Memory bias for threat in generalized anxiety disorder: the potential importance of stimulus relevance

Information processing models propose that anxious individuals are characterized by memory biases for mood-congruent threat information. However, evidence for memory biases in generalized anxiety disorder (GAD) has been mixed at best. Given the heterogeneity of concerns in GAD, previous use of nomothetic stimulus sets may have precluded detection of memory biases. Therefore, in order to guarantee the relevance of the stimuli used, in the current study individuals with GAD each individually selected words that were of personal relevance to them. Using these idiographically selected words with 23 individuals with DSM-IV GAD and 23 non-anxious controls (NACs), results showed an implicit memory bias for threat words in individuals with GAD compared with NACs. Furthermore, there was additional evidence that individuals with GAD may also be characterized by explicit memory bias for threat words. The magnitude of group differences for explicit recall of threat words was similar to those previously observed in panic disorder. Limitations and future directions are discussed.     

Social anxiety and interpretation biases for facial displays of emotion: emotion detection and ratings of social cost

The current study assessed the processing of facial displays of emotion (Happy, Disgust, and Neutral) of varying emotional intensities in participants with high vs. low social anxiety. Use of facial expressions of varying intensities allowed for strong external validity and a fine-grained analysis of interpretation biases. Sensitivity to perceiving negative evaluation in faces (i.e., emotion detection) was assessed at both long (unlimited) and brief (60 ms) stimulus durations. In addition, ratings of perceived social cost were made indicating what participants judged it would be like to have a social interaction with a person exhibiting the stimulus emotion. Results suggest that high social anxiety participants did not demonstrate biases in their sensitivity to perceiving negative evaluation (i.e. disgust) in facial expressions. However, high social anxiety participants did estimate the perceived cost of interacting with someone showing disgust to be significantly greater than low social anxiety participants, regardless of the intensity of the disgust expression. These results are consistent with a specific type of interpretation bias in which participants with social anxiety have elevated ratings of the social cost of interacting with individuals displaying negative evaluation.     

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     

Functional Neuroimaging in the Examination of Effects of Prenatal Alcohol Exposure

Functional neuroimaging offers the opportunity to understand the effect of prenatal alcohol exposure on the activities of the brain as well as providing a window into the relationship between neural activation and the behavioral outcomes that have been described in affected individuals. Several different methodologies have been used to examine the neurophysiological signal changes associated with different brain functions in prenatally exposed individuals and those diagnosed with fetal alcohol syndrome (FAS) or other fetal alcohol spectrum disorders (FASD). These include electroencephalography (EEG), positron emission tomography (PET), single-photon emission computed tomography (SPECT), and functional magnetic resonance imaging (fMRI). These studies demonstrate that it is feasible to use these technologies with this clinical population and that the damage to the central nervous system associated with prenatal alcohol exposure has widespread functional implications; however, currently, the literature in these areas is limited and unsystematic. Functional MRI with this clinical population has just begun to explore the implications of prenatal alcohol exposure with the first paper published in 2005. Other methodologies are similarly limited in scope. Nonetheless, these functional neuroimaging studies suggest that prenatal alcohol exposure, or a diagnosis of FAS, may lead to restrictions in neural efficiency or a global decrement in processing resources.     

Serotonin Transporter Genotype Moderates the Link Between Children’s Reports of Overprotective Parenting and Their Behavioral Inhibition

The goal of the current study was to examine environmental and genetic correlates of children’s levels of behavioral inhibition (BI). Participants were 100 mother child pairs drawn from the community who were part of a larger study of the intergenerational transmission of depression. Results indicated that higher levels of maternal overprotection, as reported by the child, were associated with elevations in BI among children carrying two copies of the lower expressing 5-HTTLPR alleles (S or L_G), but not among those carrying only one copy or those homozygous for the L_A allele. In addition, this interaction was specific for the social component of BI, not the nonsocial component. This relation was maintained even after statistically controlling for children’s and mother’s psychopathology. Together, these findings add to emerging research demonstrating that G × E interactions predict variation in BI during childhood.     

In search of the point of no return: the control of response processes

Control processes underlying response inhibition were examined. Six Ss performed a visual choice reaction task and were occasionally presented with a tone that told them to withhold the response. Reaction time results were in agreement with a model that assumes a race between response activation and response inhibition processes. Event-related brain potentials, electromyogram, and continuous response measures showed that responses could be interrupted at any time. Evidence was obtained for two inhibitory mechanisms: inhibition of central activation processes and inhibition of transmission of motor commands from central to peripheral structures. Results have implications for the distinction between controlled and ballistic processes.     

Pre- and poststimulus activation of response channels: a psychophysiological analysis

To examine mechanisms of response activation, we asked subjects to respond differentially to the central letter of one of four arrays--HHHHH, SSHSS, SSSSS, and HHSHH--and measured event-related brain potentials (ERPs) and electromyographic activity (EMG). For very fast responses, accuracy was at chance level for all arrays, suggesting that subjects were guessing. For intermediate latency responses, accuracy was above chance if the noise was compatible with the targets and below chance if it was incompatible, suggesting that these responses were based on partial stimulus analysis. For slow responses, accuracy was above chance for all arrays, suggesting that these responses were based on complete stimulus analysis. The occurrence and accuracy of fast responses could be predicted by examining motor potentials preceding the presentation of the array. Measures of the motor potentials in the period following the presentation of the array suggested that partial analysis of stimulus information could activate responses and that the level of response activation at the time of the EMG response was constant for trials with different response latencies. The data are discussed in terms of a response channel conception.