Stimulus complexity and prospective timing: clues for a parallel process model of time perception

Whereas many studies have considered the role of attention in prospective timing, fewer have established relations between movement complexity and prospective timing. The present study aims at assessing to what extent motion complexity interferes with prospective timing and at delineating a neuropsychophysical plausible model. We have thus designed a visual paradigm presenting stimuli in sequential pairs (reference comparison interval). Stimuli are motionless or moving according to different complexities, and stimulus complexities are intermixed within each pair. To prevent a possible attention-sharing effect, no concurrent task was required. Our study suggests that movement complexity is a key component of duration perception, and that the relative judgement of durations depends on spatio-temporal features of stimuli. In particular, it shows that movement complexity can bias subjects’ perception and performance, and that subjects detect that comparison intervals are longer than reference before their end. In the discussion, we advocate that the classical internal clock model cannot easily account for our results. Consequently, we propose a model for time perception, based on a parallel processing between comparison interval perception and the reconstruction of the reference duration.     

The developmental course of lexical tone perception in the first year of life

Perceptual reorganisation of infants' speech perception has been found from 6 months for consonants and earlier for vowels. Recently, similar reorganisation has been found for lexical tone between 6 and 9 months of age. Given that there is a close relationship between vowels and tones, this study investigates whether the perceptual reorganisation for tone begins earlier than 6 months. Non-tone language English and French infants were tested with the Thai low vs. rising lexical tone contrast, using the stimulus alternating preference procedure. Four- and 6-month-old infants discriminated the lexical tones, and there was no decline in discrimination performance across these ages. However, 9-month-olds failed to discriminate the lexical tones. This particular pattern of decline in nonnative tone discrimination over age indicates that perceptual reorganisation for tone does not parallel the developmentally prior decline observed in vowel perception. The findings converge with previous developmental cross-language findings on tone perception in English-language infants [Mattock, K., & Burnham, D. (2006). Chinese and English infants' tone perception: Evidence for perceptual reorganization. Infancy, 10(3)], and extend them by showing similar perceptual reorganisation for non-tone language infants learning rhythmically different non-tone languages (English and French).     

Theory to social action: A university‐based strategy targeting prejudice against Aboriginal Australians

The level of racism in Australia against Aboriginal Australians is well documented. This has an extremely detrimental effect on the health and wellbeing of Aboriginal Australians. One part of the solution may be anti‐prejudice strategies, but to date few strategies that include a pre‐test and a post‐test assessment have been conducted in Australia. The present study describes the interventional qualities of a cultural psychology unit at an Australian university. Results indicated that after a 6‐week period, students reported a significant reduction in prejudice, acceptance of false beliefs about Aboriginal Australians, and the perception that Aboriginal Australians unfairly receive preferential or special treatment. The article concludes that cultural psychology units have the potential to be an effective way of developing acceptance of cross‐cultural differences.     

What 50 years of research tell us about pausing under ratio schedules of reinforcement

Textbooks in learning and behavior commonly describe performance on fixed-ratio schedules as “break and run,” indicating that after reinforcement subjects typically pause and then respond quickly to the next reinforcement. Performance on variable-ratio schedules, on the other hand, is described as steady and fast, with few long pauses. Beginning with Ferster and Skinner''s magnum opus, Schedules of Reinforcement (1957), the literature on pausing under ratio schedules has identified the influences on pausing of numerous important variables, in particular ratio size and reinforcement magnitude. As a result, some previously held assumptions have been called into question. For example, research has shown that the length of the pause is controlled not only by the preceding ratio, as Ferster and Skinner and others had assumed (and as implied by the phrase postreinforcement pause), but by the upcoming ratio as well. Similarly, despite the commonly held belief that ratio pausing is unique to the fixed-ratio schedule, there is evidence that pausing also occurs under variable-ratio schedules. If such widely held beliefs are incorrect, then what about other assumptions? This article selectively examines the literature on pausing under ratio schedules over the past 50 years and concludes that although there may indeed be some common patterns, there are also inconsistencies that await future resolution. Several accounts of pausing under ratio schedules are discussed along with the implications of the literature for human performances, most notably the behaviors termed procrastination.     

Nodal structure and the partitioning of equivalence classes

By definition, all of the stimuli in an equivalence class have to be functionally interchangeable with each other. The present experiment, however, demonstrated that this was not the case when using post-class-formation dual-option response transfer tests. With college students, two 4-node 6-member equivalence classes with nodal structures of A-->B-->C-->D-->E-->F were produced by training AB, BC, CD, DE, and EF. Then, unique responses were trained to the C and D stimuli in each class. The responses trained to C generalized to B and A, while the responses trained to D generalized to E and F. Thus, each 4-node 6-member equivalence class was bifurcated into two 3-member functional classes: A-->B-->C and D-->E-->F, with class membership precisely predicted by nodal structure. A final emergent relations test documented the intactness of the underlying 4-node 6-member equivalence classes. The coexistence of the interchangeability of stimuli in an equivalence class and the bifurcation of such a class in terms of nodal structure was explained in the following manner. The conditional discriminations that are used to establish a class also imposes a nodal structure on the stimuli in the class. Thus, the stimuli in the class acquire two sets of relational properties. If the format of a test trial allows only one response option per class, responding on those trials will be in accordance with class membership and will not express the effects of nodal distance. If the format of a test trial allows more than one response option per class, responding on those trials will be determined by the nodal structure of the class. Thus, the relational properties expressed by the stimuli in an equivalence class are determined by the discriminative function served by the format of a test trial.     

