bluuebunny/crossref_metadata_2025 huggingface dataset:
M74. FACIAL EMOTION RECOGNITION ABILITY IN PATIENTS WITH SCHIZOPHRENIA AND OTHER PSYCHOTIC DISORDERS
Authors: Kjellenberg Elin , Winblad Stefan
Published: May 2020

Background

Psychotic disorders are associated with impaired facial emotion recognition (FER) and poor functional outcome. Most studies regarding facial emotion recognition have focused on schizophrenia. The aim of this study was to explore FER in patients with different psychotic disorders at psychiatric outpatient facilities. The intention was also to examine if patients diagnosed with schizophrenia differed from patients diagnosed with other psychotic disorders in the ability to recognize facial emotions.

Methods

FER was examined in forty outpatients, evenly divided between schizophrenia and other psychotic disorders and 33 healthy control persons. The ability to recognize facial emotions was assessed with The Facially Expressed Emotion Labelling (FEEL). To assess the severity of psychotic symptoms in the patient group The Structured Clinical Interview for Symptoms of Remission (SCI-SR) was used.

Results

Patients performed significantly worse than healthy controls (p<.001, r =-.28) in recognizing facial emotions in general, including expressions of fear, disgust and sadness. Subjects with a schizophrenia diagnosis performed poorer than healthy controls when depicting fear (p<.01, r=.45) or anger (p=.026, r=.36). Compared to other psychotic disorders they were less accurate in recognizing anger (p=.036, r=-.040). We did not find any significant differences between patients with other psychotic disorders and healthy controls in FER. Furthermore, patients performed significantly slower on the FEEL test (p<.001, r=0.44), including both patients with a schizophrenia diagnosis and other psychotic disorders as compared to healthy controls. Patients diagnosed with schizophrenia showed significantly more psychotic symptoms (p= .001, r= -.53). However, there were no significant differences between patients in remission (40 %) and patients with more severe psychotic symptoms regarding the FEEL measures.

Discussion

In this study, patients with psychotic disorders performed less accurately and slower on the FEEL task as compared to healthy control persons. Patients diagnosed with schizophrenia tended to exhibit more difficulties. The results from this between-group comparison should however be interpreted with caution due to limited statistical power. Since no significant difference in FEEL score was demonstrated between patients in remission and patients suffering from more severe psychotic symptoms, it could be suggested that deficits in FER are independent of current psychotic symptoms. Impaired facial emotion recognition ability may negatively influence social interaction and functional outcome and the results from this study indicate that FER should be further explored in larger cohorts of outpatients with different psychotic disorders.
M88. EVIDENCE FOR INFLAMMATION AS A PUTATIVE SHARED MECHANISM FOR INSULIN RESISTANCE AND SCHIZOPHRENIA
Authors: Perry Benjamin , Burgess Stephen , Jones Hannah , Zammit Stanley , Upthegrove Rachel , Mason Amy , Day Felix , Stewart Isobel , Langenberg Claudia , Wareham Nicholas , Jones Peter , Khandaker Golam
Published: May 2020

Background

Insulin Resistance (IR) predisposes to cardiometabolic disorders, which are common in schizophrenia and are associated with excess morbidity and mortality. The mechanisms of association remain unknown. We aimed 1) To use genetic data to examine the direction of association between IR and related cardiometabolic risk factors, and schizophrenia; 2) To examine whether inflammation could be a shared mechanism for IR and schizophrenia.

Methods

We used two-sample uni-variable Mendelian randomization (MR) to examine whether genetically-predicted IR-related cardiometabolic risk factors (Fasting insulin (FI), high-density lipoprotein (HDL), triglycerides (TG), low-density lipoprotein, fasting plasma glucose, glycated haemoglobin, leptin, body mass index, glucose tolerance and type 2 diabetes) may be causally associated with schizophrenia. We used the most recent summary statistics for genetic variants associated with schizophrenia and IR-related cardiometabolic risk factors from publicly-available large genome-wide association studies (GWAS). We used bi-directional MR to examine direction of association. To examine whether inflammation could be a shared mechanism for IR and schizophrenia, we first conducted a sensitivity analysis by performing MR using only cardiometabolic genetic variants that were also associated with inflammation, at genome-wide significance. Second, we used multi-variable MR (MVMR) to examine associations between cardiometabolic risk factors and schizophrenia after adjusting for genetically-predicted levels of C-reactive protein.

Results

In analyses using all associated genetic variants, genetically predicted levels of leptin were associated with risk of schizophrenia (OR=2.54 per SD increase in leptin; 95% CI, 1.02–6.31). In analyses using inflammation-related variants, genetically predicted levels of FI (OR=2.76 per SD increase in FI; 95% C.I., 1.31–6.17), TG (OR=2.90 per SD increase in TG; 95% C.I., 1.36–6.17), and HDL (OR=0.56 per SD increase in HDL; 95% C.I., 0.37–0.83) were associated with schizophrenia. The associations completely attenuated in MVMR analyses controlling for CRP. There was no evidence of an association between genetically-predicted schizophrenia liability and cardiometabolic factors.

