Genetic variation in dopamine availability modulates the self-reported level of action control in a sex-dependent manner

Although procrastination is a widespread phenomenon with significant influence on our personal and professional life, its genetic foundation is somewhat unknown. An important factor that influences our ability to tackle specific goals directly instead of putting them off is our ability to initiate cognitive, motivational and emotional control mechanisms, so-called metacontrol. These metacontrol mechanisms have been frequently related to dopaminergic signaling. To gain deeper insight into the genetic components of procrastination, we examined whether genetically induced differences in the dopaminergic system are associated with interindividual differences in trait-like procrastination, measured as decision-related action control (AOD). Analyzing the data of 278 healthy adults, we found a sex-dependent effect of TH genotype on AOD. Interestingly, only in women, T-allele carriers showed lower AOD values and were therefore more likely to procrastinate. Additionally, we investigated whether differences in the morphology and functional connectivity of the amygdala that were previously associated with AOD happen to be related to differences in the TH genotype and thus to differences in the dopaminergic system. However, there was no significant amygdala volume or connectivity difference between the TH genotype groups. Therefore, this study is the first to suggest that genetic, anatomical and functional differences affect trait-like procrastination independently.

The Structural and Functional Signature of Action Control

Individuals differ in their ability to initiate self- and emotional-control mechanisms. These differences have been explicitly described in Kuhl’s action-control theory. Although interindividual differences in action control make a major contribution to our everyday life, their neural foundation remains unknown. Here, we measured action control in a sample of 264 healthy adults and related interindividual differences in action control to variations in brain structure and resting-state connectivity. Our results demonstrate a significant negative correlation between decision-related action orientation (AOD) and amygdala volume. Further, we showed that the functional resting-state connectivity between the amygdala and the dorsal anterior cingulate cortex was significantly associated with AOD. Specifically, stronger functional connectivity was associated with higher AOD scores. These findings are the first to show that interindividual differences in action control, namely AOD, are based on the anatomical architecture and functional network of the amygdala.

Proper Emotion Recognition, Dysfunctional Emotion Regulation

OBJECTIVE

A considerable number of adolescents exhibit severe self-regulation deficits in affect and behavior, which are referred to as affective dysregulation (AD). AD may be conceptualized as a dimensional trait that, in its extreme form, resembles the diagnostic categories of severe mood dysregulation (SMD) or disruptive mood dysregulation disorder (DMDD). Assuming a shared pathway of psychopathology in AD and SMD, similar underlying dysfunctional mechanisms in emotion processing, particularly emotion recognition (RECOG) and regulation (REGUL), may be postulated.

METHOD

Adolescent inpatients with AD (CAD, N = 35), without AD (CCG, N = 28), and nonclinical controls (NCG; N = 28) were administered a morphed facial recognition task (RECOG). REGUL abilities, levels of irritability as well as depressive symptoms were also assessed.

RESULTS

We found no significant group differences in accuracy and thresholds for RECOG abilities. Patients with AD reported more dysfunctional REGUL strategies than did CCG and NCG. Both depression and AD, but not irritability, influenced the overall degree of maladaptive REGUL.

CONCLUSION

The broad phenotype of AD does not involve the deficits in RECOG reported for adolescents with a narrow phenotype (SMD); regarding REGUL strategies, AD seems to be associated with specific impairments.

Getting access to the self: Effects of self-management therapy on the development of self-regulation and inhibitory control in obese adolescents

BACKGROUND AND AIMS

This study investigated the role of self-regulation competencies in general and specifically in a food-related context for the control of body weight in a three-year weight loss program.

METHODS

The sample consisted of 30 male and female adolescents (age range: 11-18 years) who participated in a three-year therapy program for severe obesity (mean BMI at the beginning of the intervention was 33.6). Assessment of self-regulation competencies was conducted at three different stages (1(st)-3(rd) graduation/class year). Therefore, three independent groups of adolescents (N = 10) at these different stages were tested (initial-to final-stage of therapy). At the time of testing the BMI of these groups significantly differed from 38.8 to 28.7. Analyses of covariance were performed to determine whether the adolescents also differed in self-regulation skills like "resistance to temptation" and food-related Stroop interference along with ameliorating their energy-balance regulation.

RESULTS

In addition to the main effects of age and body mass index, adolescents further displayed significant improvements of executive functions with respect to resistance to temptation and inhibition.

CONCLUSIONS

Interventions aimed at enhancing energy-balance regulation in adolescents may further benefit from efforts to facilitate executive functions such as self-regulation and food-related cognitive inhibition.

Smooth pursuit performance in families with multiple occurrence of schizophrenia and nonpsychotic families

BACKGROUND

Eye tracking dysfunction (ETD) has been put forward as a trait marker for biological susceptibility to schizophrenia with the hope of identifying a link to specific cerebral lesions.

METHODS

Eye movements were recorded using infrared oculography in 8 families (67 members) showing multiple occurrence of schizophrenia and in 9 nonpsychotic families (80 members). Triangle wave stimuli at 15 degrees/s and 30 degrees/s were used and gains (eye velocity/target velocity), rates and amplitudes of different saccade categories (catch-up, back-up, anticipatory saccades, and squarewave-jerks) were determined.

RESULTS

In the relatives, the same deficit in maintenance of smooth pursuit performance was found as was seen in the schizophrenic patients. This deficit, which was not observed in the nonpsychotic families, consisted of lower gains for leftward as compared to rightward pursuit. This was emphasized most clearly at 30 degrees/s and was associated with an excess of catch-up saccades in the schizophrenic patients, whereas in the relatives a tendency to exhibit more and larger anticipatory saccades was observed.

