Hierarchical + Neocortical Organization

Question 1

What are subcortical structures? Name 4 of them

Answer 1

Subcortical structures are structures beneath the cerebral cortex that can sometimes supplement complex behaviour when the cortex structures for that behaviour are missing

examples of a subcortical structure are the basal ganglia, the hypothalamus, the thalamus, and the amygdala


Question 2

What can subcortical structures do in the absence of cortical structures?

Answer 2

Subcortical structures can mediate, and sometimes supplement complex behaviours when the cortex structures for that behaviour are damaged

Question 3

What is the principle of Hierarchical Organization of Function?

Answer 3

The principle of hierarchical organization of function is that each level of brain organization doesn’t necessarily perform the same function, rather that they add a new dimension of function to each other, as the hierarchy goes on 

Question 4

Mid-Brain versus Hind Brain

Answer 4

In terms of function behind brain can perform some units of movement by hissing, biting, chewing, licking, etc..

The mid brain is responsive to simple, visual, stimuli and performs subconscious action like grooming. 

Question 5

Hypothalamus v Thalamus

Answer 5

The hypothalamus and pituitary gland, regulate body temperature, whore moans and homeostasis

thalamus intakes all sensory information, except for olfactory information and projects it onto the cortex 

Question 6

Basal Ganglia

Answer 6

The basal ganglia is a cluster of nuclei that includes the caudate nuclei, the putamen, and Globus pallidus

the basal ganglia combines the automatic movements to voluntary movements, making them more biologically adaptive and easy for the specimen to do. This region is made up mostly of grey matter. 

Question 7

Cortex

Answer 7

This refers to the cerebral cortex, which is a wrinkly top layer of the brain that is made up of mostly gray matter, and consists of gyri and sulci 

Question 8

Define low decerebration. How does it compare to high decerebration?

Answer 8

Low décérébration is when the hind brain and spinal cord are disconnected from the rest of the brain. Sensory input stops going to the four brain and there is a constant loss of consciousness.

High discerebration is damaged to the diencephalon that disconnects it from portions of the midbrain that handle, coordinating vision, and hearing, and the tegmentum

Animals with high decelebration can only reply to visual and auditoris stimuli at a distance by moving towards them, they still have control of voluntary/appetite of movements. These movements get an animal from place to place and are used to satisfy needs like finding food they can they can also perform automatic movements, such as drinking water 

Question 9

Describe the behavioral state and capacity iof a diencephaliuc animal

Answer 9

Diencephalic animals behaviour has affective and motivational dimensions to it, and the fact that their emotions can build and be calm energized, and they can be sustained. These emotions are often displaced, however, and seemingly random. 

Question 10

Define Decortation? What does it cause?

Answer 10

Decortation is the removal of the cerebral cortex, keeping the basal ganglia and brainstem still intact. Decorticated animals are able to eat drink and have typical sleep cycles. They can run climb swim and even get through simple maze mazes. However, the cortex seems to control, forethought and intentional actions. Thus animals lose the ability to make nests, hoard food or have complex behaviors. 

Question 11

What is Brodmann’s Map? why is it impoartant

Answer 11

A map of a cortex divided into primary secondary and tertiary zones by way of chronological myelin and development 

Question 12

Spiny Nuerons v Aspiny Neurons

Answer 12

spiny neurons have dendritic spines which increase the surface area of the dendrites. They are generally excitable and use glutamate or aspirate as their primary neurotransmitter

Aspiny neurons lack destroying spines and are generally inhibitory- they use GABA as their primary neurotransmitter in combo with many other NT’s making Aspiny neurons very chemically and physically diverse

Question 13

Pyramidal Cells v Stellate Cells

Answer 13

These are spiny neurons that
Pyramidal: has triangular cell bodies with long axons that send infor from cortical regions to other parts of the CNS

Stellate: smaller star shaped cells whose processes are generally contained to the area the cell inhabits

Question 14

A Projection Map does…..

