Expectation Bias Research Articles

Expectancy bias mediates the link between social anxiety and memory bias for social evaluation

Social anxiety (SA) involves a multitude of cognitive symptoms related to fear of evaluation, including expectancy and memory biases. We examined whether memory biases are influenced by expectancy biases for social feedback in SA. We hypothesised that, faced with a socially evaluative event, people with higher SA would show a negative expectancy bias for future feedback. Furthermore, we predicted that memory bias for feedback in SA would be mediated by expectancy bias. Ninety-four undergraduate students (55 women, mean age = 19.76 years) underwent a two-visit task that measured expectations about (Visit 1) and memory of (Visit 2) feedback from unknown peers. Results showed that higher levels of SA were associated with negative expectancy bias. An indirect relationship was found between SA and memory bias that was mediated by expectancy bias. The results suggest that expectancy biases are in the causal path from SA to negative memory biases for social evaluation.

Surprise attracts the eyes and binds the gaze.

In recent years, researchers have become increasingly interested in the effects that deviations from expectations have on cognitive processing and, in particular, on the deployment of attention. Previous evidence for a surprise-attention link had been based on indirect measures of attention allocation. Here we used eyetracking to directly observe the impact of a novel color on its unannounced first presentation, which we regarded as a surprise condition. The results show that the novel color was quickly responded to with an eye movement, and that gaze was not turned away for a considerable amount of time. These results are direct evidence that deviations from expectations bias attentional priorities and lead to enhanced processing of the deviating stimulus.

Augmenting one-session treatment of children's specific phobias with attention training to positive stimuli

This study examined the efficacy of combining two promising approaches to treating children's specific phobias, namely attention training and one 3-h session of exposure therapy (‘one-session treatment’, OST). Attention training towards positive stimuli (ATP) and OST (ATP+OST) was expected to have more positive effects on implicit and explicit cognitive mechanisms and clinical outcome measures than an attention training control (ATC) condition plus OST (ATC+OST). Thirty-seven children (6–17 years) with a specific phobia were randomly assigned to ATP+OST or ATC+OST. In ATP+OST, children completed 160 trials of attention training responding to a probe that always followed the happy face in happy-angry face pairs. In ATC+OST, the probe appeared equally often after angry and happy faces. In the same session, children completed OST targeting their phobic situation/object. Clinical outcomes included clinician, parent and child report measures. Cognitive outcomes were assessed in terms of change in attention bias to happy and angry faces and in danger and coping expectancies. Assessments were completed before and after treatment and three-months later. Compared to ATC+OST, the ATP+OST condition produced (a) significantly greater reductions in children's danger expectancies about their feared situations/object during the OST and at three-month follow-up, and (b) significantly improved attention bias towards positive stimuli at post-treatment, which in turn, predicted a lower level of clinician-rated phobia diagnostic severity three-months after treatment. There were no significant differences between ATP+OST and ATC+OST conditions in clinician, parent, or child-rated clinical outcomes. Training children with phobias to focus on positive stimuli is effective in increasing attention towards positive stimuli and reducing danger expectancy biases. Studies with larger sample sizes and a stronger ‘dose’ of ATP prior to the OST may reveal promising outcomes on clinical measures for training attention towards positive stimuli.

