Review

1
Review

• ACT-R Modeling Language in LISP
• (clear-all)
• (define-model example)
• (chunk-type sometype step find)
• (chunk-type ball size color)
• (add-dm (chunk-name isa sometype step initial
  find red)
• (ball1 isa ball size big color red))
• (goal-focus chunk-name)
• (sgp esc t)
• (p name-of-production
• goalgt isa sometype slot1 initial find color
• gt
• retrievalgt isa ball color color
• goalgt step get-color)

2
Demo2 - human
3
LISP Basics

• Functional
• (function-name arg1 arg2)
• Value of arg passed to function
• Returns a value
• composition
• Built-in functions
• First, last, , - /
• User defined functions
• Defun

4
Lisp Basics argument passing

• (defun test (var1 key x y (size 0)) code )
• (test a x 20 y 20)
• (defun test (var1 rest args) (print args))
• (test 1 2 3 4 5)

5
LISP Basics -Variables

• Global
• (defvar name-of-varaiable nil)
• (defparameter name-of-varaiable on)
• (defconstant name-of-varaiable 3.1416
• By convention name
• People use but I am personally anti-global
  variable
• Lexical or local
• (let ((var-name1 value) var-name2 .)
• Code )

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LISP Basics - OO

• Classes
• (defclass name (super-classes)
• ((slot-name1 initform nil initarg slot-name1
  accessor slot-name1)
• (slot-name2 initform nil initarg slot-name2
  accessor slot-name2)
• (make-instance name)

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Lisp Basics - OO

• Defmethod
• Generic function
• (defmethod name ((arg1 class-of arg1) arg2)
• Code)

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Lisp Basics misc

• compiled and interpreted
• Dynamic (no linking)
• Variables dont have types, values do
• Every lisp object has a type
• Top t
• (typep obj t), (typep obj symbol)
• (type-of obj)

9
Demo2 Experiment Model
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Parameters

• Seed
• Random number generation
• Show-focus

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Control and Representation

• (chunk-type read-letters state)
• (chunk-type array letter)
• Goal Buffer - read-letters
• Control state information (task)
• State slot
• Clearer
• Not always necessary but
• Imaginal Buffer - array
• Problem state information

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Imaginal Module

• imaginal - Chunk creation
• imaginalgt
• isa array
• letter letter

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Trace

• 0.235 PROCEDURAL PRODUCTION-FIRED
  ENCODE-LETTER
• 0.235 PROCEDURAL MODULE-REQUEST
  IMAGINAL
• 0.235 PROCEDURAL CLEAR-BUFFER
  IMAGINAL
• 0.435 IMAGINAL
  CREATE-NEW-BUFFER-CHUNK IMAGINAL ISA ARRAY
• 0.435 IMAGINAL
  SET-BUFFER-CHUNK IMAGINAL ARRAY0
• Cost to create .2 seconds
• Create one at a time

14
Vision Module

• ACT-Rs eyes
• Feature Integration Theory
• Treisman (1980s)
• Two stage
• Preattentive
• Encoding
• Compatible with multiple path
• Dorsal where system
• Ventral what system

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Vision Module Memory the visicon
Device
Window
Visicon
Declarative Memory
Visual-location chunk
features
Visual-location buffer
Visual-location chunk
Visual-location chunk
features
Visual-location chunk
features
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Where System

• Productions
• Requests pre-attentive visual search
• Specifies a set of constraints
• Attribute/value pairs
• Properties or spatial location
• e.g. color red, lt screen-x 150
• Where system
• Returns a location chunk
• Specifies location of an object whose features
  satisfy the constraints
• Onsets
• Features are held in vision modules memory

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Visual location - chunk and buffer
(chunk-type visual-location screen-x screen-y
distance kind color value size
nearest)
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Trace

• 0.050 PROCEDURAL PRODUCTION-FIRED
  FIND-UNATTENDED-LETTER
• 0.050 PROCEDURAL MODULE-REQUEST
  VISUAL-LOCATION
• 0.050 PROCEDURAL MOD-BUFFER-CHUNK
  GOAL
• 0.050 PROCEDURAL CLEAR-BUFFER
  VISUAL-LOCATION
• 0.050 VISION
  Find-location
• 0.050 VISION
  SET-BUFFER-CHUNK VISUAL-LOCATION
  VISUAL-LOCATION0-0
• No time - operating in parallel, features
  immediately available

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Visual location chunk

• VISUAL-LOCATION-0-1
• ISA VISUAL-LOCATION
• SCREEN-X 130
• SCREEN-Y 159
• DISTANCE 15.0
• KIND TEXT
• COLOR BLACK
• VALUE TEXT
• HEIGHT 10
• WIDTH 20
• SIZE 0.25

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attended parameter

• visual-locationgt
• ISA visual-location
• attended nil
• No slot
• Request parameter
• Previously attended (looked at)
• nil (no)
• t (yes)
• new (no, and just appeared)

21
Testing visual-location and query module

• (P attend-letter
• goalgt
• ISA read-letters
• state find-location
• visual-locationgt
• ISA visual-location
• ?visualgt
• state free
• gt
• visualgt
• ISA move-attention
• screen-pos visual-location
• goalgt
• state attend
• )

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Checking a modules state

• Query - ?buffer-namegt
• busy, free, error
• Typically, a module processes 1 request at a time
• jamming - error - request when module is busy
• No need for visual-location because

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What System

• Productions (cognition)
• Requests move attention
• Provides location chunk
• What System
• Shifts visual attention to that location
• Encodes object at that location
• Added to Declarative Memory
• Episodic representation of visual scene
• Places encoding in visual buffer
• Calculates latency
• EMMA

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Visual Buffer and Object Chunk
(chunk-type visual-object screen-pos value
status color height width)
(P encode-letter goalgt ISA
read-letters state attend visualgt
ISA text value
letter gt goalgt letter letter
state respond )
(P attend-letter goalgt ISA
read-letters state find-location
visual-locationgt ISA
visual-location ?visualgt state
free gt visualgt ISA
move-attention screen-pos
visual-location goalgt state
attend )