Discrimination of direction of movements in pigeons following previous experience of motion/static discrimination

Two experiments examined pigeons' discrimination of directional movement using pictorial images shown on computer monitors. Stimuli consisted of the movement of a bird against a stationary background or the movement of the background behind a stationary bird. In Experiment 1, pigeons were trained to discriminate either leftward or rightward motion of either the bird or the background from stationary frames drawn from the same movies. The background-discrimination group acquired the discrimination faster than the bird-discrimination group. In Experiment 2, transfer of the discrimination from the task of Experiment 1 to a discrimination between motion directions was examined. Most of the pigeons learned this discrimination rapidly, whereas in a pilot study in which direction discrimination was trained without previous static/movement discrimination, learning was poor. It appears that an experimental history of movement against stationary discrimination promoted the pigeons' learning of the directional motion discrimination.     

On the use of discrimination to assess memory

A number of studies have made use of sensory discrimination to assess memory. These experiments have typically employed a temporal two-alternative forced choice paradigm in which the interstimulus interval (ISI) is varied. Many of these tests have shown that ISI has little or no effect on discrimination performance. This has been taken as evidence for perfect or very good memory. An alternative interpretation would be that discrimination tests lack sufficient sensitivity to reveal memory effects. In the present study, computer simulations based on signal detection theory were used to estimate the relative effects of memory noise and direct noise (i.e., noise inherent in the discrimination task) on discrimination performance. These simulations indicate that the amount of memory noise has to be quite large to cause a marked elevation in discrimination thresholds and that sensory discrimination is a relatively insensitive test of memory.     

Ask,Answer, and Announce: Three stages in perceiving and responding to discrimination

Discrimination towards members of low-status groups takes a variety of forms, and results in a variety of negative consequences for its victims. Furthermore, discrimination may influence its targets either directly (for instance, when housing discrimination makes insurance, mortgage rates, or rents higher for African Americans than for whites) or indirectly, that is via perceptions on the part of the stigmatised. In the latter case the outcomes are caused or amplified by perceptions on the part of the victim that he or she is the target of discrimination. This chapter focuses on current research concerning factors that influence the perception of discrimination and its indirect influence on individuals. We review work from our own lab as well as from the field more broadly, focusing on research that attempts to explain contextual and individual variability in how events that are potentially due to discrimination are initially perceived, subsequently interpreted, and then publicly reported or withheld.     

Contrast and inhibition in discrimination learning by the pigeon: Analysis through drug effects

In a series of four experiments, pigeons were trained on either an easy, red/green discrimination with or without a penalty for errors, or a more difficult left/right discrimination with penalty. Some groups of birds were injected with chlorpromazine or desipramine prior to acquisition sessions or to sessions following learning of the discrimination. Drug injection caused substantial impairment of acquisition or retention of the left/right discrimination alone, whereas in all discriminations the behavioral contrast effect was abolished. The results suggest that inhibition of errors depends upon the difficulty of discrimination and the presence of a penalty procedure, and determines both contrast in the saline-injected groups and the extent of impairment in the drug-injected groups.     

Impact de la discrimination envers les personnes LGBTQ+ en milieu de travail : recension systématique

In the United States, between 3% and 12% of employees are part of the LGBTQ+ community. Despite numerous anti-discrimination laws, they continue to be the target of discrimination in their workplaces. The purpose of this systematic review is to examine the impact of direct and indirect discrimination against LGBTQ+ individuals in the workplace and on the organization. Sixty-one articles published between January 2000 and June 2021 and indexed in PsycINFO, Web of Science, Business Source Premier and Gender Studies Data Base and Erudit were analyzed. The results first show that there is no consensus on the definition of discrimination and that few studies distinguish between direct and indirect discrimination. The effects of direct discrimination on individuals can be summarized into five broad categories: 1) hiding one's sexual orientation or gender identity, 2) experiencing financial consequences, 3) experiencing mental or physical health problems, 4) being excluded, and 5) feeling discomfort. The four effects of indirect discrimination on individuals are 1) hiding sexual orientation or gender identity, 2) experiencing negative emotions, 3) mental or physical health problems, and 4) lack of promotion. Finally, the five categories of consequences of direct discrimination on organizations are 1) lack of commitment and satisfaction, 2) lack of trust in the organization, 3) loss of workforce, 4) decreased performance, and 5) harassment. The only identified effect of indirect discrimination on the organization is a deteriorated work climate.     

