Social and emotional processing in Prader-Willi syndrome: genetic subtype differences

Background

People with Prader-Willi syndrome (PWS) demonstrate social dysfunction and increased risk of autism spectrum disorder, especially those with the maternal uniparental disomy (mUPD) versus paternal deletion genetic subtype. This study compared the neural processing of social (faces) and nonsocial stimuli, varying in emotional valence, across genetic subtypes in 24 adolescents and adults with PWS.

Methods

Upright and inverted faces, and nonsocial objects with positive and negative emotional valence were presented to participants with PWS in an oddball paradigm with smiling faces serving as targets. Behavioral and event-related potential (ERP) data were recorded.

Results

There were no genetic subtype group differences in accuracy, and all participants performed above chance level. ERP responses revealed genetic subtype differences in face versus object processing. In those with deletions, the face-specific posterior N170 response varied in size for face stimuli versus inverted faces versus nonsocial objects. Persons with mUPD generated N170 of smaller amplitude and showed no stimulus differentiation. Brain responses to emotional content did not vary by subtype. All participants elicited larger posterior and anterior late positive potential responses to positive objects than to negative objects. Emotion-related differences in response to faces were limited to inverted faces only in the form of larger anterior late positive potential amplitudes to negative emotions over the right hemisphere. Detection of the target smiling faces was evident in the increased amplitude of the frontal and central P3 responses but only for inverted smiling faces.

Conclusion

Persons with the mUPD subtype of PWS may show atypical face versus object processes, yet both subtypes demonstrated potentially altered processing, attention to and/or recognition of faces and their expressions.     

Selectivity of N170 in the left hemisphere as an electrophysiological marker for expertise in reading Chinese

Objective The left-lateralized N170, an event-related potential component consistently shown in response to alphabetic words, is a robust electrophysiological marker for reading expertise in an alphabetic language. In contrast, such a marker is lacking for expertise in reading Chinese, because the existing results about the lateralization of N170 for Chinese characters are mixed, reflecting complicated factors such as top-down modulation that contribute to the relative magnitudes of N170 in the left and right hemispheres. The present study aimed to explore a potential electrophysiological marker for reading expertise in Chinese with minimal top-down influence. Methods We recorded N170 responses to Chinese characters and three kinds of control stimuli in a content-irrelevant task, minimizing potential top-down effects. Results Direct comparison of the N170 amplitude in response to Chinese characters between the hemispheres showed a marginally significant left-lateralization effect. However, detailed analyses of N170 in each hemisphere revealed a more robust pattern of left-lateralization - the N170 in the left but not the right hemisphere differentiated Chinese characters from control stimuli. Conclusion These results suggest that the selectivity of N170 (a greater N170 in response to Chinese characters than to control stimuli) within the left hemisphere rather than the hemispheric difference of N170 with regard to Chinese characters is an electrophysiological marker for expertise in reading Chinese.     

Mood-congruent amygdala responses to subliminally presented facial expressions in major depression: associations with anhedonia

Background

Anhedonia has long been recognized as a key feature of major depressive disorders, but little is known about the association between hedonic symptoms and neurobiological processes in depressed patients. We investigated whether amygdala mood-congruent responses to emotional stimuli in depressed patients are correlated with anhedonic symptoms at automatic levels of processing.

Methods

We measured amygdala responsiveness to subliminally presented sad and happy facial expressions in depressed patients and matched healthy controls using functional magnetic resonance imaging. Amygdala responsiveness was compared between patients and healthy controls within a 2 (group) × 2 (emotion) design. In addition, we correlated patients’ amygdala responsiveness to sad and happy facial stimuli with self-report questionnaire measures of anhedonia.

Results

We included 35 patients and 35 controls in our study. As in previous studies, we observed a strong emotion × group interaction in the bilateral amygdala: depressed patients showed greater amygdala responses to sad than happy faces, whereas healthy controls responded more strongly to happy than sad faces. The lack of automatic right amygdala responsiveness to happy faces in depressed patients was associated with higher physical anhedonia scores.

Limitations

Almost all depressed patients were taking antidepressant medications.

Conclusion

We replicated our previous finding of depressed patients showing automatic amygdala mood-congruent biases in terms of enhanced reactivity to negative emotional stimuli and reduced activity to positive emotional stimuli. The altered amygdala processing of positive stimuli in patients was associated with anhedonia scores. The results indicate that reduced amygdala responsiveness to positive stimuli may contribute to an-hedonic symptoms due to reduced/inappropriate salience attribution to positive information at very early processing levels.     

