independence of developing language from gestural advances was suggested by the findings.     

TV cameras,public self-consciousness,and mock juror performance

In Chandler v. Florida (1981), the U.S. Supreme Court ruled that the presence of television cameras in the courtroom does not violate a defendant's constitutional right to a fair trial. Since then, several states have expanded their TV coverage rights, and the controversy has intensified. The present study tested opponents' argument that TV cameras distract jurors, thereby reducing their reliance on evidence in the decision-making process. Fifty-one community adults watched a 95-min videotape of a civil trial in the presence or absence of a camera. No effects were obtained on verdicts, awards, or a series of self-report measures. The camera did impair subjects' recall of the evidence, but this effect was dually limited—(a) consistent with an adaptation hypothesis, an initially strong distractive effect gradually diminished, resulting in a net post-trial loss of information that was not statistically significant, and (b) consistent with an individual differences hypothesis, the camera impaired the recall of subjects who were low but not high in dispositional public self-consciousness. These findings were discussed in terms of their practical implications for courtroom management and their contribution to the self-awareness literature.     

Theory and data on developmental changes in novelty preference

The present study was designed to investigate the predictive value of an informational analysis of vicarious consequences. Two levels of amount of vicarious consequences (complete, partial) were varied with three types of vicarious consequences (reward, punishment, reward-punishment). Each of six groups of preschool age boys and girls observed an adult male model receive one of the combinations of amount and type of vicarious consequences for his choices from a commodity preference series. A seventh group of boys and girls observed the model receive no consequences for his choices. After observing the model, each subject was asked to make his own choices from the commodity preference series and to recall the choices which the model made. In contradiction to the predictions of an informational analysis of vicarious consequences, the amount of vicarious consequences did not differentially affect the recall of modeled behavior while the type of vicarious consequences did have a differential effect.     

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.     

Stimulus factors and listening strategies in auditory memory: An experimental demonstration

Three experiments are reported in which digits spoken at different rates were recalled and monitored. In Experiment I, digits to be recalled were embedded in varying levels of noise. In Experiment II noise was presented only during the inter-digit intervals, either to the same or to the opposite ear as the digits. In Experiment III Ss monitored these sequences for a specified digit and reported its successor. Stimulus rate and signal-to-noise ratio affected perceptual processing time, as evidenced by the frequency and relative proportion of item and order errors. These stimulus factors induce listening strategies that influence the shape of the serial position curve and that persist after stimulus conditions are changed. The data are consistent with a two-stage processing model for the temporal course of speech perception and the nature of listening strategies.     

The brachium of the inferior colliculus: The human auditory pathways: A quantitative study

Counts of nerve fibers in the brachium of the inferior colliculus in man from birth to 97 years (28 brains) revealed an average on the right of 168,311/mm² and an average of 168,593/mm² on the left. The total fiber population for each level studied averaged 350,562 for section A (immediately adjacent to the inferior colliculus), 452, 372 for section B (center of brachium), and 559,242 for section C (immediately adjacent to the medial geniculate body). These figures were averaged from brains whose ages ranged from 11 to 89 years. The area of the brachium, as well as its total fiber population, increased as the medial geniculate body was approached. This indicates that fibers were entering the brachium at various points along its course from the inferior colliculus to the medial geniculate body or were leaving in the reverse direction. A lower fiber density was found in infant brains, and a loss of nerve fibers was evident in the 91- and the 97-year-old specimens.