Perceptual asymmetry differences between major depression with or without a comorbid anxiety disorder: A dichotic listening study.

Predictions that anxious and nonanxious depression would differ in perceptual asymmetry (PA), as well as in sensitivity for perceiving emotional words, were evaluated using dichotic listening tasks. A total of 149 patients having a major depressive disorder (51 with and 98 without an anxiety disorder) and 57 healthy controls were tested on fused-word and complex tone tasks. The anxious and nonanxious depression groups showed a consistent difference in PA across tasks; that is, the anxious group had a larger left-ear advantage for tones and a smaller right-ear advantage for words when compared with the nonanxious group. There was no group difference in sensitivity for perceiving emotional words. Patients having an anxious depression appear to have a greater propensity to activate right than left-hemisphere regions during auditory tasks, whereas those having a nonanxious depression have the opposite hemispheric asymmetry. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Explicit and implicit memory bias in panic disorder with agoraphobia

Thirty patients with a diagnosis of panic disorder with agoraphobia and 30 normal controls were compared on explicit memory (cued recall) and implicit memory (word stem completion) for positive, neutral, social threat, and physical threat words. The panic patients showed an explicit memory bias, but no implicit memory bias, for physical threat words. The index of explicit memory bias for physical threat words was found to correlate with anxiety sensitivity and degree of agoraphobic fear and avoidance. The index of baseline bias for threat words on the word completion task, on the other hand, correlated with trait anxiety. Although there were no correlations between explicit and implicit memory bias for physical threat words, explicit memory bias for physical threat words correlated with explicit memory bias indexes for positive words and social threat words. The results are discussed in terms of the functional role of an explicit memory bias for physically threatening events in panic disorder. The negative results on implicit memory bias are discussed in relation to earlier studies, the use of different implicit memory tasks, and the role of baseline bias on implicit memory tasks. Finally, the hypothesis is suggested that explicit and implicit memory bias for emotional information may represent two different styles of information processing, which serve as vulnerability factors for different emotional disorders.     

Cognitive Processing of Emotional Information in Depression, Panic, and Somatoform Disorder.

Emotional Stroop tasks (subliminal/supraliminal exposures), implicit memory tasks (tachistoscopic word identification), and explicit memory tasks (free recall after incidental learning) with 4 word types (physical threat, positive, negative, and neutral words) were administered to patients with major depressive disorder (n = 30), panic disorder (n = 33), somatoform disorder (n = 25), and healthy control participants (n = 33). On the Stroop task, panic patients showed subliminal interferences for physical threat and negative words, depressive patients showed supraliminal interferences for negative words, and somatoform patients showed supraliminal interferences for physical threat words. No patient groups demonstrated implicit memory biases. On the explicit memory task, depressive and panic patients showed memory biases for negative words; somatoform patients showed biases for physical threat words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in perceptual asymmetries with clinical improvement of depression and schizophrenia.

16 depressed patients, 16 schizophrenic patients, and 16 normal controls (20–50 yrs old) were given 2 dichotic listening tests and 2 cognitive tests at intervals ranging from patients' initial hospitalization to recovery. Repeated-measures ANOVA revealed that severely depressed Ss failed to obtain normal ear-superiority in either dichotic test; however, normal superiorities emerged with recovery from depression. Schizophrenic Ss initially failed to show normal right-ear superiority on a dichotic-words test but did obtain the expected left-ear advantage on a dichotic-chords test. Following treatment, schizophrenics shifted from a left-ear to a right-ear advantage in dichotic chords and also increased (although not significantly) their right-ear advantage in dichotic words. Both patient groups showed normal word-fluency but impaired spatial ability, which did not improve with recovery. Results suggest that both depression and schizophrenia are associated with a breakdown in the process of interhemispheric inhibition that mediates perceptual asymmetry. In depression, treatment returned Ss' normal patterns of asymmetry, whereas in schizophrenia, treatment created an abnormal pattern of asymmetry that may have reflected the allocation of both verbal and nonverbal material to the left hemisphere. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual asymmetry in psychosis-prone college students: Evidence for left-hemisphere overactivation.