Discussion

The IR phenotype of FI, TG and HDL could be associated with schizophrenia over and above common sociodemographic and lifestyle factors. This association is likely explained by a common inflammatory mechanism. Interventional studies are required to test whether inflammation could represent a putative therapeutic target for the treatment and prevention of cardiometabolic disorders in schizophrenia.
M93. BRAIN GENE EXPRESSION PROFILING OF INDIVIDUALS WITH DUAL DIAGNOSIS WHO DIED BY SUICIDE
Authors: Cabrera Brenda , Fresno Cristóbal , Monroy-Jaramillo Nancy , Walss-Bass Consuelo , Fries Gabriel , Glahn David , Ostrosky-Wegman Patricia , Delia Genis-Mendoza Alma , Martínez-Magaña Jaime , Enrique Díaz-Otañez Carlos , García-Dolores Fernando , González-Sáenz Eli Elier , Mendoza-Morales Roberto , Flores Gonzalo , Antonio Vázquez-Roque Rubén , Nicolini Humberto
Published: May 2020

Background

Dual diagnosis is the co-occurrence of at least one substance use disorder (SUD) and one or more mental disorders in a given individual. Despite this comorbidity is highly prevalent and associated with adverse clinical outcomes, its neurobiology remains unclear. Furthermore, patients with dual diagnosis are at higher risk for suicidal behavior in comparison with single disorder patients. Our objective was to evaluate brain gene expression patterns in individuals with dual diagnosis who died by suicide.

Methods

We compared the gene expression profile in the dorsolateral prefrontal cortex of suicides with DD (n= 10) to the transcriptome of suicides with SUD alone (n=10), suicides with mood disorders alone (n=13), and suicides without mental comorbidities (n=5). Gene expression profiles were assessed by microarrays. Microarray data quality control was performed. Then, microarray data were background corrected and quantile normalized. Differentially expressed genes among the conditions were identified by a linear model implemented in the limma package.

Results

When comparing the transcriptome of suicides with dual diagnosis to suicides with SUD alone and suicides with mood disorders alone, we identified 255 and 172 differentially expressed genes, respectively. When comparing suicides with DD to suicides without mental comorbidities, we identified 330 differentially expressed genes, mainly enriched in neurogenesis.

Discussion

Our results suggest that suicides with dual diagnosis present a gene expression profile distinct from that of suicides with a single disorder and suicides without mental disorders. Also, suicides with dual diagnosis, SUD and mood disorders exhibited alterations in the expression of synaptic genes. However, suicides with each condition (dual diagnosis, SUD or mood disorders) exhibited unique gene expression changes at different levels within synaptic signaling. These gene expression differences might contribute to the phenotypical and clinical discrepancies observed in patients with dual diagnosis and patients with a single disorder
M96. A NEW ASSESSMENT TOOL FOR FORMAL THOUGHT DISORDER IN SCHIZOPHRENIA: DOKUZ EYLUL THOUGHT DISORDER SCALE
Authors: Yalincetin Berna , Bora Emre , Binnur Akdede Berna , Alptekin Köksal
Published: May 2020

Background

Current scales of formal thought disorder (FTD) in schizophrenia have been shown to hold considerable inadequacies: 1. The concept of FTD is usually limited to positive and negative symptoms of schizophrenia 2. There is no much consideration about pragmatic disturbances. 3. There are significant inconsistencies in measurements of posFTD and negFTD dimensions (eg, merely focusing on the positive dimension); 4. As to the comprehensive scales of posFTD and negFTD, administration or assessment is time-consuming for routine clinical use and they are not user friendly. Besides, some of the FTD scales include the utilization of materials such as pictures, figures, or extended structured interviews to be able to provide speech samples of the patient. Developing a new FTD assessment tool that can be practically applied in clinic might help clinicans in diagnosis, treatment and follow-up. The aim of our study was to develop a new scale for assessment of FTD and evaluate the reliability and validity of this scale. We named our new FTD scale as Dokuz Eylul Thought Disorder Scale (DETDS). The originality of this scale is based on the fact that it involves assessment of pragmatic comprehension as well as positive and negative FTD and it can be administered and scored practically in routine clinical examination.

Methods

This study included 130 patients with schizophrenia and 35 controls. For assessing the reliability of this new scale, internal consistency, test-retest and interrater reliability analyses were conducted. The validity of the scale was assessed with concurrent validity and factor analysis methods.

Results

In the study, Cronbach’s was 0.86. The new scale has a good test-retest (r=0.83) and interrater (ICC=0.985) reliability. The posFTD subscale of the new scale showed high correlation with the posFTD subscale of the Scale for the Assessment of Positive Symptoms (SAPS) (r=0.95, p<0.001) and negFTD subscale of our scale showed high correlation with the alogia subscale of the Scale for the Assessment of Negative Symptoms (SANS) (r=0.95, p<0.001) and impoverishment of thought subscale of the Thought and Language Index (TLI) (r=0.66, p<0.001). The factor analysis revealed a 3-factor solution which explained 74.6% of the variance: 1. Positive Formal Thought Disorder, 2. Negative Formal Thought Disorder, 3. Pragmatic Comprehension Disorder.

