[On the Relationship between EMDR and Eye Movements - An Analysis of the Current State of Neurobiological Research]. / Zur Beziehung von EMDR und Augenbewegungen - Eine Analyse der aktuellen neurobiologischen Studienlage.

EMDR is an effective treatment for people diagnosed with posttraumatic stress disorder. The traditional technique of EMDR combines the activation of distressing reminders with guided rhythmic eye movements. The present article reviews the current state of research on the neurobiological correlates of the eye movements occurring during EMDR. The distinction between saccades and smooth pursuit eye movements allows for detailed analyses of ocular motor connections with cerebral networks of attention, memory and emotion. Possible consequences for research and clinical practice with EMDR are discussed.

Acute stress in patients with brain cancer during primary care.

PURPOSE: This study investigated whether diagnosis and neurosurgical removal of a brain tumour induced Acute Stress Disorder (ASD) in adults. We also aimed to identify factors associated with the development of ASD in this specific patient group and setting. METHODS: Forty-seven consecutive patients with intracranial neoplasms completed a variety of self-report questionnaires and underwent a structured clinical interview (SCID) within the first 4 weeks after tumour detection on average 1 week after neurosurgical treatment. Moreover, the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), A1 and A2 criterion and thus the characteristics of the traumatic event were explored in detail. RESULTS: ASD symptoms were common. Twenty-three percent of the patients met stringent criteria of ASD and another 4% suffered from subsyndromal ASD. Predisposing factors previously reported in literature with the exception of previous trauma could not be identified in this study (e.g., sex, age, intelligence). CONCLUSION: It has been critically discussed whether the diagnosis of ASD is appropriate in cancer patients due to the often future-related nature of cancer-related traumatic events. The diagnosis of ASD was justified in the vast majority of affected patients due to the specific, acute and past traumatic experiences in concordance with the DSM and International Statistical Classification of Diseases and Related Health Problems (ICD) trauma definitions. Thus, ASD is a common and relevant psychiatric comorbidity in patients with brain tumours. Our data highlight both the need for the routine psychological assessment as well as of psychosocial support in this early treatment phase.

Strategic use of number representation is independent of test instruction in random number generation.

The effects of different instructions on verbal random number generation were examined in 40 healthy students who attempted to generate random sequences of the digits 1 to 6. Two groups of 20 received different instructions with alternative numerical representations. The Symbolic group (Arabic digits) was instructed to randomize while continuously using the analogy of selecting and replacing numbered balls from a hat, whereas the Nonsymbolic group (arrays of dots) was instructed to imagine repeatedly throwing a die. Participants asked for self-reports on their strategies reported spontaneously occurring visuospatial imagination of a mental number line (42%), or imagining throwing a die (23%). Individual number representation was not affected by the initial instruction. There were no differences in randomization performance by group. Comprehensive understanding of the nature of the randomization task requires considering individual differences in construction of mental models.

Random number generation in bilingual Balinese and German students: preliminary findings from an exploratory cross-cultural study.

Verbal random number generation is a procedurally simple task to assess executive function and appears ideally suited for the use under diverse settings in cross-cultural research. The objective of this study was to examine ethnic group differences between young adults in Bali (Indonesia) and Kiel (Germany): 50 bilingual healthy students, 30 Balinese and 20 Germans, attempted to generate a random sequence of the digits 1 to 9. In Balinese participants, randomization was done in Balinese (native language L1) and Indonesian (first foreign language L2), in German subjects in the German (L1) and English (L2) languages. 10 of 30 Balinese (33%), but no Germans, were unable to inhibit habitual counting in more than half of the responses. The Balinese produced significantly more nonrandom responses than the Germans with higher rates of counting and significantly less occurrence of the digits 2 and 3 in L1 compared with L2. Repetition and cycling behavior did not differ between the four languages. The findings highlight the importance of taking into account culture-bound psychosocial factors for Balinese individuals when administering and interpreting a random number generation test.

Unidirectional interference in use of nondominant hand during concurrent Grooved Pegboard and random number generation tasks.

The interference effect between Grooved Pegboard task with either hand and the executive task of cued verbal random number generation was investigated. 24 normal right-handed subjects performed each task under separate (single-task) and concurrent (dual-task) conditions. Articulatory suppression was required as an additional secondary task during pegboard performance. Analysis indicated an unambiguous distinction between the two hands. Comparisons of single-task and dual-task conditions showed an asymmetrical pattern of unidirectional interference with no practice effects during pegboard performance. Concurrent performance with nondominant hand but not the dominant hand of random number generation performance became continuously slower. There was no effect of divided attention on pegboard performance. Findings support the idea that the nondominant hand on the pegboard and random number tasks draw from the same processing resources but that for the executive aspect random number generation is more sensitive to changes in allocation of attentional resources.

Are numbers special? Comparing the generation of verbal materials from ordered categories (months) to numbers and other categories (animals) in an fMRI study.

Months, days of the week, and numbers differ from other verbal concepts because they are ordered in a sequence, whereas no order is imposed on members of other categories, such as animals or tools. Recent studies suggest that numbers activate a representation of their quantity within the intraparietal sulcus (IPS) automatically, that is, in tasks that do not require the processing of quantity. It is unclear, however, whether ordered verbal materials in general and not only numbers activate the IPS in such tasks. In the present functional magnetic resonance imaging study word generation of months, numbers, and animals were compared. Word generation of numbers and nonnumerical materials from an ordered category (months) activated the IPS more strongly than generating items from a not-ordered category such as animals or the verbal control conditions. An ROI analysis of three subregions within the anterior IPS revealed that the most anterior and lateral of these regions, human intraparietal area hIP2, shows a greater sensitivity to ordered materials than the other two areas, hIP1 and hIP3. Interestingly, no difference in activation was observed within the IPS between numbers and months suggesting that the activation of the IPS might not be modulated by the additional quantity information carried by numbers.

