BrainBlog

Balkanizing the primate orbitofrontal cortex: distinct subregions for comparing and contrasting values Annals of the New York Academy of Science. 2011 Dec; 1239(1): 1-13 Rudebeck PH, Murray EA Abstract The primate orbitofrontal cortex (OFC) is often treated as a single entity, but architectonic and connectional neuroanatomy indicate that it has distinguishable parts. Nevertheless, few studies have attempted to dissociate the functions of its subregions. Here we review findings from recent neuropsychological and neurophysiological studies that do so. The lateral OFC seems to be important for learning, representing, and updating specific object-reward associations. The medial OFC seems to be important for value comparisons and choosing among objects on that basis. Rather than viewing this dissociation of function in terms of learning versus choosing, however, we suggest that it reflects the distinction between contrasts and comparisons: differences versus similarities. Making use of high...

Slower gait, slower information processing and smaller prefrontal area in older adults Age Ageing . 2011 Sep 28; Rosano C, Studenski SA, Aizenstein HJ, Boudreau RM, Longstreth WT, Newman AB Abstract BACKGROUND: slower gait in older adults is related to smaller volume of the prefrontal area (PFAv). The pathways underlying this association have not yet been explored. Understanding slowing gait could help improve function in older age. We examine whether the association between smaller PFAv and slower gait is explained by lower performance on numerous neuropsychological tests.Hypothesis: we hypothesise that slower information processing explains this association, while tests of language or memory will not. METHODS: data on brain imaging, neuropsychological tests (information processing speed, visuospatial attention, memory, language, mood) and time to walk 15 feet were obtained in 214 adults (73.3 years, 62% women) free from stroke and dementia. Covariates included central (white matter h...

The following paper is available as an open full-download from PLoS. It provides an interesting example of the use of stop-signal tasks in pursuing a better understanding of executive functioning and its neuroanatomical correlates: Full publication Rule-guided executive control of response inhibition: functional topography of the inferior frontal cortex. PLoS One . 2011;6(6):e20840 Cai W, Leung HC Abstract BACKGROUND: The human inferior frontal cortex (IFC) is a large heterogeneous structure with distinct cytoarchitectonic subdivisions and fiber connections. It has been found involved in a wide range of executive control processes from target detection, rule retrieval to response control. Since these processes are often being studied separately, the functional organization of executive control processes within the IFC remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: We conducted an fMRI study to examine the activities of the subdivisions of IFC during the presentation of a task cue (ru...

Looking for reading material for a longish train trip I am about to take, I decided to hit to bookshelves of my Square's Barnes & Noble to see what popular neuroscience titles might be a good diversion (as well as potential supplementary 'lighter' references, should I re-teach an introductory course to neuroscience sometime over the next year). I chose three. The first is by Elkhonon Goldberg, a revision of an earlier work, which is titled "The New Executive Brain: Frontal Lobes in a Complex World" and is available in paperback by Oxford University Press. I first met the author when I was a graduate student, so I am looking forward to reading up on what he's been up to. The second is about glial cells and is entitled, "The Root of Thought: Unlocking Glia" by Andrew Koob. Five years ago, if someone said there would be a popular offering about glia, I would have thought 'Yeah, right...' Though I do enjoy adding discussion about glia to my...