Functional connectivity between the amygdala and prefrontal cortex in medication-naive individuals with major depressive disorder

Background

Convergent evidence suggests dysfunction within the prefrontal cortex (PFC) and amygdala, important components of a neural system that subserves emotional processing, in individuals with major depressive disorder (MDD). Abnormalities in this system in the left hemisphere and during processing of negative emotional stimuli are especially implicated. In this study, we used functional magnetic resonance imaging (fMRI) to investigate amygdala–PFC functional connectivity during emotional face processing in medication-naive individuals with MDD.

Methods

Individuals with MDD and healthy controls underwent fMRI scanning while processing 3 types of emotional face stimuli. We compared the strength of functional connectivity from the amygdala between the MDD and control groups.

Results

Our study included 28 individuals with MDD and 30 controls. Decreased amygdala–left rostral PFC (rPFC) functional connectivity was observed in the MDD group compared with controls for the fear condition (p < 0.05, corrected). No significant differences were found in amygdala connectivity to any cerebral regions between the MDD and control groups for the happy or neutral conditions.

Limitations

All participants with MDD were experiencing acute episodes, therefore the findings could not be generalized to the entire MDD population.

Conclusion

Medication-naive individuals with MDD showed decreased amygdala–left rPFC functional connectivity in response to negative emotional stimuli, suggesting that abnormalities in amygdala–left rPFC neural circuitry responses to negative emotional stimuli might play an important role in the pathophysiology of MDD.     

Reduced neural activity of the prefrontal cognitive control circuitry during response inhibition to negative words in people with schizophrenia

Background

Schizophrenia is characterized by deficits in executive control and impairments in emotion processing. This study assessed the nature and extent of potential alterations in the neural substrates supporting the interaction between cognitive control mechanisms and emotion attribution processes in people with schizophrenia.

Methods

Functional magnetic resonance imaging was performed during a verbal emotional go/no-go task. People with schizophrenia and healthy controls responded to word stimuli of a prespecified emotional valence (positive, negative or neutral) while inhibiting responses to stimuli of a different valence.

Results

We enrolled 20 people with schizophrenia and 23 controls in the study. Healthy controls activated an extensive dorsal prefrontal–parietal network while inhibiting responses to negative words compared to neutral words, but showed deactivation of the midcingulate cortex while inhibiting responses to positive words compared to neutral words. People with schizophrenia failed to activate this network during response inhibition to negative words, whereas during response inhibition to positive words they did not deactivate the cingulate, but showed increased responsivity in the frontal cortex.

Limitations

Sample heterogeneity is characteristic of studies of schizophrenia and may have contributed to more variable neural responses in the patient sample despite the care taken to control for potentially confounding variables.

Conclusion

Our results showed that schizophrenia is associated with aberrant modulation of neural responses during the interaction between cognitive control and emotion processing. Failure of the frontal circuitry to regulate goal-directed behaviour based on emotion attributions may contribute to deficits in psychosocial functioning in daily life.     

Elevated cognitive control over reward processing in recovered female patients with anorexia nervosa

Background

Individuals with anorexia nervosa are thought to exert excessive self-control to inhibit primary drives.

Methods

This study used functional MRI (fMRI) to interrogate interactions between the neural correlates of cognitive control and motivational processes in the brain reward system during the anticipation of monetary reward and reward-related feedback. In order to avoid confounding effects of undernutrition, we studied female participants recovered from anorexia nervosa and closely matched healthy female controls. The fMRI analysis (including node-to-node functional connectivity) followed a region of interest approach based on models of the brain reward system and cognitive control regions implicated in anorexia nervosa: the ventral striatum, medial orbitofrontal cortex (mOFC) and dorsolateral prefrontal cortex (DLPFC).

Results

We included 30 recovered patients and 30 controls in our study. There were no behavioural differences and no differences in hemodynamic responses of the ventral striatum and the mOFC in the 2 phases of the task. However, relative to controls, recovered patients showed elevated DLPFC activity during the anticipation phase, failed to deactivate this region during the feedback phase and displayed greater functional coupling between the DLPFC and mOFC. Recovered patients also had stronger associations than controls between anticipation-related DLPFC responses and instrumental responding.