Answer 14

Shows areas of the cortex that process specific sensory information and produce movement and breaks the down into primary secondary and tertiary areas

Question 15

Primary Areas v Secondary Areas v Tertiary Areas

Answer 15

Primary Areas recieve info from major sensory systems or send much data to motor systems

Secondary Areas are usually nearby the primary areas and help elaborate the info recieved by the primary areas

Tertiary Areas are the cortical areas that don’t have any specific specialized but assisted in multiple functions

Question 16

Give an example of a secondary area and what it does

Answer 16

Pré motor cortex

Question 17

Give an example of a tertiary area and what it does

Question 18

List the cortical layers and their functions

Answer 18

Each of the four to six layers of the neocortex has different functions, different afferents, and different efferents. Cells of the middle cortical layers, especially in and around layer IV, constitute an input zone of sensory analysis: they re- ceive projections from other cortical areas and from other areas of the brain. The cells of layers V and VI constitute an output zone, sending axons to other cortical areas or other brain areas.

Question 19

The thickness of a cortical layer depends on….

Answer 19

Whether it is motor or somatic and what Function it serves

Question 20

Specific Afferent v Non-Specific

Answer 20

1. Specific afferents bring information (e.g., sensory information) to an area of the cortex and terminate in relatively discrete cortical regions, usually in only one or two layers. Specific afferents include projections from the thalamus as well as from the amygdala. Most of these projections terminate in layer IV, although projections from the amygdala and certain thalamic nuclei may terminate in the more superficial layers

Nonspecific afferents presumably serve general functions, such as maintaining a level of activity or arousal so that the cortex can process information. They terminate diffusely over large regions of the cortex—in some cases, over all of it. Nonspecific afferents even release their trans- mitter substances into the extracellular spac

Question 21

What are Cortical Columns

Answer 21

interactions between the cortical layers take place vertically, within the neurons directly above or below adjacent layers. Less interaction takes place with cells more than a couple of millimeters on either side. This vertical bias forms the basis for a second type of neocortical organization: columns or modules

Question 22

Define Multimodal Cortex. Give an example

Question 23

Principle connections of cortical hieracrhy in the Primary visual cortex are…

Question 24

Define Subcortical Loops. Why are they important?

Answer 24

Reciprocal cortical-subcortical connections or feedback loops.
The neocortex above subcortical structures are constantly sending each other information looped between the neocortex, hippocampus, amygdala, striatum, and thalamus.

Subcortical loops presumably play some role in amplifying or modulating ongoing cortical activity

Question 25

What are the three main theories to the Binding Problem?

Answer 25

high-order cortical center that receives input from all of the differ- ent cortical areas and integrates (binds) them into a single perception. Although this hierarchical idea makes sense, unfortunately no such area exists. A second solution is to interconnect all of the different cortical areas so that information is somehow shared. The problem here is that not all cortical areas connect with one another, not even within a single sensory modality.

intracortical networks of connections among subsets of cortical regions. This idea has considerable appeal.
First, all cortical areas have internal connections among units with sim- ilar properties Second, through a mechanism called reentry, any cortical area can influence the area from which it receives input

Question 26

Agnosia v Aphasia

Answer 26

Agnosia is inability to recognize while aphasia is inability to produce fluent speech

Question 27

Who is Alexander Luria? Why is he important?

Answer 27

He divided the neocortex into :

The posterior cortex (parietal, occipital, and temporal lobes) is the sensory unit that receives sensations, processes them, and stores them as information (Figure 10.17A).

The anterior cortex (frontal lobe) is the motor unit that formulates inten- tions, organizes them into programs of action, and executes the programs

He assumed that :

The brain processes information serially, one step at a time.

Serial processing is hierarchical: each level adds complexity that is qualita- tively different from the processing in the preceding levels. The tertiary cortex could be considered a terminal station insofar as it receives input from the sensorimotor and perceptual areas and performs higher cognitive processes on that input.

Our perceptions of the world are unified and coherent

Question 28

Posterior Cortex v Anterior Cortex

Question 29

Whatre Luria’s Assumptions? What was wrong with them?

Question 30

Describe the Distributive Hierarchy Model

Question 31

Paralimbic Cortex

Question 32

Cingulate Cortex

Answer 32

The cingulate gyrus is an arch-shaped convolution situated just above the corpus callosum. The frontal portion is termed the anterior cingulate gyrus (or cortex). A component of the limbic system, it is involved in processing emotions and behavior regulation. It also helps to regulate autonomic motor function.