Attenuated neural reactivity to happy faces is associated with rule breaking and social problems in anxious youth

Event-related potentials indicate differential neural reactivity to species and valence information in vocal stimuli in sleeping dogs

Dogs live in a complex social environment where they regularly interact with conspecific and heterospecific partners. Awake dogs are able to process a variety of information based on vocalisations emitted by dogs and humans. Whether dogs are also able to process such information while asleep, is unknown. In the current explorative study, we investigated in N = 13 family dogs, neural response to conspecific and human emotional vocalisations. Data were recorded while dogs were asleep, using a fully non-invasive event-related potential (ERP) paradigm. A species (between 250-450 and 600-800 ms after stimulus onset) and a species by valence interaction (between 550 to 650 ms after stimulus onset) effect was observed during drowsiness. A valence (750-850 ms after stimulus onset) and a species x valence interaction (between 200 to 300 ms and 450 to 650 ms after stimulus onset) effect was also observed during non-REM specific at the Cz electrode. Although further research is needed, these results not only suggest that dogs neurally differentiate between differently valenced con- and heterospecific vocalisations, but they also provide the first evidence of complex vocal processing during sleep in dogs. Assessment and detection of ERPs during sleep in dogs appear feasible.

The domain-variant indirect association between electrophysiological response to reward and ADHD presentations is moderated by dopaminergic polymorphisms

BACKGROUND

Understanding the etiopathogenesis of attention-deficit/hyperactivity disorder (ADHD) may necessitate decomposition of the heterogeneous clinical phenotype into more homogeneous intermediate phenotypes. Reinforcement sensitivity is a promising candidate, but the exact nature of the ADHD-reward relation - including how, for whom, and to which ADHD dimensions atypicalities in reward processing are relevant - is equivocal.

METHODS

Aims were to examine, in a carefully phenotyped sample of adolescents (N = 305; Mage = 15.30 years, SD = 1.07; 39.7% girls), whether functional dopaminergic polymorphisms implicated in both reward processing and ADHD (1) are differentially associated with event-related potentials (ERPs) of reward anticipation at distinct levels of ADHD risk (nno risk = 174, nat-risk = 131, ndiagnosed = 83); and (2) moderate the indirect effect of dispositional affectivity on the association between ERPs and ADHD domains.

RESULTS

In adolescents at-risk for or with ADHD, carrying a hypodopaminergic allele was associated with enhanced ERPs of attention allocation to cue and attenuated ERPs of anticipatory attention to feedback. No associations were observed in adolescents not at-risk for or without ADHD. Controlling for age and sex, both the negative indirect effect of positive affectivity (PA) on the association between ERPs and inattention and the positive indirect effect of PA on the association between ERPs and hyperactivity/impulsivity were supported only for those with high activity dopamine transporter (DAT) alleles.

CONCLUSIONS

Reward and affective processing are promising intermediate phenotypes relevant to disentangling ADHD developmental pathways. Consistent with developmental multifinality, through the successive effects of reward anticipation and positive affectivity, functional dopaminergic variants may confer protection against inattention or risk for hyperactivity/impulsivity.

The impacts of anxiety and depressive symptoms on emotional processing in children and their parents: an event-related potential study

BACKGROUND

Anxiety and depressive symptoms are associated with dysregulated emotional processing. However, less is known about the intra-personal and inter-personal impacts of anxiety and depressive symptoms on emotional processing in children and their parents.

METHODS

In a community sample of 36 parent-child dyads (total N = 72), the current study investigated the intra- and inter-personal effects of anxiety and depressive symptoms on the child's and the parent's neurophysiological responses to emotional (i.e., pleasant and unpleasant) stimuli, indexed by the late positive potential (LPP).

RESULTS

The results indicated that children's anxiety symptoms were correlated with their enhanced LPPs to pleasant versus neutral pictures. Additionally, children's depressive symptoms related to their increased LPPs to unpleasant stimuli. Importantly, children's anxiety symptoms were associated with their parents' increased LPPs to both unpleasant and pleasant information.

CONCLUSIONS

These findings suggest that anxiety symptoms in community children were related to their own as well as their parents' emotional processing. The findings contribute to cognitive and family models of anxiety and depression and further highlight the potential role of dyadic interventions for the alleviation of impairing symptoms in children and their caregivers.

