Lateral differences in habituation of ipsilateral head-turning to repeated tactile stimulation in the human newborn

Lateral differences in habituation of ipsilateral head-turning to repeated tactile perioral stimulation following midline head restriction was studied in 44 full-term neonates. Left-sided stimulation had a significantly greater and faster decremental effect than right-sided stimulation. Even in the absence of tactile stimulation (Control Group), head-turning to the left decreased systematically whereas head-turning to the right did not. The transient efficacy of prior midline head restriction for the elimination of lateral differences in both spontaneous head movements and responsiveness to tactile input suggests that behavioral asymmetry is already well-established in the newborn.     

Pathways to fear in spider phobic children

Twenty-two children with spider phobia were interviewed about the origins of their fear. More specifically, children were asked about conditioning events, modeling experiences, and negative information transmission. To evaluate the reliability of the information provided by the children, parents were independently interviewed about the origins of their children's phobias. While 46% of the children claimed to have always been afraid, 41% ascribed the onset of their fear to aversive conditioning events. The large majority of these events were confirmed by parents. These findings cast doubts on a strong version of the non-associative account of spider phobia, i.e. the idea that spider phobia is acquired in the complete absence of learning experiences.     

Effects of monotonous stimulation on cortical alertness in fast and slow habituation groups

The present study investigated cortical alertness in Ss displaying fast and slow habituation of the evoked skin conductance response (SCR). From Sokolov's statement (Perception and the conditioned reflex, 1963, Pergamon) that the final stage of habituation is sleep, it was predicted that during monotonous stimulation, Ss displaying rapid habituation of the evoked SCR would show a more rapid decline in cortical alertness than Ss displaying slow habituation. Quantified EEG and electrodermal measures of cortical alertness were obtained from fast and slow habituation groups tested under conditions of either repetitive auditory stimulation or reduced sensory input. The results indicated that 8–13 Hz EEG abundance declined more rapidly in fast than in the slow habituation groups under both conditions of monotonous stimulation. No differences were obtained for the lower EEG frequencies (4–8 and 2–4 Hz) or for tonic electrodermal measures.     

Sex-dependent habituation to novelty in rats

Male and female rats were familiarized with one-half of an exploration box for 30 or 60 minutes. When later tested, females showed higher preferences for the other novel half than males. Females also showed higher levels of rearing and ambulation. No sex differences were evident for grooming, freezing or defecation. The results were interpreted as females having habituated to the forced-exposure novelty of the familiar half of the apparatus more rapidly than males when the familiarization period was relatively short. With a longer period, males would have had more time to reach a similar level of habituation to that attained by females familiarized for 30 minutes. Relationships between novelty preferences and both rearing and ambulation as indices of exploration were also discussed in the light of significant correlations for males only.     

Sex-dependent habituation to novelty in rats

Male and female rats were familiarized with one-half of an exploration box for 30 or 60 minutes. When later tested, females showed higher preferences for the other novel half than males. Females also showed higher levels of rearing and ambulation. No sex differences were evident for grooming, freezing or defecation. The results were interpreted as females having habituated to the forced-exposure novelty of the familiar half of the apparatus more rapidly than males when the familiarization period was relatively short. With a longer period, males would have had more time to reach a similar level of habituation to that attained by females familiarized for 30 minutes. Relationships between novelty preferences and both rearing and ambulation as indices of exploration were also discussed in the light of significant correlations for males only.     

Processing of phobic stimuli and its relationship to outcome

In the present study, we explored factors related to successful treatment outcome in a sample of participants with fear of spiders. We specifically examined the relationship of general memory, memory for the phobic stimulus, memory for anxious responses, and perceived self-efficacy to treatment outcome. Forty-eight participants who were afraid of spiders participated in two sessions of in vivo exposure therapy. On day 1, participants completed measures of general memory, memory for the phobic stimulus, recall of anxiety level during exposure tasks, and self-efficacy during exposure tasks. At post-treatment, better memory for anxious responses, but not memory for the phobic stimulus, was related to lower anticipatory and actual anxiety. Greater self-efficacy, on the other hand, was related to better behavioral performance.     

