HUMAN INFORMATION PROCESSING II STRUCTURE, SYSTEMS AND FUNCTION

The intial processing in visual cortesx happens is the Area 17. There are also other areas connected to it: 18,19 and additional areas. What these areas do? They process more complicated aspects of vision and there is still the principle: different areas specialize in specific aspects of visual information.

HERE THREE AREAS CAN BE SEEN. ONE IS FOR PROCESSING FORMS AND FEATURES, SECOND IS FOR COLOR AND THIRD FOR MOTION THAT MEANS SEPARATE ASPECTS ARE PROCESSED IN SEPARATE AREAS

 BUT THE INFORMATION FROM THE SEPARATE AREAS MUST BE SYNCHRONIZED AND INTEGRATED.  THIS MEANS THE AREAS MUST BE INTERCONNECTED AND THIS IS WHAT IS OBSERVED: ON THE PICTURE INTERCONNECTIONS DISCOVERED BY EXPERIMENTS ARE SHOWN.  SO THE STRUCTURE OF VISUAL CORTEX IS : LARGE NUMBER OF SPECIALIZED PROCESSING AREAS INTERCONNECTED IN COMPLICATED WAYS

WE DO NOT FEEL ANYTHING ABOUT OPERATION OF THESE SYSTEMS, EVERYTHING IS PERFECT- SO HOW CAN WE KNOW THAT THESE SYSTEMS REALLY EXIST AND OPERATE? ONE METHOD IS TO LOOK FOR RESPONSES FROM NEURONS FOR CERTAIN VISUAL STIMULI USING ELECTRODES CONNECTED TO DIFFERENT AREAS OF THE BRAIN ANOTHER METHOD IS TO SEE WHAT HAPPENS TO PEOPLE IN WHICH SOME STRUCTURES IN THE BRAIN ARE DAMAGED, THIS IS SHOWN IN NEXT PICTURES

VISUAL DAMAGE

PEOPLE WITH DAMAGED CORTEX HAVE VISUAL PROBLEMS WHEN THE DAMAGE IS IN COLOR AREA, THEY CAN’T REPRESENT COLORS DAMAGES MAY ALSO IMPAIR OBJECT RECOGNITION

WE HAVE COVERED NOW THE LOWER LEVELS OF VISUAL PROCESSING -THOSE INVOLVED IN THE DETECTION AND REPRESENTATION OF SMALL FEATURES BUT VISUAL SYSTEM IS ABLE TO DO MANY THINGS BEYOND THIS WHICH ARE OF OUR SPECIAL INTEREST: -REPRESENT (MEMORIZE) VERY COMPLEX 3-D OBJECTS -RECOGNIZE COMPLEX OBJECTS DESPITE THEIR LOCATION, CHANGES IN LIGHT AND EVEN HUGE CHANGES IN APPEARANCE -REPRESENT COMPLEX VISUAL SCENES, EVEN THOSE WHICH CONSTANTLY CHANGE IN TIME -EXTRACT INFORMATION FROM VERY COMPLEX SCENES - AND MANY OTHERS. HOW THIS ALL IS DONE???

HOW THIS ALL IS DONE? OUR KNOWLEDGE OF HIGHER LEVELS OF VISUAL PROCESSING IS LIMITED: -WE DO NOT KNOW EXACTLY HOW VISUAL SYSTEM COMPOSES GLOBAL INFORMATION FROM FEATURES -HOW/WHERE INFORMATION IS MEMORIZED? -HOW OBJECTS ARE RECOGNIZED? -HOW OBJECT PARAMETERS ARE CALCULATED?  IT SEEMS THAT THERE ARE SPECIALIZED STRUCTURES FOR PROCESSING THIS KIND OF INFORMATION – WE THINK ABOUT ”LEVELS OF PROCESSING”

WE THINK THE ORGANIZATION IS LIKE IN THE PICTURE HERE: LOOK FROM BOTTOM TO THE TOP MORE AND MORE COMPLEX PROCESSING IS DONE, FROM LOW LEVEL PROCESSING IN RETINA TO CORTEX AT HIGHER LEVELS. MORE COMPLEX INFORMATION AT HIGHER LEVEL IS PROCESSED BASED ON RESULTS FROM LOWER LAYER LEVELS IN VISUAL SYSTEM

