Effects of adding a second reinforcement alternative: implications for Herrnstein's interpretation of r(e)

Herrnstein's hyperbola describes the relation between response rate and reinforcer rate on variable-interval (VI) schedules. According to Herrnstein's (1970) interpretation, the parameter r(e) represents the reinforcer rate extraneous to the alternative to which the equation is fitted (the target alternative). The hyperbola is based on an assumption that extraneous reinforcer rate remains constant with changes in reinforcer rate on the target alternative (the constant-r(e) assumption) and that matching with no bias and perfect sensitivity occurs between response and reinforcer ratios. In the present experiment, 12 rats pressed levers for food on a series of 10 VI schedules arranged on the target alternative. Across conditions, six VI values and extinction were arranged on a second alternative. Reinforcer rate on the second alternative, r2, negatively covaried with reinforcer rate on the target alternative for five of the six VI values on the second alternative, and significant degrees of bias and undermatching occurred in response ratios. Given covariation of reinforcer rate on the second and target alternatives, the constant-r(e) assumption can be maintained only by assuming that reinforcer rate from unmeasured background sources, rb, covaries with reinforcer rate on the second alternative such that their sum, r(e), remains constant. In a single-schedule arrangement, however, r(e) equals rb and thus rb is assumed to remain constant, forcing a conceptual inconsistency between single- and concurrent-schedule arrangements. Furthermore, although an alternative formulation of the hyperbola can account for variations in bias and sensitivity, the modified equation also is based on the constant-r(e) assumption and therefore suffers from the same logical problem as the hyperbola when reinforcer rate on the second alternative covaries with reinforcer rate on the target alternative.     

Group Session Rating Scale: Preliminary psychometrics in substance abuse group interventions

Background: Although ultra‐brief outcome and process measures have been developed for individual therapy, currently there are no ultra‐brief alliance measures for group therapy. Method: The current study examined 105 clients in group therapy for issues related to substance abuse or with issues related to the substance abuse of a significant other. We tested whether a newly developed group therapy alliance measure – the Group Session Rating Scale would be related to other commonly used group process measures (Working Alliance Inventory, Group Cohesion, Group Climate) and early change (change over the first four sessions of group therapy). Results: The findings provided support for reliability based on Cronbach alphas and test‐retest coefficients. Additionally, the GSRS was a one‐factor measure that was related to other group process measures as well as predicted early change. Discussion: Clinical implications for how to utilise ultra‐brief outcome and alliance measures are provided.     

Factors influencing the salience of temporal cues in the discrimination of synthetic Japanese monkey (Macaca fuscata) coo calls

If temporal position of a frequency inflection is the most salient communication cue in Japanese macaque smooth early and smooth late high coos, then macaques should perceive coos differing only along the early-late dimension as belonging to different classes. The perceived similarity of synthetic coos and temporally reversed variants were evaluated, using multidimensional scaling of macaque discrimination latencies. Original calls and calls temporally reversed in the frequency domain could be discriminated if the peak was near a call endpoint but not if the frequency peak in the original call was near the coo midpoint. Perceived similarity of such calls was inversely related to the amount of frequency modulation. Temporal reversals of amplitude contours were also conducted. Although macaques are quite sensitive to amplitude increments, reversal of the relatively flat amplitude contours of these calls did not affect discrimination responses.     

The natural emergence of reasoning about the afterlife as a developmental regularity

Participants were interviewed about the biological and psychological functioning of a dead agent. In Experiment 1, even 4- to 6-year-olds stated that biological processes ceased at death, although this trend was more apparent among 6- to 8-year-olds. In Experiment 2, 4- to 12-year-olds were asked about psychological functioning. The youngest children were equally likely to state that both cognitive and psychobiological states continued at death, whereas the oldest children were more likely to state that cognitive states continued. In Experiment 3, children and adults were asked about an array of psychological states. With the exception of preschoolers, who did not differentiate most of the psychological states, older children and adults were likely to attribute epistemic, emotional, and desire states to dead agents. These findings suggest that developmental mechanisms underlie intuitive accounts of dead agents' minds.     

