Hemisphere asymmetry and the processing of emotional words in anxiety

Anxiety and Depression in Patients with Intracranial Arachnoid Cysts-A Prospective Study

BACKGROUND

Arachnoid cysts yield cognitive deficits that are normalized after surgical cyst decompression.

OBJECTIVE

The present study aimed to investigate whether arachnoid cysts also affect symptoms of anxiety and depression, and if surgical cyst decompression leads to reduction of these symptoms.

METHODS

Twenty-two adult patients (13 men and 9 women) with symptomatic temporal or frontal cysts were included in this questionnaire (Hospital Anxiety and Depression Scale [HADS])-based prospective study. The mean time between answering the preoperative questionnaire and surgery was 37 days. The patients answered the same HADS questionnaire 3-6 months postoperatively.

RESULTS

Preoperatively, both patients with frontal (N = 4) and patients with temporal (N = 18) cyst had higher mean HADS anxiety scores than those found in the general population. For patients with temporal cyst, there was a significant or near-significant difference in anxiety and depression scores and the combined scores between those with right-sided cysts and those with left-sided cysts. Postoperatively, the HADS scores normalized and were no longer different from those of the general population. The difference in scores between patients with right and left temporal cyst also disappeared.

CONCLUSIONS

Patients with arachnoid cyst have higher levels of anxiety and depression than do the general population and these scores were normalized after decompressive cyst surgery. We further found a hemispheric asymmetry: patients with a right temporal cyst showed higher anxiety, depression, and combined scores than did patients with a left temporal cyst. Also, this disparity normalized after cyst decompression. Thus, arachnoid cysts seem to affect not only cognition but also the level of affective symptoms.

Positive schizotypy scores correlate with left visual field interference for negatively valenced emotional words: A lateralized emotional Stroop study

Fourteen men scoring high and 14 men scoring low on a positive schizotypy scale participated in a lateralized emotional Stroop task. Vocal reaction times for color naming of neutral, positive and negative emotional words were recorded. Across participants, the color naming of neutral and emotional words was slightly faster to right than to left visual field presentations. In men with high scores on positive schizotypy, the presentation of negative words to the left visual field (right hemisphere) resulted in significant affective interference with color naming, which was significantly larger than in men with low scores. Correlational analysis also showed that positive schizotypy was significantly associated with emotional interference in response to LVF negative words. The outcome is discussed in terms of right hemispheric engagement in negative emotions in high positive schizotypic men.

The Lateralized Emotional Stroop Task: Left Visual Field Interference in Women

In a visual hemifield emotional Stroop task, 54 women were asked to name the color of laterally flashed emotional and neutral words while ignoring their semantic content. Vocal reaction times for color naming were recorded. The participants exhibited significant emotional interference effects in the left visual field, which tended to be larger for negative words than for positive words. Participants with higher trait anxiety scores exhibited larger interference for positive words in the left relative to the right visual field. The outcome indicates that, in women, emotional Stroop interference arises in the right rather than in the left hemisphere, with a larger impact of negative than of positive words, and with trait anxiety modulating the lateralized interference for positive words.

Dissociating prelexical and postlexical processing of affective information in the two hemispheres: effects of the stimulus presentation format

Using a lexical decision task, the authors investigated whether brain asymmetries in the detection of emotionally negative semantic associations arise only at a perceptually discriminative stage at which lexical analysis is accurate or can already be found at crude and incomplete levels of perceptual representation at which word-nonword discrimination is based solely on guessing. Emotionally negative and neutral items were presented near perceptual threshold in the left and right visual hemifields. Word-nonword discrimination performance as well as the bias to classify a stimulus as a "word" (whether or not it actually is a word) were assessed for a normal, horizontal stimulus presentation format (Experiment 1) and for an unusual, vertical presentation format (Experiment 2). Results show that while the two hemispheres are equally able to detect affective semantic associations at a prelexical processing stage (both experiments), the right hemisphere is superior at a postlexical, perceptually discriminative stage (Experiment 2). Moreover, the findings suggest that only an unusual, nonoverlearned stimulus presentation format allows adequate assessment of the right hemisphere's lexical-semantic skills.

