Attention orienting and inhibitory control across the different mood states in bipolar disorder: an emotional antisaccade task

How do bipolar disease states affect positive and negative emotion processing? Insights from a meta-analysis on the neural fingerprints of emotional processing

BACKGROUND

Functional magnetic resonance imaging studies on emotion processing in patients with bipolar disorder (BD) show hyperactivity of limbic-striatal brain areas and hypoactivity in inferior frontal areas compared to healthy participants. However, heterogeneous results in patients with different disease states and different valences of emotional stimuli have been identified.

METHODS

To integrate previous results and elucidate the impact of disease state and stimulus valence, we conducted a systematic literature search for journal articles in the Web of Science Core Collection including MEDLINE databases and employed a coordinate-based-meta-analysis of functional-MRI studies comparing emotion processing in BD-patients with healthy participants using seed-based d mapping (SDM) to test for between-subjects-effects. We included 31 studies published before 11/2022 with a total of N = 766 BD-patients and N = 836 controls.

RESULTS

Patients with BD showed hyperactivated regions involved in salience processing of emotional stimuli (e.g., the bilateral insula) and hypoactivation of regions associated with emotion regulation (e.g., inferior frontal gyrus) during emotion processing, compared to healthy participants. A more detailed descriptive analysis revealed a hypoactive (anterior) insula in manic BD-patients specifically for negative in comparison to positive emotion processing.

DISCUSSION

This meta-analysis corroborates the overall tenor of existing literature that patients with BD show an increased emotional reactivity (hyperactivity of salience-processing regions) together with a lower (cognitive) control (hypoactivity of brain areas associated with emotion regulation) over emotional states. Our analysis suggests reduced interoceptive processing of negative stimuli in mania, pointing out the need for longitudinal within-subject analyses of emotion processing.

Increased error rate and delayed response to negative emotional stimuli in antisaccade task in obsessive-compulsive disorder

Ample evidence links impaired inhibitory control, attentional distortions, emotional dysregulation, and obsessive-compulsive disorder (OCD). However, it remains unclear what underlies the deficit that triggers the OCD cycle. The present study used an antisaccade paradigm with emotional valences to compare eye movement patterns reflecting inhibitory control and attention switching in OCD and healthy control groups. Thirty-two patients with OCD and thirty healthy controls performed the antisaccade task with neutral, positive, and negative visual images served as fixation stimuli. Presentation of the fixation stimulus overlapped with target stimuli appearance for 200 ms. The OCD group showed more errors to negative stimuli than the control group and they also performed antisaccades more slowly to negative and neutral stimuli than positive ones. Other patterns, including mean gaze velocity of correct antisaccades did not differ between groups. The mean gaze velocity of correct antisaccades was higher for negative and positive stimuli than for neutral stimuli in both groups. The peak velocity parameter did not show any differences either between groups or between valences. The findings support a hypothesis that an attentional bias toward negative stimuli interferes with inhibitory control in OCD.

Abnormal eye movement features in patients with depression: Preliminary findings based on eye tracking technology

BACKGROUND

Saccadic eye movement (SEM) has been considered a non-invasive potential biomarker for the diagnosis of depression in recent years, but its application is not yet mature. In this study, we used eye-tracking technology to identify the eye movements of patients with depression to develop a new method for objectively identifying depression.

METHODS

Thirty-six patients with depression as the depression group, while thirty-six matched healthy individuals as the control group were recruited and completed eye movement tests, including two tasks: the prosaccade task and the antisaccade task. iViewX RED 500 eye-tracking instruments from SMI were used to collect eye movement data for both groups.

RESULTS

In the prosaccade task, there was no difference between the depression and control groups(t = 0.019， P > 0.05). In general, with increasing angle, both groups showed significantly higher peak velocity (F = 81.72， P < 0.0001), higher mean velocity (F = 32.83, P = 0.000), and greater SEM amplitude (F = 24.23, P < 0.0001). In the antisaccade task, there were significant differences in correct rate (t = 3.219, P = 0.002) and mean velocity (F = 3.253， P < 0.05) between the depression group and the control group. In the anti-effect analysis, there were significant differences in correct rate (F = 67.44, P < 0.0001) and accuracy (F = 79.02, P < 0.0001) between the depression group and the control group. Both groups showed longer latency and worse correct rate and precision in the antisaccade task compared with the prosaccade task.

CONCLUSION

Patients with depression showed different eye movement features, which could be potential biomarkers for clinical identification. Further studies must validate these results with larger sample sizes and more clinical populations.

Association of hospitalization with structural brain alterations in patients with affective disorders over nine years