TO GET SOME KNOWLEDGE ABOUT THE TYPE OF INFORMATION PROCESSING INVOLVED IN VISION, WE HAVE TO REALIZE WHAT THIS SYSTEM IS REALLY AIMING FOR THIS IS EMERGNING NOT ONLY FRORESEARCH ON NEURAL SYSTEM BUT FROM PSYCHOPHYSICS – EXPERIMENTS WITH VISUAL PERCEPTION  IN THE NEXT PICTURES WE WILL LOOK INTO PATTERNS WHICH ALLOW US TO GUESS ABOUT WHAT THE VISUAL SYSTEM IS REALLY DOING

WHAT IS THIS: VERTICAL LINES????

IN THIS PICTURE WE SEE APPARENT ORGANIZATION OF CIRCLES INTO VERTICAL LINES WHY? THE ONLY ANSWER IS THAT VISUAL SYSTEM MUST HAVE A PROCESSING SYSTEM WHICH IS TUNED TO GROUPS ELEMENTS INTO APPARENT LINE WHEN THEY ARE CLOSE TO EACH OTHER HERE VERTICAL DISTANCE IS SMALLER THAN HORIZONTAL AND HENCE WE SEE VERTICAL LINE STRUCTURE

HORIZONTAL LINES ???

IN THIS PICTURE WE SEE HORIZONTAL LINES, BUT THE DISTANCE BETWEEN ELEMENTS IS THE SAME WHY? THE ONLY ANSWER – OUR VISUAL SYSTEM HAS PROCESSING SYSTEM TUNED IN SUCH A WAY THAT GROUPS IDENTICAL ELEMENTS STRONGER THAN DIFFERENT ELEMENTS

DIAGONAL LINES????

THE SAME RULE AS BEFORE APPLIES HERE TOO THIS IS ILLUSTRATION OF SO CALLED LAWS OF GROUPING WHICH WERE DISCOVERED BY PSYCHOLOGISTS ONE IMPORTANT GOAL OF VISUAL SYSTEM IS TO DETECT STRUCTURES AND OBJECTS. SO IT HAS TO GROUP FEATURES SINCE IT WANTS TO DETECT MEANINGFUL OBJECTS VISUAL SYSTEM HAS ACTIVE GROUPING PROPERTY, IT GROUPS BASED ON APPARENT PROPERTIES

KANIZSA TRIANGLE STRONG ILLUSION OF APPARENT OBJECTS

GROUPING LAWS COVER VERY BROAD RANGE OF FEATURES HERE WE HAVE VIRTUAL TRIANGLE THE WHITE TRIANGLE DOES NOT EXIST, YET IT IS JUMPING OUT OF THE PICTURE. THE VISUAL SYSTEM DISCOVERS VERTICES OF THE TRIANGLE MADE BY BLACK CIRCLES THEN IT GROUPS THEM TOGETHER, THE EFFECT IS ENHANCED BY THE FACT THAT SIDES OF THE TRIANGLE COINCIDE WITH LINE ENDINGS OF THE TRIANGLE BENEATH NOTE THAT THE SYSTEM DETECTS THE SECOND TRIANGLE BENEATH AND THAT THE TRIANGLES ARE EQUILATERAL

OVERLAPPING SQUARES OR NOT??? HERE WE DISCOVER FUNDAMENTAL PROPERTY OF PROCESSING DONE IN VISUAL SYSTEM EXPLAINED NEXT

WHY WE SEE HERE THREE OVERLAPPING SQUARES AND NOT ONE FULL SQUARE AND TWO SQUARES WITH CUTOUTS ???? NOTE THAT ONLY ONE SQUARE IS FULLY VISIBLE, OTHERS ARE COVERED, IN FACT THEY MAY NOT BE SQUARES THIS IS BECAUSE THE VISUAL SYSTEM PROCESSING IS TUNED TO PRODUCE INTERPRETATION WHICH IS MOST LIKELY TO HAPPEN IN THE WORLD BUT THIS INTERPRETATION MAY BE SOMETIMES WRONG TOO, ALTHOUGH WE WOULD BE SURPRISED IF IT WOULD REALLY BE SO !!!