Limitations

The results we obtained using monetary stimuli might not generalize to other forms of reward.

Conclusion

Unaltered neural responses in ventral limbic reward networks but increased recruitment of and connectivity with lateral–frontal brain circuitry in recovered patients suggests an elevated degree of self-regulatory processes in response to rewarding stimuli. An imbalance between brain systems subserving bottom–up and top–down processes may be a trait marker of the disorder.     

Amygdala and insula response to emotional images in patients with generalized social anxiety disorder

Background

Functional brain imaging studies have demonstrated amygdala and insula hyper-reactivity to probes of social threat in participants with generalized social anxiety disorder (gSAD). The amygdala and insula are known to serve broad functions in emotional processing, including integration of affective information. However, few studies have examined brain responses in socially anxious participants during general emotional processing. We examined brain response to emotionally evocative images in patients with gSAD and matched healthy controls.

Methods

Eleven patients with gSAD who were not taking psychotropic medications and did not have psychiatric comorbidities and 11 matched healthy controls underwent functional magnetic resonance imaging while viewing blocks of emotionally salient (positive, negative, neutral) pictures.

Results

Participants with gSAD exhibited enhanced bilateral amygdala and insula reactivity to negative (v. neutral) images compared with healthy controls who did not exhibit enhanced reactivity. Within the gSAD group, the extent of amygdala activation was correlated with social anxiety severity, whereas the extent of insula activation was correlated with trait anxiety.

Limitations

The small sample size may have limited our ability to detect group differences in other relevant brain regions and in behavioural measures.

Conclusion

In addition to prior findings of probes of social information processing, our findings suggest that the amygdala and insula responses are hyper-reactive to general emotional images with negative emotional content and that these brain regions may play divergent roles in their representation of different phenotypes.     

Cognitive behavioural therapy attenuates the enhanced early facial stimuli processing in social anxiety disorders: an ERP investigation

Background

Previous studies of patients with social anxiety have demonstrated abnormal early processing of facial stimuli in social contexts. In other words, patients with social anxiety disorder (SAD) tend to exhibit enhanced early facial processing when compared to healthy controls. Few studies have examined the temporal electrophysiological event-related potential (ERP)-indexed profiles when an individual with SAD compares faces to objects in SAD. Systematic comparisons of ERPs to facial/object stimuli before and after therapy are also lacking. We used a passive visual detection paradigm with upright and inverted faces/objects, which are known to elicit early P1 and N170 components, to study abnormal early face processing and subsequent improvements in this measure in patients with SAD.

Methods

Seventeen patients with SAD and 17 matched control participants performed a passive visual detection paradigm task while undergoing EEG. The healthy controls were compared to patients with SAD pre-therapy to test the hypothesis that patients with SAD have early hypervigilance to facial cues. We compared patients with SAD before and after therapy to test the hypothesis that the early hypervigilance to facial cues in patients with SAD can be alleviated.

Results

Compared to healthy control (HC) participants, patients with SAD had more robust P1–N170 slope but no amplitude effects in response to both upright and inverted faces and objects. Interestingly, we found that patients with SAD had reduced P1 responses to all objects and faces after therapy, but had selectively reduced N170 responses to faces, and especially inverted faces. Interestingly, the slope from P1 to N170 in patients with SAD was flatter post-therapy than pre-therapy. Furthermore, the amplitude of N170 evoked by the facial stimuli was correlated with scores on the interaction anxiousness scale (IAS) after therapy.

Conclusions

Our results did not provide electrophysiological support for the early hypervigilance hypothesis in SAD to faces, but confirm that cognitive-behavioural therapy can reduce the early visual processing of faces. These findings have potentially important therapeutic implications in the assessment and treatment of social anxiety. Trial registration HEBDQ2014021

     

Genotype over-diagnosis in amygdala responsiveness: affective processing in social anxiety disorder

Background

Although the amygdala is thought to be a crucial brain region for negative affect, neuroimaging studies do not always show enhanced amygdala response to aversive stimuli in patients with anxiety disorders. Serotonin (5-HT)–related genotypes may contribute to interindividual variability in amygdala responsiveness. The short (s) allele of the 5-HT transporter linked polymorphic region (5-HTTLPR) and the T variant of the G-703T polymorphism in the tryptophan hydroxylase-2 (TPH2) gene have previously been associated with amygdala hyperresponsivity to negative faces in healthy controls. We investigated the influence of these polymorphisms on amygdala responsiveness to angry faces in patients with social anxiety disorder (SAD) compared with healthy controls.