Discussion

Our findings showed that DETDS is a reliable and valid scale which can be used in assessing FTD in patients with schizophrenia in routine clinical use. Unlike most scales of FTD that are available in the literature, but similar to SANS, SAPS, and PANSS, it is practical to use because it is based on clinical interview. Another strength of DETDS is that it intensifies the posFTD and negFTD dimensions and scores them hierarchically in terms of severity. The fact that the new scale covers pragmatic comprehension disorders also presents an innovation to the literature.
S71. CLINICAL, BEHAVIOURAL AND NEURAL VALIDATION OF THE POSITIVE AND NEGATIVE SYMPTOM SCALE (PANSS) AMOTIVATION FACTOR
Authors: Kaliuzhna Mariia , Kirschner Matthias , Carruzzo Fabien , Hartmann Matthias , Martin Bischof , Seifritz Erich , Tobler Philippe N , Kaiser Stefan
Published: May 2020

Background

Negative symptoms of schizophrenia are suggested to map onto two distinct factors – amotivation and diminished expression, which relate to different aspects of behaviour and neural activity. Most research in patients with schizophrenia is conducted with broad symptom assessment scales, such as the PANSS, for which factor solutions allowing the distinction between amotivation and diminished expression have only recently been reported. We aimed to establish whether the PANSS factor structure corresponds to the well-established two-factor structure of the Brief Negative Symptom Scale (BNSS) and whether it allows distinguishing specific behavioural and neuronal correlates of amotivation.

Methods

In study 1 (N=120) we examined the correlations between the PANSS factors and the BNSS factors. In study 2 (N=31) we examined whether PANSS amotivation is specifically associated with reduced willingness to work for reward in an effort-based decision making task. In study 3 (N=43) we investigated whether PANSS amotivation is specifically correlated with reduced ventral striatal activation during reward anticipation using functional magnetic resonance imaging.

Results

On the clinical level, the PANSS amotivation and diminished expression were highly correlated with their BNSS counterparts. On the behavioural level, PANSS amotivation factor but not the diminished expression factor was specifically associated with reduced willingness to invest effort to obtain a reward. On the neural level, PANSS amotivation was specifically associated with ventral striatal activation during reward anticipation.

Discussion

Our data confirm that the two domains of negative symptoms can be measured with the PANSS and are linked to specific aspects of behaviour and brain function. To our knowledge, this is the first study employing behavioural and neural measures to validate a new approach to clinical measurement of negative symptoms. Our results warrant a re-analysis of previous work that used the PANSS to further substantiate the distinction between the two factors in behavioural and neuroimaging studies.
S79. REINFORCEMENT LEARNING ABNORMALITIES IN INDIVIDUALS AT CLINICAL HIGH RISK AND IN THE FIRST EPISODE OF PSYCHOSIS
Authors: Datta Raktima , Strauss Gregory , Kraguljac Nina , Howie Sydney , Lahti Adrienne
Published: May 2020

Background

Prior studies indicate that chronic schizophrenia (SZ) is associated with a specific profile of reinforcement learning abnormalities. These impairments are characterized by: 1) reductions in learning rate, and 2) impaired Go learning and intact NoGo learning. Furthermore, each of these deficits are associated with greater severity of negative symptoms, consistent with theoretical perspectives positing that avolition and anhedonia are associated with deficits in generating, updating, and maintaining mental representations of reward value hat are needed to guide decision-making. However, it is unclear whether these deficits extend to earlier phases of psychotic illness and when individuals are unmedicated.

Methods

Two studies were conducted to examine reinforcement learning deficits in earlier phases of psychosis. In study 1, participants included 35 participants with first episode psychosis (FEP) and 25 healthy controls (HC). Study 2 included 17 antipsychotic naïve individuals who met criteria for attenuated psychosis syndrome (APS) (i.e., those with a prodromal syndrome) and 18 matched healthy controls (HC). In both studies, participants completed the Temporal Utility Integration Task, a measure of probabilistic reinforcement learning that contained Go and NoGo learning blocks. Participants in the clinical groups also completed neuropsychological testing and standard clinical interviews designed to determine symptom severity and diagnosis.

Results

FEP displayed impaired Go learning and intact NoGo learning. In contrast, APS did not display impairments in Go or NoGo learning at the group level. Negative symptoms were not significantly associated with reinforcement learning in APS participants. However, greater impairments in Go learning were associated with increased cross-sectional risk for conversion on the NAPLS risk calculator score in the APS group.

