Symmetry,scale types,and generalizations of classical physical measurement

A review is presented of a number of recent results concerning fundamental measurement structures with a particular emphasis on generalizations of physical measurement. Relational structures are classified in terms of richness and redundancy of their automorphism groups (i.e., in terms of their symmetries). By means of this classification, the possible types of measurement scales are described, and the possibilities for structures with concatenation operations (either associative or nonassociative and either positive or intensive) and for conjoint structures whose automorphisms factor into component automorphisms are explicitly spelled out. Certain conjoint structures with concatenation operations on components are viewed as generalizations of classical physical measurement and some of their most important algebraic and representational properties are explored.     

Training and testing determinants of short-term associative suppression of phototaxic behavior in Hermissenda

Hermissenda crassicornis shows both short- and long-term retention of conditioning following light-rotation pairings. Previous research has shown that prolonged training (50 trials per session, three consecutive daily sessions) produces a suppression of phototaxis lasting for days. This long-term retention reflects associative learning processes, with little or no contribution of nonassociative learning. In contrast, both associative learning and nonassociative behavioral modification contribute to short-term retention following a single session of five pairing trials. In this paper, we describe important associative and nonassociative determinants of short-term changes in phototaxis. In Experiment 1, animals received successive hourly tests for phototaxis in either a horizontal or a vertical orientation. Repeated testing resulted in decreased phototaxis which was especially pronounced for animals tested horizontally. Experiments 2-4 demonstrated that both repeated handling of animals and repeated periods of dark adaptation prior to each phototaxic test contributed to the development of phototaxic suppression with repeated testing. These nonassociative influences on phototaxis interacted with the gravitational orientation employed during behavioral testing, being most pronounced for testing in the horizontal orientation. An implication of these findings is that attempts to demonstrate short-term pairing-specific suppression will be most successful when nonassociative contributions are minimized (by testing animals vertically). Experiment 5 tested this prediction. We also tested the influence of training light intensity and the stimulus specificity of conditioned suppression. Animals received either five paired or five random presentations of light and rotation. Training light intensity was either moderate or bright. Following training, animals were tested for either suppression of phototaxis or suppression of negative geotaxis, using either a horizontal or a vertical testing orientation. Consistent with previous results, horizontally tested animals exhibited pronounced nonassociative suppression following training. The use of a bright training light also produced nonassociative suppression. However, when trained with a light of moderate intensity and tested vertically, Hermissenda showed associative suppression of phototaxis (significant paired--random difference) but not geotaxis (no paired--random difference). In a final experiment we observed that the longer the period of dark adaptation (prior to testing) the longer the phototaxic latency.(ABSTRACT TRUNCATED AT 400 WORDS)     

Homeostatic theory of drug tolerance: a general model of physiological adaptation

At the heart of homeostatic theory is the idea that explicit or implicit behavioral demands placed on physiological systems are required for the biological detection of homeostatic disturbances. The detection of drug-induced disturbances is required to drive the development of all systemic tolerance, both associative and nonassociative (i.e., both forms of tolerance are behaviorally contingent). A wide range of findings ranging from morphine-induced analgesia to ethanol-induced hyposexuality shows that contingent tolerance is pervasive and may be universal. The theory also stipulates that behavioral demands placed on the target system will govern the loss of both associative and nonassociative tolerance (physiological). The present formulation integrates contingent, associative, and nonassociative tolerance and drug-opposite withdrawal reactions within a unified theory.     

Nonassociative learning processes determine expression and extinction of conditioned fear in mice

Freezing to a tone following auditory fear conditioning is commonly considered as a measure of the strength of the tone-shock association. The decrease in freezing on repeated nonreinforced tone presentation following conditioning, in turn, is attributed to the formation of an inhibitory association between tone and shock that leads to a suppression of the expression of fear. This study challenges these concepts for auditory fear conditioning in mice. We show that acquisition of conditioned fear by a few tone-shock pairings is accompanied by a nonassociative sensitization process. As a consequence, the freezing response of conditioned mice seems to be determined by both associative and nonassociative memory components. Our data suggest that the intensity of freezing as a function of footshock intensity is primarily determined by the nonassociative component, whereas the associative component is more or less categorical. We next demonstrate that the decrease in freezing on repeated nonreinforced tone presentation following conditioning shows fundamental properties of habituation. Thus, it might be regarded as a habituation-like process, which abolishes the influence of sensitization on the freezing response to the tone without affecting the expression of the associative memory component. Taken together, this study merges the dual-process theory of habituation with the concept of classical fear conditioning and demonstrates that sensitization and habituation as two nonassociative learning processes may critically determine the expression of conditioned fear in mice.     

