German physicians' perceptions and views on complementary medicine in pediatric oncology: a qualitative study.

Complementary and alternative medicine (CAM) use in children with cancer has a high prevalence. If (parents of) patients bring up the topic of CAM, pediatric oncologists (POs) face considerable challenges regarding knowledge and professional behavior. In this study, we explore German POs' understanding of CAM and related attitudes as well as challenges and strategies related to CAM discussions by means of semi-structured interviews analyzed according to principles of qualitative thematic analysis with parents of children with cancer. We could conduct 14 interviews prior to theoretical saturation. The interviews had a duration of 15-82 min (M = 30.8, SD = 18.2). Professional experience in pediatric oncology was between 0.5 and 26 years (M = 13.8, SD = 7.6). Main themes identified were a heterogeneous understanding and evaluation of CAM, partly influenced by personal experiences and individual views on plausibility; the perception that CAM discussions are a possible tool for supporting parents and their children and acknowledgement of limitations regarding implementation of CAM discussions; and uncertainty and different views regarding professional duties and tasks when being confronted with CAM as a PO. Our interdisciplinary interpretation of findings with experts from (pediatric) oncology, psychology, and ethics suggests that there is need for development of a consensus on the minimal professional standards regarding addressing CAM in pediatric oncology.

Dorsal posterior cingulate cortex encodes the informational value of feedback in human-computer interaction.

In communication between humans as well as in human-computer interaction, feedback is ubiquitous. It is essential for keeping up the dialogue between interaction partners, evaluating the adequacy of an action, or improving task performance. While the neuroscientific view on feedback has largely focused on its function as reward, more general definitions also emphasise its function as information about aspects of one's task performance. Using fMRI in a computer-controlled auditory categorisation task, we studied the neural correlates of the informational value of computer-given feedback independent of reward. Feedback about the correctness of a decision, compared with feedback only indicating the registration of a decision, increases activation of the dorsal posterior cingulate cortex, supporting this region's role in adapting to behaviourally relevant information. Both conditions elicit equally strong activation of the dorsal striatum which does not support an interpretation of feedback information as a type of reward. Instead, we suggest that it reflects a more fundamental aspect of human interaction behaviour, namely the establishment of a state that enables us to continue with the next step of the interaction.

Delays in Human-Computer Interaction and Their Effects on Brain Activity.

The temporal contingency of feedback is an essential requirement of successful human-computer interactions. The timing of feedback not only affects the behavior of a user but is also accompanied by changes in psychophysiology and neural activity. In three fMRI experiments we systematically studied the impact of delayed feedback on brain activity while subjects performed an auditory categorization task. In the first fMRI experiment, we analyzed the effects of rare and thus unexpected delays of different delay duration on brain activity. In the second experiment, we investigated if users can adapt to frequent delays. Therefore, delays were presented as often as immediate feedback. In a third experiment, the influence of interaction outage was analyzed by measuring the effect of infrequent omissions of feedback on brain activity. The results show that unexpected delays in feedback presentation compared to immediate feedback stronger activate inter alia bilateral the anterior insular cortex, the posterior medial frontal cortex, the left inferior parietal lobule and the right inferior frontal junction. The strength of this activation increases with the duration of the delay. Thus, delays interrupt the course of an interaction and trigger an orienting response that in turn activates brain regions of action control. If delays occur frequently, users can adapt, delays become expectable, and the brain activity in the observed network diminishes over the course of the interaction. However, introducing rare omissions of expected feedback reduces the system's trustworthiness which leads to an increase in brain activity not only in response to such omissions but also following frequently occurring and thus expected delays.

Delayed system response times affect immediate physiology and the dynamics of subsequent button press behavior.

System response time research is an important issue in human-computer interactions. Experience with technical devices and general rules of human-human interactions determine the user's expectation, and any delay in system response time may lead to immediate physiological, emotional, and behavioral consequences. We investigated such effects on a trial-by-trial basis during a human-computer interaction by measuring changes in skin conductance (SC), heart rate (HR), and the dynamics of button press responses. We found an increase in SC and a deceleration of HR for all three delayed system response times (0.5, 1, 2 s). Moreover, the data on button press dynamics was highly informative since subjects repeated a button press with more force in response to delayed system response times. Furthermore, the button press dynamics could distinguish between correct and incorrect decisions and may thus even be used to infer the uncertainty of a user's decision.

Human striatum is differentially activated by delayed, omitted, and immediate registering feedback.

The temporal contingency of feedback during conversations is an essential requirement of a successful dialog. In the current study, we investigated the effects of delayed and omitted registering feedback on fMRI activation and compared both unexpected conditions to immediate feedback. In the majority of trials of an auditory task, participants received an immediate visual feedback which merely indicated that a button press was registered but not whether the response was correct or not. In a minority of trials, and thus unexpectedly, the feedback was omitted, or delayed by 500 ms. The results reveal a response hierarchy of activation strength in the dorsal striatum and the substantia nigra: the response to the delayed feedback was larger compared to immediate feedback and immediate feedback showed a larger activation compared to the omission of feedback. This suggests that brain regions typically involved in reward processing are also activated by non-rewarding, registering feedback. Furthermore, the comparison with immediate feedback revealed that both omitted and delayed feedback significantly modulated activity in a network of brain regions that reflects attentional demand and adjustments in cognitive and action control, i.e., the posterior medial frontal cortex (pMFC), right dorsolateral prefrontal cortex (dlPFC), bilateral anterior insula (aI), inferior frontal gyrus (Gfi), and inferior parietal lobe (Lpi). This finding emphasizes the importance of immediate feedback in human-computer interaction, as the effects of delayed feedback on brain activity in the described network seem to be similar to that of omitted feedback.