Source localization of EEG activity during hypnotically induced anxiety and relaxation

The engagement of different brain regions which implement subjectively experienced emotional states in normals is not completely clarified. Emotional states can conveniently be induced by hypnosis-based suggestions. We studied brain electric activity during hypnotically induced anxiety and relaxation in 11 right-handed normals (5 males, 6 females, mean age 26.5+/-7.6 years). After induction of light hypnosis, anxiety and then relaxation was suggested using a standardized text (reverse sequence in half of the subjects). Nineteen-channel, eyes-closed EEG (20 artifact-free s/subject) was analyzed (source localization using FFT approximation and low resolution electromagnetic tomography, LORETA). Global tests revealed the strongest difference (P<0.005) between EEG source gravity center locations during the two emotional states in the excitatory beta-2 EEG frequency band (18.5-21 Hz). Post hoc tests showed that the sources were located more right during anxiety than during relaxation (P=0.01). LORETA specified that anxiety showed maximally stronger activity than relaxation in right Brodmann area 10, and relaxation showed maximally stronger activity than anxiety in left Brodmann area 22. Clearly, the two induced emotional states were associated with activity of different neural populations. Our results agree with reports on brain activity shifted to the right (especially fronto-temporal) during negative compared with positive emotions, and support the role of beta-2 EEG frequency in emotional states.

Quality of life self-assessment as a function of lateralization of lesion in candidates for epilepsy surgery

PURPOSE

This prospective study aimed to investigate the relationship(s) of the laterality of the epileptogenic lesion to personality factors, emotional processing, and the subjective experience of quality-of-life (QOL) self-assessment in candidates for epilepsy surgery.

METHODS

Patients who were candidates for epilepsy surgery were studied. Eighteen of them (aged 19-61 years) had localization-related epilepsy in the right temporal lobe (RTLE), 18 (aged 21-50 years) had localization-related epilepsy in the left temporal lobe (LTLE), and 20 were demographically matched normal subjects. The Spielberger Trait/State Anxiety questionnaire and the QOLIE-31 questionnaire for self-assessment of quality of life were used. One-way analysis of variance, Pearson correlations, and linear regression analyses were performed on group and anxiety levels and QOLIE variables.

RESULTS

LTLE patients systematically showed higher levels of anxiety and lower self-estimates of the quality of their lives when compared with RTLE patients. All anxiety measures were highly correlated with Total QOL in LTLE (p < 0.05) but not in RTLE patients; however, different parameters of QOL showed different relationships with measures of anxiety. Results of multiple regression analyses suggested that the level of anxiety was relatively stable and less affected by QOL factors in LTLE as compared with RTLE patients (p = 0.03).

CONCLUSIONS

A high level of anxiety shown by LTLE patients may represent a personality trait and cause a response bias in overreporting of negative symptoms and a decreased self-assessment of QOL. It may also present a presurgical risk factor, particularly for patients with LTLE lesions. Appropriate patient counseling is advised.

Activation of left posterior cingulate gyrus by the auditory presentation of threat-related words: an fMRI study

This study investigated the cortical response to hearing threat-related and neutral words using functional magnetic resonance imaging (fMRI) in 16 coronal planes. Right-handed volunteers listened to (i) neutral words alternating with no words as the control condition, and (ii) neutral words alternating with threat-related words as the experimental condition. Threat-related words compared to neutral words activated left posterior cingulate gyrus in eight of 10 subjects with activation most prominent in the retrosplenial region. Patterns of activation produced by neutral words compared to no words included bilateral temporal and frontal regions but not posterior cingulate. The retrosplenial cingulate region has recently been implicated in episodic memory processes. We discuss the possible role of the posterior cingulate cortex in processes involving emotion and memory and in anxiety disorders.

Pre- and post-stimulus processes in affective task and event-related desynchronization (ERD): do they discriminate anxiety coping styles?

The present investigation was designed to study whether pre-stimulus (as measured by EEG power in the time interval before the stimulus presentation) and post-stimulus (as measured by event-related desynchronization (ERD)) processes of alpha components in two frequency bands (8-10 and 10-12 Hz) and their scalp distribution discriminate among anxiety coping styles in an affective task. We investigated this question by using a sample of 30 college students who were split into three groups consisting of 10 low-anxious (LA) and 10 high-anxious (HA) subjects, and 10 repressors (RE). In the present study, positive and negative emotions were operationalized by winning and losing certain amounts of money in gambling situation while measuring ERD to positive and negative feedback stimuli. The main findings of the prestimulus data analyses suggest that the prestimulus level of alpha power is sensitive to the anxiety coping styles. In terms of ERD effects, HA individuals were marked by relatively larger left-hemisphere activation compared to low-anxious subjects and repressors. Further, in contrast to LA and RE, the phenomena observed in our experiment of increased and extended ERD over time in HA in response to negative feedback stimulation implies that threatening information (loss of money) is more persistently activated in subjects with high anxiety. Although preliminary, the reported findings are of potential importance because they could lead to the development of a new psychophysiological measure of relevance to personality.