Biomedical subjects

Roman Ferstl

Publications and source records attributed to Roman Ferstl.

10 recordsLinked to original sources

PubMed2006

Delay of gratification and executive performance in individuals with schizophrenia: putative role for eating behavior and body weight regulation.

OBJECTIVE: Impairment in executive functions and disturbed weight regulation are common features in individuals with schizophrenia on antipsychotics. Still, the clinical management of weight gain, including educational programs, is insufficient. Therefore, we hypothesized that distinct executive impairment is associated with the inability to self-control food intake. METHOD: In the present study we investigated the performance in a paradigm analyzing the executive subfunction "delay of gratification" in individuals with schizophrenia (n=29) compared with controls (n=23) and the interrelationship between delay of gratification, overall executive functioning, reported eating behavior and the BMI. We applied a board-game paradigm to operationalize delay of gratification: on designated fields individuals need to decide about a small amount of immediate reinforcement versus double the amount in the end. Appetite and eating behavior were assessed by self-report scales, executive functioning by BADS. RESULTS: We found that the patients performed significantly worse in our paradigm and that this is associated with lower executive functioning. However, the interrelationship between all parameters is complex: there is a significant positive correlation between the reported perceived appetite and executive functioning whereas the reported restrained eating behavior, significantly more frequent in patients, is correlated with low executive functioning and high disinhibition in eating situations. CONCLUSIONS: We conclude that executive functions are necessary to successfully manage eating behavior. Thus, better understanding of the cognitive mechanisms might help to support the patients more efficiently in their tough job to keep control.

Adult↗

PubMed2006

Central odor processing in subjects experiencing helplessness.

The aim of the present study was to investigate whether central nervous odor processing is affected by the temporary experience of helplessness. To induce helplessness, an unsolvable social discrimination test in combination with false feedback was used. The EEG was recorded from 60 scalp locations, while two standard odors were presented via a constant-flow olfactometer. Helplessness attenuated olfactory stimulus processing at an early perceptual stage: the P2 and P3-1 amplitudes were reduced in response to both odors. Furthermore, the early potentials (N1, P2 and P3-1) of the chemosensory event-related potential (CSERP) appeared with longer latencies when subjects received negative feedback. The state effects of helplessness resemble the deviations in the CSERP found in depressed patients, suggesting a general mood effect.

Adolescent↗

PubMed2006

The human brain is a detector of chemosensorily transmitted HLA-class I-similarity in same- and opposite-sex relations.

Studies on subjective body odour ratings suggest that humans exhibit preferences for human leucocyte antigen (HLA)-dissimilar persons. However, with regard to the extreme polymorphism of the HLA gene loci, the behavioural impact of the proposed HLA-related attracting signals seems to be minimal. Furthermore, the role of HLA-related chemosignals in same- and opposite-sex relations in humans has not been specified so far. Here, we investigate subjective preferences and brain evoked responses to body odours in males and females as a function of HLA similarity between odour donor and smeller. We show that pre-attentive processing of body odours of HLA-similar donors is faster and that late evaluative processing of these chemosignals activates more neuronal resources than the processing of body odours of HLA-dissimilar donors. In same-sex smelling conditions, HLA-associated brain responses show a different local distribution in male (frontal) and female subjects (parietal). The electrophysiological results are supported by significant correlations between the odour ratings and the amplitudes of the brain potentials. We conclude that odours of HLA-similar persons function as important social warning signals in inter- and intrasexual human relations. Such HLA-related chemosignals may contribute to female and male mate choice as well as to male competitive behaviour.

Adult↗

PubMed2005

Chemosensory anxiety signals augment the startle reflex in humans.

