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HUMAN INFORMATION PROCESSING. OTHER SYSTEMS AND ORGANIZATION.
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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 TO REVERSED LEFT-RIGHT PICTURES
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
ONE ANGLE OR TWO CHOPSTICKS ? • MORE PICTURES ILLUSTRATING VISUAL ALGORITHMS • THE SYSTEM CREATES STABLE REPRESENTATION
WE SEE HERE ILLUSORY CONTOURS OF OBJECTS VISUAL SYSTEM IS REALLY GOOD IN EXTRACTING THEM
JUNCTIONS ARE CRITICAL FOR OBJECT PERECPTION COMPARE LEFT AND RIGHT SIDES
LIGHT DIRECTION • VISUAL SYSTEM ASSUMES THAT LIGHT IS COMING FROM TOP SAME PICTURE UPSIDE DOWN
IN ALL FIGURES GREY ELEMENTS HAVE THEY SAME INTENSITY BUT PERCEIVED INTENSITY DEPENDS ON THE SURROUNDING AREA. VISUAL SYSTEM IS THUS NOT AN OBJECTIVE LIGHT INTENSITY MEASURING DEVICE
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-TRANSMITTER VESTIBULAR SYSTEM
COCHLEA – SOUND TRANSDUCER MODEL OF COHLEAR TRANSDUCER SOUND PRESSURE IS CHANGED INTO FLUID PRESSURE UT OUTPUT IS MAXIMUM FOR CERTAIN FREQUENCY AT 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 BRAIN WE 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)
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 • THE STRUCTURE OF HEARING SYSTEM
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 SOURCES IN SPACE IS BASED ON MEASURING DIFFERENCES IN TIME OF SOUND ARRIVAL BETWEEN THE EARS. THIS MUST BE VERY PRECISE MEASUREMENT, ON THE ORDER OF 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
CERTAIN TONES HAVE HARMONY, THEY SOUND NICE TO US, OTHR TONES NOT. WE ARE PROBABLY BORN WITH A SYSTEM WHICH PROCESSES TONES AND THUS WE ARE PREDISPOSED FOR CERTAIN SOUNDS WHICH ARE ”NATURAL” FOR US
SPEECH PROCESSING SYSTEM A COMPLEX ELASTIC MECHANICAL SYSTEM CONTROLLED ELECTRICALLY FOR REGULATION OF AIRFLOW
BASIC UNITS OF SPEECH –PHONEMS USING THESE UNITS SPEECH CAN BE GENERATED HEARING AND SPEECH ARE PRECISLY MATCHED TO EACH OTHER SPEECH CAN BE RECOGNIZED EVEN AT HIGH LEVEL OF NOISE AND INTERFERENCE (COCTAIL PARTY EFFECT, MANY PEOPLE ARE TALKING AT THE SMAE TIME BUT WE ARE ABLE TO CONCENTRATE ON ONE SPEAKER.
VESTIBULAR SYSTEM NOTE 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 IN DARK 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
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
WHAT IS PAIN? IT IS SIGNALLING FROM THE BODY TO THE BRAIN ABOUT IMPROPER OPERATION THE BRAIN CHANGES ITS ACTION TO DEAL WITH THE PROBLEM THERE IS ALSO A SYSTEM FOR IHIBITING THE PAIN SIGNALS • PAIN SYSTEM
IT IS ACTIVATION OF TOUCH AND PAIN SYSTEM IN ORDER TO STIMULATE OTHER BRAIN STRUCTURES PERHAPS IMMUNE SYSTEM IS STIMULATED??? • ACUPUNCTURE
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 THAT SENSORY 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!