LIMBIC SYSTEM AND MEMORY CSMU Anatomy Department By Caleb Tinashe Munikwa Group 214

Limbic system and memory

Embed Size (px)

Citation preview

Page 1: Limbic system and memory




CSMU Anatomy Department


Caleb Tinashe Munikwa

Group 214

Page 2: Limbic system and memory

The limbic system is composed of structures in

the brain that deal with Emotions(such as anger ,

happiness and fear) as well as Memory

Page 3: Limbic system and memory

It supports a variety of functions including adrenaline flow, emotion,

behavior, motivation, long-term memory, and olfaction. Emotional life is

largely housed in the limbic system, and it has a great deal to do with

the formation of memories.

The limbic system (or paleomammalian brain) is a complex set of

brain structures located on both sides of the thalamus, right under the

cerebrum. It’s a collection of structures from the telencephalon,

diencephalon, and mesencephalon. It includes the olfactory bulbs,

hippocampus, amygdala, anterior thalamic nuclei, fornix, columns of

fornix, mammillary body, septum pellucidum, habenular commissure,

cingulate gyrus, parahippocampal gyrus, limbic cortex, and limbic

midbrain areas ass shown in the above slide.

Page 4: Limbic system and memory


Memory is a process in which information is encoded , stored

and retrieved

Memory is a complex relationship between brain neurons

The major parts of the Limbic System involved in Memory are

: Amygdala

: Hippocampus

: cingulate gyrus

Page 5: Limbic system and memory
Page 6: Limbic system and memory

Information flows from the outside world through our sight

, hearing , smelling , testing and touch sensors

Therefore memory is simply ways we store and recall

things we have sensed

We store memory in areas located throughout the cortex ,

some data moves into short term memory and finally into

long term memory

Page 7: Limbic system and memory


Page 8: Limbic system and memory


Almond shaped masses of neurons on

either side of the thalamus at the lower end of

the hippocampus

It is for emotion , arousal , storing of

memory and stimulation of the hippocampus

in remembering of events for future


Page 9: Limbic system and memory


Page 10: Limbic system and memory



Connections of neurons that fire repeatedly

again and again in a particular pattern, archive long

term potentiation (LTP) becoming more and more


Hence creating memory and ready to fire the

exact same way in the future

LTP firing makes it more easy to remember as a

result of a particular strengthened pattern of firing


Page 11: Limbic system and memory



Page 12: Limbic system and memory

Memory is not stored in one combination of LTP but in

numerous combinations of neurons like in the above


The mesh of neurons in the above slide might be the

memory of your first kiss

It is stored in various networks, the events leading to

your 1st kiss are stored in another network, the way it felt

in another network , the way it smelled in another


Hence all added up making up the memory of your first


Page 13: Limbic system and memory


Page 14: Limbic system and memory




The amygdala is responsible for recognition/ distinguishing

male from female and in turn feeling aroused by the opposite


Females have a larger amygdala than males hence are

more emotional and tend to remember the finest details of

events than males e.g they can link the color red to their

break up memory because the first thing she saw

immediately after her break up was a red car.

Page 15: Limbic system and memory

On the same note males have smaller amygdala

compared to that of the opposite gender and tend to be less


Homosexuals have a larger than amygdala compared to

that of heterosexuals whose memory recognizes people of

the same gender as arousing.

Damage to the amygdala causes individual to have an

impaired ability to interpret emotional aspect of facial


Page 16: Limbic system and memory


Page 17: Limbic system and memory

The cingulate gyrus provides a pathway

from the thalamus to the hippocampus and is

responsible for associating memories of smell

with pain or pleasant memories

Page 18: Limbic system and memory


Page 19: Limbic system and memory


Consist of two horns that curve back from the amygdala

Responsible for converting short term memories into long

termed memories, works with the amygdala for storage

Damage couples to every day memory fades away ( A

condition depicted in the films [ Memento and 50 1st

dates ]

Page 20: Limbic system and memory


Page 21: Limbic system and memory


The hippocampus consolidates new memories in an event

that creates temporally links among cortex neurons e.g ‘’red’’

gets stored in the visual area of the cortex and the sound of

the bitten apple gets stored in the auditory area

When one remembers the new fact ‘’delicious apple’’ the

new memory converges on the hippocampus , which sends

them along the same path several times to strengthen the


Page 22: Limbic system and memory

The information follows a pathway called the papez

circuit starting at the hippocampus , circulating through

more of the limbic system (to pick up any emotional

associations like ‘’happy warm day’’ and spatial

associations like ‘’apple orchard’’

Then to various parts of the cortex and back to the

hippocampus ,making the information flow around the

circuit many times strengthens the links(LTP) enough that

they stabilize and no longer need the hippocampus to

bring the data together therefore becoming long term


Page 23: Limbic system and memory


Page 24: Limbic system and memory


Short term memory is the type of memory that

enables you to speak back the last sentence of a

conversation when someone accuses you of not


It stores only data that catches your attention like a

police car behind you or following direction

STM is small it holds about 7 independent items at

one time such as carrying numbers when calculating


Page 25: Limbic system and memory


Page 26: Limbic system and memory

Long term memory has a large capacity and contains

memories that are decades old in addition to memories that

arrived several minutes ago.

Memories of LTM are relatively permanent are not likely

to be lost and can be divided into two Explicit and Implicit

Explicit memory measures requires a participant to

remember information e.g in exam

Implicit memory measure requires the participants to

perform a task without making a conscious effort to recall

the past because of previous experiences e.g playing music

or tennis.

Page 27: Limbic system and memory


spatial memory is the part of memory

responsible for recording information about

one's environment and its spatial orientation.

For example, a person's spatial memory is

required in order to navigate around a familiar


Page 28: Limbic system and memory


Page 29: Limbic system and memory

Amnesia can also be caused temporarily by the use of various

sedatives and hypnotic drugs. Essentially, amnesia is loss of memory.

The memory can be either wholly or partially lost due to the extent of

damage that was caused. There are two main types of amnesia:

retrograde amnesia and anterograde amnesia. Retrograde amnesia is

the inability to retrieve information that was acquired before a

particular date, usually the date of an accident or operation. In some

cases the memory loss can extend back decades, while in others the

person may lose only a few months of memory. Anterograde amnesia

is the inability to transfer new information from the short-term store

into the long-term store. People with this type of amnesia cannot

remember things for long periods of time. These two types are not

mutually exclusive. Both can occur within a patient at one time.

Page 30: Limbic system and memory

Storage capacity of a human brain is 2,5 petabytes

{Paul Reber} of information .Equivalence of recording a

TV channel continuously for 300 years. That is a lot of

information that we have learned , seen ,experienced


Page 31: Limbic system and memory