Repeated hospitalizations are a characteristic of severe disease courses in patients with affective disorders (PAD). To elucidate how a hospitalization during a nine-year follow-up in PAD affects brain structure, a longitudinal case-control study (mean [SD] follow-up period 8.98 [2.20] years) was conducted using structural neuroimaging. We investigated PAD (N = 38) and healthy controls (N = 37) at two sites (University of Münster, Germany, Trinity College Dublin, Ireland). PAD were divided into two groups based on the experience of in-patient psychiatric treatment during follow-up. Since the Dublin-patients were outpatients at baseline, the re-hospitalization analysis was limited to the Münster site (N = 52). Voxel-based morphometry was employed to examine hippocampus, insula, dorsolateral prefrontal cortex and whole-brain gray matter in two models: (1) group (patients/controls)×time (baseline/follow-up) interaction; (2) group (hospitalized patients/not-hospitalized patients/controls)×time interaction. Patients lost significantly more whole-brain gray matter volume of superior temporal gyrus and temporal pole compared to HC (p_FWE = 0.008). Patients hospitalized during follow-up lost significantly more insular volume than healthy controls (p_FWE = 0.025) and more volume in their hippocampus compared to not-hospitalized patients (p_FWE = 0.023), while patients without re-hospitalization did not differ from controls. These effects of hospitalization remained stable in a smaller sample excluding patients with bipolar disorder. PAD show gray matter volume decline in temporo-limbic regions over nine years. A hospitalization during follow-up comes with intensified gray matter volume decline in the insula and hippocampus. Since hospitalizations are a correlate of severity, this finding corroborates and extends the hypothesis that a severe course of disease has detrimental long-term effects on temporo-limbic brain structure in PAD.

Association Between the Fronto-Limbic Network and Cognitive and Emotional Functioning in Individuals With Bipolar Disorder: A Systematic Review and Meta-analysis

Importance

Individuals with bipolar disorder (BD) experience cognitive and emotional dysfunctions. Various brain circuits are implicated in BD but have not been investigated in a meta-analysis of functional magnetic resonance imaging (fMRI) studies.

Objective

To investigate the brain functioning of individuals with BD compared with healthy control individuals in the domains of emotion processing, reward processing, and working memory.

Data Sources

All fMRI experiments on BD published before March 2020, as identified in a literature search of PubMed, Embase, Web of Science, Cochrane Library, PsycInfo, Emcare, Academic Search Premier, and ScienceDirect. The literature search was conducted on February 21, 2017, and March 2, 2020, and data were analyzed from January 2021 to January 2022.

Study Selection

fMRI experiments comparing adult individuals with BD and healthy control individuals were selected if they reported whole-brain results, including a task assessing at least 1 of the domains. In total, 2320 studies were screened, and 253 full-text articles were evaluated.

Data Extraction and Synthesis

A total of 49 studies were included after selection procedure. Coordinates reporting significant activation differences between individuals with BD and healthy control individuals were extracted. Differences in brain region activity were tested using the activation likelihood estimation method.

Main Outcomes and Measures

A whole-brain meta-analysis evaluated whether reported differences in brain activation in response to stimuli in 3 cognitive domains between individuals with BD and healthy control individuals were different.

Results

The study population included 999 individuals with BD (551 [55.2%] female) and 1027 healthy control individuals (532 [51.8%] female). Compared with healthy control individuals, individuals with BD showed amygdala and hippocampal hyperactivity and hypoactivation in the inferior frontal gyrus during emotion processing (20 studies; 324 individuals with BD and 369 healthy control individuals), hyperactivation in the orbitofrontal cortex during reward processing (9 studies; 195 individuals with BD and 213 healthy control individuals), and hyperactivation in the ventromedial prefrontal cortex and subgenual anterior cingulate cortex during working memory (20 studies; 530 individuals with BD and 417 healthy control individuals). Limbic hyperactivation was only found during euthymia in the emotion and reward processing domains; abnormalities in frontal cortex activity were also found in individuals with BD with mania and depression.

Conclusions and Relevance

This systematic review and meta-analysis revealed evidence for activity disturbances in key brain areas involved in cognitive and emotion processing in individuals with BD. Most of the regions are part of the fronto-limbic network. The results suggest that aberrations in the fronto-limbic network, present in both euthymic and symptomatic individuals, may be underlying cognitive and emotional dysfunctions in BD.

Task-irrelevant emotional faces impact BOLD responses more for prosaccades than antisaccades in a mixed saccade fMRI task

Cognitive control allows individuals to flexibly and efficiently perform tasks by attending to relevant stimuli while inhibiting distraction from irrelevant stimuli. The antisaccade task assesses cognitive control by requiring participants to inhibit a prepotent glance towards a peripheral stimulus and generate an eye movement to the mirror image location. This task can be administered with various contextual manipulations to investigate how factors such as trial timing or emotional content interact with cognitive control. In the current study, 26 healthy adults completed a mixed antisaccade and prosaccade fMRI task that included task irrelevant emotional faces and gap/overlap timing. The results showed typical antisaccade and gap behavioral effects with greater BOLD activation in frontal and parietal brain regions for antisaccade and overlap trials. Conversely, there were no differences in behavior based on the emotion of the task irrelevant face, but trials with neutral faces had greater activation in widespread visual regions than trials with angry faces, particularly for prosaccade and overlap trials. Together, these effects suggest that a high level of cognitive control and inhibition was required throughout the task, minimizing the impact of the face presentation on saccade behavior, but leading to increased attention to the neutral faces on overlap prosaccade trials when both the task cue (look towards) and emotion stimulus (neutral, non-threatening) facilitated disinhibition of visual processing.

