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The influence of the dopamine agonist Ritalin-® on performance in a card sorting task involving a monetary reward component was tested in 43 healthy male participants. It was investigated whether Ritalin-® would have differential behavioral effects as a function of the participants' parental bonding experiences and the personality variable "Novelty Seeking". When activity and performance accuracy were stimulated my monetary reward, Ritalin-® reduced activity in response to reward and added to the reward-induced increase in performance accuracy. However, performance accuracy after drug challenge was improved only in the low care participants. In the high care participants, it was contrarily impaired. This observation suggests that the successful therapeutic administration of Ritalin-® in ADHD may be influenced by early life parental care. Suggesting an association between the personality dimension of "Novelty Seeking" and the dopamine system, high "Novelty Seeking" scores positively correlated with sensitivity to Ritalin-® challenge.
The distractor-response binding effect (Frings & Rothermund, 2011; Frings, Rothermund, & Wentura, 2007; Rothermund, Wentura, & De Houwer, 2005) is based on the idea that irrelevant information will be integrated with the response to the relevant stimuli in an episodic memory trace. The immediate re-encounter of any aspect of this saved episode " be it relevant or irrelevant " can lead to retrieval of the whole episode. As a consequence, the previously executed and now retrieved response may influencing the response to the current relevant stimulus. That is, the current response may either be facilitated or be impaired by the retrieved response, depending on whether it is compatible or incompatible to the currently demanded response. Previous research on this kind of episodic retrieval focused on the influence on action control. I examined if distractor response binding also plays a role in decision making in addition to action control. To this end I adapted the distractor-to-distractor priming paradigm (Frings et al., 2007) and conducted nine experiments in which participants had to decide as fast as possible which disease a fictional patient suffered from. To infer the correct diagnosis, two cues were presented; one did not give any hint for a disease (the irrelevant cue), whereas the other did (the relevant cue). Experiments 1a to 1c showed that the distractor-response binding effect is present in deterministic decision situations. Further, experiments 2a and 2b indicate that distractor-response binding also influences decisions under uncertainty. Finally, experiments 3a to 3d were conducted to test some constraints and underlying mechanisms of the distractor-response binding effect in decision making under uncertainty. In sum, these nine experiments provide strong evidence that distractor-response binding influences decision making.
List-method directed forgetting (LMDF) is the demonstration that people can intentionally forget previously studied information when they are asked to forget what they have previously learned and remember new information instead. In addition, recent research demonstrated that people can selectively forget when cued to forget only a subset of the previously studied information. Both forms of forgetting are typically observed in recall tests, in which the to-be-forgotten and to-be-remembered information is tested independent of original cuing. Thereby, both LMDF and selective directed forgetting (SDF) have been studied mostly with unrelated item materials (e.g., word lists). The present study examined whether LMDF and SDF generalize to prose material. Participants learned three prose passages, which they were cued to remember or forget after the study of each passage. At the time of testing, participants were asked to recall the three prose passages regardless of original cuing. The results showed no significant differences in recall of the three lists as a function of cuing condition. The findings suggest that LMDF and SDF do not occur with prose material. Future research is needed to replicate and extend these findings with (other) complex and meaningful materials before drawing firm conclusions. If the null effect proves to be robust, this would have implications regarding the ecological validity and generalizability of current LMDF and SDF findings.