Auditory feedback does not influence random number generation: Evidence from profoundly deaf adults with cochlear implant.

Oral random number generation is a widely used neuropsychological task engaging a number of overlapping neural systems of attention, number representation, response generation, and working memory. Although phonological processing is known to be essential for random number generation no information exists on the significance of the auditory feedback of hearing one's own voice on task performance. We therefore examined the influence of auditory feedback in 15 profoundly deaf adults with cochlear implants in a device-on/off experiment. No significant effects of occluding auditory feedback on random number generation were noted, thus supporting an internal response-monitoring model independent of auditory condition.

Effects of regular switching between languages during random number generation.

Random number generation is a task that engages working memory and executive processes within the domain of number representation. In the present study we address the role of language in number processing by switching languages during random number generation (numbers 1-9), using German (L1) and English (L2), and alternating L1/L2. Results indicate large correspondence between performance in L1 and L2. In contrast to nonswitching performance, randomization with alternating languages showed a significant increase of omitted responses, whereas the random sequences were less stereotyped, showing significantly less repetition avoidance and cycling behavior. During an intentional switch between languages, errors in language sequence appeared in 23% of responses on the average, independently of the quality of randomization but associated with a clear persistence of L2. These results indicate that random number generation is more closely linked to auditory-phonological representation of numerals than to visual arabic notation.

Random number generation in native and foreign languages.

The effects of different levels of language proficiency on random number generation were examined in this study. 16 healthy right-handed students (7 women, 9 men; aged 22 to 25 years, M=23.8, SD=.83) attempted to generate a random sequence of the digits 1 to 9 at pacing frequencies of 1, 1.5, and 2 Hz. Randomization was done in German (native language L1), English (first foreign language L2), and French (second foreign language L3). There was a pattern of redundancy and seriation tendencies, increasing with speed of generation for all languages (L1-L3). While using L2 and L3, responses slowed and the number of errors committed increased. Further, there was a peculiar pattern of dissociation in nonrandom performance with an increase of habitual counting in ones and a strong reduction of counting in twos. All effects were most pronounced when subjects used L3 and 2-Hz pacing rates. Slowing and nonrandomness was not correlated with self-assessment parameters regarding language proficiency. We suggest that in a task involving number activation in a nonnative language, lack of proficiency will interfere with random number generation, leading to interruptions and rule breaking, at least when reaching the limits of attentional capacity at higher pacing rates.

Changes in cortical dynamics in the preictal stage of a migraine attack.

Neurophysiologic studies suggest that migraineurs without aura have a dysfunction of cortical information processing in the pain-free interval. In this study, the advanced method of nonlinear multielectrode sleep-EEG analysis is used to investigate changes of cortical activity in the preictal time span. Five patients (four women, one man; age range, 29 to 58 years) experiencing migraine without aura participated in the study. The patients spent two blocks in the sleep laboratory. The first block was taken in a headache-free interictal time interval, and the second block when the onset of a migraine attack was most likely. After a nocturnal migraine attack, the patient was asked to mark the maximum of migraine pain in a surface-head scheme. The comparison of preictal and interictal EEGs enabled the authors to obtain a topographical view of changes in cortical dynamics. In each patient map, an area was found that displayed a pronounced focus indicating the region of maximum change in dimensional complexity. It shows a clearly recognizable correspondence with the scalp topography of the later pain perception. These findings indicate an association between cortical status and pain lateralization in the preictal time span.

Morning headaches in patients with sleep disorders: a systematic polysomnographic study.

OBJECTIVES: Patients with sleep disorders suffer more often from headache after awakening than healthy subjects. However, it still is a matter of controversy whether this applies only to patients with sleep apnea syndrome (SAS) or also to patients with other diagnoses of sleep disorders. METHODS: We asked all patients in our sleep laboratory about the frequency of past headaches and also ascertained the occurrence of morning headaches after awakening in the sleep laboratory. Polysomnographic recordings from nights before morning headache were compared with nights without following headache. Four hundred and thirty-two patients with sleep disorders (age range 18-86 years, 37% women) and 30 healthy subjects (age range 24-55 years, 27% women) participated in this prospective study. RESULTS: The reported frequency of past headaches and the frequency of morning headache in the sleep laboratory were significantly increased in patients with SAS and other sleep disorders compared with healthy subjects. The occurrence of morning headache in the sleep laboratory was associated polysomnographically with a decrease in total sleep time, sleep efficiency and amount of rapid eye movement sleep and with an increase in the wake-time during the preceding night. CONCLUSIONS: We conclude that morning headaches in patients with sleep disorders might be associated with particular disturbances of the preceding night's sleep. We speculate that dysregulation in anatomically identical central regions modulating sleep and nociception might be relevant to morning headache, rather than one particular sleep disorder such as SAS.

Correlation between tests of attention and performance on grooved and Purdue pegboards in normal subjects.

This study investigated the relation between tests of manual dexterity and attentional functions with 49 normal, right-handed medical students (26 women, 23 men, ages 19-30 years) who were assessed with a Purdue Pegboard Test, Grooved Pegboard Test, and a Test for Attentional Performance, comprising measures of tonic and phasic alertness and divided attention. Weak to moderately high partial correlations controlling for finger size were obtained between pegboard test performance of the left hand and phasic alertness (r = .31-.50). Purdue Pegboard Assembly subtest scores were weakly correlated with divided attention (r = -.39). These findings suggest that attention is an important determinant of performance for manual dexterity tests of the nondominant hand.