Oro-mucosal administration of oxytocin using medicated lollipops alters social attention, similar to intranasal and lingual routes: Implications for therapeutic use

A key functional effect of intranasal administration of the neuropeptide oxytocin is on top-down control of social attention. However, an oro-mucosal administration route may be better tolerated for chronic therapeutic use and evidence suggests that some functional effects of oxytocin can be mediated via peripheral routes. The current study investigated if oxytocin administered orally using medicated lollipops can both increase blood oxytocin concentrations and influence social attention and state anxiety. In a randomized, double-blind, clinical trial adult male participants received oral oxytocin (24IU) or placebo 30-min before completing a well-established anti-saccade paradigm which can assess treatment effects on both top-down and bottom-up attention. Oxytocin administration modulated top-down social attentional processing by increasing anti-saccade error rates on both social and non-social stimuli although it only increased response latencies for social cues. Anti-saccade errors were also positively associated with the proportionate increase in plasma oxytocin concentrations. A comparison analysis showed that oral oxytocin administration increased blood concentrations to a similar degree as given by lingual spray, although less than when given intranasally. Importantly, attentional and anxiolytic effects of oxytocin in the anti-saccade task were similar across intranasal, lingual, and oral administration routes. These findings demonstrate that oral administration of oxytocin, similar to via intranasal and lingual routes, can modulate top-down social attention and state anxiety and support its potential for therapeutic use. They also provide further evidence that functional effects of exogenously administered oxytocin can be mediated indirectly either by crossing the blood brain barrier or producing receptor mediated vagal stimulation, as opposed to via direct entry into the brain.

Oral Administration of Oxytocin, Like Intranasal Administration, Decreases Top-Down Social Attention

BACKGROUND

The neuropeptide oxytocin (OXT) modulates social cognition by increasing attention to social cues and may have therapeutic potential for impaired social attention in conditions such as autism spectrum disorder. Intranasal administration of OXT is widely used to examine the drug's functional effects in both adults and children and is assumed to enter the brain directly via this route. However, OXT can also influence brain function through increased blood concentrations, and we have recently shown that orally (lingual) administered OXT also modulates neural responses to emotional faces and may be better tolerated for therapeutic use. Here, we examine whether 24 IU OXT administered orally can facilitate social attention.

METHODS

In a randomized, placebo-controlled pharmacologic study, we used a validated emotional antisaccade eye-tracking paradigm to explore the effects of oral OXT on bottom-up and top-down attention processing in 80 healthy male participants.

RESULTS

Our findings showed that in terms of top-down attention, oral OXT increased errors for both social (angry, fearful, happy, sad, and neutral emotion faces) and nonsocial stimuli (oval shapes) in the antisaccade condition but increased response latencies only in the social condition. It also significantly reduced post-task state anxiety, but this reduction was not correlated with task performance. A comparison with our previous intranasal OXT study using the same task revealed that both routes have a similar effect on increasing antisaccade errors and response latencies and on reducing state anxiety.

CONCLUSIONS

Overall, our findings suggest that oral administration of OXT produces similar effects on top-down social attention control and anxiety to intranasal administration and may therefore have therapeutic utility.

Depressive Symptoms Account for Loss of Positive Attention Bias in ADHD Patients: An Eye-Tracking Study

OBJECTIVES

Depression and ADHD often co-occur and are both characterized by altered attentional processing. Differences and overlap in the profile of attention to emotional information may help explain the co-occurence. We examined negative attention bias in ADHD as neurocognitive marker for comorbid depression.

METHODS

Patients with depression (n = 63), ADHD (n = 43), ADHD and depression (n = 25), and non-psychiatric controls (n = 68) were compared on attention allocation toward emotional faces. The following eye-tracking indices were used: gaze duration, number of revisits, and location and duration of first fixation.

RESULTS

Controls revisited the happy faces more than the other facial expressions. Both the depression and the comorbid group showed significantly less revisits of the happy faces compared to the ADHD and the control group. Interestingly, after controlling for depressive symptoms, the groups no longer differed on the number of revisits.

CONCLUSION

ADHD patients show a relative positive attention bias, while negative attention bias in ADHD likely indicates (sub)clinical comorbid depression.

Attentional engagement and inhibitory control according to positive and negative symptoms in schizophrenia: An emotional antisaccade task

Despite schizophrenia (SZ) is characterized by a high psychopathological heterogeneity, the underlying psychological mechanisms that result in different clinical profiles are unclear. This study examined the cognitive processing of emotional faces (angry, happy, neutral, and sad) by means of assessing inhibitory control (antisaccade task) and attentional engagement (prosaccade task) with the eye-tracking paradigm. Firstly, two clinical SZ subgroups classified according to the predominance of positive (PSZ; n = 20) or negative symptoms (NSZ; n = 34) and a control group of 32 individuals were compared. Secondly, the association between prosaccade and antisaccade measurements and the severity of positive and negative symptoms were analyzed. The PSZ group showed slower antisaccades when angry faces were displayed, and higher positive symptoms were associated with slower prosaccade latencies to ones. Conversely, the NSZ group made overall slower prosaccades with an emotional advantage for angry faces, and higher negative symptoms were associated with faster antisaccade latencies to ones. Hence, whereas positive SZ profile is related to a lack of attentional engagement and an impaired inhibitory control to threatening information; negative SZ profile is linked to a lack of attentional engagement to faces, mainly with non-threat ones, and with an advantage to ignore distracting threatening stimuli. These findings support affective information-processing theories suggesting a hypersensitivity to threat for positive SZ profiles, and a desensitization to socio-emotional information for negative ones. Consequently, characterizing psychological mechanisms of SZ may allow improving current treatments to threat management when positive symptoms are predominant, or emotion sensitization when negative symptoms prevail.

Depression and Cognitive Impairment: Current Understanding of Its Neurobiology and Diagnosis

BACKGROUND

Eye movement is critical for obtaining precise visual information and providing sensorimotor processes and advanced cognitive functions to the brain behavioral indicator.

