Filtern
Volltext vorhanden
- nein (28) (entfernen)
Erscheinungsjahr
- 2008 (28) (entfernen)
Dokumenttyp
- Wissenschaftlicher Artikel (26)
- Monographie/Sammelband (1)
- Dissertation (1)
Sprache
- Englisch (28) (entfernen)
Gehört zur Bibliographie
- ja (28)
Institut
- Department Psychologie (28) (entfernen)
The aim of the present study was to investigate the test-retest reliability of the olfactory detection threshold subtest of the Sniffin" Sticks test battery, if administered repeatedly on 4 time points. The detection threshold test was repeatedly conducted in 64 healthy subjects. On the first testing session, the threshold test was accomplished 3 times (T(1) = 0 min, T(2) = 35 min, and T(3) = 105 min), representing a short-term testing. A fourth threshold test was conducted on a second testing session (T(4) = 35.1 days after the first testing session), representing a long-term testing. The average scores for olfactory detection threshold for n-butanol did not differ significantly across the 4 points of time. The test-retest reliability (Pearson"s r) between the 4 time points of threshold testing were in a range of 0.43-0.85 (P < 0.01). These results support the notion that the olfactory detection threshold test is a highly reliable method for repeated olfactory testing, even if the test is repeated more than once per day and over a long-term period. It is concluded that the olfactory detection threshold test of the Sniffin" Sticks is suitable for repeated testing during experimental or clinical studies.
The boundary paradigm (Rayner, 1975) with a novel preview manipulation was used to examine the extent of parafoveal processing of words to the right of fixation. Words n + 1 and n + 2 had either correct or incorrect previews prior to fixation (prior to crossing the boundary location). In addition, the manipulation utilized either a high or low frequency word in word n + 1 location on the assumption that it would be more likely that n + 2 preview effects could be obtained when word n + 1 was high frequency. The primary findings were that there was no evidence for a preview benefit for word n + 2 and no evidence for parafoveal-on-foveal effects when word n + 1 is at least four letters long. We discuss implications for models of eye-movement control in reading.
Objective To demonstrate that children homozygous for the 10-repeat allele of the common dopamine transporter (DAT1) polymorphism who were exposed to maternal prenatal smoke exhibited significantly higher hyperactivity-impulsivity than children without these environmental or genetic risks. Study design We performed a prospective longitudinal study from birth into early adulthood monitoring the long-term outcome of early risk factors. Maternal prenatal smoking was determined during a standardized interview with the mother when the child was 3 months old. At age 15 years, 305 adolescents participated in genotyping for the DAT1 40 base pair variable number of tandem repeats polymorphism and assessment of inattention, hyperactivity-impulsivity, and oppositional defiant/conduct disorder symptoms with die Kiddie- Sads-Present and Lifetime Version. Results There was no bivariate association between DAT1 genotype, prenatal smoke exposure and symptoms of attention deficit hyperactivity disorder. However, a significant interaction between DAT1 genotype and prenatal smoke exposure emerged (P =.012), indicating that males with prenatal smoke exposure who were homozygous for the DAT1 10r allele had higher hyperactivity-impulsivity than males from all other groups. In females, no significant main effects of DAT1 genotype or prenatal smoke exposure or interaction effects on any symptoms were evident (all P >.25). Conclusions This study provides further evidence for the multifactorial nature of attention deficit hyperactivity disorder and the importance of studying both genetic and environmental factors and their interaction.
Parsing costs as predictors of reading difficulty : an evaluation using the Potsdam Sentence Corpus
(2008)
This study investigated whether older adults could acquire the ability to perform 2 cognitive operations in parallel in a paradigm in which young adults had been shown to be able to do so (K. Oberauer & R. Kliegl, 2004). Twelve young and 12 older adults practiced a numerical and a visuospatial continuous memory updating task in single-task and dual-task conditions for 16 to 24 sessions. After practice, 9 young adults were able to process the 2 tasks without dual- task costs, but none of the older adults had reached the criterion of parallel processing. The results suggest a qualitative difference between young and older adults in how they approach dual-task situations.
Sequence learning at optimal stimulus-response mapping : evidence from a serial reaction-time task
(2008)
We propose a new version of the serial reaction time (SRT) task in which participants merely looked at the target instead of responding manually. As response locations were identical to target locations, stimulus - response compatibility was maximal in this task. We demonstrated that saccadic response times decreased during training and increased again when a new sequence was presented. It is unlikely that this effect was caused by stimulus - response (S - R) learning because bonds between (visual) stimuli and (oculomotor) responses were already well established before the experiment started. Thus, the finding shows that the building of S - R bonds is not essential for learning in the SRT task.
Neuronal activity in area LIP is correlated with the perceived direction of ambiguous apparent motion (Z. M. Williams, J. C. Elfar, E. N. Eskandar, L. J. Toth, & J. A. Assad, 2003). Here we show that a similar correlation exists for small eye movements made during fixation. A moving dot grid with superimposed fixation point was presented through an aperture. In a motion discrimination task, unambiguous motion was compared with ambiguous motion obtained by shifting the grid by half of the dot distance. In three experiments we show that (a) microsaccadic inhibition, i.e., a drop in microsaccade frequency precedes reports of perceptual flips, (b) microsaccadic inhibition does not accompany simple response changes, and (c) the direction of microsaccades occurring before motion onset biases the subsequent perception of ambiguous motion. We conclude that microsaccades provide a signal on which perceptual judgments rely in the absence of objective disambiguating stimulus information.