Methods

We used positron emission tomography with oxygen 15-labelled water to assess regional cerebral blood flow in 34 patients with SAD and 18 controls who viewed photographs of angry and neutral faces presented in counterbalanced order. We genotyped all participants with respect to the 5-HTTLPR and TPH2 polymorphisms.

Results

Patients with SAD and controls had increased left amygdala activation in response to angry compared with neutral faces. Genotype but not diagnosis explained a significant portion of the variance in amygdala responsiveness, the response being more pronounced in carriers of s and/or T alleles.

Limitations

Our analyses were limited owing to the small sample and the fact that we were unable to match participants on genotype before enrolment. In addition, other imaging techniques not used in our study may have revealed additional effects of emotional stimuli.

Conclusion

Amygdala responsiveness to angry faces was more strongly related to serotonergic polymorphisms than to diagnosis of SAD. Emotion activation studies comparing amygdala excitability in patient and control groups could benefit from taking variation in 5-HT–related genes into account.     

Impact of acute administration of escitalopram on the processing of emotional and neutral images: a randomized crossover fMRI study of healthy women

Background

Acute neural effects of antidepressant medication on emotion processing biases may provide the foundation on which clinical outcomes are based. Along with effects on positive and negative stimuli, acute effects on neutral stimuli may also relate to anti-depressant efficacy, yet these effects are still to be investigated. The present study therefore examined the impact of a single dose of the selective serotonin reuptake inhibitor escitalopram (20 mg) on positive, negative and neutral stimuli using pharmaco-fMRI.

Methods

Within a double-blind, randomized, placebo-controlled crossover design, healthy women completed 2 sessions of treatment administration and fMRI scanning separated by a 1-week washout period.

Results

We enrolled 36 women in our study. When participants were administered escitalopram relative to placebo, left amygdala activity was increased and right inferior frontal gyrus (IFG) activity was decreased during presentation of positive pictures (potentiation of positive emotion processing). In contrast, escitalopram was associated with decreased left amygdala and increased right IFG activity during presentation of negative pictures (attenuation of negative emotion processing). In addition, escitalopram decreased right IFG activity during the processing of neutral stimuli, akin to the effects on positive stimuli (decrease in negative appraisal).

Limitations

Although we used a women-only sample to reduce heterogeneity, our results may not generalize to men. Potential unblinding, which was related to the subjective occurrence of side effects, occurred in the study; however, manipulation check analyses demonstrated that results were not impacted.

Conclusion

These novel findings demonstrate that a single dose of the commonly prescribed escitalopram facilitates a positive information processing bias. These findings provide an important lead for better understanding effects of antidepressant medication.     

Intranasal Oxytocin Lessens the Attentional Bias to Adult Negative Faces: A Double Blind within-Subject Experiment

Objective

Oxytocin is a neuropeptide that is involved in social emotional processing. A leading hypothesis is that oxytocin facilitates positive prosocial behaviors; the peptide may also play a more general role in inhibiting withdrawal-related social behaviors. The present study examined these possibilities.

Methods

A double-blind, placebo controlled crossover design was used with 31 healthy women. Forty-five minutes following the administration of 40 IU of intranasal oxytocin or a placebo, the participants were presented with two dot probe tests with pairs of face stimuli depicting emotional and neutral faces in adults.

Results

Oxytocin specifically reduced the attention bias toward the location of the faces of adults showing negative emotions, particularly in the case of disgust. Oxytocin did not enhance the attentional bias toward adult happy faces. The effect of oxytocin toward adult negative emotion was correlated with the sensitivity of the drive in the behavioral motivational system.

Conclusion

Oxytocin reduces attention to negative social emotions in adults, which supports oxytocin serves to inhibit withdrawal-related social behaviour.     

Decreased cognitive control in response to negative information in patients with remitted depression: an event-related potential study

Background

Major depressive disorder (MDD) is associated with difficulty disengaging attention from emotionally negative information. Few studies have investigated whether euthymic individuals with a history of depression (remitted MDD [rMDD]) show similar deficits, and little is known about concomitant neurophysiological features of such deficits. To fill these gaps, we investigated cognitive control over emotional stimuli in participants with rMDD and controls without history of depression or psychopathology.

