The document discusses cognitive architectures, which are engineering approaches for modeling cognitive systems like humans. It notes that cognitive architectures aim to provide a unified set of mechanisms to explain various cognitive functions like language, problem solving, dreaming, goal-directed behavior, symbol usage, and learning. The document then reviews several specific cognitive architectures, including Soar, ACT-R, LIDA, and 4CAPS. It also discusses challenges in creating cognitive architectures that integrate symbolic and sub-symbolic approaches and can be implemented on neural hardware at large scales.

1. Research Circle – PHD – 2016
By, Amr Kamel Ahmed
Supervised by, Dr. Alaa Hamdi

2.  Cognitive architecture is an engineering approach for
modeling cognitive systems.
 Cognitive systems could be bug, bird, animal or human
 But in most cases it is human
 It doesn’t model static structure only
 It models cognitive behavior also

3.  A single set of mechanisms that account for all of cognition
(using the term broadly to include perception and motor
control). For example,
 Language
 Problem solving
 Dreaming.
 Some of the things a UTC must explain are:
 How intelligent organisms respond flexibly to the
environment
 How they exhibit goal-directed behavior and choose goals
rationally (and in response to interrupts: see previous point)
 How they use symbols
 How they learn from experience

4.  Psychology
 Evaluating cognitive models
 Studying learning techniques and methods
 Understanding cognition models of specific tasks i.e.
 Vehicle driving
 Computer Programming
 Robotics
 Transformation from systems that do limited low level tasks
extremely well to systems that perform wide range of tasks
with acceptable results
 Artificial Brain Projects

5.  Symbolic Architectures
 Soar
 ACR-R
 Sub-Symbolic
Architectures
 LEABRA
 Hybrid Architectures
 LIDA
 Biologically Inspired
Architectures
• 4CAPS
• ACR-R
• LIDA
 Emotional &
Motivational
Architectures
 Emotion Machine

6. Cognitive Architectures

7.  The roots of the distinction of human memory returns to Atkinson-
Shiffrin model proposed in 1968
 They assert that human memory has three separate components:-
 Sensory register, where sensory information enters memory.
 Short-Term store, also called working memory or short-term memory,
which holds inputs from sensory register and long-term store.
 Long-Term store, where information which has been rehearsed in the
short-term store is held indefinitely.

8.  Each sensor has its own sensory register
 Do not process information carried by stimulus
 Detect and hold information for use by Short-Term memory
 Information only transferred to short-term memory when
attention is given to it, otherwise decays rapidly and forgotten
 Iconic Memory:-
 Sensory memory associated with visual system.
 It was experimentally shown that it is separated to short-term and
long-term memory
 Decays after 0.5 – 1.0 seconds
 Echoic Memory
 Associated with auditory system
 Holds superficial aspects of sound (e.g. pitch, temp or rhythm)
 Having duration between 1.5 and 5 seconds

9.  Attended information is transferred to Short-Term Memory (STM)
 Information that enters STM decays and lost as well as sensory
memory
 However it usually stays longer than sensory memory (18 – 20 seconds)
 Information can stay at STM for much longer time through rehearsal
 Information in STM doesn’t have to be of the same modality
 Example, written text enters as visual can be held as auditory and vise
versa
 There is limit to the amount of information that can be held in STM to
7 +/- 2 chuncks

10.  It is a process involves repeating information over and over
in order to get the information processed and stored in
memory
 There are two types of rehearsal
 Maintenance rehearsal
 It is useful in maintaining information in STM. However; it is not an
effective way of having information processed and transferred into
Long-Term Memory
 Example, repeating a phone number out loud until put the number
onto the phone to make the call.
 Elaborative Rehearsal
 This type of rehearsal if more effective in transfering information
from STM to Long-Term Memory
 It involves thinking about the meaning of the information and
connecting it to other information already stored in memory

11.  Is the memory stage where information can be stored for long periods
of time.
 Information can be maintained in Long-Term Memory (LTM)
indefinitely
 Two types:-
 Explicit Memory (Declarative) refers to all memories that are
consciously available, includes:-
 Episodic Memory:-
 Refers to memory for specific events in time as well as supporting their formation
and retreival
 Semantic Memory
 Refers to memory of factual information such as meaning of word
 Autobiographical Memory
 Refers to knowledge about events and personal experience from an individual’s
own life.
 Similar to episodic but it is related to individual lifespan
 Implicit Memory (Procedural Memory)
 Refers to the use of objects or movements of the body
 Such as how to use a pencil, drive a car or ride a bicycle

12. Cognitive Architectures

13.  Soar is a general cognitive
architecture for developing
systems that exhibit
intelligent behavior
 It has been in use since 1983
 evolving through many
different versions to where it
is now Soar, Version 9
 http://soar.eecs.umich.edu/

14.  Adaptive Control of
Thought – Rational (ACT-
R)
 The ACT theory has origins
in the Human Associative
Memory (HAM) theory of
human memory
 A production system was
proposed that procedural
knowledge was
implemented by
production rules

15.  includes three major brain
systems:
 Posterior cortex
 Perceptual and semantic
processing
 Using slow, integrative learning
 Hippocampus
 Specialized for rapid encoding
of novel information
 Using fast, arbitrary learning
 Frontal cortex / basal ganglia
complex
 Active and flexible maintenance
of goals and other context
information,
 Serves to control or bias
processing throughout the
system

16.  Action-Centered Subsystem (ACS)
 Control actions
 i.e., to maintain and apply procedural
knowledge
 Non-Action-Centered Subsystem
(NACS)
 to maintain general knowledge
 i.e., declarative knowledge
 Motivational Subsystem (MS)
 to provide underlying motivations
for perception, action, and
cognition, in terms of providing
impetus and feedback
 Meta-Cognitive Subsystem (MCS)
 to monitor, direct, and modify the
operations of the other
subsystems for better
performance

17.  Based primarily on Global Workspace Theory
 LIDA simplified cognitive cycle constitutes a unit of sensing,
attending and acting
 LIDA cognitive cycle divided into three phases:-
 Understanding phase
 Attention / conscious phase
 Action selection phase

19.  Cognitive computing aims to develop a coherent, unified,
universal mechanism inspired by the mind’s capabilities
 it seeks to implement a unified computational theory of
the mind
 2007, IBM developed C2 mammalian scale near real-time
cortical simulator
 A notable C2 innovation is the memory efficient
representation of synaptic state significantly increasing
model scale.
 In 2013, IBM introduced the TrueNorth neuromorphic
CMOS chip.
 It consists of 4096 HW cores
 Each one simulating 256 programmable neurons
 Each neuron has 256 programmable synapses

21.  Although there are hybrid cognitive architectures which
includes both symbolic and sub-symbolic subsystems
however they are separated islands
 There are no integration between symbolic and sub-
symbolic subsystems that enables the usage of symbolic
representations based on sub-symblic platform.
 All symbolic representations relies only on Von Neumann
architecture
 There is no sub-symbolic architecture that allow causality

22.  How to create symbolic cognitive architecture relies on
neural-based platform
 How to build neural-based hardware platform suitable for
cognitive architectures:-
 Nano scale neurons
 Very low power consumption
 Low cost of implementation
 Scalable to include massive number of neurons (10^8 neurons
scale)
 How to integrate both paradigms into single cognitive
architecture that realizes Allen Newell aspects for Unified
Theory of Cognition

23. Thank You 