The hypothesis that psychosis-prone students demonstrate a pattern of exaggerated perceptual asymmetry across both left- and right-hemisphere dichotic-listening tasks (consonant-vowel [CV] and tonal contour discrimination) was investigated. Ss who scored high on the Perceptual Aberration or Magical Ideation scale or both (n?=?20) demonstrated a significantly exaggerated right-ear advantage on a CV task in relation to normal control Ss (n?=?27) but showed a reduced left-ear advantage on a tone task. The hypothesis of exaggerated functional lateralization across hemispheres in the psychosis-prone Ss was not supported, but the results are consistent with a hypothesis of left hemisphere overactivation in this sample. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of stress and anxiety on the processing of threat stimuli.

Two experiments extended the work of C. MacLeod and A. Mathews (see record 1989-23867-001) and examined whether a cognitive bias for threat information is a function of state or trait anxiety. Color-naming and attention deployment tasks were used to assess the effects of a stress manipulation procedure on attentional responses in high and low trait anxious Ss. Ss under high stress selectively allocated processing resources toward threat stimuli, irrespective of their trait anxiety level. There was no consistent evidence of a cognitive bias associated with trait anxiety, and the effect of the stress manipulation did not apppear to be mediated by state anxiety. It was suggested that trait factors do not modify attentional biases associated with acute stress but may influence such biases when stress is prolonged. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Explicit memory in anxiety disorders.

Two experiments were conducted to study selective memory bias favoring anxiety-relevant materials in patients with anxiety disorders. In the 1st experiment, 32 patients with generalized anxiety disorder (CAD), 30 with social phobia (speaking anxiety), and 31 control participants incidentally learned CAD-relevant words, speech anxiety-relevant words, strongly pleasant words, and words with a neutral valence. Participants did not show any explicit memory bias for threatening materials. Thirty patients suffering from panic disorder (PD) with agoraphobia and 30 controls took part in the 2nd experiment. The design was similar to the 1st experiment. This time a highly specific selective memory bias for threatening words was found. Words describing symptoms of anxiety were better recalled by PD patients. Results are consistent with previous findings but are inexplicable by existing theories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective listening asymmetry in preschool children.

42 right-handed preschoolers listened to dichotic presentations of digit names in 2 experimental sessions. Ss were told to report only the digit arriving at the designated ear; the target ear was designated prior to the dichotic presentation in one session (precuing condition) and after the presentation in the other session (postcuing condition). A significant right-ear superiority was found for all 3 dependent variables: number of correct identifications, total number of digits reported from each ear, and number of intrusion errors. Thus, the procedure demonstrated a marked asymmetry and, therefore, left lateralization of verbal processing in children as young as 3 yrs of age. Since the magnitude of asymmetry was as great in the precuing condition as in the postcuing condition, input factors (perceptual or attentional factors) are sufficient to account for the right-ear superiority. There was no age difference in degree of right-ear advantage. Correlations between asymmetry scores in the 2 sessions ranged between .60 and .68 for the 3 dependent variables. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Outcome of cognitive–behavioral therapy for depression: Relation to hemispheric dominance for verbal processing.

Unmedicated depressed outpatients were tested on dichotic syllable and complex tone tests prior to receiving 16 weekly sessions of cognitive therapy (n?=?31 ) or 6–12 weeks of placebo treatment (n?=?45). Cognitive-therapy responders had twice the right-ear (left hemisphere) advantage for syllables when compared with nonresponders but did not differ from nonresponders on the nonverbal task. The larger right-ear advantage in cognitive-therapy responders was due to better right-ear accuracy; they did not differ from nonresponders in left-ear accuracy. No differences in perceptual asymmetry or accuracy were found between placebo responders and nonresponders. Right-ear accuracy for syllables was the best predictor of response to cognitive therapy in a logistic regression analysis. The findings suggest that greater left-hemisphere advantage for verbal processing is associated with more favorable outcome of cognitive therapy for depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit memory bias in anxiety.