Methods

We collected 128-channel event-related potentials (ERPs) while participants performed a cued emotional conflict task. During the task, a cue instructed the participant to respond to the actual or opposite valence of an upcoming happy or sad face.

Results

We enrolled 15 individuals with rMDD and 18 controls in our study. Event-related potentials showed no group differences in response to the cues, highlighting preserved preparatory processes when anticipating an emotional conflict. However, relative to the control group, the rMDD group responded more slowly and showed reduced N450 amplitudes on trials that required disengaging from negative faces (pressing “happy” in response to a sad face).

Limitations

The sample size was small, and the null finding in the cue-locked N2 analyses may be owing to low power.

Conclusion

Our results suggest a selective deficit in cognitive control over sad stimuli in individuals with rMDD. Additional studies will be required to pinpoint whether the current findings stem from impairments in response conflict, conflict monitoring and/or attentional disengagement in response to sad stimuli. Moreover, future studies are warranted to evaluate whether decreased cognitive control in response to negative information might increase the risk for future depressive episodes.     

Smooth Pursuit Eye Movement,Prepulse Inhibition,and Auditory Paired Stimuli Processing Endophenotypes Across the Schizophrenia-Bipolar Disorder Psychosis Dimension

Background:

This study examined smooth pursuit eye movement (SPEM), prepulse inhibition (PPI), and auditory event-related potentials (ERP) to paired stimuli as putative endophenotypes of psychosis across the schizophrenia-bipolar disorder dimension.

Methods:

Sixty-four schizophrenia probands (SZP), 40 psychotic bipolar I disorder probands (BDP), 31 relatives of SZP (SZR), 26 relatives of BDP (BDR), and 53 healthy controls (HC) were tested. Standard clinical characterization, SPEM, PPI, and ERP measures were administered.

Results:

There were no differences between either SZP and BDP or SZR and BDR on any of the SPEM, PPI, or ERP measure. Compared with HC, SZP and BDP had lower SPEM maintenance and predictive pursuit gain and ERP theta/alpha and beta magnitudes to the initial stimulus. PPI did not differ between the psychosis probands and HC. Compared with HC, SZR and BDR had lower predictive pursuit gain and ERP theta/alpha and beta magnitudes to the first stimulus with differences ranging from a significant to a trend level. Neither active symptoms severity nor concomitant medications were associated with neurophysiological outcomes. SPEM, PPI, and ERP scores had low intercorrelations.

Conclusion:

These findings support SPEM predictive pursuit and lower frequency auditory ERP activity in a paired stimuli paradigm as putative endophenotypes of psychosis common to SZ and BD probands and relatives. PPI did not differ between the psychosis probands and HC. Future studies in larger scale psychosis family samples targeting putative psychosis endophenotypes and underlying molecular and genetic mediators may aid in the development of biology-based diagnostic definitions.Key words: psychosis, schizophrenia, bipolar disorder, smooth pursuit eye movement, prepulse inhibition, auditory ERP     

Have we met before? Neural correlates of emotional learning in women with social phobia

Background

Altered memory processes are thought to be a key mechanism in the etiology of anxiety disorders, but little is known about the neural correlates of fear learning and memory biases in patients with social phobia. The present study therefore examined whether patients with social phobia exhibit different patterns of neural activation when confronted with recently acquired emotional stimuli.

Methods

Patients with social phobia and a group of healthy controls learned to associate pseudonames with pictures of persons displaying either a fearful or a neutral expression. The next day, participants read the pseudonames in the magnetic resonance imaging scanner. Afterwards, 2 memory tests were carried out.

Results

We enrolled 21 patients and 21 controls in our study. There were no group differences for learning performance, and results of the memory tests were mixed. On a neural level, patients showed weaker amygdala activation than controls for the contrast of names previously associated with fearful versus neutral faces. Social phobia severity was negatively related to amygdala activation. Moreover, a detailed psychophysiological interaction analysis revealed an inverse correlation between disorder severity and frontolimbic connectivity for the emotional > neutral pseudonames contrast.

Limitations

Our sample included only women.

Conclusion

Our results support the theory of a disturbed corticolimbic interplay, even for recently learned emotional stimuli. We discuss the findings with regard to the vigilance–avoidance theory and contrast them to results indicating an oversensitive limbic system in patients with social phobia.     