Adolescent ADHD and electrophysiological reward responsiveness: A machine learning approach to evaluate classification accuracy and prognosis

We evaluated event-related potential (ERP) indices of reinforcement sensitivity as ADHD biomarkers by examining, in N=306 adolescents (M_age=15.78, SD=1.08), the extent to which ERP amplitude and latency variables measuring reward anticipation and response (1) differentiate, in age- and sex-matched subsamples, (i) youth with vs. without ADHD, (ii) youth at-risk for vs. not at-risk for ADHD, and, in the with ADHD subsample, (iii) youth with the inattentive vs. the hyperactive/impulsive (H/I) and combined presentations. We further examined the extent to which ERP variables (2) predict, in the ADHD subsample, substance use (i) concurrently and (ii) prospectively at 18-month follow-up. Linear support vector machine analyses indicated ERPs weakly differentiate youth with/without (65%) - and at-risk for/not at-risk for (63%) - ADHD but better differentiate ADHD presentations (78%). Regression analyses showed in adolescents with ADHD, ERPs explain a considerable proportion of variance (50%) in concurrent alcohol use and, controlling for concurrent marijuana and tobacco use, explain a considerable proportion of variance (87 and 87%) in, and predict later marijuana and tobacco use. Findings are consistent with the dual-pathway model of ADHD. Results also highlight limitations of a dichotomous, syndromic classification and indicate differences in neural reinforcement sensitivity are a promising ADHD prognostic biomarker.

The late positive potential during affective picture processing: Associations with daily life emotional functioning among adolescents with anxiety disorders

Pediatric anxiety disorders are characterized by potentiated threat responses and maladaptive emotion regulation (ER). The Late Positive Potential (LPP) is a neural index of heightened attention to emotional stimuli. Anxious individuals typically exhibit a larger LPP to unpleasant stimuli, but the LPP may also be blunted to unpleasant and pleasant stimuli for those with co-morbid depression. While a larger LPP is thought to reflect greater emotional reactivity, it is unknown to what extent variation in the LPP to laboratory stimuli corresponds to daily emotional functioning. We assessed the LPP in the laboratory in response to unpleasant, pleasant, and neutral images in combination with ecological momentary assessment of emotional reactivity and regulation in daily life among youth (9-14 years old; 55 % female) with anxiety disorders (ANX, N = 130) and no psychiatric diagnoses (ND, N = 47). We tested whether LPP amplitudes to unpleasant and pleasant stimuli (vs. neutral) are greater in ANX (vs. ND) youth and whether LPP amplitudes inversely correlate with co-morbid depression symptoms. We also examined associations between the LPP and daily life emotional functioning among ANX and ND youth. We found no group-by-valence effects on LPP amplitudes. Within ANX youth, higher depression symptoms were associated with smaller LPP amplitudes to unpleasant, but not pleasant, stimuli relative to neutral stimuli. Larger LPP amplitudes to emotional (relative to neutral) stimuli were correlated with use of specific ER strategies among ANX and ND youth but not emotional reactivity. While the LPP may reflect initial emotional reactivity to laboratory stimuli, it is associated with ER behaviors, and not emotional reactivity, in daily life.

Loss and Frontal Striatal Reactivities Characterize Alcohol Use Severity and Rule-Breaking Behavior in Young Adult Drinkers

BACKGROUND

Alcohol misuse is associated with externalizing behaviors, including rule breaking. Studies have implicated altered reward processing in externalizing behaviors and alcohol misuse. Here, we investigated whether reward or punishment reactivity more significantly influenced alcohol use severity and rule-breaking behavior in young adult drinkers.

METHODS

We curated data from the Human Connectome Project and identified 181 binge (132 men) and 288 nonbinge (97 men) drinkers performing a gambling task during brain imaging. Alcohol use severity was quantified by the first principal component of principal-component analysis of all drinking measures. We analyzed the imaging data using published routines and evaluated the results at a corrected threshold. We examined the interrelationship between imaging and clinical metrics with mediation and path analyses.

RESULTS

Compared with nonbingers, bingers showed more severe rule-breaking behavior and responded significantly faster during post-loss than during post-win trials. Compared with nonbingers, bingers demonstrated greater inferior/middle frontal gyrus and cerebellum activations in loss-predominating blocks but no differences in regional responses to win-predominating blocks, relative to an interblock baseline. The right caudate body showed loss reactivity that was positively correlated with the rule-breaking score. No regional responses to wins were significantly correlated with the rule-breaking score. Mediation and path analyses demonstrated significant models with inferior/middle frontal gyrus and caudate reactivity to loss interrelating rule breaking and alcohol use severity.