Interoception - the perception of bodily processes - plays a crucial role in the subjective experience of emotion, consciousness and symptom genesis. As an alternative to interoceptive paradigms that depend on the participants" active cooperation, five studies are presented to show that startle methodology may be employed to study visceral afferent processing. Study 1 (38 volunteers) showed that startle responses to acoustic stimuli of 105 dB(A) intensity were smaller when elicited during the cardiac systole (R-wave +230 ms) as compared to the diastole (R +530 ms). In Study 2, 31 diabetic patients were divided into two groups with normal or diminished (< 6 ms/mmHg) baroreflex sensitivity (BRS) of heart rate control. Patients with normal BRS showed a startle inhibition during the cardiac systole as was found for healthy volunteers. Diabetic patients with diminished BRS did not show this pattern. Because diminished BRS is an indicator of impaired baro-afferent signal transmission, we concluded that cardiac modulation of startle is associated with intact arterial baro-afferent feedback. Thus, pre-attentive startle methodology is feasible to study visceral afferent processing. rnVisceral- and baro-afferent information has been found to be mainly processed in the right hemisphere. To explore whether cardiac modulation of startle eye blink is lateralized as well, in Study 3, 37 healthy volunteers received 160 unilateral acoustic startle stimuli presented to both ears, one at a time (R +0, 100, 230, 530 ms). Startle response magnitude was only diminished at R +230 ms and for left-ear presentation. This lateralization effect in the cardiac modulation of startle eye blink may reflect the previously described advantages of right-hemispheric brain structures in relaying viscero- and baro-afferent signal transmission. rnThis lateralization effect implies that higher cognitive processes may also play a role in the cardiac modulation of startle. To address this question, in Study 4, 25 volunteers responded first by 'fast as possible' button pushes (reaction time, RT), and second, rated perceived intensity of 60 acoustic startle stimuli (85, 95, or 105 dB; R +230, 530 ms). RT was divided into evaluation and motor response time. Increasing stimulus intensity enhanced startle eye blink, intensity ratings, and RT components. Eye blinks and intensity judgments were lower when startle was elicited at a latency of R +230 ms, but RT components were differentially affected. It is concluded that the cardiac cycle affects the attentive processing of acoustic startle stimuli. rnBeside the arterial baroreceptors, the cardiopulmonary baroreceptors represent another important system of cardiovascular perception that may have similar effects on startle responsiveness. To clarify this issue, in Study 5, Lower Body Negative Pressure at gradients of 0, -10, -20, and -30 mmHg was applied to unload cardiopulmonary baroreceptors in 12 healthy males, while acoustic startle stimuli were presented (R +230, 530 ms). Unloading of cardiopulmonary baroreceptors increased startle eye blink responsiveness. Furthermore, the effect of relative loading/unloading of arterial baroreceptors on startle eye blink responsiveness was replicated. These results demonstrate that the loading status of cardiopulmonary baroreceptors also has an impact on brainstem-based CNS processes. rnThus, the cardiac modulation of acoustic startle is feasible to reflect baro-afferent signal transmission of multiple neural sources, it represents a pre-attentive method that is independent of active cooperation, but its modulatory effects also reach higher cognitive, attentive processes.rn
Cognitive performance is contingent upon multiple factors. Beyond the impact of en-vironmental circumstances, the bodily state may hinder or promote cognitive processing. Af-ferent transmission from the viscera, for instance, is crucial not only for the genesis of affect and emotion, but further exerts significant influences on memory and attention. In particular, afferent cardiovascular feedback from baroreceptors demonstrated subcortical and cortical inhibition. Consequences for human cognition and behavior are the impairment of simple perception and sensorimotor functioning. Four studies are presented that investigate the mod-ulatory impact of baro-afferent feedback on selective attention. The first study demonstrates that the modulation of sensory processing by baroreceptor activity applies to the processing of complex stimulus configurations. By the use of a visual masking task in which a target had to be selected against a visual mask, perceptual interference was reduced when target and mask were presented during the ventricular systole compared to the diastole. In study two, selection efficiency was systematically manipulated in a visual selection task in which a target letter was flanked by distracting stimuli. By comparing participants" performance under homogene-ous and heterogeneous stimulus conditions, selection efficiency was assessed as a function of the cardiac cycle phase in which the targets and distractors were presented. The susceptibility of selection performance to the stimulus condition at hand was less pronounced during the ventricular systole compared to the diastole. Study one and two therefore indicate that inter-ference from irrelevant sensory input, resulting from temporally overlapping processing traces or from the simultaneous presentation of distractor stimuli, is reduced during phases of in-creased baro-afferent feedback. Study three experimentally manipulated baroreceptor activity by systematically varying the participant- body position while a sequential distractor priming task was completed. In this study, negative priming and distractor-response binding effects were obtained as indices of controlled and automatic distractor processing, respectively. It was found that only controlled distractor processing was affected by tonic increases in baro-receptor activity. In line with study one and two these results indicate that controlled selection processes are more efficient during enhanced baro-afferent feedback, observable in dimin-ished aftereffects of controlled distractor processing. Due to previous findings that indicated baro-afferent transmission to affect central, rather than response-related processing stages, study four measured lateralized-readiness potentials (LRPs) and reaction times (RTs), while participants, again, had to selectively respond to target stimuli that were surrounded by dis-tractors. The impact of distractor inhibition on stimulus-related, but not on response-related LRPs suggests that in a sequential distractor priming task, the sensory representations of dis-tractors, rather than motor responses are targeted by inhibition. Together with the results from studies one through three and the finding of baroreceptor-mediated behavioral inhibition tar-geting central processing stages, study four corroborates the presumption of baro-afferent signal transmission to modulate controlled processes involved in selective attention. In sum, the work presented shows that visual selective attention benefits from in-creased baro-afferent feedback as its effects are not confined to simple perception, but may facilitate the active suppression of neural activity related to sensory input from distractors. Hence, due to noise reduction, baroreceptor-mediated inhibition may promote effective selec-tion in vision.
