Facilitation and impairment of conditioning in the preweanling rat after prior exposure to the conditioned stimulus

Olfactory aversion conditioning of preweanling rats, 10 or 18 days postnatal, was tested after some had been given nonreinforced experience with the to-be-conditioned odor stimulus. In three experiments, it was established that the amount of prior exposure to the CS determined the effectiveness of conditioning. For both ages, odor-shock conditioning was more likely impaired with longer durations of preexposure. This effect was more apparent in the older animals. Low to moderate degrees of prior exposure to the CS under some conditions facilitated, rather than impaired, olfactory conditioning in the 10-day-old rat. This result is in agreement with one previous study in which facilitation in learning was reported for this age after short-term preexposure to the CS. The present study adds to previous data on differential effects of CS preexposure on conditioning. Although the conditions under which facilitation rather than impairment occurs are not yet clear, age-related differences in the effects of CS preexposure were apparent in the present experiments.     

Classical conditioning of jaw movements in the pigeon: Acquisition and response topography

Previous studies have shown (1) that the form of the pigeon’s conditioned keypecking response resembles that of its ingestive pecking response, (2) that both ingestive and conditioned pecking in the pigeon are compound responses, including both transport (neck-movement) and gape (jaw-movement) components, and (3) that during operant conditioning or autoshaping of pecking behavior, the gape component comes under the associative control of the CS. In the present study, the gape component was experimentally isolated and a classical conditioning paradigm (water US) was used to bring jaw movements under the control of a CS (light). The results indicate that the topography of the jaw-movement CR is very similar to, though more variable than, that of the UR. They are consistent with the hypothesis that reported similarities in the form of ingestive and conditioned pecking responses reflect, in part, classical conditioning of the gape component.     

The differential expression of male sexual behavior in the Lewis, Fischer and Sprague-Dawley rat strains

Several indices of sexual behavior were characterized for male rats of the Lewis (LEW), Sprague-Dawley (SD) and Fischer (F344) strains. Males were permitted access to a receptive female of their own strain for five 50-min sessions every fifth day. LEW males emitted longer latencies (first mount, intromission, ejaculation and post-ejaculatory interval) and lower frequencies (mounts, intromissions, ejaculations, intromission ratio) relative to F344 males, with the SD strain in general, lying intermediate. Following this assessment, males of each strain were randomly assigned to females of their own or another strain to ascertain whether differences were due to differential female receptivity. Although there were no significant differences during this phase indicative of differential receptivity, the sample size may preclude a definitive interpretation of such results. The data were discussed in the context of other behavioral differences between the strains and the possible neurobiological mechanisms underlying these differences.     

Applying Konorski’s model of classical conditioning to signal-centered behavior in the rat: Some functional similarities between hunger CRs and sign-tracking

Two experiments were conducted to investigate functional similarities between “hunger CRs” of Konorski’s (1967) model of appetitive classical conditioning and sign-tracking behavior in rats. Konorski’s model predicts that hunger CRs will be facilitated (1) when a nonrein-forced stimulus similar to the reinforced CS is introduced, and (2) when some CS presentations are unexpectedly nonreinforced. In Experiment 1, hungry rats acquired a leverpress response to a retractable lever that was paired with response-independent food. Following this training, a second lever was introduced whose presentation was not followed by food. The effect of the presence of this second lever was to facilitate responding to the original lever. In Experiment 2, single-lever autoshaping training was followed by a shift from 100% pairing of the lever with food to only 50% of the lever presentations being followed by food. The introduction of partial reinforcement produced an immediate and durable increase in leverpressing. The findings of both experiments are consistent with predictions from Konorski’s model of classical conditioning if sign-tracking is considered as a “hunger CR.”     

Classical conditioning of vocalizations in the rat: Acoustic characteristics of the CR and UCR

Classically conditioned shock-elicited vocalizations in the adult rat were acoustically analyzed and described, The fundamental frequency of the CRs ranged between 2,000 and 3,600 Hz, with overtones that extended well into the ultrasonic range and with durations lasting approximately 1÷2 sec. Major differences between CR and UCR signals were apparent. The CR vocalizations had little frequency variation and little or no noise, while the UCR vocalizations were associated with highly irregular frequencies and broad-band noise. Post-shock vocalizations had combined features of the CR and UCR sounds. It is suggested that the differences between the CR and UCR are related to the CR being the emotional cry and the UCR the pain cry.     

TV,technology, and McCarthyism: crafting the democratic renaissance in an age of fear

One of the most watched political events in the United States at mid‐century, the Army‐McCarthy hearings coincided with the early period of the reception and evaluation of television as a force in society. Although optimistic rhetoric often attends the rise of new technologies, worries and fears about the power of television pervaded coverage of the hearings. The popular press expressed concern that Edward R. Murrow and Joseph McCarthy exercised unrivaled control over television viewers. Murrow and McCarthy became condensation symbols in a new struggle over control of the airwaves, and their highly publicized standoff established discursive rules for thinking about the power of audiences, journalists, and politicians.     

