Effective use of the blank comparison procedure in simple discrimination by infant capuchin monkeys: A methodological note

In studies of simple and conditional discrimination, procedures are needed to measure those aspects of stimuli that control behavior. The blank comparison procedure is one such procedure. It was designed explicitly for assessing S+ and S- functions when discriminative stimuli are presented simultaneously. In this procedure, a neutral stimulus serves sometimes as S+ and sometimes as S-. Its discriminative function is defined in relation to other stimuli in the display. The present study aimed to prepare 2 infant female capuchin monkeys for the effective use of the blank comparison procedure in a simple discrimination task. First, simple discrimination training was applied up to a stable accuracy criterion of ≥90%. This training was followed by the replacement of S+ and then of S- stimuli with new stimuli. Ultimately, trials with the blank comparison were introduced. Following this sequence, both monkeys immediately displayed highly accurate blank-comparison performances without the need for stimulus control shaping or other preparatory discrimination training. Thus, this procedure sequence may be an efficient, effective method for establishing blank-comparison baselines for experimental analyses of S+/S- discriminative functions and perhaps for other applications in teaching simple and conditional discrimination performances to this species and others.     

The Need to Present a Perfect Body Image: Development of a New Measure of Perfectionistic Self-Presentation

Perfectionistic self-presentation is linked to different clinical conditions and specially to eating disorders. In fact, the role that the drive to reach “perfection” and display it to others plays on eating and body image-related symptoms has long been the target of theoretical and empirical interest. However, an instrument that specifically assessed the need to present a perfect body image to others did not exist. The current study presents the development and validation of the Perfectionistic Self-Presentation Scale – Body Image (PSPS-BI), a measure designed to assess the need to present a perfect body image to others by displaying a flawless physical appearance and by occulting perceived imperfections in a public context. Three studies that included a total of 364 males and 541 females with ages between 18 to 38 years, were used to examine the structure and psychometric properties of the scale. Results showed that PSPS-BI presents two factors that measure the concealment of body imperfections and the display of body perfection. PSPS-BI revealed good internal reliability and temporal stability. Also, the PSPS-BI revealed good concurrent validity, tested with measures of perfectionism, body image flexibility, and general and eating psychopathology. Furthermore, a mediational analysis indicated that the need to present a perfect body image to others fully mediates the relationship between a general measure of perfectionistic self-presentation and drive for thinness, in both men and women. PSPS-BI showed good preliminary evidence as a reliable and accurate measure that seems to offer new possibilities to the research field of body image and eating-related difficulties.     

Comparing the Social Images of Youth In and Out of Residential Care

The literature indicates that youths in residential care have been associated with negative social images. However, there have been few studies focused on these social images, specifically, comparing them with the images of youths in normative contexts. To address this issue, we conducted two studies comparing the social images people have about youths in residential care to those they hold about youths living out of care. Both studies were conducted in Portugal: Study 1 explores these images through an open‐ended questionnaire; Study 2 examines these images with a quantitative instrument. Overall, the results indicate that the perception about youths in residential care was more negative than the perception about youths out of care. Additionally, the first study probed the effect of socioeconomic status of the youths on the social images held about them and the second examined the role of the respondents' professional contact with youth in care population on these social images. The implications of the social images people have about youth in residential care for the research and intervention towards the wellbeing of this population are discussed. Copyright © 2016 John Wiley & Sons, Ltd.     

Dynamic decision making: a comparison of approaches

This paper is concerned with a specific type of problem, namely dynamic decisions, for which most techniques fail to provide adequate solutions. Here, we present two of the most promising optimization techniques, partially observable Markov decision processes (POMDP) and dynamic decision networks (DDN), while arguing which is the most suitable for this problem domain. Copyright © 2000 John Wiley & Sons, Ltd.     

Is Phonological Encoding in Naming Influenced by Literacy?

We examined phonological priming in illiterate adults, using a cross-modal picture-word interference task. Participants named pictures while hearing distractor words at different Stimulus Onset Asynchronies (SOAs). Ex-illiterates and university students were also tested. We specifically assessed the ability of the three populations to use fine-grained, phonemic units in phonological encoding of spoken words. In the phoneme-related condition, auditory words shared only the first phoneme with the target name. All participants named pictures faster with phoneme-related word distractors than with unrelated word distractors. The results thus show that phonemic representations intervene in phonological output processes independently of literacy. However, the phonemic priming effect was observed at a later SOA in illiterates compared to both ex-illiterates and university students. This may be attributed to differences in speed of picture identification.     

