Associative learning in the marsupials Didelphis albiventris and Lutreolina crassicaudata..

A procedure to study associative learning in didelphid marsupials (Didelphis albiventris and Lutreolina crassicaudata) was developed, based on the use of an appetitive unconditioned stimulus, discrete conditioned stimuli, and multiple-behavior recordings of freely moving animals. In Experiments 1 and 2, three basic conditioning phenomena were reported: differential conditioning, stimulus reversal, and summation. A specific behavior developed during the excitatory signal, independently of the particular stimulus involved, consisting of rhythmic, goal-centered, sagittal head movements, highly similar across subjects and species. Unlike previous experiments on Pavlovian conditioning in marsupials, the use of differential conditioning in within-subjects designs, with appropriate counterbalance of stimuli, precludes interpretation of these results in terms of pseudoconditioning, sensitization, or sensory-perceptual effects. These results open the possiblity for systematic research on the comparative, developmental, and neuropsychological aspects of learning to which marsupials can contribute as models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative learning changes intrinsic to Hermissenda Type A photoreceptors.

The eyes of the nudibranch mollusc Hermissenda contain 2 classes of photoreceptors. Type B photoreceptors exhibit increased light responses (LRs) and membrane excitability after repeated pairings of light and rotation and play an important role in the mediation of associatively produced reductions in phototactic behavior. Type A photoreceptors (TAPs) have also been shown to change with associative training. In previous research it was not possible to determine whether the effects of associative training reflected changes in synaptic input to TAPs or intrinsic changes in somatic conductances. In the present study, intracellular recordings from synaptically isolated TAPs were obtained on retention days after training, and pairing-specific decreases in light-induced generator potentials and decreases in resting input resistance were observed. Current- and voltage-clamp analysis of TAPs from untrained animals revealed that an important determinant of the steady-state LR was a calcium-activated K+ current (IK–Ca). Thus, TAPs also appear to be a primary site for associative information storage in Hermissenda. It is suggested that enhancement of IK–Ca by associative training may contribute to the diminished LR of TAPs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contingency learning and causal detection in Hermissenda: I. Behavior.

The addition of extra light-alone or rotation-alone presentations to sequences of light-rotation pairings reduced the associative suppression of phototaxic behavior for the nudibranch Hermissenda. Training-induced changes in Type B photoreceptor light responses were found to parallel the training-induced behavioral changes in the intact animal. The decremental effects of the degraded contingency treatments upon neural and behavioral changes normally occasioned by light-rotation pairings reflected two processes. One factor was the increased stimulation frequency entailed by degraded contingency training. The second factor reflected the specifically unpaired character of the added light-alone or rotation-alone presentations, independent of frequency changes. The attenuation of phototaxic suppression was not because of a general habituation process or adaptation to the effects of either visual or vestibular stimulation. Instead, attenuation seemed to reflect a local interference effect of interspersed unpaired stimuli. The present experiments demonstrate a sensitivity to stimulus contingencies for Hermissenda similar to that of many vertebrates and indicate that contiguity and contingency relations are both encoded and stored in the Type B photoreceptors. The results indicate that similar neurophysiological mechanisms are involved. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Configural learning in two species of marsupial (Setonix brachyurus and Sminthopsis crassicaudata).

Four experiments examined the ability of quokkas (Setonix brachyurus) and fat-tailed dunnarts (Sminthopsis crassicaudata) to solve 2 configural tasks: transverse and negative patterning. Transverse patterning requires the simultaneous solution of 3 overlapping discrimination problems (A+B-, B+C-, C+A-). Both species could solve the nonoverlapping (elemental) version of this task (U+V-, W+X-, Y+Z-), but only dunnarts solved the transverse patterning task. Negative patterning requires conditioned responses to 2 stimuli when presented separately but not together (A+, B+, AB-). Both species formed a selective conditioned response to A+ and B+ stimuli and inhibited responding to a simple nonreinforced stimulus (C-), but only dunnarts successfully inhibited responding to the AB- compound to solve the negative patterning task. These experiments are the first to demonstrate configural learning in a marsupial. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative sequence learning in humans.

