Cross-Modal Transfer of Shape is Difficult to Demonstrate in One-Month-Olds

We tested 1-month-olds for cross-modal transfer of shape between touch and vision using a procedure described by Meltzoff and Borton, but including controls for side bias and stimulus preference. In Experiment 1 (N = 48), infants' looking times to smooth and nubby visual stimuli were not influenced by previous oral exposure to one of the shapes during the preceding 90 s, except for an effect on the first test trial in one group; this effect could have been due to limited cross-modal transfer, to Type 1 error, or to side bias, possibly interacting with a small stimulus preference. The failure of that effect to replicate in a group (N = 16) with less side bias (Experiment 2) suggests that it was not due to cross-modal transfer. Experiment 3 (N = 32), an exact replication of Meltzoff and Borton's experiment, also failed to yield evidence of cross-modal transfer. Overall, there is not good evidence that 1-month-olds can transfer information about these shapes from touch to vision. Future studies exploring the ability to transfer information about other shapes will be easier to interpret if they include controls for side bias and stimulus preference.     

Active- and passive-avoidance learning in inbred mice: Transfer of training effects

The performance of four groups of mice of two genotypes (DBA/2J and C57BL/6J) was observed in two avoidance situations. Two groups, one of each strain, were given a maximum of 30 conditioning trials in an active avoidance situation followed by a maximum of 30 trials in a passive avoidance situation. The other two groups, one of each strain, were given passive avoidance conditioning first, followed by active avoidance conditioning. Positive transfer of training was observed in both genotypes for mice that received active avoidance conditioning prior to passive avoidance conditioning. Little or no transfer was observed from passive to active avoidance in either strain.     

Summation of undetected excitation following extinction of the CER

The effects of compounding two conditioned stimuli (CSs), each of which had been extinguished to varying degrees in different groups of rats given identical acquisition training, was examined within the conditioned emotional response paradigm. Greater suppression to the compound than to the individual CSs was observed following 6, 12, 48, 72, and 96 stimulus extinction trials, although after only 12 extinction trials suppression to the individual stimuli was no longer observed. The amount of compound suppression decreased progressively as the number of extinction trials increased until, after 120 extinction trials on each stimulus, the compound no longer elicited observable suppression. Control group data indicated that the observed summation effect could not be attributed to disinhibition. The possible role of the summation of undetected excitation in studies examining configurai conditioning, avoidance conditioning and reinstatement is discussed briefly.     

A transfer of control test for contextual associations

A transfer of control experiment measured the associative properties of contextual stimuli from three standard classical conditioning paradigms. After baseline training on a Sidman avoidance schedule, dogs received aversive conditioning using excitatory, inhibitory, or truly random conditioning procedures in the presence of a manipulable background stimulus. As predicted by current theory (Rescorla & Wagner, 1972; Wagner & Rescorla, 1972), the contextual stimulus was excitatory after serving as the background during conditioning of a CS? and was neutral when it had been part of the background for conditioning of a CS+. The background to the truly random procedure was also neutral. This last result contrasts with Rescorla and Wagner’s theory.     

Preexposure to situational cues and shock intensity in two-way avoidance learning

Four groups of rats (n = 16) received 65 two-way avoidance learning trials. The groups differed with respect to the amount of exposure (0 or 4 h) to the situational cues of the apparatus prior to avoidance learning and the intensity of shock (.3 or 1.6 mA) during learning. Superior avoidance performance with weak as compared to strong shock was obtained in the nonpreexposed groups. This inverse relationship between avoidance performance and shock intensity, typical of two-way avoidance learning, was eliminated in the preexposed groups. Presumably, a latent inhibition effect occurred in the strong-shock group, which resulted in a retardation of the conditioning of fear to the situational cues and a consequent improvement in performance. The results are consistent with the effective reinforcement theory, which emphasizes in aversive learning the detrimental effect of large amounts of fear remaining following a response.     

