PubMed · 15890862
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
James W Aldridge. 2005-05-13. Interpreting correlation as causation?. https://doi.org/10.1126/science.308.5724.954
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
A prominent theory in neuroscience suggests reward learning is driven by the discrepancy between a subject's expectation of an outcome and the actual outcome itself. Furthermore, it is postulated that midbrain dopamine neurons relay this mismatch to target regions including the ventral striatum. Using functional MRI (fMRI), we tested striatal responses to prediction errors for probabilistic classification learning with purely cognitive feedback. We used a version of the Rescorla-Wagner model to generate prediction errors for each subject and then entered these in a parametric analysis of fMRI activity. Activation in ventral striatum/nucleus-accumbens (Nacc) increased parametrically with prediction error for negative feedback. This result extends recent neuroimaging findings in reward learning by showing that learning with cognitive feedback also depends on the same circuitry and dopaminergic signaling mechanisms.
Explore the source record for details and available documents.
Modern brain imaging techniques usually allow a very good differential diagnosis of intracerebral lesions, but in some cases the differential diagnosis is difficult. We report the case of a 52 year old male with acute brachiofacial paresis and a hyperintense lesion with mass effect and ring-enhancement in basal ganglia suspiciously to a tumor. The neurosurgeons recommend stereotactical brain biopsy for diagnosis, but the patient recovered in following time gradually and in repeated computer tomographic images contrast enhancement disappeared and a hypodense zone in the basal ganglia remains. Our case demonstrates that brain infarctions can mimick glioblastoma in taking cystic appearance and contrast enhancement. Stereotactic biopsy would have been a precipitated invasive procedure in this case.