Using dynamic field theory to rethink infant habituation

Much of what psychologists know about infant perception and cognition is based on habituation, but the process itself is still poorly understood. Here the authors offer a dynamic field model of infant visual habituation, which simulates the known features of habituation, including familiarity and novelty effects, stimulus intensity effects, and age and individual differences. The model is based on a general class of dynamic (time-based) models that integrate environmental input in varying metric dimensions to reach a single decision. Here the authors provide simulated visual input of varying strengths, distances, and durations to 2 coupled and interacting fields. The 1st represents the activation that drives "looking," and the 2nd, the inhibition that leads to "looking away," or habituation. By varying the parameters of the field, the authors simulate the time course of habituation trials and show how these dynamics can lead to different depths of habituation, which then determine how the system dishabituates. The authors use the model to simulate a set of influential experiments by R. Baillargeon (1986, 1987a, 1987b) using the well-known "drawbridge" paradigm. The dynamic field model provides a coherent explanation without invoking infant object knowledge. The authors show that small changes in model parameters can lead to qualitatively different outcomes. Because in typical infant cognition experiments, critical parameters are unknown, effects attributed to conceptual knowledge may be explained by the dynamics of habituation.     

Habituation to repeated stress: get used to it

Habituation, as described in the landmark paper by Thompson et al. [Thompson, R. F., & Spencer, W. A. (1966). Habituation: A model phenomenon for the study of neuronal substrates of behavior. Psychological Review, 73(1), 16–43], is a form of simple, nonassociative learning in which the magnitude of the response to a specific stimulus decreases with repeated exposure to that stimulus. A variety of neuronal and behavioral responses have been shown to be subject to habituation based on the criteria presented in that paper. It has been known for several decades that the magnitude of hypothalamic–pituitary–adrenal (HPA) activation occurring in response to a stressor declines with repeated exposure to that same stressor. For some time this decline has been referred to as “habituation” in the stress neurobiology literature. However, how this usage compares to the definition proposed by Thompson and Spencer has not been systematically addressed. For this special issue, we review the stress neurobiology literature and examine the support available for considering declines in HPA response to repeated stress to be response habituation in the sense defined by Thompson and Spencer. We conclude that habituation of HPA activity meets many, but not all, important criteria for response habituation, supporting the use of this term within the context of repeated stress. However, we also propose that response habituation can, at best, only partially explain the phenomenon of HPA habituation, which also involves well-known negative feedback mechanisms, activation of broad stress-related neural circuitry and potentially more complex associative learning mechanisms.     

Reconceptualizing inhibition of return as

Inhibition of return (IOR) is an effect on spatial attention whereby reaction times to a target presented at a location where a stimulus had recently been presented are increased, as opposed to when a target is presented at a new location. Despite early reports that habituation is not responsible for the IOR effect, the human cognitive literature provides indirect evidence in favor of the possibility. In addition, recent neurophysiological studies provide direct support for the idea that habituation is at least a contributing source for the IOR effect. The present article describes how habituation may account for the IOR effect and explores some of the predictions that this hypothesis suggests.     

Dynamic changes in reinforcer effectiveness: satiation and habituation have different implications for theory and practice

Reinforcers lose their effectiveness when they are presented repeatedly. Early researchers labeled this loss of effectiveness as satiation without conducting an experimental analysis. When such an analysis is conducted, habituation provides a more precise and empirically accurate label for the changes in reinforcer effectiveness. This paper reviews some of the data that suggest that habituation occurs to repeatedly presented reinforcers. It also argues that habituation has surprisingly different implications than satiation for theory and practice in behavior analysis. For example, postulating that habituation occurs to repeatedly presented reinforcers suggests ways for maintaining the strength of an existing reinforcer and for weakening the strength of a problematic reinforcer that differ from those implied by an account in terms of satiation. An habituation account may also lead to different ways of conceptualizing the regulation of behavior. For example, habituation may be a single-process contributor to the termination of behaviors that are usually attributed to satiation (e.g., ingestive behaviors such as eating and drinking), fatigue (e.g., energetic behaviors such as running), the waning of attention (e.g., cognitive behaviors such as studying), and pharmacodynamic factors (e.g., drug taking).     

