human information processing other systems and organization
Post on 21-Dec-2015
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HUMAN INFORMATIONPROCESSING
OTHER SYSTEMS AND ORGANIZATION
Four volunteers lived for an entire month in the strange reverse world we see while shaving or applying lipstick. Wearing special 'prism spectacles' designed to reverse their vision meant that to go left they had to turn right, and if they looked one way to catch a tennis ball, it would hit them on the back
BRAIN ADAPTATION TOREVERSED LEFT-RIGHTPICTURES
It took three weeks of adaptation for correct answers to appear, suggesting that a new imagined hand representation was emerging; the volunteers said they could visualize their own hands in two ways and could even choose between the two images.
Brain scans associated activity with these new hand images in a region called 'Broca's area' that creates mental pictures of movement. These imagined images help us plan -- and mimic -- movements says Rushworth; explaining why a non-cricketer for example, could do a passable impression of Brian Lara after seeing him in action.
The results lend weight to an emerging theory that this brain region helps us adapt when what we see and what we experience clash, Rushworth adds. This brings possible implications for understanding how brain-damage patients recover, he says, but will be of little clinical use at present
• MORE PICTURES
ILLUSTRATING
VISUAL ALGORITHMS
- THE SYSTEM
CREATES STABLE
REPRESENTATION
ONE ANGLE OR
TWO
CHOPSTICKS ?
WE SEE HERE ILLUSORY CONTOURS OF OBJECTS VISUAL SYSTEM IS REALLY GOOD IN EXTRACTING THEM
JUNCTIONS ARE CRITICAL FOR OBJECTPERECPTION COMPARE LEFT AND RIGHT SIDES
• VISUAL SYSTEM ASSUMES THAT LIGHT
IS COMING FROM TOP
LIGHT DIRECTION
SAME PICTURE UPSIDE DOWN
• IN ALL FIGURES GREY ELEMENTS HAVE
THEY SAME INTENSITY
BUT PERCEIVED INTENSITY DEPENDS ON THESURROUNDING AREA. VISUAL SYSTEM IS THUSNOT AN OBJECTIVE LIGHT INTENSITY MEASURINGDEVICE
• WHERE IS THE LIGHT SOURCE?
• WE CAN ESTABLISH ITS POSITION FROM
SHADOWS OF OBJECTS
• OBJECTS CAN BE EASILY RECOGNIZED
FROM MOTION OF DOTS IF THEY ARE
MOUNTED ON THE OBJECT
• VISUAL SYSTEM IS ONE IMPORANT
PART OF HIP BUT THERE ARE OTHERS:
- ACOUSTICAL SYSTEM- HAPTIC SYSTEM (TOUCH)- VESTIBULAR (ORIENTATION IN SPACE)- SMELL- TASTE
• ACOUSTICAL SYSTEM
HEARING + SOUND/SPEECH PRODUCTION
THIS IS MATCHED RECEIVER-TRANSMITTERVESTIBULARSYSTEM
• COCHLEA – SOUND TRANSDUCER
SOUND PRESSURE IS CHANGED INTOFLUID PRESSURE
MODEL OF COHLEARTRANSDUCER
UT
OUTPUT IS MAXIMUM FOR CERTAIN FREQUENCYAT SOME POSITION ALONG THE TRANSDUCER
• HAIRS – CHANGE THE MECHANICAL
SIGNAL INTO ELECTRICAL
• ACOUSTICAL SIGNALS – CAN BE
ANALYZED IN TIME AND FREQUENCY OR
BOTH. AND BOTH SYSTEMS SEEM TO
BE PRESENT IN THE BRAINWE ARE ABLE TO DETECT PRECISELY FREQUENCY OF TONES
E.G. SINUSOIDS
AND POSITION OF SOUNDS IN TIME
E.G. CLICKS
IN THE ACOUSTICAL CORTEX THERE ARE TIME DETECTORS (PLACE) AND FREQUENCY DETECTORS. BOTH TYPE OF SYSTEMS OPERATE AT SOME FREQUENCY RANGES (TOP)
FILTERS ARE BROADLY TUNED
(BOTTOM)
• THE STRUCTURE OF HEARING SYSTEM
WE CAN SEE SEVERAL STAGES FOM COCHLEA TO
CORTEX
SUPERIOR OLIVARY NUCLEUS IS THE PLACE
WHERE SPATIAL SOUND
PROCESSING STARTS
MAPPING INTO FREQUENCY
AND SPACE LOCATIONS IS
PRESENT, LIKE IN VISION
IT WAS FOR LOCAL SIGNAL
FEATURES
WE HAVE´SENSITIVITIES FOR DIFFEERENT FREQUENCIES, HIGHEST IS
IN MIDDLE RANGE
MUSIC FROM INSTRUMENTS CAN BE VERY EFFICIENTLY RECOGINZED. THIS MUST BE BASED ON DETAILED FREQUENCY AND TIME ANALYSIS
LOCALIZATION OF SOUND SOURCESIN SPACE IS BASED ON MEASURINGDIFFERENCES IN TIME OF SOUND ARRIVALBETWEEN THE EARS. THIS MUST BE VERYPRECISE MEASUREMENT, ON THE ORDEROF TENS OF MICROSECONDS
SOUND LOCALIZATION IS QUITE PRECISE
BUT HEAD MOVEMENTS AND VISUAL
CUES HELP A LOT, ERRORS IN LOCATION
CAN BE SEEN IN PICTURES
MUSIC PROCESSING....