Conditioned placebo effect in dogs decreases separation related behaviours

In humans, placebo effect can be produced by giving verbal information and also by conditioning when, after repeated administration of an active substance, an inactive compound that just looks like the drug administered before, can produce the effect of the active substance. Conditioned placebo effect has been reported in rodents, however, the dog (Canis familiaris) may also provide a promising model species. In our study dogs’ behaviour was observed while they were repeatedly separated from their owners in the same unfamiliar room. First, subjects did not receive any pre-treatment (Baseline trial), then they participated in either of two different conditioning contexts: after having received either sedative drug (Conditioned group) or non-sedating vitamin (Control group) treatment, subjects participated in 3 conditioning trials on consecutive days. Finally, in the ‘Test trial’, both groups were separated from their owners after receiving placebo (non-sedating vitamin). Results show significant effect of the sedative drug conditioning; when comparing the change from Baseline to Test trials in the Conditioned and the Control groups, conditioned subjects showed less active signs of distress (U(26)=48, p=0.021) and more passive behaviours (U(26)=50, p=0.027). We also investigated the association between dogs’ susceptibility to conditioned placebo effect and their expectancy bias towards positive outcomes and found a positive correlation (r(12)=0.697, p=0.008), suggesting that dogs with more positive expectations are more responsive to placebo treatment. Considering previous human findings about stronger responsiveness to placebo in optimistic people, our results support the validity of the application of a dog model towards a better understanding of some aspects of the placebo phenomena in humans.

THE 2013 LAWRENCE R. KLEIN LECTURE: BEHAVIORAL AND DESCRIPTIVE FORMS OF CHOICE MODELS†

Empirical work on choice models, especially on relatively new topics or data sets, often starts with descriptive, or what is colloquially referred to as “reduced form,” results. Our descriptive form formalizes this process. It is derived from the underlying behavioral model, has an interpretation in terms of fit, and can sometimes be used to quantify biases in agents' expectations. We consider estimators for the descriptive form of discrete choice models with interacting agents that take account of approximation errors as well as unobservable sources of endogeneity. We conclude with an investigation of descriptive forms for two-period entry models.

Prior probability and feature predictability interactively bias perceptual decisions

Anticipating a forthcoming sensory experience facilitates perception for expected stimuli but also hinders perception for less likely alternatives. Recent neuroimaging studies suggest that expectation biases arise from feature-level predictions that enhance early sensory representations and facilitate evidence accumulation for contextually probable stimuli while suppressing alternatives. Reasonably then, the extent to which prior knowledge biases subsequent sensory processing should depend on the precision of expectations at the feature level as well as the degree to which expected features match those of an observed stimulus. In the present study we investigated how these two sources of uncertainty modulated pre- and post-stimulus bias mechanisms in the drift-diffusion model during a probabilistic face/house discrimination task. We tested several plausible models of choice bias, concluding that predictive cues led to a bias in both the starting-point and rate of evidence accumulation favoring the more probable stimulus category. We further tested the hypotheses that prior bias in the starting-point was conditional on the feature-level uncertainty of category expectations and that dynamic bias in the drift-rate was modulated by the match between expected and observed stimulus features. Starting-point estimates suggested that subjects formed a constant prior bias in favor of the face category, which exhibits less feature-level variability, that was strengthened or weakened by trial-wise predictive cues. Furthermore, we found that the gain on face/house evidence was increased for stimuli with less ambiguous features and that this relationship was enhanced by valid category expectations. These findings offer new evidence that bridges psychological models of decision-making with recent predictive coding theories of perception.

Les freins psychologiques à l’inclusion professionnelle des personnes en situation de handicap psychique