Artificial grammer learning by infants: an auto‐associator perspective

This paper reviews a recent article suggesting that infants use a system of algebraic rules to learn an artificial grammar (Marcus, Vijayan, Bandi Rao & Vishton, Rule learning by seven‐month‐old infants. Science, 183(1999), 77–80). In three reported experiments, infants exhibited increased responding to auditory strings that violated the pattern of elements they were habituated to. We argue that a perceptual interpretation is more parsimonious, as well as more consistent with a broad array of habituation data, and we report successful neural network simulations that implement this lower‐level interpretation. In the discussion, we discuss how our model relates to other habituation research, and how it compares to other neural network models of habituation in general, and models of the Marcus et al. (1999) task specifically.     

Effects of stimulus duration and intensity on the rate and specificity of behavioural habituation

Tone stimuli were presented to rats once per day until habituation was reached. Neither the duration nor the intensity of the stimulus affected the rate of habituation. Habituation was specific to both these stimulus parameters as shown by the distraction produced by either an increase or a decrease in the original stimulus value. It is suggested that some of the discrepancies in the literature might be resolved if a distinction is drawn between habituation of orienting responses and the decrement of more specific responses.     

Examining individual differences in infants’ habituation patterns using objective quantitative techniques

The assessment of individual differences in infant habituation patterns is important for answering basic questions about continuity in cognitive development. Nevertheless, there are flaws with existing methods for determining relevant parameters of the cognitive processes associated with habituation. In this paper, a more rigorous, model-based alternative approach is illustrated. The approach demonstrates how the habituation data of individual infants may be fit by specific functions, how habituation may be distinguished from random responding, and how the parameter estimates of individual infants’ habituation functions might be analyzed for meaningful subgroups or clusters. The model-based approach provides novel insights about individual subgroups when applied to a real habituation data set and thereby demonstrates the feasibility and utility of the techniques advocated.     

Pattern preferences at birth and their interaction with habituation-induced novelty preferences

Three experiments are described which relate to models of infant visual preferences, and to the ways in which preferences can be modified or created by habituation. In all experiments newborn babies were used as subjects. In Experiments equated 1 and 2 infants were presented with pairs of stimuli that were equated for contour density but which differed in spatial frequency components. The preferences obtained give support to Banks and Salapatek's (1981, Journal of Experimental Child Psychology, 31, 1-45) model of infant preferences which predicts that the maximally preferred stimulus will be that which contains high amplitude spatial frequency components falling within the age group's peak contrast sensitivity. In Experiment 3 an infant-controlled habituation procedure was used. The results obtained suggest that strong natural preferences based on the infants' peak contrast sensitivity cannot be changed by habituating infants either to the preferred or to the nonpreferred member of a stimulus pair. However, where no prior preference exists between two stimuli that are perceptually highly discriminable, very strong novelty preferences are found after habituating newborns to either stimulus. The results suggest that the contrast sensitivity model can be a powerful predictor of preferential looking in newborns, and in addition are further evidence that preferences based on experience can be found from birth.     

从母亲的敏感性到学步儿的依恋安全性：内部工作模式的桥梁作用

采用视觉习惯化实验程序、陌生情境技术及母亲行为Q分类方法对41名14个月的学步儿及其母亲进行了学步儿内部工作模式、学步儿在陌生情境中的依恋类型以及母亲在母婴互动中的敏感性的评估。结果发现：(1)不安全型的学步儿预期看护者对他们痛苦的信号是无回应的。(2)以自身为中心的母亲的学步儿预期看护者是无回应的。(3)潜类别分析的结果发现母亲敏感性影响学步儿依恋行为的2种关系模式：类别1, 以孩子为中心的母亲的学步儿更容易形成看护者是有回应的预期, 持这种预期的学步儿在陌生情境程序中表现出安全依恋行为; 类别2, 以自身为中心的母亲养育出的学步儿更容易对看护者形成无回应的预期, 并在陌生情境中表现出不安全依恋行为。研究表明：内部工作模式在母亲的敏感性和学步儿的依恋安全性之间起着重要的内部机制作用—— 母亲的敏感性行为的累积促进了学步儿内部工作模式关于母亲的预期, 这种预期又进一步引导着学步儿的依恋行为。     

PLS model building: A multivariate approach to personality test data

The aim of this study was to demonstrate how personality test data can be plotted with a multivariate method known as Partial Least Squares of Latent Structures (PLS). The basic methodology behind PLS modeling is presented and the example demonstrates how a PLS model of personality test data can be used for diagnostic prediction. Principles for validating the models are also presented. The conclusion is that PLS modeling appears to be a powerful method for extracting clinically relevant information from complex personality test data matrixes. It could be used as a complement to more hard modeling methods in the process of examining a new area of interest.     

