Anorexia and conditioned taste aversions in the rat

The present study examined whether or not certain anorexic agents produced flavor aversions. Rats showed comparable anorexia when injected with lithium chloride, ammonium sulfate, arginine·HCl, and d-glucose. Only lithium chloride produced a flavor aversion to either a novel liquid or food. Only arginine was found to interfere with the formation or recall of an association. The effects of the other chemicals were discussed in terms of the relationship between anorexia and induced sickness.     

Effects of schedule and magnitude of reinforcement under conditions of thirst motivation

In contrast to a recent finding (Macdonald, G. E., & De Toledo, L. Learning and Motivation, 1974, 5, 288–298.) the results of three experiments investigating various partial reinforcement (PRF) manipulations under conditions of thirst motivation demonstrated strong similarity to analogous manipulations involving food reward. Specifically, for animals receiving water reinforcement, PRF was shown to generate greater resistance to extinction than continuous reinforcement (Expt 1 & 3), the schedule of reinforcement was shown to interact with level of acquisition (Expt 1 and 2), and the magnitude of the partial reinforcement extinction effect was shown to be a function of reward magnitude (Expt 3). These results provide strong evidence that mechanisms which operate in partial reinforcement situations are highly similar, regardless of the type of appetitive reinforcement.     

Evidence for the Big Five in analyses of familiar English personality adjectives

Studies of the natural language are a prime source of the Big-Five model, yet the factor analysis of a large, representative, and non-clustered set of English-language personality adjectives in a large sample has not yet been published. In order to test the hypothesis that finding the Big Five depends on biasing the variable selection with an investigator's preferred non-familiar terms, we present the factor analysis of 435 familiar adjectives in a combined sample (N=899) of 507 self- and 392 peer ratings. The five-factor solution reproduced the Big Five with high clarity, demonstrating generally very high correlations with Goldberg's adjective markers of the Big Five. The Intellect factor had a more moderate correlation, due to its de-emphasis of the creativity components of Factor V, a phenomenon that may occur commonly with the lexical Intellect factor.     

Parental Involvement and Adolescents’ Academic Achievement: Latent Profiles of Mother and Father Warmth as a Moderating Influence

Parental involvement in their adolescents’ education plays an important role in promoting their children's academic outcomes. Yet, more research is needed to examine the relationship between parenting practices and parental warmth as well as to consider the potential joint contribution of warmth from both fathers and mothers. Thus, the primary purpose of the current study is to examine the extent to which patterns of parental warmth across fathers and mothers moderate the association between parental involvement and adolescents’ grade point average (GPA) and school engagement behaviors. Latent profile analysis was conducted to identify disparate profiles of fathers’ and mothers’ warmth within a nationally representative sample of 2,306 youths (51% male; mean age = 15.31 years, SD = 1.50; 77% non-Hispanic White) residing in opposite-sex, two-parent families from Wave I and II of the National Longitudinal Study of Adolescent to Adult Health. Latent-class enumeration processes support a five-profile solution characterized by differences in levels of parental warmth and congruency across parents: (a) Congruent High Warmth, (b) Congruent Moderate Warmth, (c) Congruent Low Warmth, (d) Incongruent High Mother/Low Father Warmth, and (e) Incongruent Low Father/Lower Mother Warmth. Subsequent multiple linear regression analyses reveal a moderating effect for Congruent Low Warmth on the relationship between parental involvement and adolescents’ GPA. Ultimately, the results show that variation in parental warmth exists across fathers and mothers with differing impact on adolescents’ outcomes. Excluding one parent without considering the joint effects of both parents will not produce an accurate and precise understanding of parenting in research or practice.     

Applying prospect theory to pilot weather-related decision-making: The impact of monetary and time considerations on risk taking behaviour

One of the key findings of prospect theory is that people tend to treat potential gains differently to potential losses. Consistent with earlier findings across a range of areas, pilots were risk averse when faced with an uncertain situation involving monetary gains and risk seeking when faced with a monetary loss. Prospect theory has largely been used to explore monetary decision-making; however, “time” is potentially a more important consideration for pilots than money. For example, how much time can be flown with the current fuel onboard. It was found that pilots' decision behaviour changed when faced with a decision involving time, with pilots risk averse for both a time gain and a time loss situation. Pilots appeared to prefer to know precisely the time required for a journey, rather than take a gamble on a potential short cut. Evidence also suggests pilots were more likely to take risks in situations that they perceive they have more control over (e.g. air traffic delays) compared to dynamic weather-related events. There was some evidence to suggest pilots do not consider a decision in terms of an end state, but rather in terms of losses and gains from their current state. The final part of the study found evidence that it may be possible to predict pilot risk taking behaviour using self-report decision frames.     

Atypical depression: enhanced right hemispheric dominance for perceiving emotional chimeric faces

Two studies compared hemispatial bias for perceiving chimeric faces in patients having either atypical or typical depression and healthy controls. A total of 245 patients having major depressive disorder (MDD) or dysthymia (164 with atypical features) and 115 controls were tested on the Chimeric Faces Test. Atypical depression differed from typical depression and controls in showing abnormally large right hemisphere bias. This was present in patients having either MDD or dysthymia and was not related to anxiety, physical anhedonia, or vegetative symptoms. In contrast, patients having MDD with melancholia showed essentially no right hemisphere bias. This is further evidence that atypical depression is a biologically distinct subtype and underscores the importance of this diagnostic distinction for neurophysiologic studies.     

Psychometric Modeling of response speed and accuracy with mixed and conditional regression

Human performance in cognitive testing and experimental psychology is expressed in terms of response speed and accuracy. Data analysis is often limited to either speed or accuracy, and/or to crude summary measures like mean response time (RT) or the percentage correct responses. This paper proposes the use of mixed regression for the psychometric modeling of response speed and accuracy in testing and experiments. Mixed logistic regression of response accuracy extends logistic item response theory modeling to multidimensional models with covariates and interactions. Mixed linear regression of response time extends mixed ANOVA to unbalanced designs with covariates and heterogeneity of variance. Related to mixed regression is conditional regression, which requires no normality assumption, but is limited to unidimensional models. Mixed and conditional methods are both applied to an experimental study of mental rotation. Univariate and bivariate analyzes show how within-subject correlation between response and RT can be distinguished from between-subject correlation, and how latent traits can be detected, given careful item design or content analysis. It is concluded that both response and RT must be recorded in cognitive testing, and that mixed regression is a versatile method for analyzing test data.I am grateful to Rogier Donders for putting his data at my disposal.