Control of pecking response form in the pigeon: Topography of ingestive behaviors and conditioned keypecks with food and water reinforcers

In Experiment 1, the form of keypecks produced in an autoshaping procedure with food or water reinforcers was compared with that of eating and drinking responses. Because the responses involve a number of different effector systems, several elements of response form were measured, including peck force and duration, gape, and eye closure. Gape was the only measure to reliably distinguish between both ingestive responses and between conditioned keypecks reinforced with food or water. With either reinforcer, keypecks had greater force than did ingestive behaviors. In Experiment 2, a transition between two forms of keypeck was produced by manipulating deprivation and reinforcer conditions. Some measures appeared to vary in a dichotomous manner between two discrete response forms; gape showed a gradual and continuous change involving the production of intermediate forms of the response. It was concluded that the control of conditioned response form involves theconstruction of the response from movements produced by several effector systems, each with potentially different sources of control.     

What the rat’s nose tells the rat’s mouth: Long delay aversion conditioning with aqueous odors and potentiation of taste by odors

In Experiment 1, olfactory bulbectomized and control rats were trained using operant conditioning to determine the taste threshold of aqueous amyl acetate. Concentrations below gustatory threshold were used in Experiments 2–5 to compare the effectiveness of odors with various concentrations of saccharin as cues for illness. The results showed the following: (1) The effectiveness of odor and taste was directly related to concentration; (2) the strength of an aversion to a concentration of taste could be matched by an appropriate concentration of an odor; (3) odor was as effective as taste with CS-US delays of 4 h; and (4) an effective odor potentiated an aversion to an otherwise ineffective taste. The results challenge the privileged role accorded tastes in food aversion learning and the manner in which tastes are held to interact with odors according to the sensory-and-gate channeling analysis of potentiation (Rusiniak, Hankins, Garcia, & Brett, 1979).     

A behavioral field approach to general activity: Sex differences and food deprivation in the rat

Male and female rats under different levels of food deprivation were observed in an enclosed chamber equipped with several manipulanda. Dependent variables included: time spent in immobility, grooming, exploration, and different types of manipulation (e.g., sand-digging); sequential dependencies between different kinds of behaviors; and ultrasonic activity counts. Results showed that deprivation generally increased exploration and manipulation and decreased immobility. Deprivation also increased the variability of bout lengths but had little effect on sequential dependencies or activity counts. These results provide evidence for the response-selection function rather than the energizing function of food deprivation. Various sex-related factors appearing in the data were also described. The present findings of sex differences and deprivation effects were presented as examples of state-generated behavioral fields.     

Blocking in eyelid conditioning: Effect of changing the CS-US interval and introducing an intertriai stimulus

Kamin’s three-stage blocking paradigm was investigated in rabbit eyelid conditioning, Two manipulations were examined. A change in the CS-US interval from Stage 1 to Stage 2 did not attenuate blocking. The introduction of a salient stimulus during the intertriai interval in Stage 2 also failed to attenuate blocking. The first result is not consistent with Kamin’s interpretation of the blocking effect in terms of US surprisingness. The second resuit is inconsistent with a prediction based on the Rescorla-Wagner model.     

A behavior field approach to instrumental learning in the rat: II. Training parameters and a stage model of extinction

Three runway experiments tested a stage model of extinction which postulated an orderly succession of three qualitatively different stages: habit, trial and error, and resolution. The model predicted that Stage 1 should be characterized by perseveration of habitual routes (i.e., response persistence) and the absence of competing responses; Stage 2, by an increase in investigatory behavior (response variation and hole exploration) and biting behavior; Stage 3, by a decrease in the competing responses of Stage 2 and continued increase in goal avoidance and substitution behavior (e.g., sand-digging). These predictions were largely confirmed. Further, Experiments 1 and 2 showed that, as expected by the model, continuous reinforcement (CRF) resulted in more practice of habitual routes in acquisition and greater response persistence, while partial reinforcement (PRF) resulted in more route variation and hole exploration in acquisition and greater goal persistence which was attributable to prior reinforcement of a trial-and-error coping strategy. Results of Experiment 3, which combined training trials and reward magnitudes orthogonally, supported the prediction that response persistence was positively related to training trials, and goal persistence negatively related to reward magnitudes. All three experiments demonstrated an inverted-U function in investigatory and biting behavior, as predicted by the stage model.     

Signal-directed behavior in the rat: Interactions between the nature of the CS and the nature of the UCS

Two experiments are described, which involved the investigation of interactions between the nature of the conditioned stimulus (CS) and the nature of the unconditioned stimulus (UCS) in producing signal-centered behavior. In Experiment 1, rats received response-independent heat reinforcement in a cold environment. For some groups, this heat UCS was signaled by presentations of a standard aluminum retractable lever; for other groups, it was signaled by a retractable lever covered in acrylic fur (furry lever CS). Only the subjects that received the furry lever CS paired with heat exhibited differential CS-contact behavior, when compared with unpaired, aluminum lever, and warm control subjects. In Experiment 2, hungry rats received pairings of either an aluminum or a furry lever with food (UCS). When compared with unpaired controls, only the subjects that received the aluminum lever paired with food showed differential signal-directed behavior; the subjects receiving the furry lever CS did not show differential contact with the CS, but instead exhibited differential food tray entry behavior during CS presentation. In the two studies, the signal-directed behavior exhibited by subjects resembled either thermoregulatory or feeding behaviors characteristic of rats. The results suggest that signal-directed behavior is determined by a complex interaction between the ecological relevance of the CS and the nature of the UCS—an interaction that can best be described in terms of a behavior systems model of conditioned responding.     