Cross-modal transfer as a function of initial training level in classical conditioning with the rabbit

Initial reinforced training with a conditioned stimulus (CSA) from one sensory modality subsequently facilitates the rate of acquisition of the rabbit’s nictitating membrane response to a second conditioned stimulus (CSB) from a different sensory modality. In Experiment 1, the level of transfer was a direct function of the number of CSA-US pairings (0, 15, 30, 60, and 120). In Experiment 2, cross-modal transfer appeared to be maximal after initial training was conducted to a performance criterion as small as two CRs to CSA. The results are discussed with respect to theories of transfer, particularly a layered network model of conditioning that suggests that CR acquisition to each CS depends on two sequentially organized associations, one unique to the CS and one that is common to all associations involving the target response system.     

Transfer testing after serial feature-ambiguous discrimination in Pavlovian keypeck conditioning

Four experiments were performed to explore modulatory transfer after serial feature-ambiguous (F-A) discrimination (X→A+, A?, X→B?, B+) in Pavlovian keypeck conditioning (autoshaping) with pigeons. Diffuse features were used in the first three experiments, and no modulatory transfer was found: (1) There was no modulatory transfer between two concurrently trained F-A tasks; (2) modulatory transfer to conditioned and then extinguished stimuli was not observed; and (3) responding to the targets (A and B) after their contingencies were reversed was not affected by presentation of their original feature stimulus (X). Transfer between two serial F-A tasks was obtained in the last experiment, in which keylights were used as features, but other evidence indicated that this was due to stimulus generalization between the features. Together, the results strongly suggest that specific target-food occasion setting or configural learning is the underlying mechanism of F-A discrimination.     

A context-specific detrimental effect of UCS preexposure on place conditioning with morphine

The effect of morphine preexposure on place conditioning with morphine was investigated. In the first experiment, five injections of 10 mg/kg morphine were administered to rats prior to place conditioning or taste-aversion training with morphine. Although this number of preexposures retarded taste-aversion learning, there was no effect on place conditioning. In subsequent experiments we investigated the role of context blocking in UCS preexposure in place conditioning. In one experiment, preexposure to five morphine injections prior to place conditioning resulted in a reduced place preference, compared with preexposure and place conditioning in different contexts. However, the overall detrimental effect of morphine preexposure was questionable, because the rats that were preexposed were only marginally different from those that were not preexposed. In a final experiment we examined the effect of a context change from preexposure to place conditioning with 15 preexposures and demonstrated a detrimental effect of preexposure on place conditioning that was context specific. These results support a role of classical conditioning in place-preference conditioning with morphine.     

Stimulus nonequivalences in go/no-go avoidance discriminations: Sensory,drive, and response factors

Previous work with rats showed slower active avoidance (AA) and passive avoidance (PA) learning in a light-go/noise-light no-go task (L⁺NL^?) than in a noise-go/light-noise no-go task (N⁺LN^?), independently of noise intensity and of presence or absence of AA pretraining. Experiment I compared these two tasks and the corresponding discriminations with a compound AA and a simple PA signal. The latter were learned at a faster rate, with only negligible differences between the two types of stimulus arrangements (NL⁺L^? vs LN⁺N^?). Experiment II investigated the acquisition and reversal of four go/no-go tasks with a simple AA signal, with either a simple or a compound no-go signal and asymmetrical reinforcement, i.e., with an extinction instead of a PA contingency during the presentation of no-go signals. As in previous experiments with symmetrical reinforcement, the groups with a simple no-go signal (L⁺N^?, N⁺L^?) acquired AA with little or no generalization to the other stimulus. In reversal, however, the L⁺N^? group (formerly N⁺L^?) responded to the no-go signal much more frequently than the other (N⁺L^?, formerly L⁺N^?). Both the L⁺NL^? and the N⁺LN^? groups gave a large number of responses to the extinction signal, but the differences between the two groups were at least as large as in previous work with a PA contingency. These data show that perceptual or attentional phenomena cannot explain stimulus nonequivalences in situations with a compound no-go signal. Furthermore, the similar nonequivalences found in situations with and without differential fear conditioning (AA-extinction tests vs AA-PA tests) leads to complex, highly speculative models concerning possible interactions between response and drive-modulating properties of various stimuli.     

