The rubber hand illusion increases heat pain threshold.

BACKGROUND: Accumulating evidence shows that manipulations of cortical body representation, for example, by simply viewing one's own body, can relieve pain in healthy subjects. Despite the widespread use of the rubber hand illusion (RHI) as an effective experimental tool for the manipulation of bodily awareness, previous studies examining the analgesic effect of the RHI have produced conflicting results. METHOD: We used noxious heat stimuli to induce finger pain in 29 healthy subjects, and we recorded the participants' pain thresholds and subjective pain ratings during the RHI and during the control conditions. Two control conditions were included in our experiment - a standard one with reduced illusion strength (asynchronous stroking control) and an additional one in which the participants viewed their own hand. RESULTS: Raw data showed that both the RHI and the vision of the own hand resulted in slightly higher pain thresholds than the asynchronous stroking control (illusion: 47.79 °C; own-hand: 47.99 °C; asynchronous: 47.52 °C). After logarithmic transformation to achieve normality, paired t-tests revealed that both increases in pain threshold were significant (illusion/asynchronous: p = 0.036; own-hand/asynchronous: p = 0.007). In contrast, there was no significant difference in pain threshold between the illusion and the own-hand conditions (p = 0.656). Pain rating scores were not log-normal, and Wilcoxon singed-rank tests found no significant differences in pain ratings between the study conditions. CONCLUSION: The RHI increases heat pain threshold and the analgesic effect of the RHI is comparable with that of seeing one's own hand. The latter finding may have clinical implications.

Sensitivity and specificity of Addenbrooke's Cognitive Examination, Mattis Dementia Rating Scale, Frontal Assessment Battery and Mini Mental State Examination for diagnosing dementia in Parkinson's disease.

INTRODUCTION: Among the non-motor features of Parkinson's disease (PD), cognitive impairment is one of the most troublesome problems. Highly sensitive and specific screening instruments for detecting dementia in PD (PDD) are required in the clinical practice. METHODS: In our study we evaluated the sensitivity and specificity of different neuropsychological tests (Addenbrooke's Cognitive Examination, ACE; Frontal Assessment Battery, FAB and Mattis Dementia Rating Scale, MDRS) in 73 Parkinson's disease patients without depression. By receiver operating characteristic curve analysis, these screening instruments were tested against the recently established clinical diagnostic criteria of PDD. RESULTS: Best cut-off score for ACE to identify PDD was 80 points (sensitivity = 74.0%, specificity = 78.1%). For FAB the most optimal cut-off value was 12 points (sensitivity = 66.3%, specificity = 72.2%); whereas for MDRS it was 125 points (sensitivity = 89.8%, specificity = 98.3%). Among the examined test batteries, MDRS had the best clinicometric profile for detecting PDD. CONCLUSION: Although the types of applied screening instruments might differ from movement disorder clinic to clinic within a country, determination of the most specific and sensitive test for the given population remains to be an important task. Our results demonstrated that the specificity and sensitivity of MDRS was better than those of ACE, FAB and MMSE in Hungary. However, further studies with larger sample size and more uniform criteria for participation are required to determine the most suitable screening instrument for cognitive impairment.

Phobic anxiety in 11 nations. Part I: Dimensional constancy of the five-factor model.

The Fear Survey Schedule-III (FSS-III) was administered to a total of 5491 students in Australia, East Germany, Great Britain, Greece, Guatemala, Hungary, Italy, Japan, Spain, Sweden, and Venezuela, and submitted to the multiple group method of confirmatory analysis (MGM) in order to determine the cross-national dimensional constancy of the five-factor model of self-assessed fears originally established in Dutch, British, and Canadian samples. The model comprises fears of bodily injury-illness-death, agoraphobic fears, social fears, fears of sexual and aggressive scenes, and harmless animals fears. Close correspondence between the factors was demonstrated across national samples. In each country, the corresponding scales were internally consistent, were intercorrelated at magnitudes comparable to those yielded in the original samples, and yielded (in 93% of the total number of 55 comparisons) sex differences in line with the usual finding (higher scores for females). In each country, the relatively largest sex differences were obtained on harmless animals fears. The organization of self-assessed fears is sufficiently similar across nations to warrant the use of the same weight matrix (scoring key) for the FSS-III in the different countries and to make cross-national comparisons feasible. This opens the way to further studies that attempt to predict (on an a priori basis) cross-national variations in fear levels with dimensions of national cultures.

