The Brain

� Lesion

� tissue destruction�

� a brain lesion is a naturally or experimentally caused destruction of brain tissue

Electroencephalogram (EEG)

� an amplified recording of the waves of electrical activity that sweep across the brain�s surface

� these waves are measured by electrodes placed on the scalp

Event Related Potential:� ERP

PET Scan: detects where a radioactive form of glucose goes while the brain performs a given task

MRI Scan (magnetic resonance imaging)
a technique that uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of soft tissue

MRI

Functional MRI (fMRI)

The Brain

� Brainstem

� the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull

� responsible for automatic survival functions

� Medulla �

� base of the brainstem

� controls heartbeat and breathing

The Brainstem

Brainstem

Brainstem

� Reticular Formation

� a nerve network in the brainstem that plays an important role in controlling arousal

� Circadian Rhythms

� Thalamus

� the brain�s sensory switchboard, located on top of the brainstem

� it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

Brian Stem

� Cerebellum

� the �little brain� attached to the rear of the brainstem

� it helps coordinate voluntary movement and balance

The Limbic System

Limbic System

The Brain

� Limbic System

� a doughnut-shaped system of neural structures at the border of the brainstem and cerebral hemispheres

� associated with emotions such as fear and aggression and drives such as those for food and sex�

� includes the hippocampus, amygdala, and hypothalamus.

� Amygdala [ah-MIG-dah-la]

� two almond-shaped neural clusters that are components of the limbic system and are linked to emotion

The Limbic System

� Electrode implanted in reward center

The Brain: Limbic System

� Hypothalamus

� neural structure lying below (hypo) the thalamus; directs several maintenance activities

� eating

� drinking

� body temperature

� helps govern the endocrine system via the pituitary gland

� is linked to emotion

The Cerebral Cortex

The Cerebral Cortex

Nobel Prize Winners:� Hubel & Weisel

Hubel and Wiesel

Hubel and Weisel

o There are cell that fire to only vertical lines

o Others fire to only horizontal lines

o Others fire on to specific types of movements, etc.

The Cerebral Cortex

� Functional MRI scan shows the visual cortex activated as the subject looks at faces

The Cerebral Cortex

Temporal Lobe

o Visual perception, object recognition, categorization

o Face Recognition: Face Fusiform Area (mainly the right side)

Temporal Lobes

o Auditory perception, especially language and names

Temporal Lobes

o Hippocampus� Transfer of information from STM to LTM

The Cerebral Cortex

Parietal Lobe

o Integration of sensory information

o Integration of information and body knowledge

Parietal Lobe: Body knowledge

The Cerebral Cortex

� Motor Cortex

� area at the rear of the frontal lobes that controls voluntary movements

� Sensory Cortex

� area at the front of the parietal lobes that registers and processes body sensations

The Cerebral Cortex

The Cerebral Cortex

Frontal Lobe

o Higher Order Functions

n Problem Solving

n Reasoning

o Planning and Executive Function

o Consciousness and Awareness

o Impulse Control

o Knowledge of time (past, present, future)

Association Areas

� More intelligent animals have increased �uncommitted� or association areas of the cortex

Our Divided Brain

� Corpus Callosum

� large band of neural fibers

� connects the two brain hemispheres

� carries messages between the hemispheres

Split Brain

� a condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers (mainly those of the corpus callosum) between them

Split Brain