The aim of the present study was to investigate whether chemosensory anxiety signals can activate behavioral withdrawal systems in humans. Twelve male university students donated their axillary sweat in two situations: right before an oral academic examination (anxiety condition) and during ergometric training (exercise condition). Subjective ratings revealed that the odor donors experienced significantly more anxiety and less pleasure during the anxiety condition than during the exercise condition. Seven subjects (three females) participated in the psychophysiological experiment. The chemosensory stimuli from pooled sweat samples of the donors, and from unused cotton pads (pad condition) were presented via a constant-flow olfactometer. Acoustic startle probes (100 dB (A)) were delivered during and between the presentations of the chemosensory stimuli. Only three subjects were able to discriminate the chemosensory stimuli of the human sweat samples from room air. However, the startle reflex amplitude (EMG of the eyeblink response) recorded in the context of chemosensory anxiety signals was increased, as compared to the amplitude recorded in the context of chemosensory stimuli from either exercise (p = 0.018) or cotton pad (p = 0.012). It is concluded that chemosensory anxiety signals may pre-attentively prime defensive behavior.

Acoustic Stimulation↗

PubMed2004

Positive emotional priming of facial affect perception in females is diminished by chemosensory anxiety signals.

Chemosensory communication of anxiety is a common phenomenon in vertebrates and improves perceptual and responsive behaviour in the perceiver in order to optimize ontogenetic survival. A few rating studies reported a similar phenomenon in humans. Here, we investigated whether subliminal face perception changes in the context of chemosensory anxiety signals. Axillary sweat samples were taken from 12 males while they were waiting for an academic examination and while exercising ergometric training some days later. 16 subjects (eight females) participated in an emotional priming study, using happy, fearful and sad facial expressions as primes (11.7 ms) and neutral faces as targets (47 ms). The pooled chemosensory samples were presented before and during picture presentation (920 ms). In the context of chemosensory stimuli derived from sweat samples taken during the sport condition, subjects judged the targets significantly more positive when they were primed by a happy face than when they were primed by the negative facial expressions (P = 0.02). In the context of the chemosensory anxiety signals, the priming effect of the happy faces was diminished in females (P = 0.02), but not in males. It is discussed whether, in socially relevant ambiguous perceptual conditions, chemosensory signals have a processing advantage and dominate visual signals or whether fear signals in general have a stronger behavioural impact than positive signals.

Adult↗

PubMed2003

A mechanism converting psychosocial stress into mononuclear cell activation.

Little is known about the mechanisms converting psychosocial stress into cellular dysfunction. Various genes, up-regulated in atherosclerosis but also by psychosocial stress, are controlled by the transcription factor nuclear factor kappaB (NF-kappaB). Therefore, NF-kappaB is a good candidate to convert psychosocial stress into cellular activation. Volunteers were subjected to a brief laboratory stress test and NF-kappaB activity was determined in peripheral blood mononuclear cells (PBMC), as a window into the body and because PBMC play a role in diseases such as atherosclerosis. In 17 of 19 volunteers, NF-kappaB was rapidly induced during stress exposure, in parallel with elevated levels of catecholamines and cortisol, and returned to basal levels within 60 min. To model this response, mice transgenic for a strictly NF-kappaB-controlled beta-globin transgene were stressed by immobilization. Immobilization resulted in increased beta-globin expression, which could be reduced in the presence of the alpha1-adrenergic inhibitor prazosin. To define the role of adrenergic stimulation in the up-regulation of NF-kappaB, THP-1 cells were induced with physiological amounts of catecholamines for 10 min. Only noradrenaline resulted in a dose- and time-dependent induction of NF-kappaB and NF-kappaB-dependent gene expression, which depended on pertussis-toxin-sensitive G protein-mediated phosphophatidylinositol 3-kinase, Ras/Raf, and mitogen-activated protein kinase activation. Induction was reduced by alpha(1)- and beta-adrenergic inhibitors. Thus, noradrenaline-dependent adrenergic stimulation results in activation of NF-kappaB in vitro and in vivo. Activation of NF-kappaB represents a downstream effector for the neuroendocrine response to stressful psychosocial events and links changes in the activity of the neuroendocrine axis to the cellular response.

Adrenocorticotropic Hormone↗

PubMed2003

Recovery of spatial memory and persistence of spatial orientation deficits after traumatic brain injury during childhood.