Mental health in the workplace today are ubiquitous and cause significant dysfunction in organizations (turnover, absenteeism, presenteeism, early retirement, long sick…). Statements of professional unfitness for depression is of particular concern. The human and financial costs associated with the support of mental disability is important, in France it is estimated to 14 billion euros. Mental disorder in the workplace also has a significant impact on the individual. If not always leads to actual inability to work, it usually causes, from the disclosure of the disorder, professional inequalities related to perceived environmental work disability. Therefore, this type of public remains largely on the sidelines of a stable occupation and all forms of recognition and undergo disqualifications and some forms of exclusion. Instead of saving, the workplace can promote relapse and even constitute a real obstacle to improving health. These exclusionary behavior result in persistent employment resistance in France and elsewhere, especially because of the prejudice of employers. These resistances persist despite legal obligations in this regard (e.g. in France: Law of 11 February 2005 on Equal Rights and Opportunities). To address the issue of sustainable professional inclusion (recruitment, integration and job preservation) of people with mental disabilities, studies are especially developed for the rehabilitation in the workplace of this public or accompanying us in their professional reintegration into protected workplaces. We propose a reflection on the adaptation of knowledge about psychological processes of hiring discrimination in the particular employment situation of people with mental disabilities in ordinary workplaces. Researches on social representations, stereotypes and prejudices applied in the workplace help to understand the negative attitudes and resistance to the hiring of people with mental disabilities despite regulations. Representations of professional efficiency, cognitive bias in social perception, personological expectations and responsibilities about the success of the employment integration of new employees strongly impact the hiring and integration behaviors of actors of the company. Nevertheless, the influence of the organizational context was highlighted in the researches in psychology of organizations. Recruitment and integration practices implemented by organizations, the procedures used to recruit (procedural justice) and the quality of interpersonal treatment of individuals (interpersonal justice) are essential elements of socialization. Disability is recognized as a particularly salient dimension and effective in activating cognitive processes biased. Individual and/or collective courses of action as persuasive communication, suppression and dilution of stereotypes, self-regulation of prejudice, intergroup contact and the sharing of values, affirmative action, promoting diversity, are proposed to modify these psychological barriers. However, their effectiveness is moderated by various individual factors such as the level of prejudice of actors, their previous work experience of disabled workers, their commitment to the values promoted by the organization for example, or organizational and structural factors such as the characteristics of the organization, the degree of formalization of hiring procedures, social policy of the organization and how it is conveyed and received by workers… These studies support the conclusion that the process of professional inclusion of public considered as "non-standard" is complex. These tracks remain to be tested under the mental disability taking into account the type of company and characteristics of actors that constitute them.

Predicting the unpredictable: critical analysis and practical implications of predictive anticipatory activity.

A recent meta-analysis of experiments from seven independent laboratories (n = 26) indicates that the human body can apparently detect randomly delivered stimuli occurring 1–10 s in the future (Mossbridge etal., 2012). The key observation in these studies is that human physiology appears to be able to distinguish between unpredictable dichotomous future stimuli, such as emotional vs. neutral images or sound vs. silence. This phenomenon has been called presentiment (as in “feeling the future”). In this paper we call it predictive anticipatory activity (PAA). The phenomenon is “predictive” because it can distinguish between upcoming stimuli; it is “anticipatory” because the physiological changes occur before a future event; and it is an “activity” because it involves changes in the cardiopulmonary, skin, and/or nervous systems. PAA is an unconscious phenomenon that seems to be a time-reversed reflection of the usual physiological response to a stimulus. It appears to resemble precognition (consciously knowing something is going to happen before it does), but PAA specifically refers to unconscious physiological reactions as opposed to conscious premonitions. Though it is possible that PAA underlies the conscious experience of precognition, experiments testing this idea have not produced clear results. The first part of this paper reviews the evidence for PAA and examines the two most difficult challenges for obtaining valid evidence for it: expectation bias and multiple analyses. The second part speculates on possible mechanisms and the theoretical implications of PAA for understanding physiology and consciousness. The third part examines potential practical applications.

Observer bias in animal behaviour research: can we believe what we score, if we score what we believe?

Most observers in behaviour studies are aware of relevant information about the animals being observed. We investigated whether observer expectations influence subjective scoring methods during a class practicum. Veterinary students were trained in recording negative and positive interactions between pigs, in scoring the degree of panting in cattle and in applying qualitative behaviour assessment (QBA) using a fixed set of terms for assessing hens' behaviour. The students applied these methods in three trials in which they were shown duplicated video recordings of the same animals: the original and a slightly modified version (to prevent recognition at second viewing). When scoring the duplicated recordings they were told either correct or false information about the conditions in which the animals had been filmed. The false information reflected plausible study scenarios in ethology and was used to create expectations about the outcome. As in reality the students scored the identical behaviour twice, the difference in the scores for the original and modified recordings reflects expectation bias due to providing different contextual information. In all trials there was evidence of expectation bias: students scored the ratio of positive to negative interactions higher when told that the observed pigs had been selected for high social breeding value, they scored cattle panting higher when told that the ambient temperature was 5 °C higher than in reality, and in the QBA they indicated more positive and fewer negative emotions when told that the hens were from an organic instead of a conventional farm. The magnitude of the bias in the QBA trial was related to the opinion of the students about hen welfare in organic versus conventional farms. Although veterinary students may not be representative of practising ethologists, these findings do indicate that observer bias could influence subjective scores of animal behaviour and welfare.