Discussion

Findings provide new evidence for areas of spared and impaired reinforcement learning in early phases of psychosis. Similar to chronic SZ, FEP was associated with impaired Go learning, and intact NoGo learning. Reinforcement learning is more spared in those at clinical high-risk, except those at greatest risk for conversion, where Go learning deficits are more pronounced. These findings suggest that reinforcement learning deficits may emerge early among those who are at clinical high risk for developing psychosis and that they are already pronounced by illness onset in the first episode. Importantly, these reinforcement learning deficits do not appear to be a byproduct of illness chronicity or antipsychotic medication use, but rather a consequence of the illness itself.
S106. MONITORING SOCIAL FUNCTIONING THROUGH A MOBILE-BASED APPLICATION FOR YOUTH AT-RISK OF PSYCHOSIS: 2-MONTH FEASIBILITY STUDY
Authors: Santesteban-Echarri Olga , Tang Jacky , Fernandes Jaydon , Addington Jean
Published: May 2020

Background

Youth at clinical high-risk (CHR) for developing psychosis are characterized by long-standing social deficits and isolation compared to healthy youth. Because poor social functioning is predictive of transition to psychosis, it is important to monitor its fluctuations. Objectives: 1) To test initial usability of an app (SOMO); and 2) to confirm that SOMO is acceptable, feasible, and safe to monitor daily social functioning among youth at clinical high-risk (CHR) for developing psychosis.

Methods

Participants: 24 CHR participants (12–30 years old) used SOMO for 2 months to test its initial feasibility to monitor social functioning. Measures: 1) SOMO comprises 13 daily questions regarding social interactions in-person or online covering: type of relationship, time spent together, quality of the interaction, activities done, conflict and resolution, meaningfulness of the interaction, subjective opinion of the socialization, and level of loneliness. 2) Social functioning was assessed with the Social Functioning Scale (GF:S), which assesses peer relationships, peer conflict, age-appropriate intimate relationships, and involvement with family members. 3) Qualitative data of the SOMO was gathered through the 23-item Mobile Application Rating Scale (MARS) covering questions about engagement, functionality, aesthetics, information provided, and subjective quality of SOMO. Analyses. a) Descriptive information of 1) usability data (i.e., loggings, social relationships, ad meaningfulness) and 2) the app quality ratings (i.e., engagement, functionality, aesthetics, and information) was collected.

Results

There were 750 loggings over the 2-month testing period, with 50% of participants logging in at least every other day. Participants had 690 in-person interactions and 497 online interactions. The most meaningful interactions were considered the ones with their partner, followed by interactions with friends, casual friends, family, others and strangers in-person respectively. Participants reported conflict in 18.2% of their interactions. SOMO obtained a high overall score on the MARS (M=4.38). Ratings for engagement (M=3.91), functionality (M=4.54), aesthetics (M=4.56), information (M=4.51), subjective score (M=3.89), and perceived impact in behavior (M=3.52) were higher than other relevant mHealth apps. All participants rated SOMO as safe. Social functioning did not change significantly after using SOMO.

Discussion

SOMO demonstrated initial acceptability, feasibility, and safety among CHR participants.
S111. A REAL ENVIRONMENT BASED VIRTUAL REALITY APPLICATION TO IMPROVE PHYSICAL HEALTH OF PATIENTS WITH SCHIZOPHRENIA
Authors: Alptekin Koksal , Kartelli Faik , Berger Markus , Hoşgelen Emine Ilgın , Erinç Simay , Yerlikaya Deniz , Özbek Yağmur , Ercegil Gonca , Yener Görsev , Kılınç Oğuz , Binnur Akdede Berna
Published: May 2020

Background

Physical illnesses such as hypertension, diabetes, and cardiovascular diseases are much more common in patients with schizophrenia compared to general population. Besides the rate of schizophrenia patients benefiting from general health services have been quite low. These physical illnesses don’t only cause bad prognosis but also decrease the quality of life and increase the risk of early death. Many schizophrenia studies in recent years have found that patients with schizophrenia have died very early compared to normal population. The most important reasons of developing physical illnesses in schizophrenia are decrease in physical activity, nutrition problems, weight gain, smoking cigarettes, alcohol and substance abuse, unhealthy lifestyles.

Emerging new technologies may lead to the discovery of new treatment techniques in psychiatric disorders and related problems. Virtual reality (VR) as one of these new technologies, is composed of imitated real environments on computers. Most of virtual reality environments are about visual experiences by means of computer screen. Virtual reality is used for presenting reality experience and it is a 3D computer program of existing or non-existing environments. Although virtual reality in treatment of schizophrenia is new to the science, it has promising results to improve positive symptoms of schizophrenia. Also, VR technology may be useful to improve psychosocial functioning among the patients with schizophrenia. The aim of this study is to investigate the effect of VR physical health program on physical health parameters such as nutrition, psychomotor activity, smoking cigarettes and lifestyle.

