Classical conditioning of the rabbit's nictitating membrane response under fixed and mixed CS-US intervals

The rabbit's nictitating membrane response was classically conditioned to a tone CS, followed by an electric shock US, at two randomly alternating CS-US interstimulus intervals (ISIs). Different groups were exposed to different proportions of 200- and 700-msec ISIs. The study revealed: (a) CR percentage was a direct function of the proportion of 200-msec ISIs; (b) trials to the first test-trial CR were an inverse function of the proportion of 200-msec ISIs; (c) CR onset latencies decreased over training; (d) CR peak latencies coincided with the temporal loci of the US; and (e) groups exposed to both ISIs acquired double-peaked CRs. Moreover, the amplitudes of nictitating membrane responses in the present experiment paralleled certain quantitative aspects of the free operant key peck response rates of pigeons trained under two mixed inter-reinforcement intervals. The results were discussed with respect to the micromolar response shaping and macromolecular CS-trace accounts of classical conditioning.     

Human covariation judgment: Accuracy and strategy

Judgment strategy is proposed as a contributor to the variability of findings in past research on human covariation judgment. Mathematically sophisticated judgment strategies will accurately judge all event covariations. However, faulty judgment rules will also produce correct judgments of many event relationships. Several methods have been used in past research to identify subjects' strategies of covariation judgment. Each of these methods indicates that humans employ simplistic, error-prone rules to judge event relationships. Shifts in covariation strategy use are proposed as a source of past findings that judgment accuracy depends on the decision conditions.     

The value of being imitated

Theories and research on the topics of attraction, conformity, and imitation support the view that the relational stimulus arising from being imitated serves a reinforcing function. To examine this possibility, 48 preschool children performed a task in which some neutral stimuli were repeatedly associated with an adult's matching the behavior of the subject, and other neutral stimuli were associated with the same adult's mismatching the behavior of the subject. Preference for the stimuli associated with being matched was greater at the end of training than earlier, and the overall preference for the matched stimuli exceeded chance. The results are considered in terms of the thesis that similarity arising from being imitated served a reinforcing function and the thesis that response strategies were adopted by the children.     

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.     

The effects of retention interval on preschool children's short-term memory of verbal items

The short-term recall of word-triads was tested, comparing retention over three types of intervals within 24 preschoolers. Retention was significantly lower in the 16 sec unfilled interval condition than in the immediate test condition. This result, predicted from preschoolers' rehearsal deficiency, differs from those obtained in previous adult and child studies. A filled interval condition, requiring irrelevant verbal activity during the 16 sec period, significantly reduced recall from that of the unfilled interval condition. Recognition of the word items on a subsequent recognition test was greater than chance and was not affected by interval condition. This suggests that the condition effects in short-term recall did not disrupt the long-term storage of the items.     

Introtacts as predictors of discrimination performance in kindergarten children

Kindergarten children were given simultaneous discrimination tasks with two irrelevant dimensions varying within settings. Prior to each block of eight feed-back trials, the children were asked to attempt to provide a statement of the solution. The introtacts thus provided were found to have several of the desirable characteristics that have been reported for older children with either introtact or blank-trial probes, but which have not been found previously for kindergarten children with the blank-trial probe. Classification of the children according to the trial block on which they first verbalized the correct relevant dimension was found to account for more than 60% of the total variability in discrimination performance. The introtacts were also used to assign parameters to theoretical prediction equations, with nearly two-thirds of the total variability in discrimination performance accounted for by the theory. Extension of the method to other models is discussed.     

Effective list length and part-whole transfer in first-graders' multitrial free recall

First-gradens' multitrial free recall shows an effective list-length (ELL) effect: an initial recall gain followed by a constant output level that fluctuates in item content. The part-whole transfer paradigm was used to investigate ELL. The ELL effect occurred in whole-list learning regardless of whether the prior task consisted of relevant practice, irrelevant practice, or an unrelated task. Relevant part-list learning resulted in positive transfer which declined from a high to a marginal level over the course of whole-list learning. Other analyses indicated a general deficit in the use of strategies. A response-strength model was used to explain the ELL effect and the transfer results.     

The influence of introversion/extraversion on the skin conductance response to stress and stimulus intensity

A series of studies compared skin conductance level (SCL) for introverts and extraverts during a series of tones varying in both stimulus intensity (SI) and the amount of stress preceding the tones. When a difficult paired-associate task preceded the tones, both groups were about the same for 83 dB tones but extraverts were much higher at 103 dB, introverts failing to show an increase as a function of SI. There were no differences between the two groups following a simple paired-associate task, both groups showing a similar increase with increased SI. Finally, SCL was higher for introverts than extraverts during tones preceded by a rest period, and this was especially true for the early trials and for lower SI (75 and 83 dB compared with 100 and 103 dB). Taken together, these results suggest that SCL is higher for extraverts at higher levels of arousal but that the reverse is true for lower levels of arousal. This relationship is consistent with the theory that introverts have a “weak nervous system” which develops transmarginal or protective inhibition under stress.     

Analyzing the random control procedure: Effects of paired and unpaired CSs and USs on autoshaping the chick's key peck with heat reinforcement

A series of five experiments using a total of 264 subjects investigated the effects of paired and unpaired key light (CS) and heat (US) stimuli on autoshaping the chick's key peck. Experiment 1 established that paired presentations of CS and US promoted a more rapid rise in key pecking than did randomly presented CSs and USs and that the specific sequence of stimuli under the random control procedure affected key pecking performance. Experiment 2 used a trace conditioning procedure to determine the role of the CS-US interval on autoshaping and to define empirically unpaired CSs and USs. Key pecking declined as the trace delay interval was increased from 0 to 25 sec; at 25 sec, no conditioning of key pecking occurred. Experiments 3–5 assessed the effects on autoshaped key pecking of (a) number of daily CS-US pairings, (b) added unpaired CS presentations, and (c) added unpaired US presentations, since paired and random control schedules differed in all of these respects. Reduction in the number of CS-US pairings slowed the acquisition of key pecking as did the concurrent addition of nonreinforced CSs and unsignaled USs. These results support theories of association formation that stress the effects of both paired and unpaired CSs and USs.     