Communication of stereotypes in the classroom: biased language use of German and Turkish adolescents

Little is known about the linguistic transmission and maintenance of mutual stereotypes in interethnic contexts. This field study, therefore, investigated the linguistic expectancy bias (LEB) and the linguistic intergroup bias (LIB) among German and Turkish adolescents (13 to 20 years) in the school context. The LEB refers to the general phenomenon of describing stereotypes more abstractly. The LIB is the tendency to use language abstraction for in-group protective reasons. Results revealed an unmoderated LEB, whereas the LIB only occurred when foreigners were in the numerical majority, the classroom composition was perceived as a learning disadvantage, or the interethnic conflict frequency was high. These findings provide first evidence for the use of both LEB and LIB in an interethnic classroom setting.

Identifying optimal parameters for quantification of changes in pelvic movement symmetry as a response to diagnostic analgesia in the hindlimbs of horses

Subjective evaluation of the response to diagnostic analgesia of hindlimb lameness is influenced by expectation bias. Quantification of pelvic movement with inertial measurement units is possible, but it is unclear which measure of movement symmetry best reflects the changes seen after diagnostic analgesia. To test our hypothesis that objective measures closely relating to those used for subjective visual lameness scoring (quantifying the difference between sacral upward or downward movement or between movement amplitudes of the left and right tubera coxae) would show the largest and most consistent response. Retrospective analysis of subjective and objective clinical lameness data. Thirteen horses with hindlimb lameness underwent visual lameness scoring and independent gait assessment with inertial measurement units. Established objective measures were calculated and changes before/after diagnostic analgesia regressed against the change in lameness grade. Slopes of regression lines were calculated and confidence intervals assessed. All objective parameters showed variation between horses and across lameness grades. The following 3 measures documented a consistent increase in symmetry for each grade of change in lameness score: difference between sacral displacement minima; upward movement difference; and range of motion difference between the tubera coxae. Several pelvic parameters are suitable for objective quantification of changes after diagnostic analgesia in hindlimb-lame horses. A change of 9-13% per lameness grade can be expected. Upward movement of the tubera coxae is the most sensitive objective measure for quantifying a response to diagnostic analgesia. However, when assessed visually, this measure requires simultaneous focusing on pelvic and limb movements. Other parameters that show a similar response might be more easily perceived, requiring only assessment of tubera coxae range of motion or downward displacement of the sacrum without simultaneous focus on limb movement.

Expectancy bias in anxious samples.

Although it is well documented that anxious individuals have negative expectations about the future, it is unclear what cognitive processes give rise to this expectancy bias. Two studies are reported that use the Expectancy Task, which is designed to assess expectancy bias and illuminate its basis. This task presents individuals with valenced scenarios (Positive Valence, Negative Valence, or Conflicting Valence), and then evaluates their tendency to expect subsequent future positive relative to negative events. The Expectancy Task was used with low and high trait anxious (Study 1: n = 32) and anxiety sensitive (Study 2: n = 138) individuals. Results suggest that in the context of physical concerns, both high anxious samples display a less positive expectancy bias. In the context of social concerns, high trait anxious individuals display a negative expectancy bias only when negatively valenced information was previously presented. Overall, this suggests that anxious individuals display a less positive expectancy bias, and that the processes that give rise to this bias may vary by type of situation (e.g., social or physical) or anxiety difficulty.