Behavioural and neural correlates of self-focused emotion regulation in social anxiety disorder

Background

In healthy individuals, voluntary modification of self-relevance has proven effective in regulating subjective emotional experience as well as physiologic responses evoked by emotive stimuli. As social anxiety disorder (SAD) is characterized by both altered emotional and self-related processing, we tested if emotion regulation through self-focused reappraisal is effective in individuals with SAD.

Methods

While undergoing 3 T functional magnetic resonance imaging, individuals with SAD and matched healthy controls either passively viewed neutral and aversive pictures or actively increased or decreased their negative emotional experience through the modification of self-relevance or personal distance to aversive pictures. Participants rated all pictures with regard to the intensity of elicited emotions and self-relatedness.

Results

We included 21 individuals with SAD and 23 controls in our study. Individuals with SAD reported significantly stronger emotional intensity across conditions and showed a nonsignificant tendency to judge pictures as more self-related than controls. Compared with controls, individuals with SAD showed an overactivation in bilateral temporoparietal regions and in the posterior midcingulate cortex during the passive viewing of aversive compared with neutral pictures. During instructed emotion regulation, activation patterns normalized and no significant group differences were detected.

Limitations

As no positive pictures were presented, results might be limited to the regulation of negative emotion.

Conclusion

During passive viewing of aversive images, individuals with SAD showed evidence of neural hyperreactivity that may be interpreted as increased bodily self-consciousness and heightened perspective-taking. During voluntary increase and decrease of negative emotional intensity, group differences disappeared, suggesting self-focused reappraisal as a successful emotion regulation strategy for individuals with SAD.     

Systematic review of ERP and fMRI studies investigating inhibitory control and error processing in people with substance dependence and behavioural addictions

Background

Several current theories emphasize the role of cognitive control in addiction. The present review evaluates neural deficits in the domains of inhibitory control and error processing in individuals with substance dependence and in those showing excessive addiction-like behaviours. The combined evaluation of event-related potential (ERP) and functional magnetic resonance imaging (fMRI) findings in the present review offers unique information on neural deficits in addicted individuals.

Methods

We selected 19 ERP and 22 fMRI studies using stop-signal, go/no-go or Flanker paradigms based on a search of PubMed and Embase.

Results

The most consistent findings in addicted individuals relative to healthy controls were lower N2, error-related negativity and error positivity amplitudes as well as hypoactivation in the anterior cingulate cortex (ACC), inferior frontal gyrus and dorsolateral prefrontal cortex. These neural deficits, however, were not always associated with impaired task performance. With regard to behavioural addictions, some evidence has been found for similar neural deficits; however, studies are scarce and results are not yet conclusive. Differences among the major classes of substances of abuse were identified and involve stronger neural responses to errors in individuals with alcohol dependence versus weaker neural responses to errors in other substance-dependent populations.

Limitations

Task design and analysis techniques vary across studies, thereby reducing comparability among studies and the potential of clinical use of these measures.

Conclusion

Current addiction theories were supported by identifying consistent abnormalities in prefrontal brain function in individuals with addiction. An integrative model is proposed, suggesting that neural deficits in the dorsal ACC may constitute a hallmark neurocognitive deficit underlying addictive behaviours, such as loss of control.     

Atypical vertical sound localization and sound-onset sensitivity in people with autism spectrum disorders

Background

Autism spectrum disorders (ASDs) are associated with auditory hyper- or hyposensitivity; atypicalities in central auditory processes, such as speech-processing and selective auditory attention; and neural connectivity deficits. We sought to investigate whether the low-level integrative processes underlying sound localization and spatial discrimination are affected in ASDs.

Methods

We performed 3 behavioural experiments to probe different connecting neural pathways: 1) horizontal and vertical localization of auditory stimuli in a noisy background, 2) vertical localization of repetitive frequency sweeps and 3) discrimination of horizontally separated sound stimuli with a short onset difference (precedence effect).

Results

Ten adult participants with ASDs and 10 healthy control listeners participated in experiments 1 and 3; sample sizes for experiment 2 were 18 adults with ASDs and 19 controls. Horizontal localization was unaffected, but vertical localization performance was significantly worse in participants with ASDs. The temporal window for the precedence effect was shorter in participants with ASDs than in controls.