Previous investigations of recall and recognition for threatening information in clinically anxious subjects have yielded equivocal results. The present study contrasts implicit (word completion) with explicit (cued recall) memory and shows that indices of bias for emotional material derived from the two types of memory are independent of one another. The explicit measure was correlated with trait anxiety scores, but did not clearly distinguish between subjects with clinical anxiety states and normal control subjects. On the implicit memory measure, clinically anxious subjects produced more threat word completions, but only from a set to which they had recently been exposed. These results are taken as evidence that internal representations of threat words are more readily or more persistently activated in anxiety states, although they are not necessarily better elaborated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response to hyperventilation and inhalation of 5.5% carbon dioxide-enriched air across the DSM-III—R anxiety disorders.

198 anxiety disorder patients, under criteria of the Diagnostic and Statistical Manual of Mental Disorders-III-Revised (DSM-III-R), and 25 nonanxious control Ss underwent challenges of 90 sec of voluntary hyperventilation and 15 min of 5.5% carbon dioxide in air. Panic disorder Ss showed a greater subjective response to both challenges than did Ss with other anxiety disorders, who in turn responded more than did control Ss. Furthermore, Ss with panic disorder as an additional diagnosis tended to report more subjective response than did anxiety disorder Ss without panic disorder. The best prechallenge predictor of response to each procedure was a measure of fear of physical symptoms. The findings support previous results that have pointed to a greater fear or anxiety-inducing effect of these challenge procedures in panic disorder patients, as compared with other Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Level-of-processing effects in word-completion priming: A neuropsychological study.

Recent reviews (A. S. Brown & D. B. Mitchell, see record 82:16176; B. Challis & D. R. Brodbeck, see record 79:30007) concluded that level-of-processing (LOP) manipulations affect priming in perceptual tasks, contrary to earlier suggestions that such tasks are insensitive to LOP. In 3 experiments with amnesic patients and control Ss, the authors examined the effect of LOP manipulations on priming in word-stem and word-fragment completion and on recognition memory. Amnesic patients exhibited reduced or near-zero LOP effects in word-completion priming compared with controls. LOP affected recognition memory for both amnesic patients and control Ss, confirming that the LOP manipulation affected explicit memory. When the effect of explicit retrieval on control performance was reduced by using a low-level encoding task, priming was the same for amnesic patients and controls. The authors suggest that LOP effects in word-completion priming tasks reflect the influence of explicit retrieval, which can be used usefully by control Ss but much less so by amnesic patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Comparison of Attentional Biases and Memory Biases in Women With Social Phobia and Major Depression.

Cognitive processes play an important role in the etiology and maintenance of anxiety and depression. Current theories differ, however, in their predictions regarding the occurrence of attentional biases and memory biases in depression and anxiety. To allow for a systematic comparison of disorders and cognitive processes, 117 women (35 with generalized social phobia, 27 with major depression, and 55 healthy controls) participated in a test of visual attention (visual search), an explicit memory test (free recall), and an implicit memory test (anagram solving). Both clinical groups exhibited attentional biases for disorder-related words, whereas only depressed participants showed clear evidence of explicit and implicit memory biases. The implications of these results for competing theories are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Left-ear superiority in children for processing auditory emotional material.

Investigated hemispheric asymmetries in children for processing auditory material varying in emotional intonation or verbal content. 31 kindergartners, 32 4th graders, and 32 8th graders reported on the emotional content and on the verbal content of dichotically presented sentences. Ss listened to tapes of 4 phrases spoken in tones that were happy, sad, angry, or neutral and to sentences that varied in verbal content only. Ss also completed a handedness questionnaire and a hearing test. All age groups showed a left-ear advantage for reporting on the emotional material and a right-ear advantage for reporting on the verbal material. For the emotional task, the degree of ear asymmetry did not vary significantly as a function of emotional category. Findings indicate the the right hemisphere is specialized for mediating auditory emotional stimuli as early as 5 yrs of age. (45 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anxiety and lateral cerebral function.