METHODS

In this article, we present a narrative review of the eye-movement paradigms (such as fixation, smooth pursuit eye movements, and memory-guided saccade tasks) in major depression.

RESULTS

Characteristics of eye movement are considered to reflect several aspects of cognitive deficits regarded as an aid to diagnosis. Findings regarding depressive disorders showed differences from the healthy population in paradigms, the characteristics of eye movement may reflect cognitive deficits in depression. Neuroimaging studies have demonstrated the effectiveness of different eye movement paradigms for MDD screening.

CONCLUSION

Depression can be distinguished from other mental illnesses based on eye movements. Eye movement reflects cognitive deficits that can help diagnose depression, and it can make the entire diagnostic process more accurate.

Do emotional stimuli interfere with response inhibition? evidence from the antisaccade paradigm

When it comes to measuring cognitive control and inhibition, the antisaccade paradigm is a popular task to apply. Usually, simple, perceptually and affectively neutral stimuli, e.g. white circles, are used. Recently, researchers also employed a version of the paradigm displaying emotional faces. Differences in cognitive processing due to stimulus size and emotional valence have not been investigated yet. Thus, in the present study, we applied both versions of the antisaccade paradigm in a healthy sample. In addition, we used scrambled faces to control for stimulus size and emotional valence. We hypothesised slower reaction times and higher error rates for emotional face stimuli compared to circular and scrambled ones as well as significant differences between individual emotions. In contrast to our hypotheses, results showed faster reaction times fewer errors for emotional faces compared to circular and scrambled stimuli. Furthermore, ANOVA models showed no meaningful differences between different emotions. Our study shows specific patterns in inhibitory control due to stimulus size and valence in an antisaccade eye-tracking task.

Attentional biases to emotional scenes in schizophrenia: An eye-tracking study

Attentional biases to emotional information may play a key role in the onset and course of schizophrenia. The aim of this experiment was to examine the attentional processing of four emotional scenes in competition (happy, neutral, sad, threatening) in 53 patients with schizophrenia and 51 controls. The eye movements were recorded in a 20-seconds free-viewing task. The results were: (i) patients showed increased attention on threatening scenes, compared to controls, in terms of attentional engagement and maintenance; (ii) patients payed less attention to happy scenes than controls, in terms of attentional maintenance; (iii) whereas positive symptoms were associated with a late avoidance of sad scenes, negative symptoms were associated with heightened attention to threat. The findings suggest that a threat-related bias and a lack of sensitivity to positive information may represent an underlying psychological mechanism of schizophrenia. Importantly, schizophrenia symptoms modulated the attentional biases, which has aetiological and therapeutic implications.

Using Smartphone Sensor Data to Assess Inhibitory Control in the Wild: Longitudinal Study

Background

Inhibitory control, or inhibition, is one of the core executive functions of humans. It contributes to our attention, performance, and physical and mental well-being. Our inhibitory control is modulated by various factors and therefore fluctuates over time. Being able to continuously and unobtrusively assess our inhibitory control and understand the mediating factors may allow us to design intelligent systems that help manage our inhibitory control and ultimately our well-being.

Objective

The aim of this study is to investigate whether we can assess individuals’ inhibitory control using an unobtrusive and scalable approach to identify digital markers that are predictive of changes in inhibitory control.

Methods

We developed InhibiSense, an app that passively collects the following information: users’ behaviors based on their phone use and sensor data, the ground truths of their inhibition control measured with stop-signal tasks (SSTs) and ecological momentary assessments (EMAs), and heart rate information transmitted from a wearable heart rate monitor (Polar H10). We conducted a 4-week in-the-wild study, where participants were asked to install InhibiSense on their phone and wear a Polar H10. We used generalized estimating equation (GEE) and gradient boosting tree models fitted with features extracted from participants’ phone use and sensor data to predict their stop-signal reaction time (SSRT), an objective metric used to measure an individual’s inhibitory control, and identify the predictive digital markers.

Results

A total of 12 participants completed the study, and 2189 EMAs and SST responses were collected. The results from the GEE models suggest that the top digital markers positively associated with an individual’s SSRT include phone use burstiness (P=.005), the mean duration between 2 consecutive phone use sessions (P=.02), the change rate of battery level when the phone was not charged (P=.04), and the frequency of incoming calls (P=.03). The top digital markers negatively associated with SSRT include the standard deviation of acceleration (P<.001), the frequency of short phone use sessions (P<.001), the mean duration of incoming calls (P<.001), the mean decibel level of ambient noise (P=.007), and the percentage of time in which the phone was connected to the internet through a mobile network (P=.001). No significant correlation between the participants’ objective and subjective measurement of inhibitory control was found.

Conclusions

We identified phone-based digital markers that were predictive of changes in inhibitory control and how they were positively or negatively associated with a person’s inhibitory control. The results of this study corroborate the findings of previous studies, which suggest that inhibitory control can be assessed continuously and unobtrusively in the wild. We discussed some potential applications of the system and how technological interventions can be designed to help manage inhibitory control.

Eye movements in anorexia nervosa: State or trait markers?

OBJECTIVE

Differences in saccadic eye movements are widely reported in mental illnesses, and can indirectly inform our understanding of neurobiological and cognitive underpinnings of psychiatric conditions, including anorexia nervosa (AN). Preliminary research has suggested that individuals with AN may show specific eye movement abnormalities; whether these deficits are representative of state or trait effects is, however, unclear. The aim of this study was to identify whether there are demonstrable differences in performance on saccadic eye movement tasks in individuals with current AN (c-AN), those who are weight-restored from AN (wr-AN), biological sisters of individuals with AN (AN-sis), and healthy controls (HC).