CONCLUSIONS

The results confirm the hypothesis that eye-tracking dysfunction is a phenotypic marker for genetic liability to schizophrenia. Neurophysiologically, a cerebral dysfunction which includes one or more of the oculomotor centers can be assumed in subjects who carry a genetic susceptibility to schizophrenia.

Phase grating from ordered polymer lattices for optica image preprocessing

The 'inverted' retina of the human eye can beemulated by multilayer gratings from polymer latexparticles located in the image plane of opticalsystems. This so called OPTO-RETINA provides v. Laueinterference patterns in visible light with atrichromatic characteristic containing,simultaneously, local spatiotemporal direction anddistance information, which are relevant to 3Dspatial vision and 4D spatiotemporal Fouriercorrelator-optical preprocessing in shape andmotion analysis.As a first step in the realization of OPTO-RETINAproperties the formation of hexagonally orderedmonolayers of polystyrene latex sphereswith diameters in the~μm range is reported and firstresults of diffraction and dispersion of white lightby these layers obtained by conoscopical opticalmicroscopy are presented.

Production of interferon-gamma in families with multiple occurrence of schizophrenia

Dysfunction of T-cell mediated immunity, which is indicated by deficient production of interleukin-2 (IL-2) and elevated levels of the soluble interleukin-2 receptor (sIL-2R), has been consistently demonstrated in schizophrenia. Recent studies on interferon-gamma (IFN-gamma), a cytokine which is also produced by T-helper cells, have indicated a lowered production in acute schizophrenia. It is not known whether this deficit is restricted to cases of acute schizophrenia or whether it is also present in residual schizophrenia and in first degree relatives, and therefore might be associated with genetic liability to the disease. We investigated 27 individuals (schizophrenics and first degree relatives) of 6 families with multiple occurrence of schizophrenia and 27 age- and sex-matched healthy controls. The production of IFN-gamma was lowered only in the acutely ill schizophrenic individuals, when compared to both controls and first degree relatives. In the context of current knowledge, this result indicates that the production of IFN-gamma can be discussed as a marker of acute exacerbation of schizophrenia, but it is not likely to represent a phenotypic marker of a genetic trait associated with the disease.

Eye tracking dysfunction is a putative phenotypic susceptibility marker of schizophrenia and maps to a locus on chromosome 6p in families with multiple occurrence of the disease

The difficulties in defining the borders of the schizophrenia spectrum is one major source of variance in linkage studies of schizophrenia. The employment of biological markers may prove advantageous. Due to empirical evidence, eye tracking dysfunction (ETD) has been discussed to be the most promising marker for genetic liability to schizophrenia. With respect to the recent progress in genomic scans, which have pointed to the short arm of chromosome 6, we carried out a scan of the 6p21-23 region with 16 microsatellite markers to test for linkage between chromosomal markers and ETD as well as schizophrenia. We tested 5 models of inheritance of ETD and found maximum two-point lod scores of 3.51 for D6S271 and 3.44 for D6S282. By including these markers in a multipoint analysis, a lod score of 4.02 was obtained. In the case of schizophrenia, 7 models were tested; however, with non-significant results. Our findings, together with another recent linkage report, point to the possibility of a second susceptibility locus for schizophrenia which may be located centromeric to the HLA region. Also, the evidence of ETD being a susceptibility marker for schizophrenia receives further support.

Eye tracking dysfunction in families with multiple cases of schizophrenia

There is increasing evidence that the genetic predisposition for schizophrenia in families affects more individuals than those fulfilling the criteria for schizophrenia. This finding is supposed to be one of the major problems in molecular genetic schizophrenia research, especially when linkage studies are employed. Eye-tracking dysfunction (ETD), which is conceived as a possible phenotypic marker for genetic liability to schizophrenia, may offer considerable advantages. However, there is only little information from families with multiple occurrence of schizophrenia. It is still unclear whether in these families ETD aggregates with diagnoses from the schizophrenia spectrum. This first report from an ongoing study presents the results of 48 individuals from 6 multiplex families. Smooth-pursuit eye movements were recorded by infrared reflectometry and assessed by quantitative measurement techniques. Along with the high degree of psychiatric morbidity in these families, in 56.3% of the individuals ETD was assessed. Reduced mean pursuit gain was present in 39.6%. The distribution of eye-tracking dysfunction resembles the distribution of schizophrenia-related psychiatry morbidity.

Olfactory and gustatory stimuli in food-aversion learning of rats

Two studies of food-aversion learning in the rat examined some crucial conditions for the potentiation of an odor component by a novel taste. Wistar rats were exposed twice to an odor-taste compound and then were treated either immediately or the next day with lithium chloride, a noxious substance. Immediately poisoned rats acquired an aversion to the odor component when it was paired with a familiar taste. Only in one experimental condition did some weak conditioning occur: when the new odor was presented together with a new taste. Thus, the classical phenomenon of overshadowing of the less salient odor component by the more salient taste was observed in all of our studies. This was true for situations in which the odor was presented near the drinking spout as well as for situations in which the odor was presented at some distance in front of the drinking source (Experiment 1). In addition, the weaker an odor component was, the more easily it was overshadowed by the taste (Experiment 2). All results fit well into classical rules of Pavlovian conditioning and fail to support the assumption that special mechanisms exist in food-related odor conditioning in rats.