DOT 4

• Each neuron produced different amounts of the three proteins, giving it a distinctive color—in the same way that a color printer can make any color by mixing only three colored inks in differing proportions. Because each neuron was labeled with its own distinctive color, the pathways of neural axons could be traced to their destinations through the cellular morass. This technique has been dubbed brainbow.
• light-sensitive ion channels that are found in the cell membranes of certain bacteria and algae.

  Opsins
• inserting an opsin gene into a particular type of neuron, a neuroscientist could use light to hyperpolarize or depolarize neurons. This novel method is known as ____________.

  optogenetics
• A single set of procedures developed for the investigation of a particular behavioral phenomenon is commonly referred to as a

  behavioral paradigm
• The goal of these early tests was to discriminate between patients with psychological problems resulting from structural brain damage and those with psychological problems resulting from functional, rather than structural, changes to the brain. This approach proved unsuccessful.

  SINGLE-TEST APPROACH
• This grew out of the failures of the single-test approach. The objective stayed the same—to identify brain-damaged patients—but the testing involved standardized batteries (sets) of tests rather than a single test.

  STANDARDIZED-TEST-BATTERY APPROACH
• an approach largely developed by Luria and other Soviet Union neuropsychologists. began to be used routinely in a few American neuropsychological research institutions in the 1960s. This approach proved highly successful in research, and it soon spread to clinical practice. It now predominates in both the research laboratory and the neurological ward.

  CUSTOMIZED-TEST-BATTERY APPROACH
• first published in 1955 and standardized in 1981 on a sample of 1,880 U.S. citizens between 16 and 71. This is composed of many subtests and is often the first test administered, because knowing a patient’s IQ can help a neuropsychologist interpret the results of subsequent tests.

  Wechsler Adult Intelligence Scale (WAIS)
• the most widely used test of short-term memory

  digit span subtest
• use to screen language related deficits

  token test
• injecting the anesthetic sodium amytal into either the left or right carotid artery in the neck.

  sodium amytal test
• sequences of spoken digits are presented to volunteers through stereo headphones. Three digits are presented to one ear at the same time that three different digits are presented to the other ear. Then, they are asked to report as many of the six digits as they can.

  dichotic listening test
• proven instrumental in the assessment and study of this pattern. Patients are first shown a list of words and asked to study them; they are not asked to remember them. Then, at a later time, they are asked to complete a list of word fragments, many of which are fragments of words from the initial list.

  Repetition priming tests
• The first assumption is that each complex cognitive process results from the combined activity of simple cognitive processes called _________.

  constituent cognitive processes
• The problem with this approach (by Peterson and colleagues) is that many parts of the brain that would be active during the test period would have nothing to do with the constituent cognitive process of forming a word association; much of the activity recorded would be associated with other processes such as seeing the words, reading the words, and speaking. This was developed to address this problem.

  paired-image subtraction technique
• The paired-image subtraction technique involves obtaining functional brain images during several different cognitive tasks.
• Interpretation of difference images is complicated by the fact that there is substantial brain activity when humans sit quietly and let their minds wander—this level of activity has been termed the brain’s default mode.
• Brain structures typically active in the default mode but less active during cognitive or behavioral tasks are collectively referred to as the default mode network.
• Brain structures typically active in the default mode but less active during cognitive or behavioral tasks are collectively referred to as the default mode network, and their pattern of activity is known as the resting state-fMRI (R-fMRI).
• mean (averaged) difference image emphasizes areas of activity that are common to many volunteers and de-emphasizes areas of activity that are peculiar to a few of them.