Methods

Patients who met DSM-V schizophrenia diagnostic criteria from Dokuz Eylül University School of Medicine, Schizophrenia and Psychosis Outpatient Clinic were included into the study. In this study, a virtual reality laboratory has been established and physical health improvement program by using virtual reality technology with real life experiences has been developed for patients with schizophrenia.

Results

None of the patients reported motion sickness due to exposure to real environment during or after immersive process of VR. There were significant changes regarding the physical health parameters.

Discussion

VR physical health program may be useful to improve physical health-related problems such as obesity, psychomotor inactivity and smoking cigarettes.
S130. ALTERNATIVE METRICS TO QUANTIFY PREMATURE MORTALITY IN MENTAL DISORDERS. A POPULATION-BASED COHORT STUDY
Authors: Weye Nanna , Momen Natalie , Christensen Maria , Iburg Kim ,   NBP Health Metrics Collaborators, McGrath John , Plana-Ripoll Oleguer
Published: May 2020

Background

The Global Burden of Disease (GBD) study uses Years of Life Lost (YLLs) to quantify premature mortality. This is a useful metric from many perspectives, however because GBD acknowledges only a small number of mental disorders as causes of death (CoDs), the true impact of mental disorders on premature mortality is underestimated. Recently, methods have been introduced that compare people with a disorder to the general population by estimating Life Years Lost (LYLs). The aim of this study was to present register-based estimates of both YLLs and LYLs related to mental disorders.

Methods

We used nationwide registers to examine a cohort of all 6,989,627 people aged 0–94 years living in Denmark in 2000–2015. Using the GBD approved set of mental health-related CoDs (eating disorders, drug use disorders, alcohol use disorder and suicide), YLLs were estimated. In addition, we calculated all-cause and cause-specific differences in life expectancy after a mental disorder diagnosis as excess LYLs between those with a specific mental disorder and the age- and sex-matched general Danish population. The disorders of interest were alcohol use disorder, drug use disorders, schizophrenia, bipolar disorders, depressive disorders, anxiety disorders, eating disorders, personality disorders, developmental intellectual disability, autism spectrum disorders, ADHD and conduct disorder. Excess LYLs related to counts of comorbid mental disorders were also examined (i.e. those diagnosed with at least two, three or four disorders).

Results

Alcohol use disorder and suicide were the leading causes of YLLs (alcohol use disorder: Men 568.7 YLLs, women 155.5 YLLs per 100,000 person-years; suicide: Men 590.1 YLLs, women 202.3 YLLs per 100,000 person-years). However, all mental disorders were associated with shorter life expectancies using LYLs. Men and women diagnosed with any mental disorder had 11.22 (95% CI 11.09; 11.35) and 7.89 (95% CI 7.76; 8.01) years shorter life expectancies respectively, and the difference increased in those with comorbid mental disorders. Drug use disorders were associated with the largest excess LYLs (17.99 (95% CI 17.49; 18.53) in men and 15.29 (95% CI 14.70; 15.88) in women), however common disorders such as depressive disorders and anxiety disorders were also associated with substantive premature mortality (e.g. in men, 8.27 and 7.52 LYLs, respectively). Schizophrenia was associated with 13.80 (95% CI 13.47; 14.14) excess LYLs in men and 11.77 (95% CI 11.38; 12.13) in women.

Discussion

Register-based studies allow the calculation of precise individual YLLs and LYLs. The novel LYL metric seems to better capture the true impact of mental disorders on premature mortality and also facilitates the exploration of comorbidity and specific CoDs in those with mental disorders.
S224. TREATMENT IN THE PSYCHOSIS FIRST EPISODE PROGRAM “ZüRCHER ERSTPSYCHOSEN NETZWERK (ZEN)”: QUALITY CONTROL OF THE OUTCOME
Authors: Metzler Sibylle , Maatz Anke , Zehnder Ursina , Paust Tobias , Gubler Joyce , Walitza Susanne , Franscini Maurizia
Published: May 2020

Background

The treatment in the years following a first-psychosis episode is most crucial as typically, the illness onset occurs in a delicate phase of the young adults (Correll, 2018).

To address the specialities in the care for this patient population both, the Child and Adolescent, together with the adult department of the Psychiatric University Hospital Zürich implemented the ZEN psychosis first episode program.

Members of the specialized team connected in their function as network coaches in a systemic approach all players of the patient’s social and medical network. The better communication on transition points such as to adult department, together with possibilities of low-threshold treatment, aimed to improve treatment adherence and reduce repeated hospitalisations.

The study’s main objective was to evaluate the efficacy of the program and with that optimize the treatment process in daily clinical routine. A jurisdictional inquiry has been requested by Swiss Ethics Committees on research involving humans in Zurich and the present study project is classified as quality control of the clinical treatment.

Methods

Participants of the ZEN Program included in 2017 and 2018 were followed up to duration of 24 months. The following measures were assessed before and after enrolment in the program: Satisfaction with life, measured with the Manchester Short Assessment of Quality of Life (MANSA; Priebe et al., 1999); Number of rehospitalisations and coercive treatment; Global assessment of functioning (GAF) (Endicott et al., 1976); and measures of Social and vocational recovery.

