A Pavlovian analysis of food-attraction conditioning in the snailHelix aspersa

Following brief pairing of an odor with a feeding experience (food-attraction conditioning), snails will lower their tentacles when subsequently presented with that odor alone. Three experiments investigated the possible behavioral mechanism mediating food-attraction conditioning in the snailHelix aspersa. It is suggested that food-attraction conditioning is an example of Pavlovian conditioning. In this case, the odor (conditioned stimulus) is paired with oral stimulation (unconditioned stimulus), which elicits lowering of the tentacles (unconditioned response). Following conditioning, the odor comes to elicit lowering of the tentacles (conditioned response). Experiment 1 ruled out nonassociative effects, such as habituation and sensitization, using an unpaired control group. Experiment 2 provided further evidence against a role for habituation of neophobia, through the demonstration of extinction following conditioning. In Experiment 3, an omission procedure was used to rule out the possible role of instrumental contingencies.     

Travelling the Unpaved Road to Democracy from Communism: A Cross‐Cultural Perspective on Change

The basic subject of this article is change, how one copes with it, how it can or cannot be guided. More specifically, the author, a Czech‐American scholar, examines the processes and the trauma of the post‐1989 transition in his country of birth with an eye to how education, particularly higher education, can contribute to a successful outcome to transition affecting all of society while undergoing transition itself. Crucial to the presentation and arguments of the author is his conviction that the period of communist rule in Czechoslovakia, as in the other central and eastern European countries, was intellectually and morally damaging. For the citizens of the Czech Republic as well as for those of the other central and eastern European countries who also experienced communism and who are now trying to recover from it, it is necessary that they develop a clear understanding of what communism really represented and what it did to them. For them to gain this understanding, the catharsis that goes with it, and the possibility of developing successful reforms that will move their countries forward in a constructive way, they must develop a number of cross‐cultural skills through familiarity with a number of social science and educational disciplines that were more‐or‐less closed to them. The author proposes ways in which these skills can be learned and education at all levels profoundly reformed.     

Self-modeling as an intervention to increase student classroom participation

The effect of self-modeling as an intervention to increase individual participatory behavior in the classroom was investigated using a multiple baseline design across three second grade students with a follow-up. In addition, a control student was employed to further investigate the effects of the intervention. Self-modeling is defined as the positive change in behavior resulting from spaced viewing of oneself on edited tapes depicting exemplary behavior. Students viewed edited videotapes of themselves successfully volunteering to participate in class by raising their hand. The three students, during baseline, had a mean participation rate ranging between 8% and 24% compared with the control student's rate ranging between 53% and 63%. During intervention, the mean participation rate ranged between 28% and 60% compared with the control student's rate ranging between 43% and 46%. At follow-up, students had a mean percentage rate ranging between 44% and 64% compared with the control student's rate of 53%. Thus, they more closely approximated or surpassed the control student's mean rate of participation during intervention and follow-up, suggesting that the self-modeling intervention was effective in increasing individual participatory behavior in the classroom. © 1998 John Wiley & Sons, Inc.     

Using New Proximity Measures With Hierarchical Cluster Analysis to Detect Multidimensionality

A new approach for partitioning test items into dimensionally distinct item clusters is introduced. The core of the approach is a new item-pair conditional-covariance-based proximity measure that can be used with hierarchical cluster analysis. An extensive simulation study designed to test the limits of the approach indicates that when approximate simple structure holds, the procedure can correctly partition the test into dimensionally homogeneous item clusters even for very high correlations between the latent dimensions. In particular, the procedure can correctly classify (on average) over 90% of the items for correlations as high as .9. The cooperative role that the procedure can play when used in conjunction with other dimensionality assessment procedures is discussed.     

Generating Random Parallel Test Forms Using CTT in a Computer-Based Environment

This paper describes a procedure for automated test forms assembly based on Classical Test Theory (CTT). The procedure uses stratified random content sampling and test form pre-equating to ensure both content and psychometric equivalence in generating virtually unlimited parallel forms. The procedure extends the usefulness of CTT in automated test form construction, yielding classical item statistics based on representative sample distributions and pre-equated test forms with known psychometric characteristics. A rationale for the procedure is presented followed by an example application and discussion of psychometric considerations related to its use.     

CS modality,context conditioning,and conditioned freezing

Two studies used a one-trial-a-day aversive conditioning procedure with rats as subjects to investigate the effects of a noise versus a light CS on conditioned freezing. Experiment 1 demonstrated that less conditioned freezing was elicited by the light, although the two CSs led to similar levels of freezing to the contextual cues of the conditioning chamber. Experiment 2 replicated these outcomes and showed that the manipulation of CS intensity produced results similar to those of modality, with the more intense CSs eliciting less freezing. The second experiment also determined that freezing to contextual cues resulted from context conditioning. According to the Rescorla-Wagner model, CSs that condition poorly should generate little competition with context conditioning. Since neither the modality nor intensity factor reliably influenced context conditioning, as measured by context-evoked freezing, the studies provide no support for the view that the effects on CS-evoked freezing represent differences in the strength of conditioning to the various stimuli. This finding raises the possibility that all of the CSs conditioned well but varied in their abilities to elicit freezing because they differed in terms of the form of defensive behavior under their control.     

Increase in retention of a taste aversion by weanling rats after a long interval

Weanling rats were tested for retention of an aversion to a novel flavor (chocolate milk) that had been conditioned as a single-element conditioned stimulus (CS) or in compound with a novel ambient odor (banana). The presence of the ambient odor during conditioning had no effect on flavor aversion shortly thereafter, confirming previous results. The flavor aversion observed 21 days after conditioning, however, was significantly stronger for pups conditioned with the single-element CS than for those given the flavor-odor compound as the CS. This retention effect was due to a surprisingincrease in the conditioned aversion observed 21 days after conditioning with the single-element CS. A second experiment confirmed this paradoxical increase in retention of the aversion to chocolate milk. This experiment also verified that no such increase occurred in retention of the conditioned aversion to a different flavor (saccharin), whether the initial aversion was strong or weak. The results may be explained in terms of generalized latent inhibition from consumption of mother’s milk.     

Concept learning by pigeons: Matching-to-sample with trial-unique video picture stimuli

Pigeons were trained to match-to-sample with several new methodologies: a large number of stimuli, computer-drawn color picture stimuli, responses monitored by a computer touch screen, stimuli presented horizontally from the floor, and grain reinforcement delivered onto the picture stimuli. Following acquisition, matching-to-sample concept learning was assessed by transfer to novel stimuli on the first exposure to pairs of novel stimuli. One group (trial-unique), trained with 152 different pictures presented once daily, showed excellent transfer (80% correct). Transfer and baseline performances were equivalent, indicating that the matching-to-sample concept had been learned. A second group (2-stimulus), trained with only two different pictures, showed no evidence of transfer. These results are discussed in terms of the effect of numbers of exemplars on previous failures to find concept learning in pigeons, and the implications of the positive finding from this experiment on abstract concept learning and evolutionary cognitive development.