METHODS

Eighty participants took part in the study (n = 20/group). A set of saccadic eye movement tasks was administered, including prosaccade, antisaccade, memory-guided saccade, and visual scanpath tasks.

RESULTS

The c-AN group showed an increased rate of inhibitory errors to 10° targets on the memory-guided saccade task.

DISCUSSION

The results are discussed in terms of the potential role of the superior colliculus in AN, and that the findings may reflect a state measure of AN.

A Multimodal Analysis Combining Behavioral Experiments and Survey-Based Methods to Assess the Cognitive Effect of Video Game Playing: Good or Evil?

This study aims to bridge the gap between the discrepant views of existing studies in different modalities on the cognitive effect of video game play. To this end, we conducted a set of tests with different modalities within each participant: (1) Self-Reports Analyses (SRA) consisting of five popular self-report surveys, and (2) a standard Behavioral Experiment (BE) using pro- and antisaccade paradigms, and analyzed how their results vary between Video Game Player (VGP) and Non-Video Game Player (NVGP) participant groups. Our result showed that (1) VGP scored significantly lower in Behavioral Inhibition System (BIS) than NVGP (p = 0.023), and (2) VGP showed significantly higher antisaccade error rate than NVGP (p = 0.005), suggesting that results of both SRA and BE support the existing view that video game play has a maleficent impact on the cognition by increasing impulsivity. However, the following correlation analysis on the results across individual participants found no significant correlation between SRA and BE, indicating a complex nature of the cognitive effect of video game play.

Eye gaze and facial displays of emotion during emotional film clips in remitted patients with bipolar disorder

Background.

Aberrant emotional reactivity is a putative endophenotype for bipolar disorder (BD), but the findings of behavioral studies are often negative due to suboptimal sensitivity of the employed paradigms. This study aimed to investigate whether visual gaze patterns and facial displays of emotion during emotional film clips can reveal subtle behavioral abnormalities in remitted BD patients.

Methods.

Thirty-eight BD patients in full or partial remission and 40 healthy controls viewed 7 emotional film clips. These included happy, sad, and neutral scenarios and scenarios involving winning, risk-taking, and thrill-seeking behavior of relevance to the BD phenotype. Eye gaze and facial expressions were recorded during the film clips, and participants rated their emotional reactions after each clip.

Results.

BD patients showed a negative bias in both facial displays of emotion and self-rated emotional responses. Specifically, patients exhibited more fearful facial expressions during all film clips. This was accompanied by less positive self-rated emotions during the winning and happy film clips, and more negative emotions during the risk-taking/thrill-related film clips.

Conclusions.

These findings suggest that BD is associated with trait-related abnormalities in subtle behavioral displays of emotion processing. Future studies comparing patients with BD and unipolar depression are warranted to clarify whether these differences are specific to BD. If so, assessments of visual gaze and facial displays of emotion during emotional film clips may have the potential to be implemented in clinical assessments to aid diagnostic accuracy.

Affective cognition in bipolar disorder: A systematic review by the ISBD targeting cognition task force

BACKGROUND

Impairments in affective cognition are part of the neurocognitive profile and possible treatment targets in bipolar disorder (BD), but the findings are heterogeneous. The International Society of Bipolar Disorder (ISBD) Targeting Cognition Task Force conducted a systematic review to (i) identify the most consistent findings in affective cognition in BD, and (ii) provide suggestions for affective cognitive domains for future study and meta-analyses.

METHODS

The review included original studies reporting behavioral measures of affective cognition in BD patients vs controls following the procedures of the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement. Searches were conducted on PubMed/MEDLINE, EMBASE, and PsychInfo from inception until November 2018.

RESULTS

A total of 106 articles were included (of which nine included data for several affective domains); 41 studies assessed emotional face processing; 23 studies investigated reactivity to emotional words and images; 3 investigated explicit emotion regulation; 17 assessed implicit emotion regulation; 31 assessed reward processing and affective decision making. In general, findings were inconsistent. The most consistent findings were trait-related difficulties in facial emotion recognition and implicit emotion regulation, and impairments in reward processing and affective decision making during mood episodes. Studies using eye-tracking and facial emotion analysis revealed subtle trait-related abnormalities in emotional reactivity.

CONCLUSION

The ISBD Task Force recommends facial expression recognition, implicit emotion regulation, and reward processing as domains for future research and meta-analyses. An important step to aid comparability between studies in the field would be to reach consensus on an affective cognition test battery for BD.