How Disadvantaged Group Members Cope With Discrimination When They Perceive That Social Support Is Available1

This experiment examined how disadvantaged group members cope with discrimination when they perceive that social support is available. Women reacted to a failing test grade after ambiguous information about the probability for discrimination. With no social support, women minimized discrimination and attributed their failure to the quality of their answers. Participants were less inclined to minimize discrimination when social support was available. When they perceived that either emotional or informational support was available, women were equally likely to blame their failure on discrimination as on the quality of their answers. The results revealed less minimization of personal discrimination when both emotional and informational support were available, in which case participants blamed their failure more on discrimination and less on themselves.     

The effect of discrimination training on responses to a new stimulus

Most previous research on the effect of the duration of preceding discrimination training on responding to a new stimulus has measured the responding during extinction. To reduce effects originating in the extinction procedure itself, the present study assessed the effect of discrimination training on responses to a new negative stimulus added during continued discrimination training. Pigeons were given a new negative stimulus (blue key) after 0, 1, 3, or 9 days of discrimination training with a yellow key as the positive stimulus, and both a green key and a red key as negative. Fewer responses were made to the blue key when it was introduced after nine days of discrimination training than after less discrimination training. That effect of long discrimination training agrees with reported results from extinction tests. However, the effect of briefer discrimination training in the present study differed from reported results with extinction testing. It appears that testing during continued discrimination training eliminates a distortion present in extinction tests of the effect of discrimination training on responding to a new stimulus.     

Influence of Perceived Racial Discrimination on the Health of Immigrant Children in Canada

Racial discrimination and racism are recognized as determinants of health for adults. Less is understood regarding the influence of discrimination targeted towards parents, the family, or the cultural and children’s health. Data from the New Canadian Children and Youth Study (NCCYS) are used in this paper. The NCCYS is a national, longitudinal study of children whose families settled in urban centers of Canada. We analyzed data from individuals who settled in the metropolitan Vancouver area from six ethnic communities: Mainland China, Hong Kong, the Philippines, Iran, Afghanistan, and the Punjab who were interviewed at two times, approximately 2 years apart. Data were collected on perceived parental, family, and cultural discrimination. Our dependent variable was parent-reported child health status. Over time, perceived parental discrimination and perceived family discrimination decreased; and both forms of discrimination had a positive effect on child health. In contrast, perceived cultural discrimination increased over time and had a negative effect on child health at both times. Different forms of discrimination have different effects on child health. Racial discrimination is complex. Its influence on either increasing family cohesion, and thereby leading to improved health, or increasing stress, thereby leading to poorer health needs to be explored further.     

Perceptions of personal sex discrimination: the role of belief in a just world and situational ambiguity

The roles of belief in a just world (BJW) and discrimination against ones' group in perceptions of personal discrimination were examined. Female participants (n = 63) were personally discriminated against in a laboratory setting. We manipulated whether the experimenter appeared to discriminate against other participants, which presumably made the presence of personal discrimination less ambiguous, or did not appear to discriminate against others, which presumably made personal discrimination more ambiguous. In the no group discrimination condition, but not in the group discrimination condition, participants' perceptions of being personally discriminated against depended on individual differences in BJW: Women with a strong BJW perceived less personal discrimination than those with a weak BJW. Also, strong BJW women in the group discrimination condition perceived less personal discrimination than strong BJW women in the no group discrimination condition.     

Generalization of auditory intensity as a function of small amounts of discrimination training

Rats were trained on a two-valued auditory-intensity discrimination for 5, 2, 1 or 0 days. Then, the bar-press response rate was sampled in the presence of seven added discrimination stimuli (generalization) for seven days. Daily training sessions were 4 hr in length throughout the experiment. Only the five-day group exhibited a marked superiority on the multi-valued discrimination when contrasted with the group having had no prior simple discrimination training.     