CERTAIN TONES HAVE HARMONY, THEY SOUND NICE TO US,OTHR TONES NOT. WE ARE PROBABLY BORN WITH A SYSTEMWHICH PROCESSES TONES AND THUS WE ARE PREDISPOSEDFOR CERTAIN SOUNDS WHICH ARE ”NATURAL” FOR US
• SPEECH PROCESSING SYSTEMA COMPLEX ELASTIC MECHANICAL SYSTEM CONTROLLED
ELECTRICALLY FOR REGULATION OF AIRFLOW
• BASIC UNITS OF SPEECH –PHONEMSUSING THESE UNITS SPEECH CAN BE GENERATED
HEARING AND SPEECH ARE PRECISLY MATCHED TO EACH OTHERSPEECH CAN BE RECOGNIZED EVEN AT HIGH LEVEL OF NOISEAND INTERFERENCE (COCTAIL PARTY EFFECT, MANY PEOPLE ARETALKING AT THE SMAE TIME BUT WE ARE ABLE TO CONCENTRATEON ONE SPEAKER.
• VESTIBULAR SYSTEMNOTE THAT THE WORLD WE SEE IS STABLE, WHILE
PICTURES ON RETINAS OF EYES ARE NOT. MOVEMENTS
ARE COMPENSATED BY SIGNALS FROM VESTIBULAR
SYSTEM (ORIENTATION IN SPACE)
EXAMPLE: WHEN PERSON IS ROTATING ON A PLATFORM INDARK ROOM, HORIZONTAL LINE WILL BE DEFLECTED
• TOUCH SYSTEM
IT HAS RECEPTORS IN THE BODY.
IN THE BRAIN THERE IS MAPPING OF
THE BODY IN THE CORTEX
• VIEW OF BASIC BRAIN STRUCTURES
• MAPPING OF BODY PARTS IN THE
SOMATOSENSORY CORTEX
• SKIN RECEPTORS OF TOUCH
(CAPSULES AT THE NERVE ENDINGS)
• TOUCH SENSITIVITY THRESHOLD FOR
FEMALES OVER THE BODY
• TOUCH SENSITIVITY THRESHOLD FOR
MALES
FEMALES ARE MORE SENSITIVE!!!
• PAIN SYSTEMWHAT IS PAIN?IT IS SIGNALLING FROM THEBODY TO THE BRAIN ABOUTIMPROPER OPERATIONTHE BRAIN CHANGES ITS ACTIONTO DEAL WITH THE PROBLEMTHERE IS ALSO A SYSTEM FOR IHIBITING THE PAIN SIGNALS
• ACUPUNCTUREIT IS ACTIVATION OF TOUCHAND PAIN SYSTEM IN ORDERTO STIMULATE OTHER BRAIN STRUCTURES
PERHAPS IMMUNE SYSTEM ISSTIMULATED???
INTEGRATION OF SENSESIN BIOLOGICAL SYSTEMS
WE COULD CALL IT
”BIOLOGICAL MULTIMEDIA”
but this is ONLY A JOKE!
• PEOPLE HAVE FANTASTIC CAPABILITIES IN RECEIVING AND PRODUCING INFORMATION BY DIFFERENT SENSES AND SYSTEMS
FOR EXAMPLE THEY CAN SPEAK,
LISTEN AND DANCE AT THE SAME TIME
HOW SUCH THINGS ARE CONTROLLED
AND ORGANIZED IN THE BRAIN? LET’S SEE FIRST SOME OF THE BRAIN CAPABILITIES (SOME OF THEM QUITE FUNNY TOO)
CROSSMODAL MATCHING
HERE THE PERSON MUST RECOGNIZE OBJECT VISUALLY,RECOGNIZE OBJECT TACTILLY, COMPARE THEM AND MATCH
HOW THIS IS DONE? PROBABLY INFORMATION FROM DIFFERENT
SENSES IS STORED IN SOME GENERAL WAY, INEPENDENT FROM
PARTICULAR SENSE
SOME PEOPLE HAVE PECULIAR
EXPERIENCE: THEY FEEL E.G. SPECIFIC
SHAPE WHEN FEEL SPECIFIC TASTE
THIS IS CALLED SYNESTHESIA, ONE CAN SPECULATE THATSENSORY SIGNALS GET MIXED UP SOMWHERE
• VENTRILOQUISM - BY COORDINATING
MOVEMENTS OF A PUPPET WITH SPEECH,
VENTIRLOQUIST INDUCES STRONG ILLUSION
THAT THE PUPPET IS SPEAKING
• HOW THE COORDINATION IS DONE?