Sleep quality, sleep propensity and academic performance

We examined associations between measures of sleep propensity on the Epworth Sleepiness Scale, sleep quality on the Pittsburgh Sleep Quality Index and academic performance by GPA and grades in introductory psychology for 414 students. In the total sample, neither sleep propensity nor sleep quality correlated with GPA or introductory psychology grades. However, among students carrying a full course load, those reporting poor sleep quality performed less well on academic measures than those reporting a better quality of sleep. Further research is needed to assess the moderating influence of overall demands of daytime functioning on the association between sleep quality and academic performance.     

Explanations versus applications: the explanatory power of valuable beliefs

People hold beliefs that vary not only in their perceived truth, but also in their value to the believer--their meaning, relevance, and importance. We argue that a belief's value is determined, at least in part, by its explanatory power. Highly valuable beliefs are those that can uniquely explain and organize a diverse set of observations. Less valuable beliefs, in contrast, are those that can be explained by other observations, or that explain and organize few observations. The results of three experiments are consistent with these hypotheses. These experiments demonstrate that applying either scientific or religious beliefs to explain other observations increases the perceived value of those beliefs, whereas generating explanations for the existence of beliefs decreases their perceived value. Discussion focuses on the implications of these findings for people's resistance to explaining their own beliefs, for the perceived value of science and religion, and for culture wars between people holding opposing beliefs.     

Dreaming and bereavement

Bereavement dreams provide an important, though seldom mentioned or recognized, component of the grief process. As the unconscious presses for recognition of the pain and extent of the loss, dream material is presented to help the bereft move to a new and integrative life position. Religious symbols present themselves to give the grieving a new sense of themselves as individuals and an expanding view of the world. Grief therapists have generally ignored this important component of the grief process, and as a result, little significant clinical research has been done. A comprehensive picture of bereavement will not be developed until increased attention is given to this important area.     

Presence of administrators differentially impacts eyewitness discriminability for same- and other-race identifications

Best practice guidelines recommend that eyewitness lineup administrators be blind to a suspect's identity, but no research has investigated whether the mere presence of a lineup administrator impacts eyewitness identification decisions. Informed by social facilitation theory, we predicted that the presence of an audience would differentially impact identification accuracy for same- and other-race identifications. Participants (N = 191) viewed same- and other-race lineups either with an audience or alone. Although the presence of an audience did not directly impact identification accuracy, significant indirect effects indicated that the audience provoked evaluation apprehension which hindered other-race identification accuracy and improved same-race identification accuracy. We suggest that using double-blind lineup procedures may not sufficiently protect eyewitness identification accuracy when making other-race lineup decisions in the presence of others.     

The roles of sequencing and verbal working memory in sentence comprehension deficits in Parkinson's disease

Studies of sentence comprehension deficits in Parkinson's disease (PD) patients suggest that language processing involves circuits connecting subcortical and cortical regions. Anatomically segregated neural circuits appear to support different cognitive and motor functions. To investigate which functions are implicated in PD comprehension deficits, we tested comprehension, verbal working memory span, and cognitive set-switching in a non-linguistic task in 41 PD patients; we also obtained speech measurements reflecting motor sequencing processes that may be involved in articulatory rehearsal within working memory. Comprehension of sentences with center-embedded or final relative clauses was impaired when they could not be understood from lexical semantic content alone. Overall comprehension error rates correlated strongly with impaired set-switching and significantly with reduced working memory span and speech motor sequencing deficits. Correlations with comprehension of different sentence structures indicate that these impairments do not represent a single deficit; rather, PD comprehension deficits appear to arise from several independent mechanisms. Deficits in cognitive set-switching or underlying inhibitory processes may compromise the ability to process relative clauses. Deficits in verbal working memory appear to impair comprehension of long-distance dependencies. Speech sequencing correlated with neither set-switching nor verbal working memory span, consistent with their being supported by independent, segregated cortico-subcortical circuits.