Egocentric mental rotation in Hungarian dyslexic children.

A mental rotation task was given to 27 dyslexic children (mean age 9 years, 2 months) and to 28 non-dyslexic children (mean age 8 years, 8 months). Pictures of right and left hands were shown at angles of 0, 50, 90 and 180 degrees, and the subjects were required to indicate whether what was shown was a right hand or a left hand. It was found that, in this task, the dyslexics did not show the normal pattern of response times at different angles, and also, that they made more errors than the controls. It is argued that this result is compatible with hypothesis that, in typical cases of dyslexia, there is a malfunctioning in the posterior parietal area.

Cognitive subprocesses of mental rotation: why is a good rotator better than a poor one?

The Vanderberg-Kuse Mental Rotation Test is a standard test of mental rotation ability. Recent experiments have demonstrated that mental rotation is a complex cognitive process wherein different subprocesses (focused attention, visual scanning, perceptual decision, visual memory) play important roles in performance. We classified the population as good and poor rotators by performance of mental rotation (ns = 47: 22 men and 25 women, respectively; mean age: 20.7 yr.). To examine differences cognitive subprocesses of mental rotation of these two groups were compared. There were significant differences between poor and good rotators in performance on Raven's test and the Pieron Focused Attention test scores. The good rotators scored better because their perceptual decision-analytical intelligence (Raven) and focused attention scores were higher.

Sex differences on the hand mental rotation task for 9-yr.-old children and young adults.

The Hand Mental Rotation task is assumed to activate an egocentric spatial reference frame to realize mental rotation. This study presents significant sex differences in hand mental rotation performances between men and women (n = 23 and 25, respectively; age: 20.7 yr.). Differences in hand mental rotation in school girls and boys (ns = 48 and 41, respectively; age: 9 yr.) were not significant. Our results suggest that the change in sex differences in egocentric mental rotation may occur with developmental change. This requires further testing with a larger sample so testing can occur at several ages between 9 and 20.7 years.

Attention fixation training: training people to form cognitive maps help to control symptoms of panic disorder with agoraphobia.

Nine individuals diagnosed with panic with agoraphobia received three elements of Attentional Fixation Training (AFT): Directed attention to the external environment, directed topographical synthesis, and directed orientation in space-time to control characteristics of panic. They then walked a standard 2.5 km route and practiced these elements upon entering one of the five panic-inducing situations: (a) walking alone near a busy street with the examiner following at 20 m, (b) walking alone near a busy street with the examiner out of client's visual field, (c) shopping with the examiner present, (d) traveling on a bus alone, and (e) shopping alone. Heart rate was monitored in each of these five situations. Except for the case of using public transport, heart rate activity decreased to a considerable extent during AFT practice suggesting AFT elements provided a good way to control symptoms of panic in vivo. Results were discussed within the confines of a model suggesting that an attentional deficit, which produces a spatial disorientation disorder that maintains both panic and agoraphobia, can efficiently be overcome by means of all three AFT tools.

Opposite asymmetries in blind locomotor orientation of patients with panic agoraphobia compared to those with generalized anxiety.

Panic agoraphobic subjects constantly struggle with the accurate registration of everyday space-time dimension. They are hindered in the exploration of their surroundings by constant self-directed attention. In our investigations we examined whether during experimental goal-directed locomotion orientation insecurity would appear. The accuracy of target-directed motion, i.e. the degree of lateral deviation, was recorded in three diagnostic groups, panic agoraphobics (15 subjects), generalized anxiety patients (15 subjects), and normal controls (15 subjects), and normal controls (15 subjects). According to our results the approach vector of the panic agoraphobics deviated to the right, while in the case of generalized anxiety patients it deviated to the left, while normal controls did not deviate significantly from the middle line. Results are compatible with previous literature which associated panic with an overactivity of left-sided functions, and generalised anxiety with an overactivity of right-sided functions.