THE INTERPRETATION PRODUCED IS FOR DETECTING MOST PROBABLE OBJECTS THE UPPER FIGURE IS DETECTED AS AN ARCH OVERLAID ON THE SAWTOOH – THIS IS THE MOST PROBABLE INTERPRETATION THE BOTTOM FIGURE INTERPRETATION IS SURPRISING, BUT IT COULD ALSO BE PRODUCED IF THERE WILL BE MORE EVIDENCE ANYWAY, IF WILL SHOW UP LIKE THIS WE ACCEPT IT AS A SOLUTION BUT HARD TO ”BELIEVE”

HERE WE SEE EXAMPLE OF THREE DIMENSIONAL OBJECT INTERPRETATION. IN GENERIC VIEW BELOW (THE RIGHT ONE) WE SEE A CUBE IMMEDIATELY. BUT OTHER VIEWS ARE VERY UNUSUAL SO WE DO NOT SEE A CUBE. IN PARTICULAR THE LEFT PICTURE IS A CUBE SEEN FROM POSITION IN WHICH VERTICES ON THE MAIN DIAGONAL ARE PERFECTLY MATCHING SO WE SEE HEXAGON. BUT IF WE ARE TOLD THIS IS CUBE WE CAN SEE IT. CONCLUSION: FAST AND AUTOMATIC PROCESSING IS FOR MOST LIKELY INTERPRETATION, THERE IS ALSO PROCESSING FOR UNLIKELY INTERPRETATION BUT IT IS SLOW AND OFTEN NEEDS HINTS

LANDSCAPE? THIS PICTURE HAS VERY LITTLE CONTENT, YET INTERPRETATION AS LANDSCAPE IS NATURAL FOR US THIS PICTURE MAY SUGGEST WE HAVE BUILT-IN SYSTEM FOR DETECTION AND INTERPRETATION OF NATURAL SCENES

LIGHTING WE HAVE NO PROBLEM WITH EVALUATION WHAT WAS THE LIGHT SOURCE IN THIS SCENE AND WHERE IT WAS BASED ON SHADOW INFORMATION WE KNOW HOW THE LIGHT IS PRODUCED AND WHERE THIS SUGGESTS A STRUCTURE MUST EXIST IN OUR VISUAL SYSTEM WHICH IS ABLE TO WORK THIS OUT

HERE WE CAN EASILY INDICATE THE LIGHT DIRECTION AND FORM OF THE OBJECT BASED ON SHADOW INFORMATION

THIS PICTURE IS FLAT, VERY LITTLE PERSPECTIVE BUT WE ESTIMATE DISTANCE QUITE WELL BASED ON THE SIZE OF OBJECTS

BASED ON THE PERSPECTIVE PROJECTION VISUAL SYSTEM EXTRACTS STRONGLY 3 DIMENSIONAL SPACE PROPERTIES

APART OF THESE GLOBAL FEATURE EXTRACTION BASED ON LAWS CORRESPONDING TO PHYSICS OF THE WORLD AND LAWS OF OBJECT INTERPRETATION, VISUAL SYSTEM IS EXTREMELY POWERFUL IN OBJECT RECONGITION AND INTERPRETATION SOME EXAMPLES ARE SHOWN IN THE FOLLOWING PICTURES

CAR IS ALWAYS A CAR POSITION, QUALITY OF SKETCH IS NO PROBLEM IT IS EASY TO FIND SIMILAR OBJECTS HOW THIS IS DONE?

A CUP COFFEE IS NOT ONLY AN OBJECT BUT A CONCEPT...

CONCEPTS REFER TO THE CLASSES OF OBJECTS (LIKE CUPS, COFFEE) PROPERTIES (HOT) ACTIONS (DRINKING) SENSORY EXPERIENCE (AROMA) FEELINGS (PLEASURE) AND MORE...