Genetic background differences and nonassociative effects in mouse trace fear conditioning

Fear conditioning, including variants such as delay and trace conditioning that depend on different neural systems, is widely used to behaviorally characterize genetically altered mice. We present data from three strains of mice, C57/BL6 (C57), 129/SvlmJ (129), and a hybrid strain of the two (F(1) hybrids), trained on various versions of a trace fear-conditioning protocol. The initial version was taken from the literature but included unpaired control groups to assess nonassociative effects on test performance. We observed high levels of nonassociative freezing in both contextual and cued test conditions. In particular, nonassociative freezing in unpaired control groups was equivalent to freezing shown by paired groups in the tests for trace conditioning. A number of pilot studies resulted in a new protocol that yielded strong context conditioning and low levels of nonassociative freezing in all mouse strains. During the trace-CS test in this protocol, freezing in unpaired controls remained low in all strains, and both the C57s and F(1) hybrids showed reliable associative trace fear conditioning. Trace conditioning, however, was not obtained in the 129 mice. Our findings indicate that caution is warranted in interpreting mouse fear-conditioning studies that lack control conditions to address nonassociative effects. They also reveal a final set of parameters that are important for minimizing such nonassociative effects and demonstrate strain differences across performance in mouse contextual and trace fear conditioning.     

Relational Semantics of the Lambek Calculus Extended with Classical Propositional Logic

We show that the relational semantics of the Lambek calculus, both nonassociative and associative, is also sound and complete for its extension with classical propositional logic. Then, using filtrations, we obtain the finite model property for the nonassociative Lambek calculus extended with classical propositional logic.     

Confirmatory Measurement Model Comparisons Using Latent Means

Confirmatory factor analysis (CFA) is often used to verify measurement models derived from classical test theory: the parallel, tau-equivalent, and congeneric test models. In this application, CFA is traditionally applied to the observed covariance or correlation matrix, ignoring the observed mean structure. But CFA is easily extended to allow nonzero observed and latent means. The use of CFA with nonzero latent means in testing six measurement models derived from classical test theory is discussed. Three of these models have not been addressed previously in the context of CFA. The implications of the six models for observed mean and covariance structures are fully described. Three examples of the use of CFA in testing these models are presented. Some advantages and limitations in using CFA with nonzero latent means to verify classical measurement models are discussed.     

An analysis of behavioral plasticity in male Caenorhabditis elegans.

Caenorhabditis elegans is a simple soil-dwelling nematode which has two sexes, hermaphrodite and male. The male C. elegans is differentiated from the hermaphrodite by the presence of 14 sensory structures in the tail. In this study, we compared the behavioral responses of males and hermaphrodites to head-touch and to tap. We hypothesized that the anatomical difference in sensory structures might result in behavioral differences in the reversal response to vibratory stimulation (a tap to the side of the holding dish). In the response to increasing intensities of tap, both sexes showed an increase in response magnitude, with the males showing larger responses than hermaphrodites. In addition, the male was shown to be capable of simple nonassociative learning: it demonstrated habituation and recovery from habituation in a similar manner as the hermaphrodite. Tail-touch-induced inhibition of the reversal response appeared to be similar in males and hermaphrodites. The evidence suggests that the touch withdrawal circuit in hermaphrodites is also present in the male C. elegans, and that the subtle differences in response to tap seen in males may result from the additional sensory receptors of the copulatory bursa of the tail. It seems clear from these studies that these structures do not play a key role in the male worm's response to tap.     

Single-trace fragility theory of memory dynamics

In single-trace fragility theory, forgetting is produced by two factors, time and interference. Memory traces are assumed to have two partially coupled dynamic properties, strength and fragility. Strength determines the probability of correct recall and recognition, while fragility determines the susceptibility of the trace to the time-decay process but not to the interference process. Consolidation is assumed to be a continual reduction in the fragility of the memory trace rather than any change in strength or availability. Decreasing fragility accounts for the continually decreasing forgetting rate, the temporal character of retrograde amnesia and recovery therefrom, and the type of internal clock necessary for nonassociative recency judgments. Data are presented to indicate that interference is independent of the interval between original and interpolated learning, that nonassociative recency discriminability approaches a limit at about 30 min, and that the decay rate of long-term retention in amnesic patients is the same as in normal Ss.     

