PSYC 123 Midterm 1

What historical (and problematic) precursor to modern psychology is associated with Franz Joseph Gall?

Phrenology - the study of how bumps on the skull relate to mental functions

The observation by Hughlings Jackson that some seizures involve a stereotypical progression of movement across the body was early evidence for

Functional localization within the motor system (this type of seizure progresses across the cortex, different regions that control different parts of the body become involved, leading to this pattern)

The concept that the brain is composed of different subsystems (or modules), located in specific regions of brain tissue is known as:

Localization of function

The method that allows scientists to make inferences about what function a brain region performs from observing what behaviors are compromised or absent after damage to that region is known as:

Lesion method (a “lesion” refers to an area of damaged tissue in the brain)

A double dissociation occurs when…

One brain lesion causes a disruption in Function A but not Function B, whereas a different lesion causes a disruption in Function B but not Function A

(Keep in mind this question is using lesion studies as an example. The concept of “double dissociation” could be applied to other types of studies as well – what is important is that you get opposing patterns like this.)

Unlike MRI, positron emission tomography (PET) involves radioactive molecules.

True (small amounts)

Surgically severing the fibers of the corpus callosum does what?

Disconnects the two cerebral hemispheres

What did ancient observations show?

Brian injury linked to behavioral changes

What was the Edwin Smith Papyrus?

The first known medical document from 1700 BCE that had case studies highlighting head and spine trauma

What was special about Case 20 in the Edwin Smith Papyrus?

It describes injury to the temporal bone which resulted in the inability to speaking - demonstrating that in ancient times, there was a concept of specific brain locations being tied to certain functions

What is Phrenology?

Franz Gall’s flawed theory of functional specialization - the practice of deriving mental traits (‘faculties”) from bumps on one’s head

What are some problems with phrenology?

Unclear why those faculties, locations, size of neural region, etc.

What is one thing Phrenology got right?

Localization of function

What is localization of function?

The idea that the brain has different parts that are specialized for doing different things (e.g., an espresso machine - take one part away and one function doesn’t work)

What is mass action?

The opposing view of localization of function - that all parts of the brain have the same function (1800s view) (e.g., an air filter because the whole thing works the same way, no special parts)

What was Jean Pierre Flourens?

Scientist highly critical of phrenology and argued for equipotentiality (the idea that nay given piece of cortical tissue has the potential to support any brain function.- mass action) because he lesioned different parts of dogs brains and found that they all led to the same effect (uncoordinated movement) (BUT it’s hard to draw conclusions from a LACK of different, this doesn’t mean the two things are the same, there could be a problem with the test)

What are examples of evidence for localization of function?

1. Some seizures start at the hand then move up the arm to the body - if brain followed mass action, then all seizures would be the same, but they’re not because uncontrolled activity in different parts of the brain lead to different effects

2. Electrical stimulation and lesioning different parts of the brain resulted in contralateral movements - stimulating the left brain resulted in motor movements on the right hand and vice versa

Juhn Wada Test

• Anesthetizes left hemisphere - language stops (persons tops counting at around #6) and right hand drops

• Anesthetizes right hemisphere - language stays intact and left hand drops

• Evidence for contralateral brain

What did lateralized lesion studies show?

Example: Triangle shape made up with small rectangles

• Patients with right-hemisphere damage were good at keeping the “small picture” intact (rectangles)

• Patients with hemisphere damage were good at keeping the “big picture” intact (triangle outline)