HOW OBJECT RECOGNITION WORKS? IT HAS NO PROBLEM WITH OBJECT PARTS AND COMPLEX OBJECTS COMPOSED OF MANY PARTS IT HAS NO PROBLEM WITH COMPARING OBJECTS AND OBJECT FORMS

SOME OBJECTS CAN BE RECOGNIZED EASIER WHEN THEY ARE PLACED IN PROPER CONTEXT – THE SYSTEM HAS CAPABILITY FOR ASSOCIATIONS

IN THIS PICTURE DISTANCES ARE DISTORTED THE SYSTEM FOR COMPARING DISTANCES IS DISTURBED BY NEIGHBORING SHAPES

IN THIS PICTURE HEIGHT AND WIDTH OF THE ARCH ARE EQUAL. THE SCENE DISTURBS PROPORTIONS

PERSPECTIVE DISTORTS LENGTH OF LINES

OBJECTS WITH LARGE OUTWARD NEIGHOBOURHOOD ARE PERCEIVED LARGER

SHAPES OF OBJECTS ARE MUCH DISTORTED BY BACKGROUND

SIMILAR EFFECT HERE

THREE DIMENSIONAL OBJECTS CAN BE MENTALLY MANIPULATED TO MATCH THEM (ROTATED OR MOVED) ARE THESE OBJECTS SAME OR NOT? IT LOOKS WE CAN MATCH THEM BY MOVING AND ROTATING ”INSIDE THE BRAIN”

WHY THE RIGHT ANGLE LOOKS NICER THAN OTHERS?

MULTIPLE INTERPRETATIONS VASE OR FACES? ILLUSION CALLED BINOCULAR RIVALRY INTERPRETATION JUMPS BETWEEN THE TWO DIFFERENT POSSIBILITIES

OBJECTS BELONGING TO ONE CLASS MAY BE IN ALMOST INFINITE VARIETY OF FORMS, YET THEY ARE EASILY RECOGNIZABLE AS BELONGING TO ONE CLASS AND EVERY OBJECT IS UNIQUELY DETERMINED LETTER M HERE IS IN MANY COMPLETELY DIFFERENT FORMS

HOW SUCH RECOGNITION IS DONE? GENERIC FETURES OF LETTER M ARE VERTICES AND LINES. IF WE REPRESENT THEM BY POINTS, WE CAN STILL SEE LETTER M – IF THE POINTS ARE LOCATED IN PROPER POSITIONS: IN THIS FIGURE POSITIONS OF POINTS ARE MANIPULATED AND WE DO NOT SEE THE LETTER M WHEN THEY MOVE TOO MUCH

VISUAL SYSTEM HAS AMAZING CAPABILITIES FOR REPRESENTING, STORING, RECOGNIZING OBJECTS, SCENES, AND WORLD. IT DOES IT VERY FAST NO MATTER WHAT IS THE COMPLEXITY It can even recognize impossible objects but this takes time...

ALL THIS IS DONE BY BRAIN STRUCTURES IN CERTAIN AREAS. HERE WE SEE EXAMPLE WHAT HAPPENS WHEN TWO FIGURES ARE PRESENTED WHICH DIFFER ONLY IN DIRECTION. THE VISUALIZATION OF BRAIN ACTIVITY IS ONLY FOR THOSE AREAS WHICH HAS HIGHEST LEVEL OF ACTIVITY

HOW ALL THIS IS DONE? WE MUST HAVE A LOT OF SPECIAL PROCESSING ”HARDWARE”. SOME OF THIS HARDWARE IS FIXED FROM BIRTH, SEE HOW YOUNG INFANT CAN REPEAT COMPLEX VISUAL PATTERNS – THIS MUST BE DONE BY SYSTEM WITH WHICH IT IS BORN. SYSTEMS E.G. FOR LEARNING LETTERS, SIGNS, ETC. ARE EXISTING BUT THEY ARE ”EMPTY”, THEY CAN BE ”PROGRAMMED” BY LEARNING VISUAL SYSTEM IS A COMBINATION OF SPECIAL ”HARDWARE” SYSTEMS. SOME OF THEM ARE FIXED AND AS WE COULD SEE THEY PRODUCE MOST LIKELY INTERPRETATIONS, OTHERS CAN BE PROGRAMMED BY LEARNING