Summation: Further assessment of a configural theory

Rats received Pavlovian conditioning in which food was signalled by a visual stimulus, A+, an auditory stimulus, B+, and a compound composed of different visual and auditory stimuli, CD+. Test trials were then given with the compound AB. Experiments 1 and 2A revealed stronger responding during AB than during CD. In Experiment 2B, there was no evidence of a summation of responding during AB when A+ B+ training was conducted in the absence of CD+ trials. A further failure to observe abnormally strong responding during ABwas found in Experiment 3 for which the training trials with A+ B+ CD+ were accompanied by trials in which C and D were separately paired with food. The results are explained in terms of a configural theory of conditioning, which assumes that responding during a compound is determined by generalization from its components, as well as from other compounds to which it is similar.     

A comparison of the effects of partial reinforcement schedules using a within-subject serial autoshaping procedure

Three experiments, each using a single group of pigeons, are reported. In Experiment 1 subjects were initially trained with two stimuli, one of which was always followed by food, the other being reinforced according to a 50% partial reinforcement schedule. Subsequently a serial procedure was adopted in which an additional stimulus, C, was consistently followed by the partially reinforced CS. A second additional stimulus, A, was followed on half of its occurrences by the continuously reinforced CS, its remaining presentations being followed by nothing. The rate of autoshaped keypecking was substantially greater during A than during C. In the remaining experiments subjects received first-order conditioning with a single stimulus that was either partially (Experiment 2) or continuously (Experiment 3) reinforced. The stimuli A and C were then again introduced for serial autoshaping. Stimulus A was occasionally paired with the CS and occasionally followed by nothing, whereas stimulus C was always followed by the CS. As in Experiment 1, the rate of responding during A was greater than during C. It is proposed that one influence on the rate of autoshaped keypecking during a CS is the accuracy with which the immediate consequences of that CS are predicted.     

Pavlovian analysis of interactions between hunger and thirst

In four experiments we examined the effect of an irrelevant drive on classical conditioning with food and water. In the first experiment the irrelevant drive weakened the conditioned response in extinction. In Experiments 2 and 3, this suppressive effect was found also in acquisition. Furthermore, the presence of an irrelevant drive during nonreinforced presentations of the conditioned stimulus was found to protect the conditioned response from extinction. Experiment 4 showed that the depressive effect of the irrelevant drive is manifested only when the relevant drive is present. Taken together, these results suggest that an irrelevant drive can influence conditioned responding by modulating the representation of the unconditioned stimulus.     

Variation of the magnitude of the horizontal-vertical illusion with retinal eccentricity

The horizontal-vertical illusion was studied as a function of retinal eccentricity. It was found that the relation of illusion magnitude to vertical eccentricity is described by a U-shaped function with large amounts of reversed illusion for the more eccentric positions. Substantial effects due to horizontal eccentricity were also obtained, but these were not consistent across subjects. It is suggested that the flattening of the peripheral zones of the refracting surfaces of the eye may be involved in the variation of the illusion with retinal position, and that the astigmatic properties of the central portions of these surfaces may be a prime factor in the usual horizontal-vertical illusion.     

Moving the debate forward in small steps: A reply to Morrison

Morrison (1996) criticised the authors' 1995 evaluation on three main grounds: that it was too narrow, that it was circular, and that the model evaluated was contradictory. It is argued that the narrow focus was deliberate, that the methodology was standard and logical, and that the framework evaluated was coherent. Although the authors agree with Morrison in some respects, e.g. on the value of variety of methodology, there seems to be a basic difference in view on scientific method. The authors see research as (mainly) small steps which are erratic but generally cumulative; Morrison appears to favour grand-scale, multi-purpose research.     

The Life Attitudes Schedule Short Form: An Abbreviated Measure of Life-Enhancing and Life-Threatening Behaviors in Adolescents

An abbreviated version of the Life Attitudes Schedule (LAS) was developed, consisting of 24 items, each representing one cell of the original LAS theoretical matrix (4 content categories × 2 behavior types × 2 valence). Items were retained on the basis of high correlations with LAS total score and low correlations with gender. Psychometric properties of the LAS Short Form were robust and the Short Form total score correlated .93 with the original LAS total score. As with the original LAS, boys reported more injury-related behaviors than girls. Future research and clinical directions are suggested.     

Self-Compassion and Need Frustration Moderate the Effects of Upward Appearance Comparisons on Body Image Discrepancies

Abstract

Drawing from diverse theoretical frameworks, we examined predictors of discrepancy between current and ideal body image in a sample of 396 Greek adolescents. The participants completed assessments of the frequency of comparing oneself with someone of perceived better appearance, appearance evaluations, frustration of basic psychological needs, and appearance self-compassion. We found that upward appearance comparisons negatively predicted appearance evaluation, which in turn was a negative predictor of body image discrepancy. Moderated mediation analyses showed that appearance self-compassion buffered, whereas psychological need frustration augmented the negative effects of upward comparisons on appearance evaluation. Our findings contribute to the growing literature on body image discrepancies in adolescence by examining moderating factors that amplify or buffer such discrepancies, hence identifying viable intervention pathways.     

The typology of parricide and the role of mental illness: Data-driven approach

Parricide is a rare type of homicide in which mental illness is often an important factor. The aims of this study were (a) to describe the characteristics of parricide offenders with a focus on mental illness and clinical care and (b) to examine Heide's widely used typology of parricide through a data-driven approach. We analyzed all homicides in England and Wales between 1997 and 2014. Parricide offenders in our sample were most often male, unmarried, and unemployed, with a third of offenders diagnosed with schizophrenia; 28% had been in contact with mental health services before the offense. The latent class analysis resulted in three types of parricide offenders: middle-aged with affective disorder, previously abused, and seriously mentally Ill, which confirmed, to an extent, Heide's typology. Health and social care services should actively engage with carers of people with mental illness and support to those caring for older relatives and victims of abuse.     

Statistical learning of multiple speech streams: A challenge for monolingual infants

Language acquisition depends on the ability to detect and track the distributional properties of speech. Successful acquisition also necessitates detecting changes in those properties, which can occur when the learner encounters different speakers, topics, dialects, or languages. When encountering multiple speech streams with different underlying statistics but overlapping features, how do infants keep track of the properties of each speech stream separately? In four experiments, we tested whether 8‐month‐old monolingual infants (N = 144) can track the underlying statistics of two artificial speech streams that share a portion of their syllables. We first presented each stream individually. We then presented the two speech streams in sequence, without contextual cues signaling the different speech streams, and subsequently added pitch and accent cues to help learners track each stream separately. The results reveal that monolingual infants experience difficulty tracking the statistical regularities in two speech streams presented sequentially, even when provided with contextual cues intended to facilitate separation of the speech streams. We discuss the implications of our findings for understanding how infants learn and separate the input when confronted with multiple statistical structures.