The development of the orthographic consistency effect in speech recognition: from sublexical to lexical involvement

The influence of orthography on children's on-line auditory word recognition was studied from the end of Grade 2 to the end of Grade 4, by examining the orthographic consistency effect [Ziegler, J. C., & Ferrand, L. (1998). Orthography shapes the perception of speech: The consistency effect in auditory recognition. Psychonomic Bulletin &Review, 5, 683-689.] in auditory lexical decision and shadowing tasks. Words with rhymes that can be spelled in two different ways (inconsistent) produced longer auditory lexical decision and shadowing times and more errors than did consistent words. A similar consistency effect was also observed on pseudowords. The observation of a general consistency effect, both for words and pseudowords, in lexical decision and in shadowing suggests a widespread influence of orthography in the children's spoken word recognition system. On exactly the same material, with adult listeners we replicated the usual pattern of an orthographic consistency effect restricted to words in lexical decision [Ventura, P., Morais, J., Pattamadilok, C., & Kolinsky, R. (2004). The locus of the orthographic consistency effect in auditory word recognition. Language and Cognitive Processes, 19, 57-95; Ziegler, J. C., & Ferrand, L. (1998). Orthography shapes the perception of speech: The consistency effect in auditory recognition. Psychonomic Bulletin &Review, 5, 683-689]. A reanalysis of the lexical decision and shadowing results of Ventura et al. [Ventura, P., Morais, J., Pattamadilok, C., & Kolinsky, R. (2004). The locus of the orthographic consistency effect in auditory word recognition. Language and Cognitive Processes, 19, 57-95.] confirmed the discrepancy between the effects of orthographic consistency in child readers and adults. A further control experiment showed that orthographic consistency effects were not present in pre-readers. Results are interpreted considering the coexistence in children's reading of a mechanism of automatic access to well-specified orthographic representations of words and the persistence of grapho-phonological decoding procedures.     

The differentiation of response numerosities in the pigeon

Two experiments examined how pigeons differentiate response patterns along the dimension of number. In Experiment 1, 5 pigeons received food after pecking the left key at least N times and then switching to the right key (Mechner's Fixed Consecutive Number schedule). Parameter N varied across conditions from 4 to 32. Results showed that run length on the left key followed a normal distribution whose mean and standard deviation increased linearly with N; the coefficient of variation approached a constant value (the scalar property). In Experiment 2, 4 pigeons received food with probability p for pecking the left key exactly four times and then switching. If that did not happen, the pigeons still could receive food by returning to the left key and pecking it for a total of at least 16 times and then switching. Parameter p varied across conditions from 1.0 to .25. Results showed that when p= 1.0 or p=.5, pigeons learned two response numerosities within the same condition. When p=.25, each pigeon adapted to the schedule differently. Two of them emitted first runs well described by a mixture of two normal distributions, one with mean close to 4 and the other with mean close to 16 pecks. A mathematical model for the differentiation of response numerosity in Fixed Consecutive Number schedules is proposed.     

A modular theory of learning and performance

We describe a theory to account for the acquisition and extinction of response rate (conditioning) and pattern (timing). This modular theory is a development of packet theory (Kirkpatrick, 2002; Kirkpatrick & Church, 2003) that adds a distinction between pattern and strength memories, as well as contributing closed-form equations. We describe the theory using equations related to a flow diagram and illustrate it by an application to an experiment with repeated acquisitions and extinctions of a multiple-cued-interval procedure using rats. The parameter estimates for the theory were based on a calibration sample from the data, and the predictions for different measures of performance on a validation sample from the same data (cross-validation). The theory’s predictions were similar to predictions based on the reliability of the behavior.     

Transthyretin influences spatial reference memory

Transthyretin (TTR) is a plasma and cerebrospinal fluid carrier for thyroxine and retinol, described also to sequester the amyloid beta peptide. TTR levels have been described as decreased in the cerebrospinal fluid of patients with Alzheimer's disease. In order to investigate the role of TTR in learning and memory, we studied young adult and old TTR-null 129/Sv mice for cognitive performance. In the absence of TTR, 5-month-old mice display spatial reference memory impairment when compared to age-matched wild-type mice. Interestingly, while aging in wild-type mice is associated with a worsening reference memory performance, TTR-null mice show no further impairment with increasing age. As a result, no significant differences were found in this spatial reference task in old mice. Our data show that the absence of TTR seems to accelerate the poorer cognitive performance normally associated with aging.     

Motor acquisition rate in Brazilian infants

This study used the Alberta Infant Motor Scale (AIMS) with the aim of characterizing motor acquisition rate in 70 healthy 0–6‐month‐old Brazilian infants, as well as comparing both emergence (initial age) and establishment (final age) of each skill between the study sample and the AIMS normative data. New motor skills were continuously acquired from 0 to 6 months of age by the Brazilian infants, but their acquisition rate was non‐linear. When compared to the AIMS sample, Brazilian infants achieved lower percentiles, and their initial age to acquire skills requiring greater antigravity demand was higher. In contrast, Brazilian infants stopped exhibiting primitive patterns earlier, and their final age to acquire antigravity skills was lower. These differences in motor development are suggested to be a consequence of different parental practices and not necessarily indicate motor delay. Thus, the AIMS normative values should be adapted to cultural particularities so as to avoid that infants are misclassified as at risk for motor delay. Furthermore, an adequate assessment of motor development should consider not only the age at which a skill is emerged, but also the age at which such a skill is established in the infant's motor repertoire. Copyright © 2009 John Wiley & Sons, Ltd.