Mind tricks

Tricks of the mind: Visual hallucinations as disorders of attention.

Visual hallucinations are common across a number of disorders but to date, a unifying pathophysiology underlying these phenomena has not been described. In this manuscript, we combine insights from neuropathological, neuropsychological and neuroimaging studies to propose a testable common neural mechanism for visual hallucinations. We propose that 'simple' visual hallucinations arise from distu...

Old dogs: new tricks, old tricks, or no tricks.

tively referred to as “old dogs.” In some instances, the designation may be a term of endearment: in others, a term of derision. Virtually every chairperson must face the dilemma of dealing with these senior staff members. His or her decision will be based primarily on how productive the senior radiologist is. I have had the unique opportunity to practice radiology over the past 27 years in bot...

Pain Tricks

Vasectomy: tips and tricks

According to data from the National Study of Family Growth, vasectomy is utilized by 6-13% of American couples for their form of contraception. Physician surveys have shown that over 500,000 men undergo vasectomies per year, and more than 75% of vasectomies are performed by urologists. This chapter provides a brief history of vasectomy, as well as recommendations for preoperative counseling, an...

Stochastic Gradient Descent Tricks

Chapter 1 strongly advocates the stochastic back-propagation method to train neural networks. This is in fact an instance of a more general technique called stochastic gradient descent (SGD). This chapter provides background material, explains why SGD is a good learning algorithm when the training set is large, and provides useful recommendations.