Limits to preference and the sensitivity of choice to rate and amount of food

Studies of choice holding food‐amount ratio constant while varying food‐rate ratio within sessions showed that local changes in preference depend on relative amount of food. The present study investigated whether sensitivity of choice to food‐rate ratio and sensitivity to food‐amount ratio are independent of one another when food‐rate ratios are varied across sessions and food‐amount ratios are varied within sessions. Food deliveries for rats’ presses on the left and right levers were scheduled according to three different food‐rate ratios of 1:1, 9:1, and 1:9; each food‐rate ratio lasted for 106 sessions and was arranged independently of seven food‐amount ratios (7:1, 6:2, 5:3, 4:4, 3:5, 2:6, and 1:7 food pellets) occurring within sessions in random sequence. Each amount ratio lasted for 10 food deliveries and was separated from another by a 60‐s blackout. Sensitivity to rate ratio was high (1.0) across food deliveries. Sensitivity to amount ratio was low when food rates were equal across alternatives, but was high when rate ratio and amount ratio opposed one another. When rate ratio and amount ratio went in the same direction, choice ratio reached an elevenfold limit which reduced sensitivity to approximately zero. We conclude that three factors affect sensitivity to amount: (1) the limit to preference, (2) the equal effect on preference of amounts greater than four pellets, and (3) the absence of differential effects of switches in amount in the equal‐rates (1:1) condition. Taken together, these findings indicate that rate and amount only sometimes combine independently as additive variables to determine preference when amount ratios vary frequently within sessions.     

Alone in the Crowd: I Failed the ABGC Certification Exam

The American Board of Genetic Counseling (ABGC) certification examination (often referred to as “the board exam”) has become a milestone within the field of genetic counseling. For many, it is the final standardized test taken and indicates the examinee has met “the standards of minimal competence to practice as a genetic counselor” (Bulletin 2015). Although voluntary, certification is strongly encouraged, and in some employment situations, required. Although recent statistics indicate the majority of those who take the test pass, each year there are those who sit for the test unsuccessfully. Despite this fact, exam failure and tools for dealing with this experience are not often broached in the literature. This essay recalls my experiences with a failed exam attempt and the subsequent emotional turmoil. It also aims to start the conversation regarding the difficulty of coping with the “secret” shame of public, professional failure, and suggests there is room for further discussion and resource development in this area.     

Reference in human and non-human primate communication: What does it take to refer?

The concept of functional reference has been used to isolate potentially referential vocal signals in animal communication. However, its relatedness to the phenomenon of reference in human language has recently been brought into question. While some researchers have suggested abandoning the concept of functional reference altogether, others advocate a revision of its definition to include contextual cues that play a role in signal production and perception. Empirical and theoretical work on functional reference has also put much emphasis on how the receiver understands the referential signal. However, reference, as defined in the linguistic literature, is an action of the producer, and therefore, any definition describing reference in non-human animals must also focus on the producer. To successfully determine whether a signal is used to refer, we suggest an approach from the field of pragmatics, taking a closer look at specific situations of signal production, specifically at the factors that influence the production of a signal by an individual. We define the concept of signaller’s reference to identify intentional acts of reference produced by a signaller independently of the communicative modality, and illustrate it with a case study of the hoo vocalizations produced by wild chimpanzees during travel. This novel framework introduces an intentional approach to referentiality. It may therefore permit a closer comparison of human and non-human animal referential behaviour and underlying cognitive processes, allowing us to identify what may have emerged solely in the human lineage.     

Joint Book Reading and Receptive Vocabulary: A Parallel Process Model

The purpose of the present study was to understand the reciprocal, bidirectional longitudinal relation between joint book reading and English receptive vocabulary. To address the research goals, a nationally representative sample of Head Start children, the Head Start Family and Child Experiences Survey (2003 cohort), was used for analysis. The children were aged 3–4 years at programme entry. The mothers' average age at programme entry was 39 years old. A parallel process model was utilized to examine the growth factors of joint book reading and receptive vocabulary in parallel. Three significant findings emerged: (1) initial levels of English receptive vocabulary and joint book reading positively covaried; (2) English receptive vocabulary and joint book reading were positively and reciprocally related to each other; and (3) slopes for joint book reading and English receptive vocabulary negatively covaried. Results suggest that joint book reading can support and scaffold Head Start children's English receptive vocabulary. Reciprocally, Head Start children's English receptive vocabulary appears to predict the extent to which they engage in joint book reading at home. Moreover, the frequency of joint book reading decreases as the children demonstrate higher levels of English receptive vocabulary. Copyright © 2015 John Wiley & Sons, Ltd.     

A Social Priming Data Set With Troubling Oddities

A recent paper by Chatterjee, Rose, and Sinha (2013) reported impressively large “money priming” effects: incidental exposure to concepts relating to cash or credit cards made participants much less generous with their time and money (after cash primes) or much more generous (after credit card primes ). Primes also altered participants’ choices in a word-stem completion task. To explore these effects, we carried out re-analyses of the raw data. A number of strange oddities were brought to light, including a dramatic similarity of the filler word-stem completion responses produced by the 20 subjects who contributed most to the priming effects. We suggest that these oddities undermine the credibility of the paper and require further investigation.     

Working Memory Capacity and Self‐Explanation Strategy Use Provide Additive Problem‐Solving Benefits

The present study examined the impact of working memory capacity (WMC) on college students' ability to solve probability problems while using a self‐explanation strategy. Participants learned to solve probability problems in one of three conditions: a backward‐faded self‐explanation condition, an example problem pairs self‐explanation condition, or a control (no self‐explanation) condition. Even when accounting for the impact of WMC, learning to problem‐solve using self‐explanation led to superior problem‐solving performance. Conditions that prompted self‐explanation during problem‐solving resulted in significantly better problem‐solving performance than the control condition. These findings provide insight into the influence of individual differences on problem‐solving when strategies are provided, as well as information about the effectiveness of the self‐explanation strategy during mathematical problem‐solving. Copyright © 2016 John Wiley & Sons, Ltd.