Labeling—stereotype—discrimination

AIM: Using Link and Phelan's concept of the stigma process, public attitudes towards people with schizophrenia are examined. METHOD: In the spring of 2001, a representative population survey was conducted in Germany (n=5025). A fully structured personal interview was carried out, beginning with the presentation of a case vignette. RESULTS: Labeling as mental illness increased the likelihood that someone suffering from schizophrenia was considered as being unpredictable and dangerous. This, in turn, led to an increase of the preference for social distance. Although much weaker, labeling also had a positive effect on public attitudes insofar as it was associated with a decrease of the tendency to attribute the responsibility for the occurrence of the disorder to the afflicted person. However, this had no significant impact on the desire for social distance. There was no significant association between labeling and the anticipation of poor prognosis. There were some differences between respondents who are familiar with mental illness and those who are not. CONCLUSION: Our findings have some implications for the planning of interventions aimed at reducing stigma and discrimination because of schizophrenia. These interventions should primarily address the stereotypes of unpredictability and dangerousness since they are most likely to have a negative impact on the public's willingness to engage in social relationships with those suffering from this disorder. The interventions should also be tailored according to whether the target population is familiar with mental illness or not.     

Do discrimination tasks discourage multi-dimensional stimulus processing? Evidence from a cross-modal object discrimination in rats

Neurobiologists are becoming increasingly interested in how complex cognitive representations are formed by the integration of sensory stimuli. To this end, discrimination tasks are frequently used to assess perceptual and cognitive processes in animals, because they are easy to administer and score, and the ability of an animal to make a particular discrimination establishes beyond doubt that the necessary perceptual/cognitive processes are present. It does not, however, follow that absence of discrimination means the animal cannot make a particular perceptual judgement; it may simply mean that the animal did not manage to discover the relevant discriminative stimulus when trying to learn the task. Here, it is shown that rats did not learn a cross-modal object discrimination (requiring association of each object's visual appearance with its odour) when trained on the complete task from the beginning. However, they could eventually make the discrimination when trained on the component parts step by step, showing that they were able to do the necessary cross-modal integration in the right circumstances. This finding adds to growing evidence that discrimination tasks tend to encourage feature-based discrimination, perhaps by engaging automatic, habit-based brain systems. Thus, they may not be the best way to assess the formation of multi-dimensional stimulus representations of the kind needed in more complex cognitive processes such as declarative memory. Instead, more natural tasks such as spontaneous exploration may be preferable.     

Is right hemisphere specialization for face discrimination specific to humans?

Patterns of neural activation during face recognition were investigated in sheep by quantifying altered c-fos mRNA expression in situations where faces (sheep vs. human) can (faces upright) and cannot (faces inverted) be discriminated. Exposure to upright faces selectively increased expression significantly more in the right inferior temporal cortex than in the left, and active choice between upright faces additionally increased expression bilaterally in basal amygdala and hippocampus (CA1-4). Exposure to inverted faces did not lead to enhanced activation in the right inferior temporal cortex, amygdala or hippocampus but instead increased expression levels in the diagonal band of Broca, parietal and cingulate cortices. These results show that discrimination of upright faces in sheep preferentially engages the right temporal cortex, as it does in humans, and that performance of active choices between such faces may additionally involve the basal amygdala and hippocampus.     

How to compare two quantities? A computational model of flutter discrimination

A task that has been intensively studied at the neural level is f lutter discrimination. I argue that f lutter discrimination entails a combination of a temporal assignment problem and a quantity comparison problem, and propose a neural network model of how these problems are solved. The network combines unsupervised and one-layer supervised training. The unsupervised part clusters input features (stimulus + time window) and the supervised part categorizes the resulting clusters. After training, the model shows a good fit with both neural and behavioral properties. New predictions are outlined and links with other cognitive domains are pointed out.     

MHC molecules in the vomeronasal organ: contributors to pheromonal discrimination?

The vomeronasal organ of the accessory olfactory system detects pheromones in several vertebrate species. Recent studies of vomeronasal sensory neurons have shown that they express MHC molecules, which in the immune system help to discriminate self antigens from non-self antigens. These new findings, along with past research demonstrating MHC-based olfactory discrimination, suggest the exciting possibility that MHC molecules together with vomeronasal G-protein-coupled receptors play a role in distinguishing related individuals from unrelated ones based on pheromonal cues.     

