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.     

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.     

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.     

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.     

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 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.     

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 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.     

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.     

Coding processes in preselected and constrained movements: effect of vision

Three experiments were conducted in which visual information was manipulated either at the endpoint or during preselected, subject defined and constrained, experimenter-defined movements. In Experiments 1 and 2 the subject's task was to reproduce the movement in the absence of vision. Augmenting the terminal location of the criterion movement with vision had no differential effect on reproduction in Experiment 1, although preselected movement accuracy was significantly superior to constrained. Providing vision throughout the criterion movement in Experiment 2 not only failed to improve the accuracy of constrained movements but decreased reproduction performance in preselected movements. In Experiment 3 procedures were adopted to control the allocation of the subjects' attention during the criterion movement. The subjects reproduced by vision alone, movement alone, or with both visual and movement information available. When subjects were informed of the modality of reproduction prior to criterion presentation, they were able to ignore concurrent input from vision and attend to movement information. In the absence of precues visual information was spontaneously attended. The data were interpreted as contrary to closed-loop assumptions that additional information necessarily enhances the strength of a motor memory representation. Rather, they can be accommodated in terms of Posner, Nissen and Klein's (1976) theoretical account of visual dominance and serve to illustrate the importance of selective attention effects in movement coding.     

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 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.     

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.     

Input organization as a mediating factor in memory: A comparison of educable mentally retarded and nonretarded individuals

The effect of presentation context on the organization and recall of strongly related and weakly related words was examined in EMR adolescents and nonretarded fifth-grade children of the same mental age (131 months). In blocked presentation formats, subjects sorted words into experimenter-defined groups of four, in which the order of the groupings either changed from trial to trial (i.e., blocked-random), or was consistent across trials (i.e., blocked-consistent). In sort-prompt conditions, subjects were free to structure their own relationships among items during presentation, following instructions to form meaning-based groups (i.e., minimum-sort-prompt), or given explicit training in sorting categorization and sorting stability (i.e., maximum-sort-prompt). Both subject groups found the minimum-sort-prompt method to be as effective as the maximum-sort-prompt method for improving measures of recall and clustering relative to the blocked-random method. Nevertheless, nonretarded children showed higher levels of organization for strongly related items, and better recall and organization for weakly related items. Subsequent analyses suggested that the lower memory performance of the EMR individuals receiving weakly related items was the result of both inconsistent and poorly structured sorting schemes across trials.