The effect of intensity and frequency of intermittent punishment in acquisition on resistance to extinction of an approach response in the rat

Rats trained to make an approach response with either nonreward or 150- or 175-V shock occurring on 2, 3, or 4 of 6 daily trials showed greater resistance to extinction than continuously reinforced-unpunished controls. Persistence during extinction was a function of both the type and the frequency of response-contingent event in acquisition. The significant interaction of these two factors was best interpreted as a result of the counterconditioning of the approach response (Amsel, 1972) to anticipatory conditions which varied in similarity to the frustrative nonreward of extinction.     

Effects of contextual cues previously paired with footshock or illness on behavior and pain sensitivity in the rat

Rats were used in four experiments to study the effects on behavior and pain sensitivity of exposure to a context previously paired with footshock or injection of the emetic drug lithium chloride (LiCl). Exposure to a context previously paired with footshock or injection of LiCl provoked the species-typical defense response of freezing (Experiments 1A and 1B). Exposure to a context previously paired with footshock additionally produced hypoalgesia when rats were tested using the tailflick test (Experiment 1A). By contrast, exposure to a context previously paired with injection of LiCl produced hyperalgesia when rats were tested using the tailflick test (Experiment 1B). However, exposure to a context previously paired with injection of LiCl did provoke hypoalgesia when rats were tested for pain sensitivity using either the hotplate or formalin tests (Experiment 2), which was mediated by the release of endogenous opioid peptides (Experiment 3). These results are discussed with reference to the processes governing associative regulation of defensive behavior and pain control.     

The effect on test results of changes in task and response format required by altering the test administration from an individual to a group form

Group and individual forms of a measure were developed to assess the acquisition of behaviors desired as outcomes of instruction in science at the elementary school level. Significant differences between the scores of individuals on the group and individual measures were observed. Students demonstrated higher competence on the items employing the individual format.     

Measuring knowledge of natural selection: A comparison of the CINS,an open‐response instrument,and an oral interview

Growing recognition of the central importance of fostering an in‐depth understanding of natural selection has, surprisingly, failed to stimulate work on the development and rigorous evaluation of instruments that measure knowledge of it. We used three different methodological tools, the Conceptual Inventory of Natural Selection (CINS), a modified version of Bishop and Anderson's (Bishop and Anderson [1990] Journal of Research in Science Teaching 27: 415–427) open‐response test that we call the Open Response Instrument (ORI), and an oral interview derived from both instruments, to measure biology majors' understanding of and alternative conceptions about natural selection. We explored how these instruments differentially inform science educators about the knowledge and alternative conceptions their students harbor. Overall, both the CINS and ORI provided excellent replacements for the time‐consuming process of oral interviews and produced comparable measures of key concept diversity and, to a lesser extent, key concept frequency. In contrast, the ORI and CINS produced significantly different measures of both alternative conception diversity and frequency, with the ORI results completely concordant with oral interview results. Our study indicated that revisions of both the CINS and ORI are necessary because of numerous instrument items characterized by low discriminability, high and/or overlapping difficulty, and mismatches with the sample. While our results revealed that both instruments are valid and generally reliable measures of knowledge and alternative conceptions about natural selection, a test combining particular components of both instruments—a modified version of the CINS to test for key concepts, and a modified version of the ORI to assess student alternative conceptions—should be used until a more approprite instrument is developed and rigorously evaluated. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 1131–1160, 2008     

Disentangling genetic and environmental influences on early language development: The interplay of genetic propensity for negative emotionality and surgency,and parenting behavior effects on early language skills in an adoption study

Parenting and children's temperament are important influences on language development. However, temperament may reflect prior parenting, and parenting effects may reflect genes common to parents and children. In 561 U.S. adoptees (57% male) and their birth and rearing parents (70% and 92% White, 13% and 4% African American, and 7% and 2% Latinx, respectively), this study demonstrated how genetic propensity for temperament affects language development, and how this relates to parenting. Genetic propensity for negative emotionality inversely predicted language at 27 months (β = −.15) and evoked greater maternal warmth (β = .12), whereas propensity for surgency positively predicted language at 4.5 years (β = .20), especially when warmth was low. Parental warmth (β = .15) and sensitivity (β = .19) further contributed to language development, controlling for common gene effects.     

Interaction of activity involvement and recreational location selection behavior in Lowland City： A case study of public parks in Saga City, Japan

INTRODUCTION Public parks are representative of city green ar-eas that provide numerous recreation opportunities to the people in the community. At the same time, public parks offer social, economic, and environmental benefits. High quality park service contributes to urban quality, but requires a large city government budget on personnel, parks resources, and admini-stration to maintain public parks’ high quality of ser-vice. In order to maintain and explain the budget for public parks…