His or mine? The time course of self-other discrimination in emotion processing

This electroencephalography (EEG) study investigated at which temporal processing stages self-other discrimination in emotion processing occurs. EEG was recorded in 23 healthy participants during silent reading of unpleasant, pleasant, and neutral pronoun-noun and article--noun expressions that were related to the participants themselves, related to an unknown third person, or had no self-other reference at all. Self- and other-related pronoun--noun pairs elicited larger cortical negativity relative to the processing of article--noun pairs at left posterior electrodes as early as 200 ms after stimulus onset. In the same time windows (from 200 ms to 300 ms and 300 ms to 400 ms) the emotionality of the words enhanced event-related brain potential (ERP) amplitudes at parieto-occipital electrodes. From 350 ms onwards, processing of self-related unpleasant words elicited larger frontal negativity compared to unpleasant words that were related to the other or that had no reference at all. In addition, processing of pleasant words vs. neutral or unpleasant words elicited larger positive amplitudes over parietal electrodes from 450 ms after stimulus onset, in particular when words were self-related. Our findings demonstrate that for verbal emotional stimuli, self--other discrimination first occurs at higher-order, cortical processing stages. This is consistent with the view that categorization of information according to certain stimulus aspects (self--other reference, emotionality) occurs before its meaning is integrated.     

Non‐word repetition and non‐word discrimination in Swedish preschool children

By looking at data on expressive phonology, non‐word repetition, non‐word discrimination and phonological sensitivity in two groups of Swedish children, the common basis for tasks tapping into different levels of phonological processing is discussed. Two studies were performed, one including children with language impairment (LI) and one including children with normal language development (NL). A discrimination task consisting of non‐word pairs differing in one phoneme was developed. In both groups there was a significant correlation between non‐word repetition and phoneme identification. In children with LI phoneme identification was significantly correlated with expressive phonology. In children with NL non‐word repetition correlated significantly with non‐word discrimination, which was linked both to rhyme recognition and phoneme identification. Non‐word discrimination might be equally useful as non‐word repetition as an early screening tool and would circumvent the confounding factor of an expressive phonological impairment as well as decrease the amount of complicating factors involved in scoring procedures.     

Viewpoint survey of mental health service users’ experiences of discrimination in England 2008–2012

Purpose

Research suggests levels of discrimination among mental health service users in England are high, but fell over the course of the first phase of the Time to Change programme to reduce stigma and discrimination (2008–2011). The aim of this study was to determine changes in discrimination levels, both overall and by the area of life in which discrimination is experienced, since Time to Change began and over the first year of its second phase (2011–2012).

Method

Separate samples of mental health service users were interviewed annually from 2008 to 2012 using the Discrimination and Stigma Scale. In 2011 and 2012, social capital was also measured using the Resource Generator-UK.

Results

Sample percentages of participants reporting the experience of discrimination in one or more life areas for years 2008–2012 were 91.4, 86.5, 86.2, 87.9 and 91.0 %, respectively. A multivariable logistic regression model was performed to test for significant differences by study year, weighted to match the study population and adjusted for employment status and diagnosis as potential confounding factors. The odds of reporting discrimination in one or more life areas were significantly lower as compared to 2008 for all subsequent years except for 2012 (0.76, 95 % CI 0.49–1.19). However, a weighted multiple regression model provided evidence of decreased mean overall discrimination in 2012 as compared to 2008 (mean decrease ?7.57, 95 % CI ?11.1 to ?4.0, p < 0.001). The weighted mean number of social resources was 13.5 in 2012 as compared to 14.0 in 2011 (mean difference ?0.60, 95 % CI ?1.25 to 0.06).

Conclusions

While the overall level of discrimination across the life areas studied has fallen over 2008–2012, there is no evidence that more people using mental health services experience no discrimination. We suggest that the pattern suggesting a recent rise in discrimination following an earlier reduction may be linked to economic austerity. Further, the welfare benefits system has become an increasing source of discriminatory experience.     

Impaired auditory discrimination learning following perinatal nicotine exposure or β2 nicotinic acetylcholine receptor subunit deletion

Maternal smoking during pregnancy can impair performance of the exposed offspring in tasks that require auditory stimulus processing and perception; however, the tobacco component(s) responsible for these effects and the underlying neurobiological mechanisms remain uncertain. In this study, we show that administration of nicotine during mouse perinatal development can impair performance in an auditory discrimination paradigm when the exposed animals are mature. This suggests that nicotine disrupts auditory pathways via nicotinic acetylcholine receptors (nAChRs) that are expressed at an early stage of development. We have also determined that mice which lack nAChRs containing the β2 subunit (β2* nAChRs) exhibit similarly compromised performance in this task, suggesting that β2* nAChRs are necessary for normal auditory discrimination or that β2* nAChRs play a critical role in development of the circuitry required for task performance. In contrast, no effect of perinatal nicotine exposure or β2 subunit knockout was found on the acquisition and performance of a differential reinforcement of low rate task. This suggests that the auditory discrimination impairments are not a consequence of a general deficit in learning and memory, but may be the result of compromised auditory stimulus processing in the nicotine-exposed and knockout animals.     

