News
14.05.2012
Der nächste Termin des Forschungskolloquiums der Abteilung Biopsychologie findet statt am Dienstag, den 22.05.2012 um 18:00 Uhr mit dem Thema "Guidance of eye movements" von Peter König.
04.04.2012
09.03.2012
Contact
Ruhr-Universität Bochum
Fakultät für Psychologie
AE Biopsychologie
GAFO 05/618
D-44780 Bochum
Phone: +49 - 234 - 32 - 28213
Fax: +49 - 234 - 32 - 14377
Email: biopsychologie@rub.de
Homepage: http://www.bio.psy.rub.de
News & Views
NEW DFG RESEARCH GRANT FOR MAIK STÜTTGEN
It is widely held that spike responses of single neurons to sensory stimuli are noisy and uninformative. Accordingly, random fluctuations of individual neurons’ activity patterns are considered unimportant because downstream brain areas must perform some sort of averaging across large neuronal populations to obtain accurate information about sensory input variables. Contrary to this notion, recent studies have shown that electrical activation of single cortical neurons can indeed have behavioral relevance. For example, single-neuron stimulation in rat primary motor cortex generates movements of the facial whiskers. Moreover, stimulation of single neurons in somatosensory cortex yields a behavioral response in rats trained on a psychophysical detection task. These studies suggest that the influence of an individual cortical neuron on the local neural network is stronger than commonly thought. However, the mechanism by which the activity of a single neuron is amplified and propagated through the local neural network to eventually generate a behavioral response is unknown. The aim of the newly approved six-month research project is to begin to elucidate some of the mechanisms which underlie the phenomenon of single-cell induced behavioral responses. Together with Arthur Houweling at the University of Rotterdam, Maik will employ the juxtacellular stimulation technique to activate single neurons in the superficial layers of barrel cortex of anesthetized mice in a controlled manner while monitoring the activity of the local neural network.
News & Views
Lateralized Processing at the Cellular Level
In humans and many other animals, the two cerebral hemispheres are partly specialized for different functions. However, knowledge about the neuronal basis of lateralization is mostly lacking. The visual system of birds is an excellent model in which to investigate hemispheric asymmetries as birds show a pronounced left hemispheric advantage in the discrimination of various visual objects. Therefore, biopsychologists and theoretical neuroscientists from Bochum and Freiburg, respectively, aimed to find a neuronal correlate for three hallmarks of visual lateralization in pigeons: first, the animals learn faster with the right eye–left hemisphere; second, they reach higher performance levels under this condition; third, visually guided behavior is mostly under left hemisphere control. To this end, Josine Verhaal (now at the Munich Technical University) recorded from the left and right forebrain entopallium while the animals performed a colour discrimination task. Josine found that, even before learning, left entopallial neurons were more responsive to visual stimulation. Subsequent discrimination acquisition recruited more neuronal responses in the left entopallium and these cells showed a higher degree of differentiation between the rewarded and the unrewarded stimulus. Thus, differential left–right responses are already present, albeit to a modest degree, before learning. As soon as some cues are associated with reward, however, this asymmetry increases substantially and the higher discrimination ratio of the left hemispheric tectofugal pathway would not only contribute to a higher performance of this hemisphere but could thereby also result in a left hemispheric dominance over downstream motor structures via reward-associated feedback systems.
News & Views
Evolutionary Roots of Emotional Reactions
Possibly emotions are just a means to coordinate fast actions to stimuli that have a valence character. In the present study biological psychologists from Bochum and Würzburg planned to test if the left hemisphere preferentially controls flexion responses toward positive stimuli, while the right hemisphere is specialized toward extensor responses to negative pictures. To this end, right-handed subjects had to pull or push a joystick subsequent to seeing a positive or a negative stimulus in their left or right visual hemifield. Flexion responses were faster for positive stimuli (upper picture), while negative stimuli were associated with faster extensions responses (lower picture). Overall, performance was fastest when emotional stimuli were presented to the left visual hemifield. This right hemisphere superiority was especially clear for negative stimuli, while reaction times toward positive pictures showed no hemispheric difference. Thus, flexion and extension are indeed tightly linked to the valence of the stimulus. But the division of valence between hemispheres is not as clear. This fits to recent developments that an approach reaction (in this case visible as a flexion response) can be elicited by positive emotions as well as by anger, which is a negative emotion.
News & Views
Selective attention is boosted by smoking in schizophrenia
Smoking prevalence is highly elevated in schizophrenia compared to the general population and to other psychiatric populations. Evidence suggests that smoking may lead to improvements of schizophrenia-associated attention deficits; however, large-scale studies on this important issue are scarce. A group of psychiatrists from Berlin and biopsychologists from Bochum examined whether sustained, selective, and executive attention processes are differentially modulated by long-term nicotine consumption in 104 schizophrenia patients and 104 carefully matched healthy controls. Smoking was significantly associated with a detrimental conflict effect in controls, while the opposite effect was revealed for schizophrenia patients. Likewise, a positive correlation between a cumulative measure of nicotine consumption and conflict effect in controls and a negative correlation in patients were found. These results provide evidence for specific directional effects of smoking on conflict processing that critically dissociate with diagnosis. The data supports the self-medication hypothesis of smoking in schizophrenia and suggests selective attention as a specific cognitive domain positively targeted by nicotine consumption. The authors offer a model to explain the dissociating effects by nicotine-dopamine interactions located in the ventral tegmental area that lead to an increased prefrontal D1 receptor activation. As a consequence, smoking is disadvantageous for healthy participants with a priori favorable dopamine levels, but reinstates an advantageous D1 state in schizophrenia patients who otherwise suffer from a marked prefrontal dopamine deficit.
News & Views
The convergent evolution of neural substrates for cognition
This review by Onur Güntürkün describes a case of convergence in the evolution of brain and cognition. Both mammals and birds can organize their behavior flexibly over time and evolved similar cognitive skills. However, mammals and birds display vast differences in the organization of their forebrains with mammals having a laminated cortex. The avian forebrain displays no such lamination; hence, lamination does not seem to be a requirement for higher cognitive functions. In mammals, executive functions are associated with the prefrontal cortex. The corresponding structure in birds is the nidopallium caudolaterale. Anatomic, neurochemical, electrophysiologic and behavioral studies show these structures to be highly similar, but not homologous. Thus, despite the presence (mammals) or the absence (birds) of a laminated forebrain, 'prefrontal' areas in mammals and birds converged over evolutionary time into a highly similar neural architecture. The neuroarchitectonic degrees of freedom to create different neural architectures that generate identical prefrontal functions seem to be very limited.
Award
Das menschliche Gehirn - ein Mal- und Bastelkurs
In January 2008 the seminar "Das menschliche Gehirn - ein Mal- und Bastelkurs" (The human brain - a painting- and craftsmanship course) of the Biopsychology department was awarded on the conference "Kompetenzorientiert lehren und lernen an der RUB" for exemplary teaching.
As a result this film was made to show the concept and the realization of the seminar to a broad community.
If you enjoyed it please distribute the web location to people who might be interested in it.