In a series of experiments using the serial reaction time paradigm, the authors compared the predictions of a powerful associative model of sequence learning (the simple recurrent network; J. L. Elman, 1990) with human performance on the problem devised by A. Maskara and W. Noetzel (1993). Even though the predictions made by the simple recurrent network for variants of this problem are often counterintuitive, they matched human performance closely, suggesting that performance was associatively based rather than rule based. Simple associative chaining models of sequence learning, however, have difficulty in accommodating these results. The authors' conclusion is that, under the conditions of the experiments, human sequence learning is associatively driven, as long as this is understood to mean that a sufficiently powerful means of extracting the statistical regularities in the sequences is in play. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Language-driven concept learning: Deciphering Jabberwocky.

Four experiments assessed (Whorfian) effects of language on acquiring event categories. During learning, English-like spoken language accompanied animated scenes in some conditions. Lexical (novel verbs) and/or syntactic cues (either argument structures or prepositions) covaried with event category. Other conditions provided no language. All participants' knowledge of event categories was tested without language. Participants learned the event categories better when some aspect of language covaried with them (Experiments 1, 2, & 3; but not with sounds, Experiment 4), and better still when two aspects of language covaried (Experiments 1 & 3). However, multiple (Experiments 2 & 3) and individual language cues (Experiment 4) did not always facilitate learning. The effect of language is more complicated than providing feedback, as in supervised learning, or increasing systematicity, as in unsupervised learning. Language form induced specific expectations, with effects on learning analogous to the effects of prior theories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A sourcebook for whom? Review of Adaptive learning: Behavior modification with children.

Reviews the book, Adaptive learning: behavior modification with children by B. A. Ashem and E. G. Poser (1972). The remarkable rate of growth in the development and application of behavior modification programs over the past few years has been paralleled by an equally remarkable proliferation of books and articles. This proliferation is reflected in a recent bibliography of behavior modification bibliographies (Klein, 1973) and several listings indicating the existence of not less than 100 books on the topic (e.g., Martin, 1971; Mash, 1973). It is within this framework that the offering by Ashem and Poser of a sourcebook in behavior modification techniques for children must be considered. It is my general conclusion that while the readings included in this collection are certainly of a high enough quality, the absence of sufficient editorial integration and introduction makes them somewhat less than useful. However, for those having an initial background and wanting to get some feel for a range of applications, the book could be useful. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic and controlled response inhibition: Associative learning in the go/no-go and stop-signal paradigms.

In 5 experiments, the authors examined the development of automatic response inhibition in the go/no-go paradigm and a modified version of the stop-signal paradigm. They hypothesized that automatic response inhibition may develop over practice when stimuli are consistently associated with stopping. All 5 experiments consisted of a training phase and a test phase in which the stimulus mapping was reversed for a subset of the stimuli. Consistent with the automatic-inhibition hypothesis, the authors found that responding in the test phase was slowed when the stimulus had been consistently associated with stopping in the training phase. In addition, they found that response inhibition benefited from consistent stimulus-stop associations. These findings suggest that response inhibition may rely on the retrieval of stimulus-stop associations after practice with consistent stimulus-stop mappings. Stimulus-stop mapping is typically consistent in the go/no-go paradigm, so automatic inhibition is likely to occur. However, stimulus-stop mapping is typically inconsistent in the stop-signal paradigm, so automatic inhibition is unlikely to occur. Thus, the results suggest that the two paradigms are not equivalent because they allow different kinds of response inhibition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative learning modifies the shortening reflex in the semi-intact leech Hirudo medicinalis: Effects of pairing, predictability, and CS preexposure.

Three experiments addressed the importance of the inter-event relationships of contiguity and contingency for associative learning in the semi-intact leech. It was found that both of these relationships are important for the leech to acquire a learned association between a CS (touch) and unconditioned stimulus (UCS; shock). The learning can be extinguished if training is followed by explicitly unpaired presentations of the CS and UCS, which removes the contiguity between the stimuli. Learning is degraded by the introduction of unpredicted UCSs, as well as by unreinforced presentations of the CS (CS preexposure); both manipulations reduce the contingency between the CS and UCS. These results suggest that the associative process in both vertebrates and invertebrates share considerable functional similarity in the inter-event relationships important to learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative chunk strength in artificial grammar learning.