Oxytocin reduces top-down control of attention by increasing bottom-up attention allocation to social but not non-social stimuli - A randomized controlled trial

The neuropeptide oxytocin (OXT) may facilitate attention to social stimuli by influencing early stage bottom-up processing although findings in relation to different emotional expressions are inconsistent and its influence on top-down cognitive processing mechanisms unclear. In the current double-blind placebo (PLC) controlled between-subject design study we therefore recruited 71 male subjects (OXT = 34, PLC = 37) to investigate the effects of intranasal OXT (24IU) on both bottom-up attention allocation and top-down attention inhibition using a prosaccade and antisaccade paradigm incorporating social (neutral, happy, fearful, sad, angry faces) and non-social (oval shape) visual stimuli with concurrent eye movement acquisition. Results revealed a marginal significant interaction effect between treatment, condition and task (p = 0.054), with Bonferroni-corrected post-hoc tests indicating that OXT specifically increased antisaccade errors for social stimuli (ps < 0.04, effect sizes 0.46-0.88), but not non-social stimuli. Antisaccades are under volitional control and therefore this may indicate that OXT treatment reduced top-down inhibition. However, the overall findings are consistent with OXT acting to reduce top-down control of attention as a result of increasing bottom-up early attentional processing of social, but not non-social, stimuli in situations where the two systems are in potential conflict. Marked deficits in bottom-up attention allocation to social stimuli have been reported in autism spectrum disorder, within this context OXT may have the potential to increase early attention allocation towards social cues.

Endophenotypes in Schizophrenia: Digging Deeper to Identify Genetic Mechanisms

Schizophrenia (SZ) is a severe psychotic disorder that is highly heritable and common in the general population. The genetic heterogeneity of SZ is substantial, with contributions from common, rare, and de novo variants, in addition to environmental factors. Large genome-wide association studies have detected many variants that are associated with SZ, yet the pathways by which these variants influence risk remain largely unknown. SZ is also clinically heterogeneous, with patients exhibiting a broad range of deficits and symptom severity that vary over the course of illness and treatment, which has complicated efforts to identify risk variants. However, the underlying brain dysfunction forms a more stable trait marker that quantitative neurocognitive and neurophysiological endophenotypes may be able to objectively measure. These endophenotypes are less likely to be heterogeneous than the disorder and provide a neurobiological context to detect risk variants and underlying pathways among genes associated with SZ diagnosis. Furthermore, many endophenotypes are translational into animal model systems, allowing for direct evaluation of the neural circuit dysfunctions and neurobiological substrates. We review a selection of the most promising SZ endophenotypes, including prepulse inhibition, mismatch negativity, oculomotor antisaccade, letter-number sequencing, and continuous performance tests. We also highlight recent findings from large consortia that suggest the potential role of genes, particularly in the neuregulin and glutamate pathways, in several of these endophenotypes. Although endophenotypes require additional time and effort to assess, the insight into the underlying neurobiology that they provide may ultimately reveal the underlying genetic architecture for SZ and suggest novel treatment targets.

Do affective episodes modulate moral judgment in individuals with bipolar disorder?

BACKGROUND

Bipolar disorder (BD) patients experience altered emotional states and deficits in social adaptation that may also be involved in deontological moral judgments in which participants have to choose whether to sacrifice one person in order to save the lives of a greater number.

METHODS

In the present study we compared the utilitarian responses of BD patients in their different states (euthymia, mania, depression) and healthy controls to moral dilemmas with low (impersonal dilemma) and high (personal dilemma) emotional saliency.

RESULTS

Our findings revealed an increased tendency to utilitarian judgments in the three groups of BD patients in impersonal dilemmas relative to healthy individuals. In addition, utilitarian responses were increased during manic and depressive episodes in personal moral dilemmas relative to control group. Furthermore, we found no differences in social adaptation between utilitarian and deontological BD responders, though the depressive BD had a lower adaptation than the euthymic individuals.

LIMITATIONS

The recording of response times, the exhaustive control of medication effect, or the inclusion of a non-moral condition in the battery of moral dilemmas would provide a better characterization of moral judgment in BD.

CONCLUSIONS

For impersonal dilemmas, BD patients exhibited more utilitarian reasoning, which is also affected by emotional engagement for personal dilemmas during acute episodes of mania and depression. Social adaptation is not associated to utilitarian reasoning, but is rather influenced by mood state.

Developing Dimensional, Pandiagnostic Inhibitory Control Constructs With Self-Report and Neuropsychological Data

Trait markers, or intermediate phenotypes linking different units of analysis (self-report, performance) from the Research Domain Criteria (RDoC) matrix across populations is a necessary step in identifying at-risk individuals. In the current study, 150 healthy controls (HC) and 456 individuals with bipolar disorder (BD) Type I or II, NOS (not otherwise specified) or Schizoaffective BD completed self-report neuropsychological tests of inhibitory control (IC) and executive functioning. Bifactor analyses were used to examine the factor structure of these measures and to evaluate for invariance across groups. Bifactor analyses found modest convergence of items from neuropsychological tests and self-report measures of IC among HC and BD. The factor scores showed evidence of a general IC construct (i.e., subdomain) across measures. Importantly, invariance testing indicated that the same construct was measured equally well across groups. Groups differed on the general factor for three of the four scales. Convergence on a general IC factor and invariance across diagnosis supports the use of combined dimensional measures to identify clinical risk and highlights how prospective RDoC studies might integrate units of analysis.

Neuropsychological measurement of inhibitory control in posttraumatic stress disorder: An exploratory antisaccade paradigm

OBJECTIVE

The aim of the study was to uncover inhibitory control dynamics and assess antisaccade eye-tracking tasks for relevance in a veteran posttraumatic stress disorder (PTSD) population.

METHOD

Participants were 36 veterans enrolled at the Washington DC Veterans Affairs Medical Center. The groups (PTSD diagnosed vs. controls) did not vary between age and sex. Participants completed a testing battery of clinical neuropsychological measures and two different eye-tracking conditions, one that utilized face stimuli and one with standard shape stimuli, which test pro- (PS) and antisaccade (AS) eye movements.