Results

In Florence, results and implications will be presented for included patients.

Rates of rehospitalisations will be compared against literature. Mean relaps rates at 24 months have been reported to vary from 38% under specialized integrated care, to up to 49% under treatment as usual (Fusar-Poli et al., 2017).

Social and vocational recovery will be rated at follow-up and compared to baseline on a three-point scale (‘no’, ‘partial’ and ‘full’ recovery) (Craig et al., 2004, Garety et al., 2006).

In addition, correlation coefficients will be determined to detect any associations among sociodemographic factors and clinical data such as amount of neuroleptic medication.

Discussion

The ZEN program is specialized for patients with first episode of psychosis. The intensive care together with an intensified communication between players of a patient’s network aims to achieve better outcomes. The evaluation of the clinical program is of importance. The study provides recent data for ongoing discussions about the quality of the treatments and its cost-effectiveness compared to standard treatment.
Innovative methods for observing and changing complex health behaviors: four propositions
Authors: Chevance Guillaume , Perski Olga , Hekler Eric B
Published: May 2020

Precision health initiatives aim to progressively move from traditional, group-level approaches to health diagnostics and treatments toward ones that are individualized, contextualized, and timely. This article aims to provide an overview of key methods and approaches that can help facilitate this transition in the health behavior change domain. This article is a narrative review of the methods used to observe and change complex health behaviors. On the basis of the available literature, we argue that health behavior change researchers should progressively transition from (i) low- to high-resolution behavioral assessments, (ii) group-only to group- and individual-level statistical inference, (iii) narrative theoretical models to dynamic computational models, and (iv) static to adaptive and continuous tuning interventions. Rather than providing an exhaustive and technical presentation of each method and approach, this article articulates why and how researchers interested in health behavior change can apply these innovative methods. Practical examples contributing to these efforts are presented. If successfully adopted and implemented, the four propositions in this article have the potential to greatly improve our public health and behavior change practices in the near future.
Evolutionarily stable investments in recognition systems explain patterns of discrimination failure and success
Authors: Sheehan Michael J. , Reeve H. Kern
Published: May 2020

Many animals are able to perform recognition feats that astound us—such as a rodent recognizing kin it has never met. Yet in other contexts, animals appear clueless as when reed warblers rear cuckoo chicks that bear no resemblance to their own species. Failures of recognition when it would seem adaptive have been especially puzzling. Here, we present a simple tug-of-war game theory model examining how individuals should optimally invest in affecting the accuracy of discrimination between desirable and undesirable recipients. In the game, discriminating individuals (operators) and desirable and undesirable recipients (targets and mimics, respectively) can all invest effort into their own preferred outcome. We demonstrate that stable inaccurate recognition will arise when undesirable recipients have large fitness gains from inaccurate recognition relative to the pay-offs that the other two parties receive from accurate recognition. The probability of accurate recognition is often determined by just the relative pay-offs to the desirable and undesirable recipients, rather than to the discriminator. Our results provide a new lens on long-standing puzzles including a lack of nepotism in social insect colonies, tolerance of brood parasites and male birds caring for extra-pair young in their nests, which our model suggests should often lack accurate discrimination.

This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests'.
Rethinking recognition: social context in adult life rather than early experience shapes recognition in a social wasp
Authors: Cappa Federico , Cini Alessandro , Signorotti Lisa , Cervo Rita
Published: May 2020

Social recognition represents the foundation of social living. To what extent social recognition is hard-wired by early-life experience or flexible and influenced by social context of later life stages is a crucial question in animal behaviour studies. Social insects have represented classic models to investigate the subject, and the acknowledged idea is that relevant information to create the referent template for nest-mate recognition (NMR) is usually acquired during an early sensitive period in adult life. Experimental evidence, however, highlighted that other processes may also be at work in creating the template and that such a template may be updated during adult life according to social requirements. However, currently, we lack an ad hoc experiment testing the alternative hypotheses at the basis of NMR ontogeny in social insects. Thus, to investigate the mechanisms underlying the ontogeny of NMR inPolisteswasps, a model genus in recognition studies, and their different role in determining recognition abilities, we subjectedPolistes dominulaworkers to different olfactory experiences in different phases of their life before inserting them into the social environment of a novel colony and testing them in recognition bioassays. Our results show that workers develop their NMR abilities based on their social context rather than through pre-imaginal and early learning or self-referencing. Our study demonstrates that the social context represents the major component shaping recognition abilities in a social wasp, therefore shedding new light on the ontogeny of recognition in paper wasps and prompting the reader to rethink about the traditional knowledge at the basis of the recognition in social insects.