The present study set out to examine the recovery of spatial learning and cognitive mapping skills after severe TBI in childhood. A prospective investigation was carried out with repeated measures. Children with TBI (n = 18) and healthy matched controls (n = 18) were investigated while the children with TBI stayed in a rehabilitation facility (t0) and 4 years later (t1). Children were assessed with the Kiel Locomotor Maze, where they had to remember defined locations in an experimental chamber with completely controlled intra- and extra-maze cues until the learning criterion was reached. During probe trials, cognitive mapping strategies were assessed. Results showed (i) that spatial learning is functionally restituted 4 years post-trauma and (ii) that cognitive mapping skills are still impaired 4 years post-trauma. It was concluded that cognitive performance of children who survived a severe TBI may he overestimated, having far reaching consequences for the children.

Analysis of Variance↗

PubMed2003

The role of locomotion in the acquisition and transfer of spatial knowledge in children.

The role of locomotion in the acquisition and transfer of spatial knowledge was investigated in 144 five-, seven- and eleven-year-old children. Two experiments were conducted in the Kiel locomotor maze. In the first experiment, one group of children explored the spatial layout by walking through the maze, while another learned the maze by surveying the layout. In the second experiment, children were exposed to one of two orientation tests in the maze, one of which could be solved using "landmark orientation", the other only using a "relational place orientation". Children sitting by the side of the experimental chamber surveying the maze needed fewer trials to learn the spatial layout than children exploring the environment in the locomotion condition, but in the orientation test demanding the "relational place orientation" children who had explored the maze in the locomotion condition outperformed the children in the non-locomotion condition. Results are discussed in the context of cognitive mapping models.

Child↗

PubMed2003

Convergent and divergent effects of odors and emotions in depression.

The aim of the present study was to investigate the similarities and differences in the olfactory and visual processing of emotional stimuli in healthy subjects and in patients with major depressive disorder (MDD). Twenty-five inpatients were investigated after admission to the psychiatric clinic. Fifteen of them participated a second time, shortly before their discharge from the hospital. A group of healthy subjects, matched according to age and sex, served as a control. Chemsosensory event-related potentials (CSERPs) were recorded using the constant flow method. In addition, event-related potentials (ERPs), in response to colors and emotional slides, were obtained to control modality and emotion-specific effects. The subjects' task was to discriminate the colors (red/yellow) and odors (phenyl-ethylalcohol = rose/ isobutyraldehyde = rotten butter) according to their quality and to judge the valence of the emotional slides (IAPS slides). The EEG was recorded from 32 scalp locations. At the beginning of the therapy, visual stimulus processing was attenuated in depressive subjects at a relatively late processing level (reduced amplitudes of the P3 and pSW in response to colors and emotional slides), whereas olfactory stimulus processing had already been affected at an early level (reduced amplitudes of the P2 and P3-1 peaks in MDD patients). However, after successful medical treatment, ERPs did not differentiate between depressive patients and healthy controls. We discuss whether functional deviations within the primary olfactory cortex are responsible for the lower olfactory sensitivity, as well as for the altered emotional stimulus processing in MDD patients.

Adult↗

PubMed2003

Navigational place learning in children and young adults as assessed with a standardized locomotor search task.

Spatial behaviour was investigated using a spatial learning task based on the Radial Arm Maze, the Morris Water Maze, and open-field search-task procedures. Ninety-six healthy children from six age groups (3, 4, 5, 7, 10 and 12 years) with no history of CNS disorders were studied with respect to the emergence of position-, cue- and place responses. Participants were to detect x out of n hidden locations, frames of reference could be varied systematically, and three spatial memory errors and speed of navigation were recorded automatically. Task difficulties were equivalent for each age group. Results showed that navigational place learning was fully developed by the age of 10, whereas participants relied on cue orientation up to age 7. Even in the youngest group, the task could be achieved without relying on egocentric orientation, provided that proximal cues were presented. Most of the errors were of the reference memory type, whereas working memory errors were extremely rare. Speed of navigation markedly improved between age 5 and 7. An additional experiment showed that navigational place-learning behaviour was clearly dependent on distal cues. A third study showed that in young adults, learning of the spatial layout improved, but performance on the place task did not improve any further. No sex differences were observed.

Adolescent↗