In an initial experiment with 80 right-handed undergraduates, Ss reporting high anxiety (State-Trait Anxiety Inventory) evidenced a performance decrement that was specific to tasks presented to the right visual half-field. Given this suggestion of left-hemisphere involvement in anxiety, a 2nd experiment with 32 undergraduates examined attentional bias and lateral eye movements; high trait anxiety was associated with a right-ear attentional bias and a low incidence of left lateral eye movements. These observations suggest that anxiety, as an individual difference variable, might entail a lateral shift in cerebral function. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increased cardiac awareness in panic disorder.

Investigated cardiac perception in panic disorder with both self-report and objective measures. In Study 1, 120 patients with panic disorder, 86 infrequent panickers, and 38 patients with other anxiety disorders reported greater cardiac and gastrointestinal awareness than 62 normal control Ss. Ss with panic attacks reported greater cardiac awareness, but not gastrointestinal awareness, than those with other anxiety disorders. Studies 2 and 3 included a test of heart rate perception in which Ss silently counted their heartbeats without taking their pulse. In Study 2, 65 panic disorder patients showed better performance than 50 infrequent panickers, 27 patients with simple phobias, and 46 normal control Ss. No group differences were found in ability to estimate time intervals. In Study 3, 13 patients with panic disorder and 15 with generalized anxiety disorder showed better heart rate perception than 16 depressed patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patterns of perceptual asymmetry in depression and anxiety: Implications for neuropsychological models of emotion and psychopathology.

More than 1,000 university undergraduates were simultaneously classified as either high or low depressed and high or low anxious and given a face-processing task that typically elicits a left hemispatial bias. Depression and anxiety were associated with opposing biases in perceptual asymmetry scores. In particular, high-depressed students had smaller left hemispatial biases than low-depressed students, whereas high-anxious students had larger left hemispatial biases than low-anxious students. The results suggest that depression and anxiety may be associated with different patterns of asymmetric hemispheric function. Because the rate of comorbidity of depression and anxiety in the population is high, these findings confirm the importance of separating anxiety and depression when examining the relationship among patterns of brain activity, emotion, and psychopathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit memory for shape, body weight, and food-related words in patients with anorexia nervosa and nondieting controls.

Twelve patients with anorexia nervosa and 12 control participants watched a series of 64 words. There were 4 word types: anorexia related, positive, negative, and neutral. The last 3 types were anorexia unrelated. Anorexia-related words had the same affective valence as the neutral control words. Next, the participants completed an explicit memory test ( cued recall ) and an implicit memory test (word stem completion). Results showed a strong explicit memory bias for anorexia-related words for patients with anorexia nervosa but not for nondieting controls. There was no evidence for a similar bias in implicit memory. Results are discussed in the context of cognitive biases in psychopathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Resistance of high-anxious subjects under ego threat to perception of figural distortion.

40 college students were selected as high and 40 as low in anxiety (IPAT Anxiety Scale). Ss judged the horizontal plane while viewing a specially designed room (Leaf Room) through aniseikonic lenses. Groups of Ss were subdivided and provided either task or threat orientation to the perceptual procedure. High-anxious in comparison with low-anxious Ss required more time to recognize the perceptual distortion produced by aniseikonic lenses, and they estimated a smaller degree of distortion. Thus high anxiety appeared to retard ability to shift from familiar to unfamiliar but veridical percepts. The effects of ego threat were less clear but seemed to relate to certain inverse reaction tendencies present among high anxious Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual and conceptual memory processes in global amnesia.

To determine whether global amnesia reflects a selective deficit in conceptual processing, amnesic and control Ss performed 4 memory tasks that varied processing and retrieval requirements. A study-phase modality (auditory/visual) manipulation validated the nature of processing (perceptual and conceptual) engaged by each task. Amnesic patients were impaired on perceptual and conceptual explicit memory tasks (word-fragment and word-associate cued recall) and were intact on perceptual and conceptual implicit memory tasks (word-fragment completion and word association). These results are consistent with the view that limbic-diencephalic structures damaged in amnesia mediate, in part, processes typically engaged during explicit retrieval. The results are inconsistent, however, with the characterization of that deficit as being one of conceptual processing per se. (PsycINFO Database Record (c) 2010 APA, all rights reserved)