This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests'.
Stress signalling in acellular slime moulds and its detection by conspecifics
Authors: Briard L. , Goujarde C. , Bousquet C. , Dussutour A.
Published: May 2020

Unicellular organisms live in unpredictable environments. Therefore, they need to continuously assess environmental conditions and respond appropriately to survive and thrive. When subjected to rapid changes in their environment or to cellular damages, unicellular organisms such as bacteria exhibit strong physiological reactions called stress responses that can be sensed by conspecifics. The ability to detect and use stress-related cues released by conspecifics to acquire information about the environment constitutes an adaptive survival response by prompting the organism to avoid potential dangers. Here, we investigate stress signalling and its detection by conspecifics in a unicellular organism,
Physarum polycephalum
. Slime moulds were subjected to either biotic (i.e. nutritional) or abiotic (i.e. chemical and light) stressors or left undisturbed while they were exploring a homogeneous environment. Then, we observed the responses of slime moulds facing a choice between cues released by stressed clone mates and cues released by undisturbed ones. We found that slime moulds actively avoided environments previously explored by stressed clone mates. These results suggest that slime moulds, like bacteria or social amoeba, exhibit physiological responses to biotic and abiotic stresses that can be sensed by conspecifics. Our results establish slime moulds as a promising new model to investigate the use of social information in unicellular organisms.

This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests’.
How to learn to recognize conspecific brood parasitic offspring
Authors: Shizuka Daizaburo , Lyon Bruce E.
Published: May 2020

Recognition systems evolve to reduce the risk and costs of making recognition errors. Two main sources of recognition error include perceptual error (error arising from inability to discriminate between objects) and template error (error arising from using the wrong recognition template). We focus on how template error shapes host defence against avian brood parasites. Prior experiments in American coots (
Fulica americana
), a conspecific brood parasite, demonstrated how hosts learn to recognize brood parasitic chicks using predictable patterns of hatching order of host and parasite eggs. Here, we use these results to quantify the benefit of chick rejection as well as the cost of template error, and we then use mathematical models to explore fitness payoffs of chick recognition from different template acquisition mechanisms. We find that fitness differences between mechanisms do not fully explain aspects of the learning mechanism, such as why coots reacquire their recognition template each year. Other constraints arising from mating systems and genetic mechanisms likely influence which learning mechanism for parasitic chick recognition is optimal. Our approach highlights how mechanisms of template acquisition influence other recognition systems, including parasitic chick recognition in other brood parasite hosts.

This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests’.
The signal detection problem of aposematic prey revisited: integrating prior social and personal experience
Authors: Hämäläinen Liisa , Thorogood Rose
Published: May 2020

Ever since Alfred R. Wallace suggested brightly coloured, toxic insects warn predators about their unprofitability, evolutionary biologists have searched for an explanation of how these aposematic prey evolve and are maintained in natural populations. Understanding how predators learn about this widespread prey defence is fundamental to addressing the problem, yet individuals differ in their foraging decisions and the predominant application of associative learning theory largely ignores predators' foraging context. Here we revisit the suggestion made 15 years ago that signal detection theory provides a useful framework to model predator learning by emphasizing the integration of prior information into predation decisions. Using multiple experiments where we modified the availability of social information using video playback, we show that personal information (sampling aposematic prey) improves how predators (great tits,
Parus major
) discriminate between novel aposematic and cryptic prey. However, this relationship was not linear and beyond a certain point personal encounters with aposematic prey were no longer informative for prey discrimination. Social information about prey unpalatability reduced attacks on aposematic prey across learning trials, but it did not influence the relationship between personal sampling and discrimination. Our results suggest therefore that acquiring social information does not influence the value of personal information, but more experiments are needed to manipulate pay-offs and disentangle whether information sources affect response thresholds or change discrimination.

This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests’.
Discriminating between similar alarm calls of contrasting function
Authors: Tegtman Natalie T. , Magrath Robert D.
Published: May 2020

In a pioneering study of signal design, Marler (Marler 1955
Nature
176
, 6–8. (
doi:10.1038/176006a0
); Marler 1957
Behaviour
11
, 13–37. (
doi:10.1163/156853956X00066
)) argued that the contrasting acoustic design of hawk (seet) and mobbing alarm calls of European passerines reflected their contrasting function. Hawk alarms were high-frequency tones, warning conspecifics to flee but making localization difficult for predators, while mobbing calls were broadband and harsh, allowing easy localization and approach. Contrasting signal features are also consistent with signal detection theory. Discriminating these calls quickly is critical for survival, because hawk alarms require immediate escape. These signals should therefore be selected to be easy to discriminate, reducing the trade-off between immediate fleeing to hawk alarms and unnecessary fleeing to mobbing alarms. Despite these expectations, hawk and mobbing alarm calls of superb fairy-wrens,
Malurus cyaneus
, are surprisingly similar, raising the question of discriminability without contextual cues. We synthesized these calls on computer, made intermediates and used playbacks to test whether calls can be discriminated acoustically, and if so by what features. We found that birds used multiple acoustic features when discriminating calls, allowing fast discrimination despite overlap in individual parameters. We speculate that the similarity of fairy-wren alarm calls could enhance detectability of both signals, while multiple subtle acoustic differences reduce a trade-off with discriminability.