Disproportionate deficit in associative recognition relative to item recognition in global amnesia

In two experiments, we tested the hypothesis that medial temporal lobe (MTL) amnesic patients and, likewise, diencephalic (DNC) amnesic patients evidence a disproportionate deficit in memory for associations in comparison with memory for single items. In Experiment 1, we equated item recognition in amnesic and control participants and found that, under these conditions, associative recognition remained impaired both for MTL patients and for DNC patients. To rule out an alternative interpretation of the results of Experiment 1, in Experiment 2 we compared the performance of amnesic and control participants on a one-item recognition task and a two-item recognition task that required no memory for the association between members of word pairs. In the MTL group, when single-item recognition was equated to that of the controls, two-item nonassociative pair memory was equivalent as well. In the DNC group, nonassociative pair memory was impaired, but this impairment did not fully account for the impairment in associative memory. These findings indicate that memory for novel associations between items is disproportionately impaired in comparison with memory for single items in amnesia.     

Evolution of Nonassociative Learning: Behavioral Analysis of a Phylogenetic Lesion

A recent phylogenetic analysis of two learning-related neuromodulatory traits in mechanosensory neurons of species related to the marine molluskAplysia californicaidentified one species,Dolabrifera dolabrifera,which lacked both neuromodulatory traits. Since these traits are thought to contribute importantly to certain forms of learning and memory in the defensive withdrawal reflexes ofAplysia,in the present study, I tested the prediction that facilitatory nonassociative learning would be reduced or absent inDolabrifera.I tested the tail-mantle withdrawal reflex inDolabriferaand size-matchedAplysiafor three forms of nonassociative learning and memory: dishabituation and short- and long-term sensitization. I found that the same protocols that produced significant dishabituation, short-term sensitization, and long-term sensitization inAplysiafailed in all three cases to produce significant learning inDolabrifera.Thus, the prediction from the prior mechanistic analysis is confirmed: Dishabituation and short- and long-term sensitization are significantly reduced and perhaps abolished inDolabrifera.Although not conclusive, this phylogenetic correlation between the absence of behavioral changes and the absence of neural mechanisms thought to underlie the behavioral changes gives support to the contemporary neuromodulatory model of dishabituation and sensitization inAplysia.Furthermore, these results raise the possibility that evolutionary alteration of two specific neuromodulatory mechanisms may have directly contributed to evolutionary change in behavioral plasticity.     

Minimal conditions for additive conjoint measurement and qualitative probability

Axioms for additive conjoint measurement and qualitative probability are given. Representation theorems and uniqueness theorems are proved for structures that satisfy these axioms. Both Archimedean and nonarchimedean cases are considered. Approximations of infinite structures by sequences of finite structures are also considered.     

Semantic features and semantic categories: differences in rapid activation of the lexicon.

Robust priming was shown in a semantic categorization task for prime-target pairs which shared semantic features (e.g., pumpkin-squash). Priming facilitation for these pairs was demonstrated at extremely rapid prime exposures (28 and 43 ms) and increased with prime duration. The onset and amount of facilitation differed significantly for these semantic, nonassociative pairs and for associative-semantic prime-target pairs (e.g., cow-bull). The latter pairs produced facilitation, but later (at prime-target SOAs of 70 and 200 ms) and of lesser magnitude. These results are discussed in relation to three current models of semantic memory: spreading activation, compound cue, and distributed models.     

Overshadowing and blocking of the orientation-contingent color aftereffect: Evidence for a conditioning mechanism

Orientation-contingent color aftereffects have been interpreted by nonassociative mechanisms (adaptation of neural units that are both color and orientation specific) and by associative mechanisms (conditioning resulting from the pairing of pattern and hue). To evaluate associative accounts, contingent aftereffects were induced by exposing subjects to compound chromatic grid patterns consisting of two component gratings: one was horizontal or vertical, and the other a left- or right-learning diagonal. The ability of a component grating to elicit a color aftereffect depended on the relative salience and the aftereffect training history of the grating components. That is, orientation-contingent color aftereffects, like other conditional responses, display overshadowing and blocking. The results suggest that conditioning contributes to these aftereffects.     

