A pendulum phenomenon in the visual perception of apparent movement

In setting up an apparatus for studying the phenomenon of apparent movement it was noticed that, when a metronome was employed for making the electrical contacts in the light-circuits, the path of apparent movement between the two lights was curved instead of straight. This deviation could not be attributed to the presence of any distorting structure in the visual field, and an experimental investigation of the conditions of the phenomenon was begun. So far five different display conditions have each been observed by ten or eleven subjects individually. No subject saw more than one condition in the experimental series, and their reports indicate that the following factors, in order of importance, are effective in leading to the perception of curved apparent movement: (1) the shape of the light-stimuli, (2) the regularity of the rhythm of presentation, (3) the gradient of brightening and dimming of the lights and (4) the sound of the metronome in synchrony with the appearance of the lights.

The possible role of past experience in the perceptual process, and the relationship of this “pendular” phenomenon to Johansson's (1950) “wandering” phenomenon and to normal stroboscopic movement, are briefly discussed.     

Parent-adolescent conflict: an empirical review

Conflict between parents and adolescents is usually seen as a normal and necessary part of human development. However, treatment approaches for problematic conflict differ depending on several variables including theoretical orientation of the clinician. This article compares and contrasts psychoanalytic, systems, and social learning theories in order to determine the empirical support for each. In addition, several issues inherent in parent-adolescent conflict are reviewed including developmental stage theory, parenting styles, peer pressures, communications skills, marital conflict, drugs, school, and sex. Several studies and reviews of the literature are examined for common conclusions. Finally, an integrated and empirically supported model to explain parent-adolescent conflict is described.     

Infant clothing: Sex labeling for strangers

Labeling an infant as a boy or girl affects behavior toward the infant. While intimates know a baby's sex label and behave consistently to the baby, strangers cannot unless given a cue. Forty-eight infants and their caretakers were observed in suburban malls to see if clothing normally provides such cues; 90% of the infants were dressed in sex-typed clothes. Girls wore or carried pink (75%), yellow, ruffles, puffed sleeves, and/or dresses. Boys wore blue (79%) and/or red. Observers were able to correctly guess the sex of “labeled” infants only. Surprisingly, simultaneous caretaker interviews revealed that parents do not spontaneously mention sex as a factor in clothing choice, nor do they feel they would be very bothered by strangers' mistaking the infant's sex.     

Editorial preface

International Journal for Philosophy of Religion -     

Anxiety Sensitivity Differentially Predicts Factors of Interpersonal–Psychological Suicide Risk: A Consideration of Specificity

Recent studies have identified anxiety sensitivity (AS) as a risk factor for suicidality; however, limited work has been performed to understand this risk within the context of the interpersonal–psychological theory of suicide (IPTS; Joiner, 2005). The current study examined the relationship between overall AS, each AS subfactor (cognitive, social, and physical), and the three IPTS domains (perceived burdensomeness, thwarted belongingness, and acquired capability). While each AS subfactor uniquely predicted one IPTS domain, greater overall AS only predicted greater acquired capability, suggesting that assessment of AS at the subfactor level may offer us more information about an individual's interpersonal suicide risk.     

Attenuation of latent inhibition after compound pre-exposure: Associative and perceptual explanations

Three experiments used rats as subjects and the conditioned emotional response (CER) paradigm to examine the effect of pre-exposure to a compound stimulus on the extent of latent inhibition to an element of that compound. In Experiment 1a a group of rats exposed to a compound that comprised a tone and a click exhibited less latent inhibition to the tone than did a group that had received pre-exposure to the tone in isolation. Experiment 1b showed that pre-exposure to the tone/click compound also resulted in an attenuation of latent inhibition to the click relative to a group that was pre-exposed to the click in isolation. Experiment 2 demonstrated that latent inhibition to the tone was left intact following pre-exposure to the tone in compound with a light. This pattern of results seems to be most plausibly explained in terms of the presence and absence of generalization decrement following compound pre-exposure.     

Representation-mediated Inhibitory Learning in the Conditioned-suppression Procedure

In three experiments, rats in group I (for intermixed) were given non-reinforced exposure to two compound stimuli, AX and BX, where A and B represent different auditory cues, and X represents a visual cue. AX and BX were presented in alternation. Group B (blocked) received similar exposure except that subjects experienced a block of AX trials and then a block of BX trials. Subsequent shock reinforcement of A was found to endow B with inhibitory strength in group I, as assessed by retardation (Experiments 1 and 2) and summation tests (Experiment 3). This outcome confirms and extends the results reported by Espinet, Iraola, Bennett, and Mackintosh (1995) and constitutes a further example of mediated learning in which the associative strength of a stimulus is found to be modified as a consequence of training given to some other event with which that stimulus is associated.     

The Role of Mediated Conditioning in Acquired Equivalence

In Experiment 1 rats received initial training in which delivery of a sucrose pellet was signalled by an auditory cue. This cue was then paired with shock in a second phase of training. In a test the rats showed an unwillingness to perform an instrumental response that yielded the sucrose pellet. This was interpreted as indicating that the associatively activated representation of the pellet had acquired aversive properties during the shock-reinforced stage of training. Experiment 2 replicated this mediated conditioning effect making use of a Phase 1 training procedure, modelled on that used by Honey and Hall (1989) to demonstrate acquired equivalence of cues, in which two auditory cues were each used to signal sucrose pellets. A further test revealed that this training resulted in enhanced generalization between these two cues. It was argued that this effect is mediated by the conditioned aversive properties of the common associate of the two auditory cues.