Briefly describe the relationship between diffusion tensor ...

[Ebrown]

Briefly describe the relationship between diffusion tensor imaging (DTI) and phrenology. Ddescribe the type of information that can be gathered by DTI.
 
  What will be an ideal response?

Question 2

Briefly describe the three neurological systems defined by reinforcement sensitivity theory (Gray).
 
  What will be an ideal response?

[SVictor]

Answer to Question 1

Answer: Phrenology contained the modern concept of brain localization of function. What it lacked, in the 18^th century, was a method to correlate brain regions and behavior or experience. The use of variations in skull shape emerged because that was the only data to which practitioners had access. The modern technique of DTI is an improvement on fMRI that traces the diffusion of water in cells and gives a very detailed picture of brain structure and function. Most importantly it can provide images of connections between cortical and subcortical regions that can be correlated with behavior and experience with considerable precision.

Answer to Question 2

Answer: According to Grays reinforcement sensitivity theory (RST), there are three hypothetical brain-behavior systems: the fight-flight-freeze system (FFFS), the behavioral approach system (BAS), and the behavioral inhibition system (BIS). The FFFS system is associated with the emotion of fear and is responsible for coordinating reactions to aversive stimuli. When confronted with a potentially dangerous stimulus the brain must make an assessment and choose between aggression, running away, or freezing in place as the most appropriate response. Potentially positive stimuli activate the BAS and make a person more sensitive to reward, making one optimistic and somewhat impulsive. It is now thought that the BIS is designed to resolve conflicts when a person is faced with choices.

[Ebrown]

Thank you

[SVictor]

No problem