Neural Mechanisms Underlying Time Perception and Reward Anticipation

Findings suggest that the physiological mechanisms involved in the reward anticipation and time perception partially overlap. But the systematic investigation of a potential interaction between time and reward systems using neuroimaging is lacking. Eighteen healthy volunteers (all right-handed) participated in an event-related functional magnetic resonance imaging (fMRI) experiment that employs a visual paradigm that consists monetary reward to assess whether the functional neural representations of time perception and reward prospection are shared or distinct. Subjects performed a time perception task in which observers had to extrapolate the velocity of an occluded moving object in “reward” vs. “no-reward” sessions during fMRI scanning. There were also “control condition” trials in which participants judged about the color tone change of the stimuli. Time perception showed a fronto-parietal (more extensive in the right) cingulate and peristriate cortical as well as cerebellar activity. On the other hand, reward anticipation activated anterior insular cortex, nucleus accumbens, caudate nucleus, thalamus, cerebellum, postcentral gyrus, and peristriate cortex. Interaction between the time perception and the reward prospect showed dorsolateral, orbitofrontal, medial prefrontal and caudate nucleus activity. Our findings suggest that a prefrontal-striatal circuit might integrate reward and timing systems of the brain

Regional anatomic structures of the elbow that may potentially compress the ulnar nerve

WOS: 000267812400021PubMed: 19481960Hypothesis: Traumatic injuries to the ulnar nerve at the elbow are a frequent problem as it is vulnerable to stretching and compression with motion of the upper limb. The aim of the present study was to explore the course of the ulnar nerve at the elbow and forearm and to determine possible anatomical structures that may cause compression of this structure. Materials and methods: We examined 12 upper limbs from cadavers. The length of any fibrous bands, and if present, their distance to the medial epicondyle was recorded. Results: On 5 sides a fibrous band originating from the medial intermuscular septum was observed to cross over the ulnar nerve. The average length of the fibrous band was 5.7 cm, and it attached to the medial epicondyle. The mean length of the ulnar nerve as it coursed in the cubital tunnel was 3.8 cm. In 4 of the cases, the ulnar nerve was covered by muscle fibers originating from the flexor digitorum superficialis and extending to the flexor carpi ulnaris. On 5 sides we observed fibrous thickenings, and on 8 sides vascular structures were found crossing over the ulnar nerve. Discussion: The cubital tunnel is the most common site of compression of the ulnar nerve. Numerous surgical procedures are recommended for cubital tunnel syndrome. Simple decompression is used most commonly. Although surgical procedures are reported to provide efficient pain relief and functional recovery, residual or recurrent symptoms have been reported. Reasons for such recurrences may be more proximal or distal compression of the ulnar nerve as seen in our study. Conclusion: Knowledge of possible compression sites of the ulnar nerve is important to the surgeon so that complications are avoided and postoperative recurrence is decreased. Level of evidence: Basic science study. (C) 2009 Journal of Shoulder and Elbow Surgery Board of Trustees

Neural Mechanisms Underlying Time Perception and Reward Anticipation

Parmi les débats ayant marqué la scène politique israélienne au cours de l’année 2005, figure en bonne place la controverse qui a opposé le président de la Cour suprême, Aharon Barak, à la ministre de la Justice sur la nomination de trois juges à la Cour. Cette controverse s’est cristallisée autour de la candidature de la professeure de droit, Ruth Gavison, à laquelle s’est fermement opposé Aharon Barak du fait de sa critique virulente de l’orientation politique et de l’activisme judiciaire d..

Yumuşak ve sert doku malzeme deney sistemine elektronik veri toplama biriminin eklenmesi

TÜBİTAK SBAG AYD Proje01.02.200