In 4 experiments, adherence to grammatical rules and associative chunk strength (including different measures, each calculated on the basis of the frequency with which bigrams and trigrams present in the test strings appeared in the learning strings) were manipulated independently in the test phase of an artificial grammar learning task. When participants learned few items of the grammar (Experiments 1A and 2A), the associated items were more often classified as grammatical than the nonassociated ones. On the other hand, when the learning phase included most of the grammatical items (Experiments 1B and 2B), the only effect observed was an effect of grammaticality. These results suggest that, depending on the specific constraints of the tasks, knowledge based on bigrams and trigrams and knowledge based on the abstraction of the grammatical structure can be used for the classification task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Advances in the Study of Behavior: Vol. II.

Reviews the book, Advances in the Study of Behavior: Vol. II by Daniel S. Lehrman, Robert A. Hinde, Evelyn Shaw (Eds.) (1969). Like Volume I, Volume n consists of a series of professional level monographs. Each monographic chapter provides an excellent review of the contributor's research project to date. Researchers in related areas or serious students will find each article to be a stimulating report of the contributor's ongoing research in the title area. The articles thoroughly discuss the theoretical issues, report related data of other researchers and provide an excellent bibliography. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative learning modifies startle reflexes at the lateral lemniscus.

60 male albino Sprague-Dawley rats were implanted with bilateral electrodes in the ventral cochlear nucleus (VCN), ventral acoustic stria (VAS), dorsal lateral lemniscus (DLL), ventral lateral lemniscus (VLL), or the nucleus reticularis pontis caudalis (RPC). Following recovery, all Ss were conditioned to be fearful of a light by pairing a light with a shock for 10 trials on each of 2 days. One day later, startle was elicited either acoustically or electrically and in darkness or during a brief presentation of the light previously paired with the shock. In all groups, acoustic startle amplitude was significantly greater in the presence of the light than it was in darkness. Startle elicited electrically from the VCN, VAS, and VLL was also significantly increased by the light. In contrast, startle elicited electrically in the DLL or the RPC was not affected by the light despite the fact that the same Ss in the same test session had elevated acoustic startle amplitude in the presence of light. Thus, it seems that a locus has been found within the nervous system (the VLL) where a CS acts to alter neural transmission so as to affect behavior. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Sexual Behavior in the Human Female.

Reviews the book, Sexual Behavior in the Human Female by A. C. Kinsey, W. B. Pomeroy, C. E. Martin, & P. H. Gebhard (see record 1954-05526-000). According to the reviewer, this volume is the second progress report made by Kinsey and his research staff based on their fact-finding investigation of human sex behavior. The purpose of the survey is described as "an attempt...to discover what people do sexually, what factors may account for their patterns of sexual behavior, how their sexual experiences have affected their lives, and what social significance there may be in each type of behavior." Most of the statistical data presented in the volume (179 tables and 155 figures) are based on the sex histories of 5,940 white females. In all, over 16,000 histories collected over a 15-year period by the staff of the Institute for Sex Research provide the basic research data on which this report is based. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative learning and recognition memory in alcoholic Korsakoff patients.

Association learning and recognition memory were examined in 8 male alcoholic Korsakoff patients (mean age 58 yrs), and in the following 4 groups of 10 men: non-Korsakoff alcoholics (mean age 59 yrs), nonalcoholic controls (mean age 64 yrs), younger alcoholics (mean age 36 yrs), and nonalcoholic controls (mean age 37 yrs). The tasks were modeled after those used for testing memory functioning in nonhuman primates. Association learning, defined as the ability to distinguish rewarded from equally familiar nonrewarded visual stimuli, was impaired in Korsakoff patients. Korsakoff patients also were impaired on recognition memory—the ability to discriminate familiar from novel items. Results support the view of loss of multiple memory functions in alcoholic amnesia. An effect of aging was indicated by differences in performance levels between younger and older groups of non-Korsakoff participants, although the latter were superior to the Korsakoff patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative interference in the verbal learning performance of schizophrenics and normals.