Learning about qualitatively different outcomes during a blocking procedure

In four experiments, rat subjects were used in appetitive Pavlovian magazine-approach and instrumental conditioning procedures. Experiments 1 and 2 found successful blocking of the Pavlovian conditioning of X when it was reinforced in an AX compound after prior conditioning of A. This occurred whether the outcome following AX was the same as or qualitatively different from what followed A. Experiment 3 repeated those findings but also used a transfer procedure to identify the individual associations between X and outcomes. Stimulus X developed an association with the outcome following AX when that outcome differed from that following A alone but not when it was the same as that following A alone. Experiment 4 repeated that pattern of observations for the case of an X that was an instrumental discriminative stimulus. These results suggest that different associative structures may result from a qualitatively changed and unchanged outcome in a blocking experiment. The results are related to comparable findings for the case of overexpectation.     

Surprise and blocking: Effects of the number of compound trials

In an experiment on conditioned suppression of licking in thirsty rats, subjects received either one or two trials to a tone-light compound, either preceded or not preceded by four conditioning trials to the light alone. Prior conditioning to the light blocked conditioning to the tone in subjects receiving two compound trials but not in those receiving only one compound trial. The blocking observed in the two-trial groups was abolished either by the addition of an unexpected second posttrial shock 10 sec after the first on each compound trial or by the omission of an expected second, posttrial shock. The comparable operations had no effect on conditioning to the tone in the one-trial group. In this preparation, both blocking and the attenuation of blocking by surprising changes in reinforcement appear to require more than one trial to appear.     

Asymmetries in Infant Cross-Modal Transfer

3 groups of 12-month-olds were tested for cross-modal and intramodal transfer of information about shape. Infants were given either visual (V) or tactual (T) familiarization and then tested for visual recognition (V-V, T-V) or tactual recognition (T-T, V-T). Transfer was tested after either 15, 30, or 60 sec familiarization. Overall, intramodal transfer was superior to cross-modal transfer. Whereas the V-V condition was easiest of all, the T-T condition proved easier than V-T cross-modal transfer, although it was no more difficult than T-V transfer; cross-modal asymmetries appeared, with T-V easier than V-T. The asymmetry in cross-modal transfer could not be explained by intramodal factors. Possible bases for cross-modal asymmetries were discussed.     

Stimulus generalization decrement in latent inhibition to a compound following exposure to the elements or the compound

In two experiments using the taste-aversion paradigm, we attempted to replicate a result reported by Holland and Forbes (1980), in which exposure to the elements of a compound produced more interference with future conditioning (latent inhibition) to the compound than did exposure to the compound itself. In our first experiment, a compound of HC1 and sucrose was used and the amount of fluid consumed during exposure and the first conditioning trial was controlled. Rather than finding enhanced interference produced by exposure to the elements, we found reduced interference relative to exposure to the compound. In Experiment 2, a compound of NaCl and sucrose was used and a method similar to that used by Holland and Forbes was employed. We replicated the result of our Experiment 1. We interpret these results as posing problems for some associative accounts of latent inhibition but as being easily explained as an instance of stimulus generalization decrement.     

Effect of extended training on generalization of latent inhibition: an instance of perceptual learning

Four experiments examined generalization of latent inhibition (LI) as a function of the length of preexposure in a conditioned taste aversion procedure with rats. Experiment 1 showed that one or four nonreinforced presentations of a flavor compound (BX) retarded subsequent conditioning to another compound (AX). However, after eight presentations of BX, conditioning to AX occurred at the same rate as with no preexposure. These results indicate that generalization of LI decreased as the length of preexposure to BX increased. Experiment 2 replicated this effect of reducing generalization, as well as demonstrating that LI actually increased as the length of preexposure to AX increased. Experiment 3 extended the generality of the effect to a procedure in which both BX and AX were preexposed. Experiment 4 demonstrated a similar reducing-generalization effect when generalization of LI from BX to X was assessed. All of these data are consistent with the notion that prolonged preexposure to BX enhances its discriminability. Different learning mechanisms that might be responsible for this perceptual learning effect are discussed.     

Ethological analysis of predator avoidance by the paradise fish (Macropodus opercularis L.): II. Key stimuli in avoidance learning

The possible role of eyespot patterns in predator recognition by paradise fish was examined using a passive avoidance conditioning technique with various dummies or live goldfish. It was found that a low-intensity shock, although clearly uncomfortable, elicited exploratory behavior in the fish and that observable learning did not occur. However, if the paradise fish was shocked in the presence of a live goldfish or various fish dummies, exploration diminished and avoidance learning was detected. This was characterized by a considerable increase in latency to enter the shocked compartment. The most effective dummies were those with two laterally arranged eye-like spots. The possible role of species-specific key stimuli in avoidance learning and organizing defensive behavior of the paradise fish is discussed.     