RESULTS

Veterans with PTSD, t(33) = 2.2, p = .04, took longer to respond than controls in the standard condition AS. In the face condition, a group by task interaction was seen with increased latency for PTSD veterans in the AS versus PS task, F(3, 33) = 3.99, p = .05, with a large overall effect (Hedges' g = 1.18, p < .001) compared to controls. After controlling for depression, analyses suggested that only the face condition AS task significantly predicted dimensions of PTSD symptomology measured by the Clinician Administered PTSD Scale (CAPS) for veterans with PTSD.

CONCLUSIONS

This is the first study to extend AS findings to PTSD and suggests a specific capability to measure inhibitory control using eye-tracking technology. We discuss the notion that reduced capacity to regulate facial-related processing affects cognitive and attentional control networks of PTSD patients, potentially representing a core cognitive deficit.

Executive Control in Depressive Rumination: Backward Inhibition and Non-inhibitory Switching Performance in a Modified Mixed Antisaccade Task

BACKGROUND AND OBJECTIVES

The present study examines backward inhibition (BI) and non-inhibitory switching performance among depressed and healthy participants in a modified mixed antisaccade task. Specifically, sad and neutral faces were incorporated in the design to examine executive control difficulties associated with brooding trait.

METHODS

Thirty-nine participants took part in the study, including 19 depressed patients and 20 healthy control subjects. Participants completed a diagnostic interview and self-report questionnaires, including the Beck Depression Inventory and Ruminative Response Scale-Brooding Subscale. They were then instructed to complete prosaccade and antisaccade trials in the pure and mixed blocks whereby eye gazes were tracked to assess inhibition and switching efficiency.

RESULTS

For the switching effects, a significant group × brooding × task type interaction was found as hypothesized when multilevel modeling analysis was employed. Switching deficits associated with brooding was found to be greatest when sad faces were presented to depressed group. No significant results in BI or error rates were observed.

CONCLUSION

The patterns observed suggest that as opposed to BI, set shifting difficulty associated with brooding trait may be modulated by negative mood and cognition. In future research, emotional faces other than sad faces may be used to further explore if the observations could be generalized to other affective conditions.

Impaired conflict resolution and vigilance in euthymic bipolar disorder

Difficulty attending is a common deficit of euthymic bipolar patients. However, it is not known whether this is a global attentional deficit or relates to a specific attentional network. According to the attention network approach, attention is best understood in terms of three functionally and neuroanatomically distinct networks-alerting, orienting, and executive control. In this study, we explored whether and which of the three attentional networks are altered in euthymic Bipolar Disorder (BD). A sample of euthymic BD patients and age-matched healthy controls completed the Attention Network Test for Interactions and Vigilance (ANTI-V) that provided not only a measure of orienting, executive, and alerting networks, but also an independent measure of vigilance (tonic alerting). Compared to healthy controls, BD patients have impaired executive control (greater interference), reduced vigilance (as indexed by a decrease in the d' sensitivity) as well as slower overall reaction times and poorer accuracy. Our results show that deficits in executive attention and sustained attention often persist in BD patients even after complete remission of affective symptoms, thus suggesting that cognitive enhancing treatments programmed to improve these deficits could contribute to improve their functional recovery.

Hallucinations and inhibitory functioning in healthy young adults with high and low levels of hypomanic personality traits

INTRODUCTION

Hallucinations in schizophrenia and hallucination proneness in healthy young adults are associated with a common cognitive mechanism, namely impaired inhibitory control. Hallucinatory-like experiences also seem related to hypomanic symptoms in non-clinical participants; however, the mechanisms involved are unknown. We sought to examine self-reported hallucinatory/anomalous perceptual experiences in students selected for high versus low levels of hypomanic personality traits, and whether hypomania is characterised by deficient inhibitory control.

METHOD

Undergraduate students with either high (n = 26) or low (n = 28) scores on the Hypomanic Personality Scale-Revised (HPS-20) were compared on: (1) the Launay Slade Hallucination Scale-Revised (LSHS-R), a measure of hallucination proneness, (2) the Cardiff Anomalous Perceptions Scale (CAPS) and (3) the Inhibition of Currently Irrelevant Memories (ICIM) task, an index of intentional inhibition.

RESULTS

The high HPS group had higher total scores, as well as higher frequency (on CAPS only), intrusiveness and distress (CAPS) scores compared to the low HPS group. They also produced significantly more false alarms on the second run of the ICIM task than the low hypomania traits group.

CONCLUSIONS

Frequent, intrusive and distressing perceptual anomalies and proneness to hallucinations tend to occur in healthy individuals with hypomanic personality traits and may be associated with transient difficulties with inhibitory control. Inhibitory control may be a cognitive marker of vulnerability to hallucinations across diagnostic boundaries.