Objective: Only 20-25% of the variance for the two to four-fold increased risk of developing breast cancer among women with family histories of the disease can be explained by known gene mutations. Other factors must exist. Here, a familial breast cancer model is proposed in which overestimation of risk, general distress, and cancer-specific distress constitute the type of background stress sufficient to increase unrelated acute stress reactivity in women at familial risk for breast cancer. Furthermore, these stress reactions are thought to be associated with central adiposity, an independent well-established risk factor for breast cancer. Hence, stress through its hormonal correlates and possible associations with central adiposity may play a crucial role in the etiology of breast cancer in women at familial risk for the disease. Methods: Participants were 215 healthy working women with first-degree relatives diagnosed before (high familial risk) or after age 50 (low familial risk), or without breast cancer in first-degree relatives (no familial risk). Participants completed self-report measures of perceived lifetime breast cancer risk, intrusive thoughts and avoidance about breast cancer (Impact of Event Scale), negative affect (Profile of Mood States), and general distress (Brief Symptom Inventory). Anthropometric measurements were taken. Urine samples during work, home, and sleep were collected for assessment of cortisol responses in the naturalistic setting where work was conceptualized as the stressful time of the day. Results: A series of analyses indicated a gradient increase of cortisol levels in response to the work environment from no, low, to high familial risk of breast cancer. When adding breast cancer intrusions to the model with familial risk status predicting work cortisol levels, significant intrusion effects emerged rendering the familial risk group non-significant. However, due to a lack of association between intrusions and cortisol in the low and high familial risk group separately, as well as a significant difference between low and high familial risk on intrusions, but not on work cortisol levels, full mediation of familial risk group effects on work cortisol by intrusions could not be established. A separate analysis indicated increased levels of central but not general adiposity in women at high familial risk of breast cancer compared to the low and no risk groups. There were no significant associations between central adiposity and cortisol excretion. Conclusion: A hyperactive hypothalamus-pituitary-adrenal axis with a more pronounced excretion of its end product cortisol, as well as elevated levels of central but not overall adiposity in women at high familial risk for breast cancer may indicate an increased health risk which expands beyond that of increased breast cancer risk for these women.
This intervention study explored the effects of a newly developed intergenerational encounter program on cross-generational age stereotyping (CGAS). Based on a biographical-narrative approach, participants (secondary school students and nursing home residents) were invited to share ideas about existential questions of life (e.g., about one’s core experiences, future plans, and personal values). Therefore, the dyadic Life Story Interview (LSI) had been translated into a group format (the Life Story Encounter Program, LSEP), consisting of 10 90-min sessions. Analyses verified that LSEP participants of both generations showed more favorable CGAS immediately after, but also 3 months after the program end. Such change in CGAS was absent in a control group (no LSEP participation). The LSEP-driven short- and long-term effects on CGAS could be partially explained by two program benefits, the feeling of comfort with and the experience of learning from the other generation.