CONCLUSIONS

Punishment rather than reward reactivity was associated with alcohol use severity and rule breaking in young adults. The findings highlight the roles of negative emotions in psychological models of externalizing behaviors and alcohol misuse.

Adolescents and young adults differ in their neural response to and recognition of adolescent and adult emotional faces

Peer relationships become increasingly important during adolescence. The success of these relationships may rely on the ability to attend to and decode subtle or ambiguous emotional expressions that are common in social interactions. However, most studies examining youths' processing and labeling of facial emotion have employed adult faces and faces that depict emotional extremes as stimuli. In this study, 40 adolescents and 40 young adults viewed blends of angry-neutral, fearful-neutral, and happy-neutral faces (e.g., 100% angry, 66% angry, 33% angry, neutral) portrayed by adolescent and adult actors as electroencephalogram (EEG) was recorded. Participants also labeled these faces according to the emotion expressed (i.e., angry, fearful, happy, or neutral). The Late Positive Potential (LPP), an event-related potential (ERP) component that reflects sustained attention to motivationally salient information, was scored from the EEG following face presentation. Among adolescents, as peer-age faces moved from ambiguous (33%) to unambiguous (100%) emotional expression, the LPP similarly increased. These effects were not found when adolescents viewed emotional face blends portrayed by adult actors. Additionally, while both adolescents and young adults showed greater emotion labeling accuracy as faces increased in emotional intensity from ambiguous to unambiguous emotional expression, adolescent participants did not show greater accuracy when labeling peer-compared to adult-age faces. Together, these data suggest that adolescents attend more to subtle differences in peer-age emotional faces, but they do not label these emotional expressions more accurately than adults.

Reliability of reward ERPs in middle-late adolescents using a custom and a standardized preprocessing pipeline

Despite advantage of neuroimaging measures in translational research frameworks, less is known about the psychometric properties thereof, especially in middle-late adolescents. Earlier, we examined evidence of convergent and incremental validity of reward anticipation and response event-related potentials (ERPs) and here we examined, in the same sample of 43 adolescents (M_age  = 15.67 years; SD = 1.01; range: 14-18; 32.6% boys), data quality (signal-to-noise ratio [SNR]), stability (mean amplitude across trials), and internal consistency (Cronbach's α and split-half reliability) of the same ERPs. Further, because observed time course and peak amplitude of ERP grand averages and thus findings on SNR, stability, and internal consistency may depend on preprocessing method, we employed a custom and a standardized preprocessing pipeline and compared findings across those. Using our custom pipeline, reward anticipation components were stable by the 40th trial, achieved acceptable internal consistency by the 19th, and all (but the stimulus-preceding negativity [SPN]) achieved acceptable SNR by the 41st trial. Initial response to reward components were stable by the 20th trial and achieved acceptable internal consistency by the 11th and acceptable SNR by the 45th trial. Difference scores had worse psychometric properties than parent measures. Time course and peak amplitudes of ERPs and thus results on SNR, stability, and internal consistency were comparable across preprocessing pipelines. In case of reward anticipation ERPs examined here, 41 trials (+4 artifacted and removed) and, in case of reward response ERPs, 45 trials (+5 artifacted) yielded stable and internally consistent estimates with acceptable SNR. Results are robust across preprocessing methods.

Distinct aspects of emotion dysregulation differentially correspond to magnitude and slope of the late positive potential to affective stimuli

ABSTRACTEmotion dysregulation (ED) is a transdiagnostic risk factor for several forms of psychopathology. One established, integrative conceptualisation of ED that has informed our understanding of psychopathology (Gratz, K. L., & Roemer, L. (2004). Multidimensional assessment of emotion regulation and dysregulation : development, factor structure, and initial validation of the difficulties in emotion regulation scale. Journal of Psychopathology and Behavioral Assessment, 26(1), 41-54) was recently extended to account for state-level and specifically physiological aspects of ED. As such, the goal of the current study was to assess the degree to which this conceptualisation could be captured using a physiological, state-level index (i.e. the late positive potential; LPP). Participants (N=41; M_age=27.5 years, SD=11.0) completed a trait-based rating scale measure of the extended conceptualisation of ED and viewed a series of images that ranged in valence (i.e. unpleasant, pleasant, and neutral). Multilevel modelling indicated some points of convergence between rating scale scores and the LPP, and other points of divergence. Findings underscore the utility of a multi-method approach to improve understanding of key transdiagnostic characteristics across levels of analysis. Further, results are novel evidence supporting validity of the extended conceptualisation of ED.