Napping promotes inter-session habituation to emotional stimuli

The effects of a daytime nap on inter-session habituation to aversive visual stimuli were investigated. Healthy young adult volunteers viewed repeated presentations of highly negative and emotionally neutral (but equally arousing) International Affective Picture System (IAPS) photographs during two afternoon sessions separated by 2.5h. Half of the photographs were shown at both sessions (Repeated Sets) and half differed between sessions (Novel Sets). For each stimulus presentation, evoked skin conductance response (SCR), heart-rate deceleration (HRD) and corrugator supercilii EMG response (EMG), were computed and range corrected using respective maximum session-1 responses. Following each presentation, subjects rated each photograph on dimensions of pleasantness and arousability. During the inter-session interval, Nap subjects had a 120-min polysomnographically monitored sleep opportunity, whereas Wake subjects watched a non-stimulating video. Nap and Wake subjects did not differ in their subjective ratings of photographs. However, for Repeated-Set photographs, Nap subjects demonstrated greater inter-session habituation in SCR and EMG but a trend toward lesser inter-session habituation in HRD. These group differences were absent for Novel-Set photographs. Group differences across all measures were greater for negative stimuli. Occurrence of SWS during the nap was associated with greater inter-session habituation of EMG whereas occurrence of REM was associated with lesser inter-session habituation of SCR to negative stimuli. Sleep may therefore promote emotional adjustment at the level of somatic responses. Physiological but not subjective inter-session habituation to aversive images was enhanced by a daytime nap.     

Sensitivity to phobic imagery: a sensory decision theory analysis

The effects of deep muscle relaxation on anxiety were studied in a systematic desensitization context. A Sensory Decision Theory analysis of anxiety ratings to controlled imagery showed that relaxed Ss were significantly more sensitive to phobic properties of the controlled imagery than nonrelaxed Ss. The results are discussed in terms of Wolpe's theoretical basis for systematic desensitization. Sensory Decision Theory is presented as a useful technique for measuring the effects of therapy on emotional states.     

The prediction of phobic behaviour

A 10-point rating scale, a pair comparison forced choice technique and a repertory grid were used to predict phobic behaviour in a standardized avoidance situation. The rating scale and pair comparison technique were significantly more accurate than the grid, but did not differ from each other. The results were seen to be consistent with others demonstrating that simple and economic self-report measures can often be more useful than apparently more sophisticated instruments. The results can also be taken to underline the need for including a variety of measures in validity studies of the repertory grid, and the caution necessary in the clinical application of this same instrument. The generality of the present conclusions to other situations needs, however, to be demonstrated rather than assumed. Social desirability, for example, is not thought to be an important variable in the present situation.     

The effect of worry on cardiovascular response to phobic imagery

Cardiovascular response to phobic exposures has been shown to reflect the degree of emotional processing of phobic material and relates in important ways to outcome in exposure therapy. The present study investigated the effect of worry on such processing. Speech anxious subjects visualized a phobic scene for 10 trials. Three groups differed according to whether they engaged in relaxed, neutral, or worrisome thinking just prior to each scene presentation. Although the three types of thinking had no effect on cardiovascular activity during the thinking periods, subjects in the worry group displayed significantly less heart rate response to the phobic image than those in the neutral condition who had significantly less response than the relaxed condition. However, the worry group showed significantly greater subjective fear to the images than the neutral condition, with the relaxed group near to the level of the worry group and not significantly different from either of the other two conditions. The results suggest that worry may inhibit emotional processing and thus preserve cognitive/affective fear structure, and are discussed in terms of Gray's (Behavioral and Brain Sciences, 5, 469-534, 1982) theory of the behavioral inhibition system and semantic satiation effects in cognitive psychology.     

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.     

Common processes may contribute to extinction and habituation

Psychologists routinely attribute the characteristics of conditioned behavior to complicated cognitive processes. For example, many of the characteristics of behavior undergoing extinction have been attributed to retrieval from memory. The authors argue that these characteristics may result from the simpler process of habituation. In particular, conditioned responding may decrease during extinction partially because habituation occurs to the stimuli that control responding when those stimuli are presented repeatedly or for a prolonged time (e.g., the experimental context, the conditioned stimulus in classical conditioning). This idea is parsimonious, has face validity, and evokes only processes that are well established by other evidence. In addition, behavior undergoing extinction shows 12 of the fundamental properties of behavior undergoing habituation. However, this model probably cannot provide a complete theory of extinction. It provides no obvious explanation for some of the other characteristics of extinguished behavior.