环境因素对流动儿童歧视知觉的影响及群体态度的调节作用

采用整班联系、自愿参加的方式,选取北京市海淀、朝阳、昌平三个区的1350名流动儿童为被试,采用歧视知觉问卷、家庭社会经济地位问卷、班级环境气氛量表以及群体态度测验,考察家庭经济环境和学校班级环境对流动儿童歧视知觉的影响,并进一步探讨群体态度对它们关系的影响作用。结果表明:(1)家庭社会经济地位、老师支持和同学支持对于个体和群体歧视知觉具有显著的负向影响,同时,班级内聚力对于个体歧视知觉、满意程度对于群体歧视知觉也存在显著的负向影响。(2)同学支持对于个体歧视知觉的负向预测作用更为重要,老师支持则对群体歧视知觉的负向预测作用更为重要。(3)对于群体态度不同的流动儿童,环境因素对其个体和群体歧视知觉的作用存在一定差异。在个体歧视知觉方面,同学支持是态度中立组和态度偏城市儿童组的最佳预测因素,班级内聚力则是态度偏流动儿童组的最佳预测因素;在群体歧视知觉方面,老师支持对于群体态度不同组均表现出最为重要的预测作用。     

Conditional discrimination after errorless and trial-and-error training.

Children were trained on a visual discrimination by stimulus shaping, stimulus fading, or trial-and-error. Those who did not acquire the conditional discrimination received a second, different training. More children initially trained by stimulus shaping acquired the conditional discrimination than did those initially trained with stimulus fading or trial-and-error. After a history of fading or trial-and-error training, children were less likely to acquire the conditional discrimination even after the more successful procedure of shaping was later used.     

An inexpensive and automated method for presenting olfactory or tactile stimuli to rats in a two-choice discrimination task

An inexpensive and automated method for presentation of olfactory or tactile stimuli in a two-choice task for rats was implemented with the use of a computer-controlled bidirectional motor. The motor rotated a disk that presented two stimuli of different texture for tactile discrimination, or different odor for olfactory discrimination. Because the solid olfactory stimuli were placed outside the chamber in metal pods with a mesh at front for odor sampling, "washout" of odors between trials was not necessary. To avoid differential auditory cues from motor rotation, the stimuli were arranged such that on each trial the motor always rotated exactly one quarter revolution (in 1 s), left or right, to present the next stimulus at trial start. To illustrate the use of the equipment, 2 rats were trained on tactile discrimination and 2 rats on olfactory discrimination. The rats sampled the stimulus on the disk through a port on the back wall by sniffing at it (olfactory) or touching it (tactile). The task was a go-left/go-right discrimination with the stimulus on the disk being discriminative for which lever provided reinforcement. The rats reached a stable level above 90% correct after 21 and 32 training sessions for tactile and olfactory discrimination, respectively. The article outlines how the equipment was constructed from low-cost components. Inputs from and outputs to the equipment were implemented through the parallel port of a personal computer without the use of a commercial interface board. The method of automated and low-cost presentation of olfactory or tactile stimuli should be of use for a variety of experimental situations such as matching-to-sample and cross-modal discrimination.     

The Personal/Group Discrimination Discrepancy: Women Talk About Their Experiences1

Participants in research on discrimination consistently rate discrimination directed at their group higher than at themselves personally as a member of that group. In order to examine this personal/group discrimination discrepancy, women were asked to spontaneously verbalize their thoughts as they made ratings for personal and group discrimination on 11-point scales. In Study 1, university women who raised a greater number of life domains for group discrimination than for personal discrimination showed a larger personal/group discrimination discrepancy because of lower ratings for personal discrimination. An analysis of participants' protocols revealed that many attended to different domains when rating personal and group discrimination, and that these participants showed a larger personal/group discrimination discrepancy because of lower ratings for personal discrimination. Participants' ratings for group discrimination did not differ as a function of the number or content of the domains. The findings were replicated in Study 2 with working women, and are identified as two contributing factors to the personal/group discrimination discrepancy. The societal implications of the results are discussed in terms of the tendency for disadvantaged group members to downplay their personal experience with discrimination because it does not fit the stereotype of what is being experienced by the group.     

Refugee Discrimination – The Good,the Bad,and the Pragmatic

This article addresses three questions. To what extent does the current refugee regime discriminate among refugees? When is such discrimination wrong? Could discrimination ever be justified pragmatically, for the sake of admitting more refugees given political constraints? In answer to the first question, it finds discrimination is rampant. There is the kind of discrimination that gets noticed: discrimination that states choose to enact within the refugee regime. But there is also a kind of discrimination that is missed: discrimination that is a product of the regime itself. The second question proves tricky. Matters are clear at the extremes. Discrimination based on need is permissible. Discrimination based on race or religion is not. In between, we have a set of hard cases that are more difficult to judge. The article searches for relevant criteria. Finally, on the last question, the article concludes that a political leader could be justified in enacting discrimination as a pragmatic response to political constraints but that, even on such occasions, discrimination remains wrongful.     