The development of neural responses to emotional faces: A review of evidence from event-related potentials during early and middle childhood

Facial emotion processing (FEP) develops throughout childhood and provides crucial social information necessary for the interpretation and prediction of others' behaviour. This systematic review, which includes a meta-regression component, sought to explore the development of FEP event-related potentials (P100, N170, and late positive potential [LPP]) in children aged three to twelve years. Thirty-four studies, representing data from 1511 children, were included in the review. The combination of meta-regression and systematic review suggest that P100 amplitude decreases with increasing age in response to emotional facial stimuli. P100 latency may show a gradual decrease around the age of ten. In terms of the N170, it is suggested that amplitude follows a non-linear trend with age, and latency may decrease in early childhood before plateauing during middle childhood. Of note, review of the literature indicates that substantial methodological differences and high levels of heterogeneity exist. We suggest future research considers these results within the context of emotion-specific development, whilst also acknowledging how this may relate to individual social functioning skills across early-to-middle childhood.

Neural and self-reported reward responsiveness are associated with dispositional affectivity and emotion dysregulation in adolescents with evidence for convergent and incremental validity

Adolescence is a developmental period characterized by heightened reward sensitivity which, in turn, confers risk for pertinent negative outcomes, underscoring the need to better understand biological bases and behavioral correlates of reward responsiveness during this developmental phase. Our goals in the current study were to examine, in a sample of 43 typically developing adolescents (M_age  = 15.67 years; SD = 1.01; 32.6% boys), (1) evidence of convergent validity between neural and self-report reward responsiveness, (2) associations between neural reward responsiveness and self-report dispositional affectivity and emotion dysregulation (ED) and (3) evidence of incremental validity of self-report beyond neural reward responsiveness in predicting affectivity and ED. During electroencephalography (EEG), adolescents completed two experimental paradigms probing event-related potential (ERP) indices of reward anticipation and initial responsiveness to reward attainment. Following EEG, they completed self-report measures of reward responsiveness, affectivity, and ED. Findings indicated some evidence of convergent validity between enhanced ERP indices of reward anticipation and initial response to reward and greater reinforcement sensitivity; that ERP indices of both reward responsiveness aspects predicted lower negative affectivity and less ED; and evidence of incremental validity of self-report beyond neural reward responsiveness in predicting outcomes. Results underscore the utility of a multi-method framework in assessing adolescent reward responsiveness and support the relevance of reward responsiveness in explaining individual differences in dispositional affectivity and ED.

The moderating role of externalizing problems on the association between anxiety and the error-related negativity in youth

The error-related negativity (ERN) is an event-related potential that reflects error monitoring. Enhanced ERN indicates sensitivity to performance errors and is a correlate of anxiety disorders. In contrast, youth with externalizing problems exhibit a reduced ERN, suggesting decreased error monitoring. Anxiety and externalizing problems commonly co-occur in youth, but no studies have tested how comorbidity might modulate the ERN. In a sample of youth (N = 46, ages 7-19) with and without anxiety disorders, this preliminary study examined the interactive effect of anxiety and externalizing problems on ERN. Results suggest that externalizing problems moderate the relation between anxiety symptoms and ERN in youth. Anxious youth with less externalizing problems exhibited enhanced ERN response to errors. Conversely, anxious youth with greater externalizing problems demonstrated diminished ERN in response to errors. The regions of significance and proportion affected tests indicated that the moderating the effect of externalizing problems was only significant for youth with anxiety disorders. Findings suggest that enhanced neural error sensitivity could be a specific neurophysiological marker for anxiety disorders, whereas anxious individuals with comorbid externalizing problems demonstrate reduced error monitoring, similar to those with primary externalizing pathology. Results underscore the utility of examining neural correlates of pediatric anxiety comorbidity subtypes.

Multi-method assessment of irritability and differential linkages to neurophysiological indicators of attention allocation to emotional faces in young children

Facilitated attention toward angry stimuli (attention bias) may contribute to anger proneness and temper outbursts exhibited by children with high irritability. However, most studies linking attention bias and irritability rely on behavioral measures with limited precision and no studies have explored these associations in young children. The present study explores irritability-related attention biases toward anger in young children (N = 128; ages 4-7 years) engaged in a dot-probe task with emotional faces, as assessed with event-related brain potential (ERP) indices of early selective attention and multi-method assessment of irritability. Irritability assessed via semi-structured clinical interview predicted larger anterior N1 amplitudes to all faces. In contrast, irritability assessed via a laboratory observation paradigm predicted reduced P1 amplitudes to angry relative to neutral faces. These findings suggest that altered early attentional processing occurs in young children with high irritability; however, the nature of these patterns may vary with methodological features of the irritability assessments. Future investigations using different assessment tools may provide greater clarity regarding the underlying neurocognitive correlates of irritability. Such studies may also contribute to the ongoing debates about how to best define and measure irritability across the developmental spectrum in a manner that is most informative for linkage to neural processes.