Groups of recently admitted VA schizophrenics and VA nonpsychiatric patients (17 per group) were given 1 of 2 paired-associate lists. The experimental list consisted of pairs in which each stimulus had a minimal assocative connection with its response but was highly associated with another response on the list, as judged by word association norms. Comparisons of performance on this list with that on a parallel control list indicated that the presence of the cross-associates resulted in significant performance decrement (p     

Same/different abstract-concept learning by pigeons.

Eight pigeons were trained and tested in a simultaneous same/different task. After pecking an upper picture, they pecked a lower picture to indicate same or a white rectangle to indicate different. Increases in the training set size from 8 to 1,024 items produced improved transfer from 51.3% to 84.6%. This is the first evidence that pigeons can perform a two-item same/different task as accurately with novel items as training items and both above 80% correct. Fixed-set control groups ruled out training time or transfer testing as producing the high level of abstract-concept learning. Comparisons with similar experiments with rhesus and capuchin monkeys showed that the ability to learn the same/different abstract concept was similar but that pigeons require more training exemplars. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Associative interference in the paired-associate learning of remitted and nonremitted schizophrenics.

This experiment replicates a previous study which showed that recently hospitalized schizophrenics and normals did not differ in susceptibility to associative interference. 80 long-term schizophrenics were divided into remitted and nonremitted groups according to current mental status. The nonremitted Ss tended to exhibit more associative interference than either the remitted Ss or the normals in the previous study (.05     

Taste aversion learning in fyn mutant mice.

Conditioned taste aversion (CTA) learning is a robust form of classical conditioning in which animals rapidly associate a flavor with aversive internal symptoms. The present study assessed CTA learning in transgenic mice deficient in a specific nonreceptor tyrosine kinase (the fyn mutant). Fyn mutants show impaired long-term potentiation and marked deficits in acquisition of spatial learning tasks. To assess whether they are also impaired in CTA learning. fyn mutant and wild-type mice received 2 conditioning trials consisting of access to a flavored solution followed by administration of LiCl. Fyn mutant mice acquired significant CTAs following a single conditioning trial and these aversions were comparable to those seen in wild-type mice. These results indicate that the fyn mutation does not interfere with the acquisition of CTAs and hence that this mutation is not associated with a global learning deficit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Responding under basic schedules of reinforcement in the crow.

Conditioned 5 crows to key-peck for food reinforcement using standard operant-conditioning apparatus and procedures. Responding under fixed-ratio, variable-interval, variable-ratio, and fixed-interval schedules of reinforcement was successfully maintained for each S with substantial schedule requirements. Terminal patterns of response under each of the schedules were similar to those displayed by other species, with the exception that crows paused longer after reinforcement, and responded more slowly under fixed-interval schedules, than pigeons usually do. Functional relationships between measures of performance and schedule requirements were quite consistent with reports on other species. (22 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contingency learning and causal detection in Hermissenda: II. Cellular mechanisms.

Neural correlates of contingency-sensitive behavioral changes in the nudibranch Hermissenda were studied by in vitro conditioning of the isolated nervous system. The additions of unpaired light-alone or hair cell-alone stimulation presentations to sequences of light-hair cell stimulation pairings were found to attenuate the cumulative depolarization of Type B photoreceptors that normally result from pairings. Unpaired light presentations produced a transitory depression of the light-induced depolarizing generator potential of the B cell. Unpaired hair cell stimulation synaptically hyperpolarized the B photoreceptor and thus acted in a retroactive manner to partially reverse the cumulative depolarization owing to prior pairings. Behavioral experiments revealed a striking temporal specificity for the decremental effects of added light and rotational stimulation. The present experiments indicate that contiguity and contingency relations are both encoded and stored in the Type B photoreceptors, and to a first approximation reflect similar biophysical mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)