Psych 160 - Lectures 4-6

Front 1

What says that complex patterns of action require the whole of the cortex?

Back 1

Mass action

Front 2

What was Lashley's contribution to psychology? [2]

Back 2

He tested rats and said that their impairment of learning mazes was directly proportional to the amount of cortex he took out of them; came up with areal equipotentiality

Front 3

What does connectionism say?

Back 3

That there can be very sparse connections which bring two very remote parts of the brain together

Front 4

What is the functional unit of the cortex?

Back 4

Cortical columns

Front 5

What shows that different parts of the cortex have different representations, i.e., that different neurons are fated to become certain types of neurons?

Back 5

Protomaps (transcription factors control migration)

Front 6

What should "Ventricular zone – progenitor cells" make you think of?

Back 6

The more divisions that occur, the bigger your brain.

Front 7

What does the radial unit hypothesis basically say?

Back 7

That the cortex is layered

Front 8

T/F: You can actually change the size of motor cortex versus visual cortex by changing the chemicals, i.e. transcription factors! Neural migration disorders – the cells don’t make it all the way to the brain.

Back 8

True

Front 9

T/F: When talking of the somatosensory cortex, there is a certain fate to these areas but an input from the environment is also important in development and can manipulate growth and development.

Back 9

True, like ocular dominance columns

Front 10

What acts like a "way-station" from our senses to our cortex?

Back 10

The thalamus

Front 11

What is unique about the 6-layered cortex?

Back 11

It has different layers for input/output from senses and other organs

Front 12

T/F: Small cell groups in brainstem and midbrain project widely to cortex.

Back 12

True

Front 13

What hormone corresponds to the locus coeruleus, and what does it do?

Back 13

Norepinephrine, alertness

Front 14

What hormone corresponds to the substantia nigra, and what does it do?

Back 14

Dopamine, reward circuits

Front 15

What hormone corresponds to the raphe nuclei, and what does it do?

Back 15

Serotonin, sleep

Front 16

What hormone corresponds to the nucleus basalis, and what does it do?

Back 16

Acetylcholine, has been implicated in Alzheimer's

Front 17

What are wired and volume transmission in neuromodulatory systems?

Back 17

Wired transmission involves the use of hormones and is rapid, where as volume often involves dopamine and has longer time over longer distances.

Front 18

What is an example of back projection?

Back 18

Like in a CT scan, it's where many "x-rays" are formed by taking x-rays all around a 3D image

Front 19

What happens in autoradiography?

Back 19

Radioactive proline is injected into the eye and then the brain is sliced up and images are made from the radioactivity.

Front 20

What is most of the oxygen and glucose (i.e., the energy sources of the brain) used for in the brain?

Back 20

It is mostly used for restoration following the action potential

Front 21

Briefly describe PET and what it stands for.

Back 21

Positron emission tomography; a molecule of interest is tagged with a positron-emitting isotope. The positron encounters an electron and annihilation occurs which sends two gamma rays in opposite directions; the gamma rays hit the ring-crystal around the patients head and so back projection is used to create an image.

Front 22

What are the major problems with PET?

Back 22

Radiation from gamma rays; 90 seconds to work; very expensive

Front 23

Briefly describe MRI and what it stands for.

Back 23

Magnetic Resonance Imaging; magnetic field makes a net magnetic moment by making protons spin in alignment, then radio waves are applied to stimulate the resonant system, they are absorbed and then released by the system, and the strength of this signal is the number of protons at the site being studied.

Front 24

What are the advantages of MRI? [2]

Back 24

Radio waves aren't damaging and can't break chemical bonds like gamma rays can; no positron range effect, so it is more accurate

Front 25

What is the special thing about fMRI?

Back 25

They are images that vary moment to moment with brain activity

Front 26

How does fMRI work?

Back 26

It uses hemoglobin as endogenous contrast; hemoglobin supplies active brain areas with O2, and when it releases O2 it becomes paramagnetic and distorts magnetic field; so we read distortion as neuronal activity

Front 27

What happens in transcranial magnetic stimulation?

Back 27

A magnetic field penetrates the skull and induces an electric field in the brain which can inhibit motor activity (speech, etc.), or promote it by making people move or have a very strong urge to move

Front 28

What is Bereitschaftspotential?

Back 28

When electric activity precedes actual movement in the brain

Front 29

What is the source of the EEG stuff?

Back 29

PSPs

Front 30

Why is MEG also useful?

Back 30

It doesn't have the problem of penetrating the skull like EEG does

Front 31

What are both MEG and EEG subject to that can be problematic?

Back 31

The inverse problem - knowing where the signal you measured actually came from

Front 32

6: What are the 3 types of sensory receptors and their purposes?

Back 32

Tactile mechanoreceptors (light and deep touch), free nerve endings (temperature, pain, etc.) and muscle proprioception (spindle for contraction, golgi tendon for relaxation)

Front 33

To decussate is to...

Back 33

Cross over

Front 34

T/F: There is a main thalamic nucleus for each sensory modality and sometimes a secondary nucleus for alternate pathways.

Back 34

True

Front 35

What does AMPS law of the spinal cord say?

Back 35

Anterior = motor, posterior = sensory

Front 36

What is the basis of the sensory homunculus/sensory map?

Back 36

The lower limbs are medial in the spine and the upper limbs are lateral, and this continues into the VPL thalamus and into S1

Front 37

How do tactile information and pain/temperature sensitivity change in Brown-Sequard syndrome?

Back 37

Tactile information is lost ipsilateral to the lesion, and pain/temperature is lost contralateral to the lesion

Front 38

T/F: Spinal reflexes - Thus, if a load is placed on a muscle and the muscle spindle is stretched, the muscle spindle nerves will activate motor neurons in the spinal cord that oppose the load.

Back 38

True

Front 39

Central pattern generator example?

Back 39

Cat whose spinal cord was severed below the level of cord transection could still walk on treadmill

Front 40

What are 3 studies that show that sensory/motor maps are not permanent?

Back 40

MEG studies show larger pinky representation for musicians, fMRIs show more voxels in brain representative of a task that was performed over and over for 8 weeks, phantom limbs show rearrangement of somatosensory map to face