Neurophysiological evidence for distinct biases in emotional face processing associated with internalizing and externalizing symptoms in children

Attentional bias to threat has been implicated in both internalizing and externalizing disorders. This study utilizes event-related potentials to examine early stages of perceptual attention to threatening (angry or fearful) versus neutral faces among a sample of 200 children ages 6-8 years from a low-income, urban community. Although both internalizing and externalizing symptoms were associated with processing biases, the nature of the bias differed between these two symptom domains. Internalizing symptoms were associated with heightened early attentional selection (P1) and later perceptual processing (P2) of fearful faces. In contrast, externalizing symptoms were associated with reduced early attentional selection (P1) of fearful faces and enhanced perceptual processing (P2) of neutral faces, possibly indicative of a hostile interpretation bias for ambiguous social cues. These results provide insight into the distinct cognitive-affective processes that may contribute to the etiology and maintenance of internalizing and externalizing psychopathology.

Impact of pubertal timing and depression on error-related brain activity in anxious youth

Anxiety disorders are associated with enhanced error-related negativity (ERN) across development but it remains unclear whether alterations in brain electrophysiology are linked to the timing of puberty. Pubertal timing and alterations of prefrontal and limbic development are implicated in risk for depression, but the interplay of these factors on the ERN-anxiety association has not been assessed. We examined the unique and interactive effects of pubertal timing and depression on the ERN in a sample of youth 10-19 years old with anxiety disorders (n = 30) or no history of psychopathology (n = 30). Earlier pubertal maturation was associated with an enhanced ERN. Among early, but not late maturing youth, higher depressive symptoms were associated with a reduced ERN. The magnitude of neural reactivity to errors is sensitive to anxiety, depression, and development. Early physical maturation and anxiety may heighten neural sensitivity to errors yet predict opposing effects in the context of depression.

More than a face: Neural markers of motivated attention toward social and non-social reward-related images in children

Affective images engage motivational systems that shape emotional experience and cognitive processes. However, relatively little work has examined motivated attention toward distinct categories of approach motivation, particularly social motivation, in children. In the current study, event-related potentials (ERPs) were collected while children (n = 43; 22 females; M_age = 8.49 years) completed a picture-viewing task using a novel stimulus set of child relevant images representing social and non-social categories of reward-related images. Results showed that the frontal N400 (fN400) was more prominent for intrapersonal images that showed individuals playing alone or achieving rewards (e.g. medals). For the LPP, males showed the greatest reactivity to non-social object-based reward images. In contrast, females showed a larger LPP response for interpersonal images that showed scenes of social interaction between individuals. Overall, LPP reactivity to intrapersonal images was correlated with greater behavior regulation problems. Collectively, these results highlight unique patterns of neural prioritization to distinct categories of social and non-social reward-related stimuli that may serve as important markers in tracking connections between approach motivation and the development of self-regulation in children.

Specificity of Reward Sensitivity and Parasympathetic-Based Regulation among Children with Attention-Deficit/Hyperactivity and Disruptive Behavior Disorders

