nöropsikoloji

All rights reserved. No part of this publication may be reproduced, Preface cognitive neurology, namely temporolimbic epilepsy, major psychiatric syndromes, and the dementias. The last two of these chapters, those on the psychiatric syndromes and dementia, are new and address areas that were not covered in the first edition.

2008

The brain has evolved to deal with two competing requirements—it must respond quickly to familiar situations while being able to adapt to novel ones and plan for the future. Quickly responding to the immediate environment in a reflexive, or habitual, fashion is relatively straightforward: Familiar stimuli activate well-established neural pathways that produce stereotyped behaviors. This is so-called ''bottom-up,''or ''stimulus-driven,''processing.

Handbook of clinical …, 1997

2008

Neurobiology of Learning and Memory, 2009

The posterior parietal cortex has been traditionally associated with coordinate transformations necessary for interaction with the environment and with visual-spatial attention. More recently, involvement of posterior parietal cortex in other cognitive functions such as working memory and task learning has become evident. Neurophysiological experiments in non-human primates and human imaging studies have revealed neural correlates of memory and learning at the single neuron and at the brain network level. During working memory, posterior parietal neurons continue to discharge and to represent stimuli that are no longer present. This activation resembles the responses of prefrontal neurons, although important differences have been identified in terms of the ability to resist stimulation by distracting stimuli, which is more evident in the prefrontal than the posterior parietal cortex. Posterior parietal neurons also become active during tasks that require the organization of information into larger structured elements and their activity is modulated according to learned context-dependent rules. Neural correlates of learning can be observed in the mean discharge rate and spectral power of neuronal spike trains after training to perform new task sets or rules. These findings demonstrate the importance of posterior parietal cortex in brain networks mediating working memory and learning.