Magnet Resonance Imaging (MRI) and Electroencephalography (EEG) are tools used to investigate the functioning of the working brain in both humans and animal studies. Both methods are increasingly combined in separate or simultaneous measurements under the assumption to benefit from their individual strength while compensating their particular weaknesses. However, little attention has been paid to how statistical analyses strategies can influence the information that can be retrieved from a combined EEG fMRI study. Two independent studies in healthy student volunteers were conducted in the context of emotion research to demonstrate two approaches of combining MRI and EEG data of the same participants. The first study (N = 20) applied a visual search paradigm and found that in both measurements the assumed effects were absent by not statistically combining their results. The second study (N = 12) applied a novelty P300 paradigm and found that only the statistical combination of MRI and EEG measurements was able to disentangle the functional effects of brain areas involved in emotion processing. In conclusion, the observed results demonstrate that there are added benefits of statistically combining EEG-fMRI data acquisitions by assessing both the inferential statistical structure and the intra-individual correlations of the EEG and fMRI signal.
Educational researchers have intensively investigated students" academic self-concept (ASC) and self-efficacy (SE). Both constructs are part of the competence-related self-perceptions of students and are considered to support students" academic success and their career development in a positive manner (e.g., Abele-Brehm & Stief, 2004; Richardson, Abraham, & Bond, 2012; Schneider & Preckel, 2017). However, there is a lack of basic research on ASC and SE in higher education in general, and in undergraduate psychology courses in particular. Therefore, according to the within-network and between-network approaches of construct validation (Byrne, 1984), the present dissertation comprises three empirical studies examining the structure (research question 1), measurement (research question 2), correlates (research question 3), and differentiation (research question 4) of ASC and SE in a total sample of N = 1243 psychology students. Concerning research question 1, results of confirmatory factor analysis (CFAs) implied that students" ASC and SE are domain-specific in the sense of multidimensionality, but they are also hierarchically structured, with a general factor at the apex according to the nested Marsh/Shavelson model (NMS model, Brunner et al., 2010). Additionally, psychology students" SE to master specific psychological tasks in different areas of psychological application could be described by a 2-dimensional model with six factors according to the Multitrait-Multimethod (MTMM)-approach (Campbell & Fiske, 1959). With regard to research question 2, results revealed that the internal structure of ASC and SE could be validly assessed. However, the assessment of psychology students" SE should follow a task-specific measurement strategy. Results of research question 3 further showed that both constructs of psychology students" competence-related self-perceptions were positively correlated to achievement in undergraduate psychology courses if predictor (ASC, SE) corresponded to measurement specificity of the criterion (achievement). Overall, ASC provided substantially stronger relations to achievement compared to SE. Moreover, there was evidence for negative paths (contrast effects) from achievement in one psychological domain on ASC of another psychological domain as postulated by the internal/external frame of reference (I/E) model (Marsh, 1986). Finally, building on research questions 1 to 3 (structure, measurement, and correlates of ASC and SE), psychology students" ASC and SE were be differentiated on an empirical level (research question 4). Implications for future research practices are discussed. Furthermore, practical implications for enhancing ASC and SE in higher education are proposed to support academic achievement and the career development of psychology students.
There is considerable evidence for an association between chronic dysregulation of the hypothalamus-pituitary adrenal (HPA) axis, atrophy of the hippocampus (HC) and cognitive and mood changes in clinical populations and in aging. The present thesis investigated this relationship in young healthy male subjects. Special emphasis was put on measures of HC volume and function derived from structural and functional magnetic resonance imaging (MRI). Higher cortisol levels after awakening were observed in subjects with higher levels of depressive symptomatology. Larger HC volume was associated with higher cortisol levels after awakening and in response to acute stress, whereas cognitive performance was impaired in subjects with larger HC volumes. Hippocampal activation during picture encoding was reduced after stress induction, and positive associations between activation and cognitive performance before stress were not present anymore afterwards. The present findings underscore the importance of structural and functional brain imaging for psychoneuroendocrinological research. The investigation of the association between cortisol levels and hippocampal integrity in young healthy subjects elicited unexpected results and adds to the understanding of HPA dysfunction and HC atrophy in clinical and aged populations.