Ontogeny of step-through passive avoidance learning in domestic chicks: Effects of prepunishment training and cue distinctiveness

In three experiments, 1- and 4-day-old chicks (N=96) were first trained to move from one compartment into another for heat reward, and then, following 1, 24, or 48 prepunishment trials, the chicks’ step-through responses were punished with aversive wing-shocks during 24 passive avoidance (PA) trials. The major finding of these experiments was that the age dependency of PA learning of the young chick depends upon both the number of prepunishment trials and the cue differences between the safe and shock compartments. The 1-day-old chick showed an improvement in PA learning as both prepunishment trials and cue differences were increased, but the 4-day-old chicks’ PA learning was retarded by increasing the number of prepunishment trials when either identical or distinct cues were in the two compartments. These PA results suggest that the 1-day-old chick, as compared with the 4-day-old chick, is deficient in learning, or detecting changes in, stimulus- and/or response-reinforcement contingencies.     

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.     

Positive and negative patterning in human classical skin conductance response conditioning

Three experiments on classical differential conditioning of the human skin conductance response to elemental and compound stimuli are reported. Subjects in Experiment 1 received both positive and negative patterning training, followed by either positive or negative patterning transfer tests on new stimuli. In positive patterning, a compound of two stimuli is reinforced and its elements are nonreinforced. In negative patterning, the elements are reinforced and the compound is nonreinforced. Subjects in Experiments 2 and 3 received either positive or negative patterning during training, followed by transfer tests on new stimuli. In Experiment 2, the transfer series began with new elements, after which their compound was presented; in Experiment 3, the new compound was presented first in the transfer series, and then the separate elements were administered. All three experiments provided evidence of the acquisition of positive patterning, while negative patterning was found only in Experiments 2 and 3. Positive patterning transferred to new stimuli, indicating that it was not attributable solely to summation of sub-threshold excitation conditioned to the elements on reinforced compound trials. This finding, coupled with the negative patterning found in Experiments 2 and 3, provided support for the unique cue hypothesis. It was concluded that the assumed unique cue constituted a learned “rule,” and that the actual elemental stimuli were neither perceptually nor otherwise modified during the conditioning process.     

The expertise reversal effect concerning instructional explanations

The expertise reversal effect occurs when learner’s expertise moderates design principles derived from cognitive load theory. Although this effect is supported by numerous empirical studies, indicating an overall large effect size, the effect was never tested by inducing expertise experimentally and using instructional explanations in a computer-based environment. The present experiment used an illustrated introductory text and a computer program about statistical data analyses with 93 students. Retention and transfer tests were employed as dependent measures. Each learner was randomly assigned to one condition of a 2 × 2 between subjects factorial design with the two factors expertise (novices vs. ‘experts’) and explanations (with vs. without). Expertise was induced by adding expository examples and illustrations to the introductory text to enhance text coherence and facilitate text comprehension. The expertise reversal effect was replicated for the dependent measure transfer, but not for retention. Results and implications for adaptive learning environments are discussed.     

Instrumental electrodermal conditioning in the monkey (Cebus albifrons): Acquisition and long-term retention

EightCebus albifrons monkeys received 25 sessions of discriminative operant conditioning of the skin conductance response (SCR), with colored lights as discriminative stimuli and with Sidman avoidance (SS-40 sec, RS-40 sec) scheduled during one light and response-contingent shock during the other, Discriminative stimulus segments were separated by 30-sec periods of time-out from shocks and lights, Two extinction sessions were run 3 months after training, Almost from the beginning of conditioning, the monkeys made significantly more unelicited skin conductance responses in the avoidance periods than in punishment, The monkeys’ heart rates also increased significantly, but there was no difference between avoidance and punishment, SCR frequency during extinction continued to differentiate significantly between avoidance and punishment, and there was a significant increase in this differentiation from the last conditioning session to the first extinction session, but the difference then reduced in the second session, The results indicated that monkey’s SCRs are influenced by instrumental reinforcement contingencies somewhat in the same fashion as those of humans.