Robust differences in antisaccade performance exist between COGS schizophrenia cases and controls regardless of recruitment strategies

The impaired ability to make correct antisaccades (i.e., antisaccade performance) is well documented among schizophrenia subjects, and researchers have successfully demonstrated that antisaccade performance is a valid schizophrenia endophenotype that is useful for genetic studies. However, it is unclear how the ascertainment biases that unavoidably result from recruitment differences in schizophrenia subjects identified in family versus case-control studies may influence patient-control differences in antisaccade performance. To assess the impact of ascertainment bias, researchers from the Consortium on the Genetics of Schizophrenia (COGS) compared antisaccade performance and antisaccade metrics (latency and gain) in schizophrenia and control subjects from COGS-1, a family-based schizophrenia study, to schizophrenia and control subjects from COGS-2, a corresponding case-control study. COGS-2 schizophrenia subjects were substantially older; had lower education status, worse psychosocial function, and more severe symptoms; and were three times more likely to be a member of a multiplex family than COGS-1 schizophrenia subjects. Despite these variations, which were likely the result of ascertainment differences (as described in the introduction to this special issue), the effect sizes of the control-schizophrenia differences in antisaccade performance were similar in both studies (Cohen's d effect size of 1.06 and 1.01 in COGS-1 and COGS-2, respectively). This suggests that, in addition to the robust, state-independent schizophrenia-related deficits described in endophenotype studies, group differences in antisaccade performance do not vary based on subject ascertainment and recruitment factors.

Attentional capture by emotional scenes across episodes in bipolar disorder: Evidence from a free-viewing task

We examined whether the initial orienting, subsequent engagement, and overall allocation of attention are determined exogenously (i.e. by the affective valence of the stimulus) or endogenously (i.e. by the participant's mood) in the manic, depressive and euthymic episodes of bipolar disorder (BD). Participants were asked to compare the affective valence of two pictures (happy/threatening/neutral [emotional] vs. neutral [control]) while their eye movements were recorded in a free-viewing task. Results revealed that the initial orienting was exogenously captured by emotional images relative to control images. Importantly, engagement and overall allocation were endogenously captured by threatening images relative to neutral images in BD patients, regardless of their episode--this effect did not occur in a group of healthy controls. The threat-related bias in BD, which occurs even at the early stages of information processing (i.e. attentional engagement), may reflect a vulnerability marker.

Attentional bias in euthymic bipolar I disorder

Little is known about the nature of the relation between information-processing biases and affective traits in bipolar disorder. The present study was designed to investigate whether attentional biases are evident in persons diagnosed with bipolar disorder when they are in a positive mood state, and whether biases are related to indices of emotion regulation and to prior history of mood episodes. Ninety adults diagnosed with bipolar I disorder and 81 controls with no lifetime mood disorder underwent a positive mood induction and then completed an emotion face dot-probe task; participants in the bipolar disorder group also completed a self-report measure of responses to positive affect. Attentional bias was not related to a diagnosis of bipolar disorder or to symptom severity. Consistent with hypotheses, analyses within the bipolar group indicated that greater dampening of positive affect related to significantly less attention paid to the positively valenced faces. Discussion focuses on the potential role of affective traits in shaping attentional bias in bipolar disorder.

Openness predicts cognitive functioning in bipolar disorder

OBJECTIVES

Openness to experience (O) is a well-established personality factor and is associated with cognitive performance. Little is known about the personality-cognitive relationship in bipolar disorder, an illness with significant variability in mood. Cognitive evaluation is essential in psychopathology assessment as it may reflect underlying disease processes and psychosocial functional capacity. Screening using a proxy personality variable may identify those in need of comprehensive cognitive testing. We hypothesized that O and measures of cognition would associate in both the Bipolar Disorder (BD) and healthy control (HC) samples, whereas neuroticism and extraversion would correlate with cognition only in the BD sample.

METHODS

Data from a longitudinal study of BD were used to study the association between personality factors and cognitive measures of attention, executive functioning, memory and fine motor skills. Regression analyses were used to determine the variables that account for the association between personality and cognition.

RESULTS

Aspects of O explained significant cognitive variance (~5%) in both groups; this persisted when demographic variables (including BD versus HC status) were considered. Neuroticism and extraversion did not consistently correlate with cognitive performance in either group.

LIMITATIONS

There were more females in the HC group who were slightly younger compared to the BD group. We lack direct measures of positive affect, and there is a reliance on a single measure of personality.

CONCLUSIONS

BD Individuals scoring low on self-reported Openness are potential candidates for more comprehensive cognitive assessments (which represent a limited resource).

What saccadic eye movements tell us about TMS-induced neuromodulation of the DLPFC and mood changes: a pilot study in bipolar disorders

The study assumed that the antisaccade (AS) task is a relevant psychophysical tool to assess (i) short-term neuromodulation of the dorsolateral prefrontal cortex (DLPFC) induced by intermittent theta burst stimulation (iTBS); and (ii) mood change occurring during the course of the treatment. Saccadic inhibition is known to strongly involve the DLPFC, whose neuromodulation with iTBS requires less stimulation time and lower stimulation intensity, as well as results in longer aftereffects than the conventional repetitive transcranial magnetic stimulation (rTMS). Active or sham iTBS was applied every day for 3 weeks over the left DLPFC of 12 drug-resistant bipolar depressed patients. To assess the iTBS-induced short-term neuromodulation, the saccadic task was performed just before (S1) and just after (S2) the iTBS session, the first day of each week. Mood was evaluated through Montgomery and Asberg Depression Rating Scale (MADRS) scores and the difference in scores between the beginning and the end of treatment was correlated with AS performance change between these two periods. As expected, only patients from the active group improved their performance from S1 to S2 and mood improvement was significantly correlated with AS performance improvement. In addition, the AS task also discriminated depressive bipolar patients from healthy control subjects. Therefore, the AS task could be a relevant and useful tool for clinicians to assess if the Transcranial magnetic stimulation (TMS)-induced short-term neuromodulation of the DLPFC occurs as well as a “trait vs. state” objective marker of depressive mood disorder.