'Nonspecific' rather than 'nonassociative' pathways to phobias: a commentary on Poulton and Menzies

This commentary attempts to clarify the nature of contemporary associative accounts of phobias, and to describe how they might contribute to the explanation of the diversity of phobic aetiologies. It is argued that conditioning-equivalent associations underpin all phobic conditions, and that the role of experimental psychopathology research is to determine how these associations are acquired. The commentary then proceeds to discuss some of the theoretical problems with the nonassociative account of phobias as it is currently described by Poulton and Menzies, and to suggest that some interpretations of their retrospective and prospective data may not be incompatible with contemporary associative accounts. The outcome of this is that it may be more suitable to describe the fourth pathway to phobia acquisition described by Poulton and Menzies as a 'nonspecific' rather than a 'nonassociative' pathway.     

Vulnerability of skeletal and autonomic manifestations of memory in the rat to electroconvulsive shock.

A series of experiments was performed to probe the phenomenon of sparing of memory by electroconvulsive shock (ECS) when amnesia is assessed by autonomic indices. Differential vulnerability of memory as indexed by skeletal and autonomic responses was determined to be a function of a higher threshold to disruption for autonomically indexed memories. Autonomic responses spared by ECS were found to reflect underlying memory rather than artifact produced by nonassociative factors arising from the interaction of conditioned stimulus (CS), unconditioned stimulus (US), and ECS. Furthermore, retrograde amnesia gradients of different slopes were observed with skeletal and autonomic measures. Two interpretations of these phenomena are discussed. One hypothesis suggests that individual components of a memory are consolidated at different rates, whereas the other concerns the differentail sensitivity of various measures in assessing memory.     

Folded additive structures: A nonpolynomial model of some factorial interactions

A nonpolynomial measurement model for representing nonadditive compositions of stimulus dimensions is presented. This representation, which is referred to as a folded additive structure, permits the decomposition of a behavioral ordering into independent factors in some of the cases where the behavior itself does not directly reflect this independence. Psychologically, this representation corresponds to a model of behavior which assumes that (1) the effect stimulus attributes have on behavior is mediated by a single relevent psychological dimension, (2) the behavioral ordering is single-peaked over this mediating dimension and (3) the mediating dimension has a conjoint additive ordering over a set of relevent stimulus dimensions. Necessary and sufficient tests for folded additive structures are given. In addition, five psychological theories which make these assumptions are discussed.     

Affective-Evaluative Learning in Humans: A Form of Associative Learning or Only an Artifact?

The status of evaluative conditioning (EC) as a distinct form of associative learning was called in question by Field and Davey (1997, 1998, 1999), who argued that in the typical visual EC paradigm, nonassociative visual concept learning is responsible for the evaluative changes observed. Especially, the use of only within-subject control conditions instead of independent control groups was criticized. The present three experiments show (a) that EC effects can be demonstrated within another sensory modality than visual perception and (b) that EC effects are demonstrable in a between-subject design (including a successful replication attempt). A further result was that these EC effects do not require participants' conscious awareness. The data provide no support for an artifactual account of EC but suggest an interpretation of EC as a form of associative learning.     

Interference with ingestional aversion learning produced by preexposure to the unconditioned stimulus: Associative and nonassociative aspects

Preconditioning exposure to a lithium chloride unconditioned stimulus (US) interferes with the subsequent conditioning of a taste aversion. Multiple US preexposures produce a long-lasting or durable interference with aversion learning, whereas a single US exposure produces a transient interference effect. The present experiments demonstrate that the durable US preexposure effect is substantially reduced if the method of drug treatment (infusion versus injection of the drug into the peritoneal cavity) or the spatial cues present during drug treatment (home cage versus a distinctive environment) are changed between the preexposure and taste conditioning phases of the experiment. In contrast, these manipulations do not attenuate the proximal/transient US preexposure effect. These findings indicate that different mechanisms are responsible for the two US preexposure effects. The results are consistent with previous suggestions that the durable effects of lithium preexposure are due to associative interference produced by the exteroceptive stimuli that accompany drug administrations and indicate that the proximal/transient US preexposure effect is mediated by nonassociative mechanisms.