Download The Brain

yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

History of anthropometry wikipedia, lookup

Environmental enrichment wikipedia, lookup

Evolution of human intelligence wikipedia, lookup

Cortical cooling wikipedia, lookup

Intracranial pressure wikipedia, lookup

Limbic system wikipedia, lookup

Neuromarketing wikipedia, lookup

Nervous system network models wikipedia, lookup

Artificial general intelligence wikipedia, lookup

Neuroscience and intelligence wikipedia, lookup

Embodied language processing wikipedia, lookup

Causes of transsexuality wikipedia, lookup

Clinical neurochemistry wikipedia, lookup

Donald O. Hebb wikipedia, lookup

Functional magnetic resonance imaging wikipedia, lookup

Cognitive neuroscience of music wikipedia, lookup

Embodied cognitive science wikipedia, lookup

Human multitasking wikipedia, lookup

Blood–brain barrier wikipedia, lookup

Neurogenomics wikipedia, lookup

Brain wikipedia, lookup

Time perception wikipedia, lookup

Dual consciousness wikipedia, lookup

Neuroeconomics wikipedia, lookup

Activity-dependent plasticity wikipedia, lookup

Emotional lateralization wikipedia, lookup

Neuroesthetics wikipedia, lookup

Neuroinformatics wikipedia, lookup

Connectome wikipedia, lookup

Haemodynamic response wikipedia, lookup

Neurophilosophy wikipedia, lookup

Neurotechnology wikipedia, lookup

Selfish brain theory wikipedia, lookup

Brain morphometry wikipedia, lookup

Neuroanatomy wikipedia, lookup

Neuropsychopharmacology wikipedia, lookup

Brain Rules wikipedia, lookup

Sports-related traumatic brain injury wikipedia, lookup

Neurolinguistics wikipedia, lookup

Lateralization of brain function wikipedia, lookup

Human brain wikipedia, lookup

Cognitive neuroscience wikipedia, lookup

Aging brain wikipedia, lookup

Holonomic brain theory wikipedia, lookup

Neuroplasticity wikipedia, lookup

History of neuroimaging wikipedia, lookup

Neuropsychology wikipedia, lookup

Metastability in the brain wikipedia, lookup

The Brain
Lecture Overview
• Methods of Studying the Brain
• Structure of the Brain
• Localization of Function
• Brain Lateralization
• Plasticity
Studying the Brain
• Study Brain Damage
– Animal Studies
– Cases of Human Brain Damage
• Recording the Brain
– Neuroimaging
Brain Damage
• In some animal studies, damage is
produced in the laboratory.
• But neuropsychologists often study
naturally occurring cases of brain damage.
• Transcranial magnetic stimulation (TMS):
• Scientists can use TMS to study the effects of
temporary brain damage.
Recording the Brain
• Techniques are used to study the whole
• Electroencephalography
• Uses sensitive electrodes on the scalp to measure
voltages produced by brain activity
• Neuroimaging
• CT, MRI, fMRI, PET scans
Recording the Brain
• MRI and CT scans
• Study the brain’s anatomy—the size and
location of individual structures
• PET and fMRI scans
• Reveal which brain locations are particularly
active at any moment in time
Recording the Brain
• All these techniques make it clear that
most activities rely on many brain sites.
• Activities like reading or making decisions are
supported by coordinated functioning of many
different parts of brain.
Brain Anatomy
Brain Structure
• The very top of the spinal cord forms the
brain stem.
• It includes the medulla and the pons.
• Just behind these is the cerebellum.
• The midbrain is on top of the pons, and on
top of them all is the forebrain.
The Cortex
• The outer surface of forebrain is the
cerebral cortex.
• The cortex is a large, thin sheet of tissue
crumpled inside the skull.
• Some of the convolutions divide the brain into
• The frontal lobes, the parietal lobes, the occipital
lobes, and the temporal lobes
Left and Right Hemispheres
• The brain is symmetrical around the
• Most structures come in pairs:
• One on the left side
• One on the right side
Localization of Function
• Different parts of the brain serve
specialized functions
• Sensory Information
• Motor Control
• Perception
• Language
• Planning and Social Cognition
Cerebral Cortex
• Some parts serve as projection areas:
• The first receiving stations for information
coming from the sense organs (e.g.,
somatosensory projection areas)
• Departure points for signals going to the
muscles (e.g., motor projection area)
Cerebral Cortex
• Adjacent sites in the brains usually represent
adjacent parts of the body.
• Assignment of space is disproportionate:
• Usually the parts of the body that are most sensitive
to touch receive the most space (in somatosensory
projection area).
• Parts of the body that we can move with more
precision receive the most space (in primary motor
projection area)
Cerebral Cortex
• Most projection areas have contralateral
– Left hemisphere receives information from
right side of body (sensory), or controls right
side of body (motor)
– Right hemisphere receives information from
left side of body (sensory), or controls left side
of body (motor)
Cortical Damage
• Much of what we know about the cortex
comes from studying brain damage.
• Damage at identifiable sites can produce:
• Apraxias (disorders in action)
• Agnosias (disorders in perception)
• Aphasias (disorders of language)
• Disorders of planning or social cognition
• Difficulty in carrying out purposeful
movements without the loss of muscle
strength or coordination
– Disconnection between primary and nonprimary motor areas
– Able to carry out each part of a complex
movement, but disruption lies in coordination
of the movements
• Visual agnosia: disturbance in recognizing visual stimuli despite the
ability to see and describe them
• Prosopagnosia: inability to recognize faces (fusiform face area)
• Neglect Syndrome: complete inattentiveness to stimuli on one side
of the body
• Akinetopsia: inability to perceive movement
– “I see the world in snapshots – like frames of a move but most of the
frames are missing”
• Broca’s Aphasia: disturbance in speech production,
caused by damage to Broca’s area
• Agrammaticism
• Anomia
• Difficulty with articulation
• Wernicke’s Aphasia: disturbance in speech
comprehension, caused by damage to Wernicke’s area
• Disruption in recognition of spoken words
• Disruption in comprehension of the meaning of words
• Inability to convert thought into words
Disorders of Planning and Social
• Caused by damage to prefrontal area
– Disrupts executive control– processes that
allow us to direct our own cognitive activities
• e.g., setting priorities, planning, strategizing,
ignoring distractors
• The left and right hemispheres are generally similar
• However, the two hemispheres have specialized
– Left hemisphere: language
– Right Hemisphere: visual and spatial tasks
• The two halves of the brain work as an integrated whole
– Communicate with each another through commissures
• Split Brain Patients
Other Split Brain Experiments
• The brain is plastic—subject to alteration in the
way it functions, such as:
• Changes in the brain’s overall architecture
• The central nervous system can grow new neurons:
• But appears unable to do so with cortical injury
• This promotes stability in the brain’s connections but
is an obstacle to recovery from brain damage.
• Neurons are subject to alteration in the
way they function, such as:
• Changes in how much neurotransmitter a
presynaptic neuron releases
• Changes in neuron sensitivity to
• Creating new connections by growing new
dendritic spines