Word discrimination therapy: A new technique for the treatment of a phonologically based word‐finding impairment

Background: The majority of cognitive neuropsychological treatments for impairments in phonological encoding utilise some form of phonological cueing or support. Most commonly, the participant is provided with supporting information about the phonological form of a particular word (either partial or complete, auditory or written), and must then generate the word orally. The provision of target phonology facilitates initial production of the word, which can then be repeatedly trained in order to induce relearning of the appropriate lexical–phonological associations.

Aims: The aim of the current case study was to examine the effectiveness of an indirect cueing technique for the treatment of mild impairments in phonological encoding. In this treatment the participant must name pictures without assistance, but the picture names themselves share a phonological relationship (e.g., magnet, mattress, macaroni). These phonologically similar triplets incorporate a form of phonological cueing; however, the cues do not involve the direct provision of the word form.

Methods & Procedures: The case reported here, patient TV, suffers from a mild phonological encoding impairment: he produces phonemic paraphasias and other form‐related errors on longer and/or less frequent words in spontaneous speech and other spoken word production tasks. In the treatment, TV was asked to name triplets of pictures whose names were either phonologically related (sharing either initial or final phonemes) or unrelated. This procedure was repeated across 12 therapy sessions, all of which trained the same set of words. TV's pre‐treatment naming accuracy on the training words was assessed using a repeated baseline design, and was continuously reassessed throughout treatment, and also at 3 months post‐therapy. The key comparison was between words trained within phonologically related triplets and control words trained in unrelated triplets. The design also included multiple assessments on an untrained set of words to assess generalisation.

Outcomes & Results: For this mild case, naming accuracy for all words trained improved significantly. However, gains were significantly faster for the words that were trained within phonologically related triplets than those trained in unrelated triplets. Significant generalisation to untreated items was also observed, and gains on both treatment items and generalisation effects were maintained at 3 months post therapy.

Conclusion: Results from this case study suggest that this type of indirect cueing technique may be a particularly efficient method for treating mild impairments in phonological coding.     

Abnormal somatosensory temporal discrimination in Parkinson’s disease: Pathophysiological correlates and role in motor control deficits

Objective

The somatosensory temporal discrimination threshold (STDT), defined as the shortest time interval required for two tactile stimuli to be perceived as separate, is longer in patients with Parkinson’s disease (PD). In this review, we discuss STDT findings in healthy subjects and in PD patients and the relationship between altered STDT and motor disturbances.

Somatosensory temporal discrimination in Parkinson’s disease,dystonia and essential tremor: Pathophysiological and clinical implications

Objective

To investigate whether changes in the somatosensory temporal discrimination threshold (STDT) in Parkinson’s disease (PD) and dystonia reflect the involvement of specific neural structures or mechanisms related to tremor, and whether the STDT can discriminate patients with PD, dystonia or essential tremor (ET).

Is discrimination training necessary to cause changes in the P2 auditory event-related brain potential to speech sounds?

Previous studies have found that the P2 component of the auditory event-related potential (ERP) increases after speech discrimination training. We compared electrophysiological and behavioral outcomes of individuals undergoing speech discrimination training (N = 8) with an untrained control group (N = 9). Significant improvements on the behavioral speech discrimination task were found only in the trained group; however, there were similar increases in P2 amplitude in both groups. Simple exposure to repeated instances of a speech sound during the ERP recording seems sufficient lead to enhancement of P2. This interpretation was bolstered by the finding of significant change in P2 during the first and second halves of the initial ERP recording, when listeners were not required to make any discriminative response. However, the largest change in P2 occurred between rather than within recording sessions, suggesting that the effects of exposure to a speech stimulus on ERPs may have a slow time-course and are most evident after a delay. Our data challenge the view that increased P2 amplitude reflects enhanced perceptual discrimination by auditory cortex.     

Does mental health-related discrimination predict health service use 2 years later? Findings from an Australian national survey

Social Psychiatry and Psychiatric Epidemiology - Stigma and discrimination are central concerns for people with mental health problems. The aim of the study was to carry out a follow-up survey of a...     