Objective: To clarify the nature of the association between dopamine genes and smoking by examining whether genetic variability in components of the dopamine pathway could explain refined phenotypes in adolescent smoking progression. Method: Data are from an ongoing prospective study of the long-term outcome of early risk factors studied since birth. At age 15 years, 220 participants (108 males, 112 females) completed a self-report questionnaire measuring smoking behavior and were genotyped for five dopamine gene variants. Results: Smoking initiation was related to allelic variation in the dopamine D-4 receptor gene (DRD4), whereas smoking continuation and dependence showed association with the dopamine D-2 receptor gene (DRD2). Adolescents with the seven-repeat allele of the common DRD4 exon 3 polymorphism had rates of ever smoking that were significantly higher than in those with other genotypes. Once smoking started, carriers of the T allele of a single nucleotide polymorphism of DRD2 (rs4648317) reported higher rates of current smoking and scored higher on nicotine dependence than their allelic counterparts. Among current smokers, intention to quit was significantly lower in adolescents homozygous for the 10-repeat allele of the common dopamine transporter 3 untranslated region polymorphism. Conclusions: Our results provide preliminary evidence of genetic influences on different stages of smoking and suggest the importance of specific dopamine genes in smoking progression in adolescence.
Benefits of graphic design expertise in old age : compensatory effects of a graphical lexicon?
(2008)
When we fixate our gaze on a stable object, our eyes move continuously with extremely small involuntary and autonomic movements, that even we are unaware of during their occurrence. One of the roles of these fixational eye movements is to prevent the adaptation of the visual system to continuous illumination and inhibit fading of the image. These random, small movements are restricted at long time scales so as to keep the target at the centre of the field of view. In addition, the synchronisation properties between both eyes are related to binocular coordination in order to provide stereopsis. We investigated the roles of different time scale behaviours, especially how they are expressed in the different spatial directions (vertical versus horizontal). We also tested the synchronisation between both eyes. Results show different scaling behaviour between horizontal and vertical movements. When the small ballistic movements, i.e., microsaccades, are removed, the scaling behaviour in both axes becomes similar. Our findings suggest that microsaccades enhance the persistence at short time scales mostly in the horizontal component and much less in the vertical component. We also applied the phase synchronisation decay method to study the synchronisation between six combinations of binocular fixational eye movement components. We found that the vertical-vertical components of right and left eyes are significantly more synchronised than the horizontal-horizontal components. These differences may be due to the need for continuously moving the eyes in the horizontal plane in order to match the stereoscopic image for different viewing distances.
OBJECTIVES: To elucidate the potential relationship between classification of emotional faces and impaired central processing in eating disorders and to investigate the potential mediatory role of alexithymia and depression in this relationship. METHODS: Visual-evoked potentials (VEPs) to emotional faces and classification performance were assessed in 12 anorexic females and matched healthy controls. RESULTS: Patients with anorexia nervosa showed no modulation of emotional face processing and displayed significantly increased N200 amplitudes in response to all emotional categories and decreased VEPs in response to unpleasant emotional faces in the P300 time range as compared with healthy controls. They also made more mistakes in emotional face recognition, in particular, for neutral, sad, and disgusted content. CONCLUSIONS: There are marked differences in evoked potentials and emotion recognition performances of patients with anorexia nervosa and controls in facial processing. Differences in brain dynamics might contribute to difficulties in the correct recognition of facially expressed emotions, deficits in social functioning, and in turn the maintenance of eating disorders.
OBJECTIVE: Interoceptive awareness is known to be impaired in eating disorders. To date, it has remained unclear whether this variable is related to the construct of interoceptive sensitivity. Interoceptive sensitivity is considered to be an essential variable in emotional processes. The objective of the study was to elucidate this potential relationship and to clarify whether general interoceptive sensitivity is reduced in anorexia nervosa. METHODS: Using a heartbeat perception task, interoceptive sensitivity was assessed in 28 female patients with anorexia nervosa and 28 matched healthy controls. Questionnaires assessing interoceptive awareness (EDI) and several other variables were also administered. RESULTS: Patients with anorexia nervosa displayed significantly decreased interoceptive sensitivity. They also had more difficulties in interoceptive awareness. CONCLUSIONS: In addition to a decreased ability to recognize certain visceral sensations related to hunger, there is a generally reduced capacity to accurately perceive bodily signals in anorexia nervosa. This highlights the potential importance of interoceptive sensitivity in the pathogenesis of eating disorders.
The ability to perceive interoceptive signals plays a central role in many theories of emotions. The present study was designed to investigate the relationship between interoceptive awareness and the conscious processing and memory of emotional information. Heart-rate changes were recorded during baseline and affective picture presentation in two groups of participants, differing in cardiac awareness. After a 60-minute break, a recognition task was conducted. Statistical analyses revealed significantly stronger heart-rate deceleration to pleasant and unpleasant stimuli in participants with high interoceptive awareness. In the subsequent picture recognition task, participants with high interoceptive awareness demonstrated a superior recall of pleasant and unpleasant pictures, while no differences were found between interoceptive awareness groups for pictures of neutral content. Our results demonstrate a strong relationship between the perception of cardiac signals and both the processing as well as the recognition of emotional stimuli. High interoceptive awareness was related to increased physiological responses to emotional stimuli and is therefore an important mediating variable when investigating cardiovascular reactivity both in healthy subjects as well as in clinical populations.