Temporal characteristics of the influence of punishment on perceptual decision making in the human brain

Perceptual decision making is the process by which information from sensory systems is combined and used to influence our behavior. In addition to the sensory input, this process can be affected by other factors, such as reward and punishment for correct and incorrect responses. To investigate the temporal dynamics of how monetary punishment influences perceptual decision making in humans, we collected electroencephalography (EEG) data during a perceptual categorization task whereby the punishment level for incorrect responses was parametrically manipulated across blocks of trials. Behaviorally, we observed improved accuracy for high relative to low punishment levels. Using multivariate linear discriminant analysis of the EEG, we identified multiple punishment-induced discriminating components with spatially distinct scalp topographies. Compared with components related to sensory evidence, components discriminating punishment levels appeared later in the trial, suggesting that punishment affects primarily late postsensory, decision-related processing. Crucially, the amplitude of these punishment components across participants was predictive of the size of the behavioral improvements induced by punishment. Finally, trial-by-trial changes in prestimulus oscillatory activity in the alpha and gamma bands were good predictors of the amplitude of these components. We discuss these findings in the context of increased motivation/attention, resulting from increases in punishment, which in turn yields improved decision-related processing

Integrating across memory episodes: Developmental trends

Memory enables us to use information from our past experiences to guide new behaviours, calling for the need to integrate or form inference across multiple distinct episodic experiences. Here, we compared children (aged 9-10 years), adolescents (aged 12-13 years), and young adults (aged 19-25 years) on their ability to form integration across overlapping associations in memory. Participants first encoded a set of overlapping, direct AB- and BC-associations (object-face and face-object pairs) as well as non-overlapping, unique DE-associations. They were then tested on these associations and inferential AC-associations. The experiment consisted of four such encoding/retrieval cycles, each consisting of different stimuli set. For accuracy on both unique and inferential associations, young adults were found to outperform teenagers, who in turn outperformed children. However, children were particularly slower than teenagers and young adults in making judgements during inferential than during unique associations. This suggests that children may rely more on making inferences during retrieval, by first retrieving the direct associations, followed by making the inferential judgement. Furthermore, young adults showed a higher correlation between accuracy in direct (AB, BC) and inferential AC-associations than children. This suggests that, young adults relied closely on AB- and BC-associations for making AC decisions, potentially by forming integrated ABC-triplets during encoding or retrieval. Taken together, our findings suggest that there may be an age-related shift in how information is integrated across experienced episodes, namely from relying on making inferences at retrieval during middle childhood to forming integrated representations at different memory processing stages in adulthood

The presence of supposedly primitive human tools along the upper reaches of the Kizil Irmak in Anatolia

Die ersten Angaben über Flußterrassen in Ost-Anatolien wurden vor kurzem durch Izbirak (1962) und Ketin (1962) gemacht. Die Verfasser der vorliegenden Arbeit haben eine rasche und noch oberflächliche Exploration eines Terrassensystems von fünf bis sieben verschiedenen Niveaus ausgeführt entlang dem oberen Lauf des großen Kizil Irmak (des Roten Flusses) zwischen Sivas und Kayseri in Ost-Anatolien. Teilweise ist es die von Izbirak beschriebene Gegend, größtenteils geht sie aber über diese hinaus. Die Terrassenflächen sind ziemlich gleichmäßig entwickelt entlang des genannten Teils des Flusses, verschwinden aber plötzlich weiter unterhalb. Die Verfasser meinen mit Izbirak, daß die Entstehung dieser Terrassen wahrscheinlich in erster Linie tektonisch und erst an zweiter Stelle klimatisch bedingt ist. Die dritte Terrasse (von unten an gezählt) enthielt überall eine nur geringe Zahl vermutlicher primitiver Artefakten, unter ihnen einige „pebble-tools". Diese sind in vorliegendem Aufsatz beschrieben; sie stellen vielleicht einen Beweis für die Anwesenheit von frühpleistozänen Hominiden in der Türkei dar. In einem Fall wurde in dieser dritten Terrasse ein fossiler Molar eines Hipparion in situ gefunden, teilweise bedeckt mit demselben versteinerten roten Lehm, welcher auch einige der vermutlichen Artefakten einhüllte. Das Alter der Terrassen ist noch nicht genau bekannt. Es scheint aber, daß die ältesten und höchstgelegenen Tertiär sind, die Terrasse, welche die Artefakten enthält, vielleicht dem untersten Pleistozän angehört, und die untersten Terrassen in das junge Pleistozän oder gar Holozän zu stellen sind.researc

Depression is related to an absence of optimistically biased belief updating about future life events

BACKGROUND: When challenged with information about the future, healthy participants show an optimistically biased updating pattern, taking desirable information more into account than undesirable information. However, it is unknown how patients suffering from major depressive disorder (MDD), who express pervasive pessimistic beliefs, update their beliefs when receiving information about their future. Here we tested whether an optimistically biased information processing pattern found in healthy individuals is absent in MDD patients. Method MDD patients (n = 18; 13 medicated; eight with co-morbid anxiety disorder) and healthy controls (n = 19) estimated their personal probability of experiencing 70 adverse life events. After each estimate participants were presented with the average probability of the event occurring to a person living in the same sociocultural environment. This information could be desirable (i.e. average probability better than expected) or undesirable (i.e. average probability worse than expected). To assess how desirable versus undesirable information influenced beliefs, participants estimated their personal probability of experiencing the 70 events a second time. RESULTS: Healthy controls showed an optimistic bias in updating, that is they changed their beliefs more toward desirable versus undesirable information. Overall, this optimistic bias was absent in MDD patients. Symptom severity correlated with biased updating: more severely depressed individuals showed a more pessimistic updating pattern. Furthermore, MDD patients estimated the probability of experiencing adverse life events as higher than healthy controls. CONCLUSIONS: Our findings raise the intriguing possibility that optimistically biased updating of expectations about one's personal future is associated with mental health

Social feedback processing in borderline personality disorder

Background Patients with borderline personality disorder (BPD) show negative and unstable self- and other-evaluations compared to healthy individuals. It is unclear, however, how they process self- and other-relevant social feedback. We have previously demonstrated a positive updating bias in healthy individuals: When receiving social feedback on character traits, healthy individuals integrate desirable more than undesirable feedback. Here, our aim was to test whether BPD patients exhibit a more negative pattern of social feedback processing. Method We employed a character trait task in which BPD patients interacted with four healthy participants in a real-life social interaction. Afterwards, all participants rated themselves and one other participant on 80 character traits before and after receiving feedback from their interaction partners. We compared how participants updated their ratings after receiving desirable and undesirable feedback. Our analyses included 22 BPD patients and 81 healthy controls. Results Healthy controls showed a positivity bias for self- and other-relevant feedback as previously demonstrated. Importantly, this pattern was altered in BPD patients: They integrated undesirable feedback for themselves to a greater degree than healthy controls did. Other-relevant feedback processing was unaltered in BPD patients. Conclusions Our study demonstrates an alteration in self-relevant feedback processing in BPD patients that might contribute to unstable and negative self-evaluations