Limitations

The study was performed with adult participants and hence does not provide insight into the developmental aspects of auditory processing in individuals with ASDs.

Conclusion

Changes in low-level auditory processing could underlie degraded performance in vertical localization, which would be in agreement with recently reported changes in the neuroanatomy of the auditory brainstem in individuals with ASDs. The results are further discussed in the context of theories about abnormal brain connectivity in individuals with ASDs.     

Deficits in facial emotion recognition in schizophrenia: a replication study with korean subjects

Objective

We investigated the deficit in the recognition of facial emotions in a sample of medicated, stable Korean patients with schizophrenia using Korean facial emotion pictures and examined whether the possible impairments would corroborate previous findings.

Methods

Fifty-five patients with schizophrenia and 62 healthy control subjects completed the Facial Affect Identification Test with a new set of 44 colored photographs of Korean faces including the six universal emotions as well as neutral faces.

Results

Korean patients with schizophrenia showed impairments in the recognition of sad, fearful, and angry faces [F(1,114)=6.26, p=0.014; F(1,114)=6.18, p=0.014; F(1,114)=9.28, p=0.003, respectively], but their accuracy was no different from that of controls in the recognition of happy emotions. Higher total and three subscale scores of the Positive and Negative Syndrome Scale (PANSS) correlated with worse performance on both angry and neutral faces. Correct responses on happy stimuli were negatively correlated with negative symptom scores of the PANSS. Patients with schizophrenia also exhibited different patterns of misidentification relative to normal controls.

Conclusion

These findings were consistent with previous studies carried out with different ethnic groups, suggesting cross-cultural similarities in facial recognition impairment in schizophrenia.     

Facial Emotion Recognition in Schizophrenia: The Impact of Gender

Objective

Previous studies reported gender differences for facial emotion recognition in healthy people, with women performing better than men. Few studies that examined gender differences for facial emotion recognition in schizophrenia brought out inconsistent findings. The aim of this study is to investigate gender differences for facial emotion identification and discrimination abilities in patients with schizophrenia.

Methods

35 female and 35 male patients with schizophrenia, along with 35 female and 35 male healthy controls were included in the study. All the subjects were evaluated with Facial Emotion Identification Test (FEIT), Facial Emotion Discrimination Test (FEDT), and Benton Facial Recognition Test (BFRT). Patients'' psychopathological symptoms were rated by means of the Positive and Negative Syndrome Scale (PANSS).

Results

Male patients performed significantly worse than female patients on FEIT total, and negative scores. Male controls performed significantly worse than female controls on FEIT total and negative scores. On all tasks, female patients performed comparable with controls. Male patients performed significantly worse than controls on FEIT, and FEDT.

Conclusion

Women with schizophrenia outperformed men for facial emotion recognition ability in a pattern that is similar with the healthy controls. It could be claimed that male patients with schizophrenia need special consideration for emotion perception deficits.     

High-frequency repetitive transcranial magnetic stimulation to the cerebellum and implicit processing of happy facial expressions

Background

Previous research has demonstrated that the cerebellum is involved in emotive and cognitive processes. Furthermore, recent findings suggest high-frequency repetitive transcranial magnetic stimulation (rTMS) to the cerebellum has mood-improving properties. We sought to further explore the effects of cerebellar high-frequency rTMS on implicit processing of emotional stimuli and mood.

Methods

In a double-blind, crossover study, 15 healthy volunteers received 15 minutes of 20 Hz (5 s on, 5 s off) rTMS over the medial cerebellum, occipital cortex or sham in a randomized counterbalanced order on 3 consecutive days. A masked emotional faces response task measured implicit emotional processing of happy, fearful and neutral facial expressions. We used positive and negative affect scales to evaluate rTMS-related changes in mood.

Results

High-frequency rTMS over the cerebellum was associated with significant increases in masked emotional responses to happy facial expressions only. We observed no changes in consciously experienced mood.

Limitations

Although the sham rTMS served as our baseline measurement, additional pre-rTMS data showing that reaction time increases immediately after cerebellar rTMS would have made our results more compelling.

Conclusion

The results replicate and extend previous findings by establishing a direct relation between the cerebellum and emotive information-processing. The parallel between the present effects of high-frequency cerebellar rTMS and short-term antidepressant therapy regarding the change in implicit processing of positive stimuli in the absence of mood changes is notable and warrants further research.