Does somatosensory discrimination activate different brain areas in children with unilateral cerebral palsy compared to typically developing children? An fMRI study

Aside from motor impairment, many children with unilateral cerebral palsy (CP) experience altered tactile, proprioceptive, and kinesthetic awareness. Sensory deficits are addressed in rehabilitation programs, which include somatosensory discrimination exercises. In contrast to adult stroke patients, data on brain activation, occurring during somatosensory discrimination exercises, are lacking in CP children. Therefore, this study investigated brain activation with functional magnetic resonance imaging (fMRI) during passively guided somatosensory discrimination exercises in 18 typically developing children (TD) (age, M = 14 ± 1.92 years; 11 girls) and 16 CP children (age, M = 15 ± 2.54 years; 8 girls). The demographic variables between both groups were not statistically different. An fMRI compatible robot guided the right index finger and performed pairs of unfamiliar geometric shapes in the air, which were judged on their equality. The control condition comprised discrimination of music fragments. Both groups exhibited significant activation (FDR, p < .05) in frontoparietal, temporal, cerebellar areas, and insula, similar to studies in adults. The frontal areas encompassed ventral premotor areas, left postcentral gyrus, and precentral gyrus; additional supplementary motor area (SMA_proper) activation in TD; as well as dorsal premotor, and parietal operculum recruitment in CP. On uncorrected level, p < .001, TD children revealed more left frontal lobe, and right cerebellum activation, compared to CP children. Conversely, CP children activated the left dorsal cingulate gyrus to a greater extent than TD children. These data provide incentives to investigate the effect of somatosensory discrimination during rehabilitation in CP, on clinical outcome and brain plasticity.     

Functional and effective brain connectivity for discrimination between Alzheimer’s patients and healthy individuals: A study on resting state EEG rhythms

Objective

This exploratory study provided a proof of concept of a new procedure using multivariate electroencephalographic (EEG) topographic markers of cortical connectivity to discriminate normal elderly (Nold) and Alzheimer’s disease (AD) individuals.

Different effects of exogenous cues in a visual detection and discrimination task: delayed attention withdrawal and/or speeded motor inhibition?

Several studies examining spatial attention have found a discrepancy regarding the effects of exogenous cues on reaction times in visual detection and discrimination tasks. Namely, across a wide range of cue-target intervals, responses are slower for targets at cued than at uncued locations (inhibition of return) in detection tasks, whereas responses are faster for targets at cued than at uncued locations (facilitation) in discrimination tasks. Two hypotheses were proposed to account for this discrepancy. First, attention may dwell much longer on the exogenously cued location in discrimination tasks because stimuli have to be identified (i.e., the delayed attention withdrawal hypothesis). Secondly, due to increased motor preparation in detection tasks, cue-induced motor inhibition may rise much faster in these tasks than in discrimination tasks (i.e., the speeded motor inhibition hypothesis). We examined to what extent these hypotheses can account for effects of exogenous cues in a detection and discrimination task on the extrastriate P1 component, and the onset of motor activation, as indexed by the lateralized readiness potential. Some support was found for the delayed attention withdrawal hypothesis, as task-dependent cueing effects were found on the P1 component. Other aspects of our data, however, indicate that motor inhibition is also involved. Based on these findings, we propose that effects of exogenous cues in detection and discrimination tasks are determined by the interplay between two mechanisms, of which the time courses of activation may be modulated by the specific setting.     

Reduced early visual emotion discrimination as an index of diminished emotion processing in Parkinson’s disease? – Evidence from event-related brain potentials

Although Parkinson’s disease (PD) is defined by its motor symptoms, it is now well recognized that cognitive and affective domains, such as recognition of emotion from facial expressions, may also be impaired. To examine brain mechanisms involved in processing of emotion recognition from facial expressions, we obtained affective ratings and visual event-related potentials (ERPs) in response to facial expressions from 18 PD patients under dopamine-replacement therapy, and 17 healthy age- and sex-matched controls. In control subjects, the early posterior negativity (EPN) of the ERP, which is thought to reflect early perceptual emotion discrimination, was larger in response to emotional compared to neutral facial expressions. In contrast, this emotional modulation of the EPN was absent in PD patients indicating impaired early emotion discrimination. Behaviorally, PD patients showed no impairments in emotion recognition as measured by affective ratings. These findings suggest that facial emotion processing may be disrupted at an early stage of visual neural processing in PD. Absence of behavioral impairment may point to compensatory strategies of emotion recognition in medicated PD patients. Further research should clarify these dissociations between behavioral and neurophysiological levels of emotion processing in PD.     

Highly increased CSF tau protein and decreased β-amyloid (1-42) in sporadic CJD: a discrimination from Alzheimer's disease?

The aim was to quantify tau protein and beta-amyloid (Abeta42) in the CSF of patients with sporadic Creutzfeldt-Jakob disease (CJD), Alzheimer's disease (AD), and controls. Double sandwich enzyme linked immunosorbent assays (ELISAs) were used for measurements. Tau was increased 58-fold in CJD and 3.5-fold in AD compared with controls, whereas Abeta42 was decreased 0.5-fold in both CJD and AD. A cut off level for tau protein at 2131 pg/ml successfully discriminated CJD from AD (100% specificity and 93% sensitivity). Tau protein concentration in CSF is probably an additional useful marker in differentiating CJD from AD.