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.     

Selective semantic-lexical impairment of language comprehension in right-brain-damaged patients

Fifty right-brain-damaged patients and thirty-nine normal controls were given two tests of semantic-lexical discrimination (auditory language comprehension and reading comprehension) and a test of phoneme discrimination. The aims of the research consisted in checking: (A) if right-brain-damaged patients are significantly more impaired than normal controls on the tasks of semantic discrimination even when the influence of associated variables (such as unilateral spatial neglect or general mental impairment) is ruled out; and (B) if semantic-lexical disorders of right-brain-damaged patients are selective or if they are associated with disorders of phoneme discrimination. Results have shown that right hemispheric lesions consistently impair semantic-lexical discrimination but do not hamper phoneme discrimination. Some implications of these results are discussed.     

Perspective taking combats the denial of intergroup discrimination

Despite the continuing, adverse impact of discrimination on the lives of racial and ethnic minorities, the denial of discrimination is commonplace. Four experiments investigated the efficacy of perspective taking as a strategy for combating discrimination denial. Participants who adopted a Black or Latino target's perspective in an initial context were subsequently more likely to explicitly acknowledge the persistence of intergroup discrimination than were non-perspective takers (Experiments 1–3) or participants who adopted a White target's perspective (Experiment 1). Perspective taking also engendered more positive attitudes toward a social policy designed to redress intergroup inequalities (i.e., affirmative action), and this relationship was mediated by increased recognition of discrimination (Experiments 2a and 2b). Increased identification with the targeted outgroup, as reflected in automatic associations between the self and African Americans, was found to underlie the effect of perspective taking on sensitivity to discrimination (Experiment 3). The collective findings indicate that perspective taking can effectively combat discrimination denial.     

Auditory processing deficits in children with reading and language impairments: can they (and should they) be treated?

Sixty-five children with specific reading disability (SRD), 25 children with specific language impairment (SLI), and 37 age-matched controls were tested for their frequency discrimination, rapid auditory processing, vowel discrimination, and consonant–vowel discrimination. Subgroups of children with SRD or SLI produced abnormal frequency discrimination (42%), rapid auditory processing (12%), vowel discrimination (23%), or consonant–vowel discrimination (18%) thresholds for their age. Twenty-eight of these children trained on a programme that targeted their specific auditory processing deficit for 6 weeks. Twenty-five of these 28 trainees produced normal thresholds for their targeted processing skill after training. These gains were not explained by gains in auditory attention, in the ability to do psychophysical tasks in general, or by test–retest effects. The 25 successful trainees also produced significantly higher scores on spoken language and spelling tests after training. However, an untrained control group showed test–retest effects on the same tests. These results suggest that auditory processing deficits can be treated successfully in children with SRD and SLI but that this does not help them acquire new reading, spelling, or spoken language skills.     

Pilocarpine seizures cause age-dependent impairment in auditory location discrimination

Children who have status epilepticus have continuous or rapidly repeating seizures that may be life-threatening and may cause life-long changes in brain and behavior. The extent to which status epilepticus causes deficits in auditory discrimination is unknown. A naturalistic auditory location discrimination method was used to evaluate this question using an animal model of status epilepticus. Male Sprague-Dawley rats were injected with saline on postnatal day (P) 20, or a convulsant dose of pilocarpine on P20 or P45. Pilocarpine on either day induced status epilepticus; status epilepticus at P45 resulted in CA3 cell loss and spontaneous seizures, whereas P20 rats had no cell loss or spontaneous seizures. Mature rats were trained with sound-source location and sound-silence discriminations. Control (saline P20) rats acquired both discriminations immediately. In status epilepticus (P20) rats, acquisition of the sound-source location discrimination was moderately impaired. Status epilepticus (P45) rats failed to acquire either sound-source location or sound-silence discriminations. Status epilepticus in rat causes an age-dependent, long-term impairment in auditory discrimination. This impairment may explain one cause of impaired auditory location discrimination in humans.