This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests'.
The evolution of conspecific acceptance threshold models
Authors: Scharf Hannah M. , Suarez Andrew V. , Reeve H. Kern , Hauber Mark E.
Published: May 2020

How do organisms balance different types of recognition errors when cues associated with desirable and undesirable individuals or resources overlap? This is a fundamental question of signal detection theory (SDT). As applied in sociobiology, SDT is not limited to a single context or animal taxon, therefore its application can span what may be considered dissimilar systems. One of the applications of SDT is the suite of acceptance threshold models proposed by Reeve (1989), which analysed how individuals should balance acceptance and rejection errors in social discrimination decisions across a variety of recognition contexts, distinguished by how these costs and benefits relatively combine. We conducted a literature review to evaluate whether these models' specific predictions have been upheld. By examining over 350 research papers, we quantify how Reeve's models (Reeve 1989
Am. Nat.
133
, 407–435 (
doi:10.1086/284926
)) have influenced the field of ecological and behavioural recognition systems research. We found overall empirical support for the predictions of the specific models proposed by Reeve, and argue for further expansion of their applications into more diverse taxonomic and additional recognition contexts.

This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests’.
The evolution of species recognition labels in insects
Authors: Adams Seira Ashley , Tsutsui Neil Durie
Published: May 2020

The evolution of pre-zygotic reproductive isolation is a key step in the process of speciation. In many organisms, particularly insects, chemical labels are used as pheromones for species-specific mate recognition. Although an enormous body of knowledge exists regarding the patterns of pheromone chemical ecology, much less is known about the evolutionary processes that underlie the origin of new mating pheromones. Here, we examine case studies that have illuminated the origins of species-specific mating pheromones and suggest future directions for productive research.

This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests’.
Complex signals alter recognition accuracy and conspecific acceptance thresholds
Authors: Tibbetts Elizabeth A. , Liu Ming , Laub Emily C. , Shen Sheng-Feng
Published: May 2020

Many aspects of behaviour depend on recognition, but accurate recognition is difficult because the traits used for recognition often overlap. For example, brood parasitic birds mimic host eggs, so it is challenging for hosts to discriminate between their own eggs and parasitic eggs. Complex signals that occur in multiple sensory modalities or involve multiple signal components are thought to facilitate accurate recognition. However, we lack models that explore the effect of complex signals on the evolution of recognition systems. Here, we use individual-based models with a genetic algorithm to test how complex signals influence recognition thresholds, signaller phenotypes and receiver responses. The model has three main results. First, complex signals lead to more accurate recognition than simple signals. Second, when two signals provide different amounts of information, receivers will rely on the more informative signal to make recognition decisions and may ignore the less informative signal. As a result, the particular traits used for recognition change over evolutionary time as sender and receiver phenotypes evolve. Third, complex signals are more likely to evolve when recognition errors are high cost than when errors are low cost. Overall, redundant, complex signals are an evolutionarily stable mechanism to reduce recognition errors.

This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests’.
Mechanisms of recognition in birds and social Hymenoptera: from detection to information processing
Authors: Rossi Natacha , Derégnaucourt Sébastien
Published: May 2020

In this opinion piece, we briefly review our knowledge of the mechanisms underlying auditory individual recognition in birds and chemical nest-mate recognition in social Hymenoptera. We argue that even though detection and perception of recognition cues are well studied in social Hymenoptera, the neural mechanisms remain a black box. We compare our knowledge of these insect systems with that of the well-studied avian ‘song control system’. We suggest that future studies on recognition should focus on the hypothesis of a distributed template instead of trying to locate the seat of the template as recent results do not seem to point in that direction.

This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests’.
Avian egg and nestling detection in the wild: should we rely on visual models or behavioural experiments?
Authors: Avilés Jesús M.
Published: May 2020

The fields of avian egg and nestling colour detection have rapidly advanced owing to the application of visual models, which have allowed assessing of evolutionary questions considering receiver perception. Here, I first review the literature aiming to identify patterns of avian visual model usage. Second, I elaborate on limitations in the application of the receptor-noise limited perceptual (RNL hereafter) model. A systematic literature review revealed that the RNL model was the most used approach (81% of studies) in the field, and that most studies (76%) were concerned with classic evolutionary questions in avian brood parasitism. Some known limitations of the RNL model deal with model assumptions and parameterization, or, a poor consideration of post-detection neural processes. Others, however, are specific of the fields of egg and nestling discrimination and deal with the highly variable nature of ambient light at the nests, the complex colour design of eggs and nestlings, the multi-dimensional nature of perception, and the possible implication of learning. I, therefore, conclude that visual models should be used with caution to establish inference about egg and nestling discrimination, and rather be used to provide reasonable hypotheses which need to be validated with behavioural experiments.

This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests'.