Development of orientation discrimination in infancy

It has previously been found by us, with a visual evoked potential (VEP) measure, that orientation discrimination of dynamic patterns in infants can be demonstrated from around 6 weeks after birth. Experiments are reported in which orientation discrimination was measured behaviourally, in two infant control habituation procedures, with both dynamic and static patterns. When dynamic patterns identical to those in our previous VEP studies were used, the first positive evidence of orientation discrimination was found at around 6 weeks postnatally. The time course of both the VEP and the behavioural measures was similar. However, with static patterns, evidence of orientation discrimination by newborns was found if the infants were allowed to compare the habituated and novel orientations in a paired simultaneous comparison after habituation, but was not found when the habituated and novel stimulus were presented sequentially. The positive evidence of orientation discrimination in newborns supports the hypothesis that some form of orientationally tuned detectors can be used for discrimination of static patterns at birth. However, some developmental change over several weeks seems to be required before a positive electrophysiological VEP response can be measured for dynamic patterns changing in orientation.     

Locus of habituation in the human newborn

There is some controversy concerning the youngest age at which an infant will habituate to a visual stimulus or will prefer a novel to a familiar pattern. One suggestion has been that apparently successful reports of habituation and dishabituation in the newborn baby are attributable to retinal adaptation. This interpretation was tested in two experiments. In both experiments monocular conditions of viewing were used: newborns were habituated with one eye as the 'seeing' eye, and posthabituation novelty preferences investigated with the other eye. Significant preferences were found both for a novel colour (experiment 1) and for a novel shape (experiment 2), which implies that a retinal-adaptation model can be ruled out. It is suggested that the habituation effects and the subsequent novelty preferences found in the experiments are most reasonably interpreted as a function of memory formation, and evidence is presented for the storage of visual experience from birth. The results also demonstrate some form of binocular interaction in the newborn.     

Models of habituation in infancy

Research on infant cognition using habituation methods has sparked considerable controversy in recent years. At the core of the debates is the issue of whether infants have early (and possibly innate) conceptual understandings. This article reviews a range of computational models of habituation that might provide insights into such discussions. The models are assessed against key behavioral and neural features of habituation: temporal unfolding, exponential decrease, familiarity-to-novelty shift, habituation to repeated testing, discriminability of habitual items, selective inhibition and cortical-subcortical interactions. The review suggests that current models fail to offer comprehensive explanations of the behavioral phenomena.     

Habituation to irrelevant speech: effects on a visual short-term memory task

The Baddeley and Hitch (1974) formulation of short-term or working memory embodied a phonological store within the articulatory loop component of the model. Later formulations specifically postulated an acoustic filter that endowed only speech-like stimuli with obligatory access to this phonological store. This paper presents evidence that this phonological store may have two filters, one of which is subject to habituation and can therefore attenuate the entry of irrelevant speech, thus undermining the obligatory access assumption of the model. An experiment is reported in which subjects were presented with a habituation period comprising 20 min of irrelevant speech--speech to be ignored by the subject--before a test phase in which a visually presented serial recall task with concurrent irrelevant speech was performed. The effect of irrelevant speech, which impairs performance on the primary task when there is no habituation phase, is reduced markedly in those conditions where the speech used in the habituation phase is the same as that used in the test phase, if the irrelevant speech is in a language different from that presented during the subsequent trials or if the habituator is a hummed version of the irrelevant speech passage. When a nonspeech sound (pink noise) is used in the habituation phase, a large irrelevant speech effect is found in the test phase. Morris, Quayle, and Jones (1989) found that humming did not produce an irrelevant speech effect, which suggests that the first filter is permeable to humming but that the second filter is not.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fetal habituation performance: Gestational age and sex effects

Habituation is the decrement in response to repeated stimulation. Fetal habituation performance may reflect the functioning of the central nervous system (CNS) prenatally. However, basic characteristics of the prenatal habituation phenomena remain unclear, such as the relationship with gestational age (GA) and fetal sex. The current study investigated the relationship between habituation performance and both fetal sex and advancing gestational age, by comparing habituation performance at 31 and 35 weeks GA within a sample of 74 singleton pregnancies, all with normal neonatal outcomes. A vibroacoustic stimulus was used to habituate the fetus and motor responses were monitored via ultrasound. The criterion for habituation was defined as no response to five consecutive stimulus presentations. Prenatal habituation performance was found to demonstrate a developmental trend, with an increased proportion of fetuses habituating with advancing gestational age and requiring fewer stimulus presentations to satisfy the habituation criterion. Fetal sex also appears to have a moderating influence on gestational changes in habituation performance. Hence, the ongoing maturation of the fetal CNS does appear to be reflected in fetal habituation performance, indicating the need to consider the composition of fetal samples in terms of both gestational age and sex. Variability in interfetal performance was found to be high and clinical applications remain speculative.     