Hidden Skewness: On the Difficulty of Multiplicative Compounding Under Random Shocks

Multiplicative growth processes that are subject to random shocks often have a skewed distribution of outcomes. In a number of incentivized laboratory experiments we show that a large majority of participants either strongly underestimate skewness or ignore it completely. Participants misperceive the outcome distribution's spread to be far too narrow-band and they estimate the median to lie too close to the distribution's center. The observed bias in expectations is irrespective to risk preferences and fairly robust to feedback. It is consistent with a behavioral model in which geometric growth is confused with linear growth. The misperception is a possible explanation of investors' difficulties with real-world financial products like leveraged ETFs.

EPA-1780 – Are different methods to reduce placebo response in cns trials mutually exclusive or have additive effects?

Over the past two decades, numerous methodologies have been developed with the specific goal of reducing the placebo effect in CNS trials. This presentation will discuss how three of these strategies, Central Ratings, use of the SAFER interview, and use of Sequential Parallel Comparison Design (SPCD), in combination, may offer a’triple safety’ net that ensures maximum reduction of the risk of a failed trial. Central Ratings have been shown to reduce variability in ratings by limiting the pool of raters for a given trial, ensuring consistent high reliability and calibration of raters, and reduction of expectation bias due to blinding and independence from the site. Novel study designs such as SPCD have been shown to significantly reduce the overall placebo response rate of the trial by pooling data from both phases of the trial, given the marked reduction in placebo response in the placebo non-responders of phase 2 of these trials. Finally, the use of highly experienced, independent remote interviewers to administer diagnostic and treatment history checks such as the SAFER interview and to perform unbiased assessment of baseline symptom severity improves the quality of subject selection, preventing the randomization of subjects with inadequate severity of illness or without the appropriate diagnosis or treatment history. This presentation will review the evidence in support of the utility of combining these three common methodological approaches to reduce the placebo response in CNS trials, providing a’triple safety’ net for CNS trials and the opportunity to enhance signal detection.

Existence of an Equilibrium for Lower Semicontinuous Information Acquisition Functions

We consider a two-period model in which a continuum of agents trade in a context of costly information acquisition and systematic heterogeneous expectations biases. Because of systematic biases agents are supposed not to learn from others' decisions. In a previous work under somehow strong technical assumptions a market equilibrium was proved to exist and the supply and demand functions were proved to be strictly monotonic with respect to the price. Here we extend these results under very weak technical assumptions. We also prove that the equilibrium price maximizes the trading volume and further additional properties (such as the antimonotonicity of the trading volume with respect to the marginal information price).

Central bank transparency and financial market expectations: The case of emerging markets

In this paper, we study how central bank transparency influences the formation of money market expectations in emerging markets. The sample covers 25 countries for the period from January 1998 to December 2009. We find, first, that transparency reduces the bias (the difference between the money market rate and the weighted expected target rate over the contract period) in money market expectations. The effect is larger for countries with no exchange rate peg and countries with low income. Second, an intermediate level of transparency is found to have the most favorable influence on money market expectations: neither complete secrecy nor complete transparency is optimal. Finally, all subcategories of the Eijffinger and Geraats (2006) index lead to a smaller bias in expectations, with political transparency having the largest effect.

