Understanding the Brain

Electroencephalograph (EEG)Monitors the electrical activity of the brainEEG recordings are translated into line tracings called brain wavesUsed in clinical diagnosis of various neurological disorders

Electroencephalograph (EEG)

Brain Imaging- CAT ScanIn a CAT scan machine, the X-ray beam moves all around the patient, scanning from hundreds of different angles. The computer takes all this information and puts together a 3-D image of the body.Portrays only brain structure. Used to diagnose and treat a wide variety of ailments (head trauma, cancer, tumors).

Brain Imaging- PET ScanThese scans examine brain functionThey monitor chemical processes such as neurotransmittersPerson receives an injection of radioactive substanceBrain structures that are active absorb the substance and this is color coded onto a computer screen.

Brain Imaging- PET Scan

Brain Imaging- MRISimilar to CAT scan but better picture due to high resolutionPersons head is surrounded by a magnetic field and the brain is exposed to radio waves, which cause hydrogen atoms in the brain to release energy.The energy released by different structures generates an image on a computer screen.

Brain Imaging- MRI

Brain Imaging- fMRISimilar to PET but less invasive and collects precise images rapidly.It measures the movement of blood molecules (an index of neural activity).Provides both functional and structural information in the same image.

Lesioning & ESBLesioning- destroying a piece of the brainInsert an electrode into a brain structure and pass a high electric current which burns tissue

ESB (electrical stimulation of the brain)- sending an electric current into a brain structure to activate it

Three Main Regions of the BrainHindbrain- lower part of brain stem (pons & medulla), & cerebellum

Midbrain- upper brainstem (reticular formation)

Forebrain- largest & most complex part, limbic system (hippocampus, hypothalamus, thalamus, amygdala) at the center, cerebrum, cerebral cortex & lobes.

Cerebrum is divided into 4 Lobes

Frontal LobePrefrontal cortexReasoning, planning, paying attention, getting organized, decision makingMotor cortex- movement of musclesBrocas Area (only left side) production of speech

Phineas Gage- example of prefrontal cortex damage

Parietal LobeSomatosensory Cortex- controls sensory informationProcess info from body partsSense of touch, feeling temperature & painPhantom Limb syndrome

Temporal LobePrimary auditory cortexInvolves hearing, speaking, understanding written & verbal wordsWernickes Area- comprehension of language

Occipital LobePrimary visual cortexVisual processing begins

Brain PlasticityExperience can change/sculpt certain brain structures (ex: musicians)The brain can go through neural reorganization after damage- healthy neurons attempt to compensate for the loss of nearby neuronsThe adult brain can generate new neuronsBrains plasticity declines with age