Sensitization and habituation regulate reinforcer effectiveness

We argue that sensitization and habituation occur to the sensory properties of reinforcers when those reinforcers are presented repeatedly or for a prolonged time. Sensitization increases, and habituation decreases, the ability of a reinforcer to control behavior. Supporting this argument, the rate of operant responding changes systematically within experimental sessions even when the programmed rate of reinforcement is held constant across the session. These within-session changes in operant responding are produced by repeated delivery of the reinforcer, and their empirical characteristics correspond to the characteristics of behavior undergoing sensitization and habituation. Two characteristics of habituation (dishabituation, stimulus specificity) are particularly useful in separating habituation from alternative explanations. Arguing that habituation occurs to reinforcers expands the domain of habituation. The argument implies that habituation occurs to biologically important, not just to neutral, stimuli. The argument also implies that habituation may be observed in “voluntary” (operant), not just in reflexive, behavior. Expanding the domain of habituation has important implications for understanding operant and classical conditioning. Habituation may also contribute to the regulation of motivated behaviors. Habituation provides a more accurate and a less cumbersome explanation for motivated behaviors than homeostasis. Habituation also has some surprising, and easily testable, implications for the control of motivated behaviors.     

US habituation,like CS extinction,produces a decrement in conditioned fear responding that is NMDA dependent and subject to renewal and reinstatement

Just as fear can be learned, it can also be inhibited. The most common way of reducing learned fear is through extinction, where the conditioned stimulus (CS) previously paired with an aversive unconditioned stimulus (US) is repeatedly presented on its own. Another, much less commonly studied, way to inhibit learned fear is by habituating, or devaluing, the US. In this procedure, fear responding to a CS is reduced by repeatedly presenting the US in the absence of the CS following the conditioning phase. The purpose of the present study was to directly compare the effects of US habituation and CS extinction on a learned fear response (freezing). Experiment 1 demonstrated that US habituation given either after (Experiment 1A) or before (Experiment 1B) fear conditioning reduced freezing to the CS at test. We then showed that the reduction in freezing resulting from either US habituation or CS extinction was context-specific (i.e., a change in context led to a renewal of the learned fear response; Experiment 2) and, furthermore, was attenuated when a pre-test shock was given (i.e., reinstatement of fear was observed in both cases; Experiment 3). Finally, Experiment 4 demonstrated that an injection of the NMDA antagonist MK-801 prior to US habituation impaired long-term retention of the learning that takes place during this procedure. Together, these results suggest that the decrement in conditioned fear responses produced by US habituation and CS extinction could rely on overlapping processes.     

Implicit and explicit memory: Implications for the symbol-manipulation versus connectionism controversy

Summary This paper deals with three issues. First, the symbol-manipulation versus connectionism controversy is discussed briefly. Both can be seen as formalisms or languages for describing human behavior, but it is argued that these languages are not fully equivalent. The importance of the ability of connectionist models to learn autonomously, often underestimated, allows them to perform tasks that may defy formalization. Secondly, the structural and functional characteristics of a new connectionist learning model are presented. It avoids some of the psychological and biological implausibilities of currently popular models and solves some of the problems and shortcomings of these models. Thirdly, some simulation results are presented. The model successfully simulates the dissociation between explicit and implicit memory performance as found in patients with anterograde amnesia. This simulation provides an example of the advantages of using the connectionist language in the domain of memory psychology. It is also a good example of how psychological evidence can be used to improve connectionist models.The second author is supported by the Dutch Organization for Scientific Research (NWO)     

A comment on Koriat,Averill, and Malmstrom's “individual differences in habituation”

The paper considers the issues, raised by Koriat et al. (1973), of the consistency and reliability of measures of habituation currently used in personality research. It is argued that the problem of reliability is not as serious as Koriat et al. proposed and that specificity of measures of habituation is a theoretical rather than a methodological problem. It is proposed that ambiguity in the literature on the personality correlates of habituation is more likely to be due to the failure to consider the effects of stimulus conditions on habituation than to the problems of reliability and specificity.