Long-Acting Injectable Versus Oral Antipsychotics in Schizophrenia

Recent, large, randomized controlled trials (RCTs) showed no benefit of long-acting injectable (LAI) antipsychotics over oral antipsychotics in preventing relapse in schizophrenia, nor did a recent meta-analysis incorporating these studies. However, RCTs might enroll a disproportionate number of patients with better treatment adherence and lower illness severity. Mirror-image studies, which compare periods of oral antipsychotic versus LAI treatment in the same patients, might therefore better reflect the real-world impact of LAIs. A systematic literature search without language restriction was conducted using MEDLINE/PubMed, Cochrane Library, Web of Science, PsycINFO, and CINAHL until May 31, 2012. Search terms included synonyms of (1) antipsychotic(s) AND (2) schizophrenia and related disorders AND (3) depot, (long-acting) injection(s), microsphere, decanoate, palmitate, enanthate. Of 5,483 identified citations, 607 articles were fully inspected, and 582 were ineligible. Finally, 25 mirror-image studies from 28 countries that followed 5,940 patients with schizophrenia for ≥ 12 months (≥ 6 months each on oral antipsychotic and LAI treatment) met the inclusion criteria and were analyzed. Coprimary outcomes were hospitalization risk and number of hospitalizations. Secondary outcomes included hospitalization days and length of stay. LAIs showed strong superiority over oral antipsychotics in preventing hospitalization (16 studies, N = 4,066; risk ratio = 0.43; 95% CI, 0.35-0.53; P < .001) and in decreasing the number of hospitalizations (15 studies, 6,342 person-years; rate ratio = 0.38; 95% CI, 0.28-0.51; P < .001). This strong advantage was also observed for secondary outcomes and in multiple clinically relevant subpopulations and treatment groups. Results from mirror-image studies in patients eligible for clinical use of LAIs showed strong superiority of LAIs compared to oral antipsychotics in preventing hospitalization. The results were in contrast to the recent meta-analysis of RCTs, which showed no superiority of LAIs. Given the possible biases in mirror-image studies, such as expectation bias, natural illness course, and time effect, a cautious interpretation is required. Nevertheless, the population in mirror-image studies better reflects the population receiving LAIs in clinical practice.

Prior Expectations Bias Sensory Representations in Visual Cortex

Perception is strongly influenced by expectations. Accordingly, perception has sometimes been cast as a process of inference, whereby sensory inputs are combined with prior knowledge. However, despite a wealth of behavioral literature supporting an account of perception as probabilistic inference, the neural mechanisms underlying this process remain largely unknown. One important question is whether top-down expectation biases stimulus representations in early sensory cortex, i.e., whether the integration of prior knowledge and bottom-up inputs is already observable at the earliest levels of sensory processing. Alternatively, early sensory processing may be unaffected by top-down expectations, and integration of prior knowledge and bottom-up input may take place in downstream association areas that are proposed to be involved in perceptual decision-making. Here, we implicitly manipulated human subjects' prior expectations about visual motion stimuli, and probed the effects on both perception and sensory representations in visual cortex. To this end, we measured neural activity noninvasively using functional magnetic resonance imaging, and applied a forward modeling approach to reconstruct the motion direction of the perceived stimuli from the signal in visual cortex. Our results show that top-down expectations bias representations in visual cortex, demonstrating that the integration of prior information and sensory input is reflected at the earliest stages of sensory processing.

Progress in compliance research and intervention: a commentary

Progress in compliance research and intervention: a commentary

Listener Expectations and Gender Bias in Nonsibilant Fricative Perception

The nonsibilant English fricatives /f/ and /θ / are known to be acoustically nonrobust. Using /f/ and /θ/ stimuli produced in CV, VCV, and VC syllables in /i α u/ contexts spoken by 10 talkers (5 male), we first replicate previous research suggesting that the most robust cues to this contrast are in the formant transitions in adjacent vowels. We also demonstrate vowel and syllable contextual differences that point to the contrast being most robust in /u/ contexts. In a series of perception experiments we go on to demonstrate effects of bias on perception of /f/ and /θ/ that derive from the uninformative nature of the frication noise, making them vulnerable to misperception in general, and especially in low-saliency contexts where the formant transition information is less robust. In experiment 1, listeners' classification of /f/ and /θ/ demonstrated a general bias to respond /f/ for fricatives produced by females and /θ/ for those produced by males. We hypothesize that the perceived concentrations of spectral energy in the fricative are shifted based on the concentration of energy in the vowel, which depend on a talker's gender. In experiment 2, vowel and frication noise portions were cross-spliced to probe this effect, resulting in the same gender-based bias. In a final experiment the vocalic information was removed and only the frication noise was presented to listeners for classification. In this task there was a general bias for /f/, regardless of the talker gender. Overall we demonstrate topdown gender effects in perception that originate in the strong indexical properties of adjacent vowels rather than being present in the frication noise itself.