Attention-deficit/hyperactivity disorder (ADHD) is associated with disruptionsin reward sensitivity and regulatory processes. However, it is unclear whether thesedisruptions are better explained by comorbid disruptive behavior disorder (DBD)symptomology. This study sought to examine this question using multiple levels ofanalysis (i.e., behavior, autonomic reactivity). One hundred seventeen children (aged 6 to 12 years; 72.6% male; 69 with ADHD) completed theBalloon-Analogue Risk Task (BART) to assess external reward sensitivity behaviorally.Sympathetic-based internal reward sensitivity and parasympathetic-based regulationwere indexed via cardiac pre-ejection period (PEP) and respiratory sinus arrhythmia(RSA), respectively. Children with ADHD exhibited reduced internal reward sensitivity (i.e.,lengthened PEP; F(1,112)=4.01, p=0.047) compared to healthy controls and werecharacterized by greater parasympathetic-based dysregulation (i.e., reduced RSAaugmentation F(1,112)=10.12, p=0.002). However, follow-up analyses indicated theADHD effect was better accounted for by comorbid DBD diagnoses; that is, childrenwith ADHD and comorbid ODD were characterized by reduced internal rewardsensitivity (i.e., lengthened PEP; t=2.47, p=0.046) and by parasympathetic-baseddysregulation (i.e., reduced RSA augmentation; t=3.51, p=0.002) in response to rewardwhen compared to typically developing youth. Furthermore, children with ADHD and comorbid CD exhibited greater behaviorally-based external reward sensitivity (i.e.,more total pops; F(3,110)= 5.96, p=0.001) compared to children with ADHD only (t=3.87, p=0.001) and children with ADHD and ODD (t=3.56, p=0.003). Results suggest that disruptions in sensitivity to reward may be betteraccounted for, in part, by comorbid DBD.Key Words: attention-deficit/hyperactivity disorder, autonomic nervous system,disruptive behavior disorders, reward sensitivityPowered.

Event-Related Potentials during a Gambling Task in Young Adults with Attention-Deficit/Hyperactivity Disorder

Attention-deficit hyperactivity disorder (ADHD) is characterized by deficits in executive functions and decision making during childhood and adolescence. Contradictory results exist whether altered event-related potentials (ERPs) in adults are associated with the tendency of ADHD patients toward risky behavior. Clinically diagnosed ADHD patients (n = 18) and healthy controls (n = 18), aged between 18 and 29 (median 22 Yo), were screened with the Conners' Adult ADHD Rating Scales and assessed by the Mini-International Neuropsychiatric Interview, adult ADHD Self-Report Scale, and by the 60-item HEXACO Personality Inventory. The characteristic personality traits of ADHD patients were the high level of impulsiveness associated with lower values of agreeableness. All participants performed a probability gambling task (PGT) with two frequencies of the feedback information of the outcome. For each trial, ERPs were triggered by the self-paced trial onset and by the gamble selection. After trial onset, N2-P3a ERP component associated with the attentional load peaked earlier in the ADHD group than in controls. An N500 component related to the feedback frequency condition after trial onset and an N400-like component after gamble selection suggest a large affective stake of the decision making and an emphasized post-decisional evaluation of the choice made by the ADHD participants. By combining ERPs, related to the emotions associated with the feedback frequency condition, and behavioral analyses during completion of PGT, this study provides new findings on the neural dynamics that differentiate controls and young ADHD adults. In the patients' group, we raise the hypothesis that the activity of frontocentral and centroparietal neural circuits drive the decision-making processes dictated by an impaired cognitive workload followed by the build-up of large emotional feelings generated by the conflict toward the outcome of the gambling choice. Our results can be used for new investigations aimed at studying the fine spatiotemporal distribution of cortical activity, and the neural circuits that underly the generation of that activity, associated with the behavioral deficits characteristic of ADHD.

The link between optimism bias and attention bias: A neurocognitive perspective

Both optimism bias and reward-related attention bias have crucial implications for well-being and mental health. Yet, the extent to which the two biases interact remains unclear because, to date, they have mostly been discussed in isolation. Examining interactions between the two biases can lead to new directions in neurocognitive research by revealing their underlying cognitive and neurophysiological mechanisms. In the present article, we suggest that optimism bias and reward-related attention bias mutually enforce each other and recruit a common underlying neural network. Key components of this network include specific activations in the anterior and posterior cingulate cortex with connections to the amygdala. We further postulate that biased memory processes influence the interplay of optimism and reward-related attention bias. Studying such causal relations between cognitive biases reveals important information not only about normal functioning and adaptive neural pathways in maintaining mental health, but also about the development and maintenance of psychological diseases, thereby contributing to the effectiveness of treatment.

Canis familiaris As a Model for Non-Invasive Comparative Neuroscience

There is an ongoing need to improve animal models for investigating human behavior and its biological underpinnings. The domestic dog (Canis familiaris) is a promising model in cognitive neuroscience. However, before it can contribute to advances in this field in a comparative, reliable, and valid manner, several methodological issues warrant attention. We review recent non-invasive canine neuroscience studies, primarily focusing on (i) variability among dogs and between dogs and humans in cranial characteristics, and (ii) generalizability across dog and dog-human studies. We argue not for methodological uniformity but for functional comparability between methods, experimental designs, and neural responses. We conclude that the dog may become an innovative and unique model in comparative neuroscience, complementing more traditional models.