Asymmetrical retention functions for sequences of light flashes or tone bursts in the rat

In Experiment 1, rats were trained in a symbolic delayed matching-to-sample task to discriminate sample stimuli that consisted of sequences of magazine light flashes. The intertrial interval was illuminated by the houselight for Group Light, and it was dark for Group Dark. Retention functions exhibited a choose-many response bias when the delay interval was illuminated by the houselight in both groups, and no consistent response bias when the delay interval was dark. In Experiment 2, rats were trained to discriminate sample stimuli that consisted of sequences of tone bursts. During delay testing, a different tone (i.e., different frequency and location than the sample tone) was present or absent during the delay interval. The retention functions exhibited a significant choose-many bias when tone was present during the delay and a choose-few bias when tone was absent. Asymmetrical retention functions for tone burst and light flash sequences are due to the similarity between the stimulus conditions of the delay interval and the modality of the sequential event being discriminated. These results are consistent with an instructional ambiguity explanation of response biases in memory for number.     

The Unrecognized Stereotyping and Discrimination Against Singles

ABSTRACT— A widespread form of bias has slipped under our cultural and academic radar. People who are single are targets of singlism : negative stereotypes and discrimination. Compared to married or coupled people, who are often described in very positive terms, singles are assumed to be immature, maladjusted, and self-centered. Although the perceived differences between people who have and have not married are large, the actual differences are not. Moreover, there is currently scant recognition that singlism exists, and when singlism is acknowledged, it is often accepted as legitimate.     

The relationship between perceived religious discrimination and self‐esteem for Muslim Australians

Muslim Australians represent one of the fastest growing migrant groups in Australia. They are also the group who, after Indigenous Australians, experience the most discrimination. Previous research on the minority stress model confirms a link between such discrimination and mental health. However, in relation to self‐esteem and discrimination, the results are mixed, potentially reflecting whether people reject or identify with prejudiced views of them and also the type of discrimination being measured. To explore this issue further in an Australian context, we asked 49 Australian Muslims to complete Rosenberg's Self‐esteem Scale and the Perceived Religious Discrimination Scale. In support of both the minority stress model and the rejection‐identification model, we found that perceived interpersonal and systemic discrimination accounts for a small but significant variation in self‐esteem. Interpersonal discrimination was negatively related to self‐esteem, and systemic discrimination positively related. The effects of interpersonal discrimination on self‐esteem can guide therapists to interventions that help clients resist internalising discrimination experiences. The effects of institutional discrimination support therapists becoming part of the resistance to and challenging of discrimination and inequality.     

Beliefs About Gender Discrimination in the Workplace in the Context of Affirmative Action: Effects of Gender and Ambivalent Attitudes in an Australian Sample

This study investigated beliefs about gender discrimination in opportunities for promotion in organisations and their relation to gender and gender-focused ambivalent beliefs as measured, respectively, by the Ambivalent Sexism Inventory (ASI) and the Ambivalence toward Men Inventory (AMI) (Glick and Fiske, Ambivalent sexism. In M.P. Zanna (Ed.), Advances in experimental social psychology, 33: pp. 115-188, San Diego, CA: Academic, 2001a). These two inventories were administered to 225 students at Flinders University in Adelaide, Australia along with discrimination items concerning advantage, responsibility, guilt, and resentment about the advancement of men and women in the workplace. Results showed gender differences in discrimination beliefs and in the hostile and benevolent scales from the ASI and AMI. Gender differences and relations between these scales and the discrimination variables were interpreted in terms of system-justification, self and group interests, and the effects of values and beliefs about deservingness and entitlement. This study was supported by a grant from the Australian Research Council.     

The relationship between body weight and perceived weight-related employment discrimination: The role of sex and race

This study provides unique empirical evidence regarding a growing concern internationally: weight discrimination in the workplace. Using survey data from a national sample of 2838 American adults, it responds to Puhl and Brownell’s [Puhl, R., & Brownell, K. D. (2001). Bias, discrimination, and obesity. Obesity Research, 9, 788-805] call for additional research investigating the prevalence of discriminatory experience among overweight employees, and to their more specific call for research that takes sex and race into account when examining weight discrimination. The results indicate that women are over 16 times more likely than men to perceive employment related discrimination and identify weight as the basis for their discriminatory experience. In addition, overweight respondents were 12 times more likely than normal weight respondents to report weight-related employment discrimination, obese 37 times more likely, and severely obese more than 100 times more likely. The implications of the study’s findings for organizations, policy makers, overweight employees, and career counselors are discussed, and future research directions suggested.