DEEP IN THE BRAIN THERE IS A STRUCTURE CALLED
SUPERIOR COLLICULUS
• IN THIS STRUCTURE THERE ARE
NEURONS REACTING TO DIFFERENT
SENSORY INFORMATION:
THEY ARE MULTIMODAL
• STIMULATION OF DIFFERENT SENSORY AREAS OF CORTEX WILL PRODUCE
RESPONSE FROM Superior Colliculus NEURONS:
• THERE ARE MANY KINDS OF
MULTIMODAL NEURONS: SOME RESPOND TO 2 DIFFERENT SENSES
AND SOME TO 3
• THESE NEURONS HAVE CONNECTIONS
FROM LAYERS OF SINGLE SENSORY
NEURONS
• HERE WE SEE LAYER OF VISUAL
NEURONS FOR DIFFERENT ANIMALS
THEY FORM A MAP OF VISUAL SPACE
• HERE WE SEE LAYER OF AUDITORY
NEURONS
THEY FORM A MAP OF AUDITORY SPACE
• THE DIFFERENT MAPS
ARE OVERLAID ON
EACH OTHER SO THEY
MATCH!
• THESE NEURONS RESPOND TO
OVERLAPPING AREAS FROM DIFFERENT SENSORY MAPS. THEY HAVE
BROAD RESPONSE
RESPONSE PATTERNS FOR DIFFERENT
BODY AREAS
• CONTROL OF BODY MOVEMENTS
EAR POSITIONS
• REACTION OF VISUAL-ACOUSTICAL
NEURON. REPONSE IS GREATLY
ENHANCED FOR SIMULTANEOUS
VISUAL-ACOUSTICAL STIMULATION
PLEASE NOTE THAT SIGNALS ARE SYNCHRONIZED I N TIME!
• RESPONSE OF VISUAL-TOUCH
NEURON. RESPONSE IS ENHANCED
PLEASE NOTE THAT SIGNALS ARE SYNCHRONIZED I N TIME!
• TOUCH-VISUAL NEURON.
RESPONSE ENHANCED
PLEASE NOTE THAT SIGNALS ARE SYNCHRONIZED I N TIME!
• TRIMODAL NEURON- SENSITIVE TO 3
SENSES. RESPONSE TO TWO SENSES
AT A TIME
• DEPRESSION OF RESPONSE WHEN
SIGNALS ARE NOT OPTIMALLY
SYNCHRONIZED
• RECEPTIVE FIELD OF NEURON
RESPONSE INCREASEDRESPONSEDEPRESSED
STRONGEST MULTISENSORYRESPONSE
• HOW RESPONSE DEPENDS ON THE POINT OF
STIMULATION
WE CAN SEESTRONG DEPRESSIONAND ENHANCEMENT
• RESPONSE FOR VISUAL-TOUCH
NEURON
• RESPONSE FOR TOUCH-ACOUSTICAL
NEURON
• VISUAL-ACOUSTICAL RESPONSE IN
RELATION TO POSITION OF EARS
• WHAT HAPPENS IF STIMULATIONS ARE NOT SYNCHRONIZED?
ACOUSTICAL SIGNAL IS EARLIER
THAN TOUCH BY 400, 200, ... MS
• TOUCH SIGNAL IS EARLIER
• ACOUSTICAL SIGNAL IS EARLIER
THAN VISUAL, VERY STRONG PEAK
RESPONSE BETWEEN 50 AND 0 MS
• STIMULATION NOT OPTIMAL IN
SPACE
• STIMULATION MUST BE SYNCHRONIZED
IN TIME AND IN SPATIAL POSITION
TO PROVIDE MAXIMUM RESPONSE
• WHY ALL THIS IS DONE? BECAUSEMUTISENSORY SIGNALS PROVIDE MORE AND MORE PRECISE INFORMATION
THE DELAY OF 50 MS FOR OPTIMAL AUDIOVISUAL RESPONSE MIGHT BE COMING BECAUSEOF THE DEALAY IN SOUND PROPAGATION
IN 50 MS SOUND MAKESABOUT 20 M WHICH IS RANGE OF OPERATION