Neuroscience and biobehavioral reviews
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Neurosci Biobehav Rev · Jan 2005
ReviewFunctional connectivity in the brain--is it an elusive concept?
Even though functional brain connectivity is an influential concept in modern cognitive neuroscience, it is a very controversial notion. This is why further theoretical and methodological clarification are needed to help define precisely what is meant by functional connectivity and to help frame-associated issues. ⋯ Here functional connectivity is the mechanism for the coordination of activity between different neural assemblies in order to achieve a complex cognitive task or perceptual process. Our theoretical and empirical findings offer new insights into possible implications of the concept of functional connectivity for cognitive neuroscience.
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Neurosci Biobehav Rev · Jan 2005
Review Biography Historical ArticleDonald O. Hebb's synapse and learning rule: a history and commentary.
This year sees the anniversary of Donald O. Hebb's birth, in July 1904. ⋯ His core postulate, which gave rise to such eponymous expressions as the Hebbian synapse and the Hebbian learning rule, is examined in some detail, as well as the part it played in his higher-order theoretical constructs concerned with neocortical structure and function. Early models which made use of the Hebbian synapse are described, and then illustrative examples are given detailing the impact of Hebb's idea in relation to learning and memory, synaptic plasticity and stability, and the question of persistent cortical activity underlying forms of short-term memory.
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Neurosci Biobehav Rev · Jul 2004
ReviewStatistical and conceptual issues in defining post-operative cognitive dysfunction.
The occurrence of post-operative cognitive dysfunction is a distressing complication following surgery. In an effort to gain a more complete understanding of patients' cognitive recovery following surgical procedures common neuropsychological assessment tools have been adopted in a repeated measures design. It is widely regarded that this represents the most comprehensive method of determining cognitive status in this population but it has resulted in a number of statistical and conceptual difficulties in attempting to infer significant change. The current paper outlines these core difficulties and provides some potential methods to overcome these.
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Neurosci Biobehav Rev · Jul 2004
ReviewMotor and cognitive function evaluation following experimental traumatic brain injury.
Traumatic brain injury (TBI) in humans may cause extensive sensorimotor and cognitive dysfunction. As a result, many TBI researchers are beginning to assess behavioral correlates of histologically determined damage in animal models. ⋯ The ability to reliably test treatments across laboratories and multiple injury models will close the gap between treatment success in the lab and success in the clinic. The goal of this review is to describe and evaluate the tests employed to assess functional outcome after TBI and to overview aspects of cognitive, sensory, and motor function that may be suitable targets for therapeutic intervention.
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Neurosci Biobehav Rev · Jan 2004
ReviewVentral striatal control of appetitive motivation: role in ingestive behavior and reward-related learning.
The nucleus accumbens is a brain region that participates in the control of behaviors related to natural reinforcers, such as ingestion, sexual behavior, incentive and instrumental learning, and that also plays a role in addictive processes. This paper comprises a review of work from our laboratory that focuses on two main research areas: (i). the role of the nucleus accumbens in food motivation, and (ii). its putative functions in cellular plasticity underlying appetitive learning. First, work within a number of different behavioral paradigms has shown that accumbens neurochemical systems play specific and dissociable roles in different aspects of food seeking and food intake, and part of this function depends on integration with the lateral hypothalamus and amygdala. ⋯ This receptor stimulation triggers intracellular cascades that involve protein phosphorylation and new protein synthesis. It is hypothesized that activity in this distributed network (including D1 receptor activity) computes coincident events and thus enhances the probability that temporally related actions and events (e.g. lever pressing and delivery of reward) become associated. Such basic mechanisms of plasticity within this reinforcement learning network also appear to be profoundly affected in addiction.