Types produce types: An examination of personality development using Holland's theory

This study was designed to test Holland's hypothesis that parents encourage the development of their own personality types in their offspring. Data were collected by personal interviews from three freshmen classes at a large midwestern university. Parent's personality types (occupations) were compared to offsprings' personality types (expressed occupational choices) using the Kolmogorov-Smirnov one-sample test to determine whether or not the comparisons were due to chance. The results indicated that relationships existed between the personality types of fathers-sons, fathers-daughters and mothers-daughters while no relationship was confirmed between mothers-sons.     

The Home Observation for Measurement of the Environment: A rejoinder to Elardo and Bradley''s comment

The published and unpublished research pertaining to Caldwell's Home Observation for Measurement of the Environment (HOME) inventory was recently reviewed by R. Elardo and R. H. Bradley (Developmental Review, 1981, 1, 113–145). Their review was unfortunately deficient in a number of respects. For example, certain methodological issues bearing on the interpretation of the available data were either unrecognized or dismissed without adequate consideration. In addition, some of the data in the studies cited which contradicted or clouded their conclusions were omitted. An extension and reanalysis of the conclusions reached by Elardo and Bradley in light of recently published studies which were not included in their review, and data not discussed in the studies which were reviewed, is provided. Methodological problems are highlighted, and directions for future research are suggested.     

Vocational decision-making patterns among noncollege-aspiring adolescents

Vocational decision-making (VDM) behavior reported by noncollege-aspiring adolescents was measured by 32 indices derived from decision theory. Patterned differences were especially evident on indices assessing range of planning activities. Infrequent correlations were noted among indices representing each of five theoretical VDM dimensions. Cluster analysis grouped indices into four VDM clusters describing separate decision situations. A speculative model was developed to describe the relationship between VDM Clusters and performances variables. Hypotheses for later study were developed.     

The US preexposure phenomenon in the conditioned suppression paradigm: A role for conditioned situational stimuli

Four experiments evaluated possible associative and nonassociative accounts of the retardation in the acquisition of conditioned suppression produced by repeated prior exposure to an electric shock US. Associative interference resulting from conditioning of situational stimuli during preexposure to shock was suggested by the findings that signaling the occurrence of high-intensity shock with a discrete nontarget CS during the preexposure phase reduced the magnitude of the retardation effect compared to an unsignaled shock preexposure treatment (Experiments 1 and 4), nonreinforced presentations of putatively conditioned situational stimuli prior to conditioned suppression training reduced the magnitude of the retardation effect (Experiment 2), and the magnitude of the retardation effect was directly related to the intensity of preexposure shock (Experiment 3). Nonassociative interference was suggested by the finding that signaling the occurrence of low-intensity shock with a discrete nontarget CS during the preexposure phase did not reduce the magnitude of the retardation effect compared to an unsignaled shock preexposure treatment (Experiment 4). It was suggested that associative and nonassociative mechanisms govern the US preexposure phenomenon obtained in the conditioned suppression paradigm, and their relative contribution depends upon the intensity of shock.     

Development: Compared to what?: Contrast effects in age-comparative paradigms

Recent controversies about judgment competence of preschool and adolescent children are considered as being a possible product of contrast effects. That is, perceived abilities of children of a given age group may depend on the ages of the other subjects in the experiment. An experiment was done to test the possibility of contrast effects in age-comparative experiments. One group of subjects read about three experimental tasks in which 6-year-old children performed better than 4-year-olds. A second group read about 6-year-olds performing worse than 8-year-olds on the same tasks. Performance levels of 6-year-olds were the same on the two forms. For each task subjects rated the competence of each of the two age groups on the task and predicted the performance of the two groups on a related task. Undergraduate subjects' competence ratings and predictions were higher for 6-year-olds when compared to 4-year-olds than when compared to 8-year-olds. Psychology graduate students showed the same contrast effect for predictions but not for competence ratings. The results are discussed in terms of potential biases in age-comparative methods in developmental psychology.     

Bounded rationality and cognitive development: Upper limits on growth?

Piaget's characterization of formal operational thought and human judgment psychologists' model of bounded rationality are considered as two conflicting models dealing with the same domain of interest: the nature and limits of mature thought. Piaget's suggestion that the formal operational thinker brings the skills of hypothetico-deductive logic to deal adequately with environmental complexity is in sharp contrast with judgment psychologists' evidence that information-processing limitations and faulty reasoning leave decision makers poorly equipped to deal with their decision environments. While the two approaches have generated conflicting models, a look at the respective data bases demonstrates their complementarity. Considered together, the literatures in formal operations and bounded rationality make a formidable contribution to understanding the capacities and limits of mature cognition.     

The home observation for measurement of the environment (HOME) scale: A review of research

Caldwell's Home Observation for Measurement of the Environment (HOME) scale is perhaps the most widely used instrument to assess the quality of a young child's home learning environment. In this paper, the HOME'S psychometric properties and methodological uses are explored, and its utility as a research and clinical instrument is examined. Strengths of the HOME scale include the relatively wide range of information available pertaining to its psychometric properties and its use in studies of a variety of populations for a variety of purposes. Weaknesses include the fact that most research relating HOME scores to later child development is correlational. Several suggestions for future research are offered.