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A Functional Framework for Cognition

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Cognitive Neuroscience and Embodied Intelligence A Functional Framework for Cognition Based on book Cognition, Brain and Consciousness ed. Bernard J. Baars – PowerPoint PPT presentation

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Title: A Functional Framework for Cognition


1
A Functional Framework for Cognition
Cognitive Neuroscience and Embodied Intelligence
Based on book Cognition, Brain and Consciousness
ed. Bernard J. Baars
Janusz A. Starzyk
2
  • It seems that the human mind has first to
    construct forms independently before we can find
    them in things Knowledge cannot spring from
    experience alone, but only from a comparison of
    the inventions of the intellect with observed
    fact.
  • Albert Einstein (1949)

3
Functional Framework
  • The functional framework used combines two
    classical models of cognition
  • Baddeley Hitch, 1974
  • Atkinson Shiffrin, 1968
  • Yellow arrows symbolize voluntary (top-down) and
    spontaneous (bottom-up) attention.
  • Long-term memories, knowledge and skills are
    shown in grey boxes at the bottom
  • Recent version of Baddeleys Working Memory
    (2002) is in the center

4
Habits Motor skills
Declarative knowledge
4
5
Major Functions of Human Brain
6
Working Memory
Working Memory
Sensory buffers
Bottom up attentional capture
Central Executive
Top-down Voluntary Attention
Action planning
Vision
Response output
Hearing
Working Storage
Touch
Verbal Rehearsal
Visuospatial Sketchpad
Learning retrieval
Stored memories, knowledge skills
Perceptual Memory
Visual knowledge
Habits Motor skills
Autobiographical Memory
Declarative knowledge
Linguistic Semantic
6
7
Working Memory
  • The middle column of boxes are components of the
    working memory.
  • The central executive is believed to be part of
    the prefrontal lobes and has a role similar to
    executive of a large company.
  • Deals with learning tasks,
  • Supervisory control over all voluntary activities
  • Working storage involves the medial temporal
    cortex and prefrontal regions.
  • Is dynamic, hence more vulnerable to disruption.

8
Working Memory
  • The executive part of Working Memory involves the
    prefrontal lobe.
  • The verbal part --- such as rehearsing words or
    numbers silently --- involves the speech areas of
    the cortex (especially the dominant hemisphere).
    E.g., Broca and Wernicke's areas.
  • The visual part --- such as visual imagery to
    think about how to walk from one place to another
    --- seems to involve visual regions.

9
Working Memory
  • Inner senses, verbal rehearsal and visuospatial
    sketchpad, interact constantly with the long-term
    stores.
  • Verbal rehearsal/inner speech is for rehearsing
    and memorizing information and commentary on our
    current concerns, while vocal tract is inhibited.
  • Tied to linguistic and semantic component
  • Ability to temporarily hold visual and spatial
    information is referred to as Visuospatial
    sketchpad.
  • Also involves abstract and cross-modal (more than
    one sense) spatial information
  • Sensory systems begin as domain specific, but are
    interpreted as part of multimodal space.

10
Working Memory
  • Long term stores are for knowledge and practiced
    expertise.
  • Not conscious once stored, but interact
    constantly with active functions.
  • Parts of system work with others, but can also
    compete against some.
  • The output components are under frontal control
    and are related to voluntary motor functions,
    control of skeletal muscles and some mental
    functions.

11
Working Memory
Hippocampus plays an important role in forming
new episodic memories
  • Damage to the brain, medial temporal lobe (MTL)
    can result in inability to move information
  • Cognitive functions are spared, but
  • Ability to encode and retrieve new experiences
    are lost.
  • Immediate memory is needed to perform all tasks.

12
Working Memory
  • In case of the damage to MTL there is no link
    from working memory to stored memories.
  • Subsequently these new episodes cannot be
    recalled.

13
Immediate Memory
  • Immediate memory is needed even for simple
    activities like
  • Reading.
  • Face recognition.
  • Eating food.
  • Tying shoes.
  • It involves sensory-motor coordination to do
    cognitive tasks.

14
Limited and Large Memory Capacity
  • Brain is large, but its memory capacity is
    limited.
  • Brain has billions of neurons and involves
    complex sensory and motor processes.
  • Large long-term memory (LTM).
  • Short-term memory (STM) is limited to 7/-2.
  • Efficiency increased by chunking, i.e., condense
    information.
  • Low efficiency during multitasking, difficult to
    do even 2 conscious tasks.
  • Practice can improve efficiency.
  • Limited functions are associated with conscious
    experience and large capacity functions are
    generally unconscious.

15
Limited and Large Memory Capacity
  • Dual Task limits
  • In dual tasks test, as cognitive demands of one
    goes up, the efficiency of the other one goes
    down.
  • Novel problems require much effort, brain makes
    errors and tend to do them sequentially.
  • When skills refine they may be performed with
    less conscious effort.
  • Some memories are very large.
  • Episodic and biographical memories are estimated
    at 1 bln bits (Landauer, 1986).
  • Semantic and procedural memories are also very
    large.
  • Large language vocabulary with related ideas,
    sounds and written words.

16
Measuring Working Memory
  • Working memory is tested by presenting a number
    of visual stimuli for recall
  • Test may involve recalling a one shown before,
    two slides ago, three slides ago etc..
  • The longer the delay the more difficult the
    recall.
  • Measured is the recall accuracy and speed.
  • Brain activity increases with difficult tasks

17
The minds eye, ear and voice
  • In 4th century BC Aristotle suggested that visual
    images were faint copies of the visual
    sensations
  • Recent research confirms the he was right.
  • C.W. Perky (1910) showed that people confuse
    faint visual pictures with their own mental
    images.
  • Ganis (2004) write that visual imagery and
    visual perception use the same neural machinery.

18
The minds eye, ear and voice
  • Imagery tasks
  • Classic rotation stimuli
  • check whether two arbitrary shapes are the same
    or different
  • To answer the question subject mentally rotates
    one shape to match the other
  • Classic tower task
  • Roll color ball from one pocket to another one
  • How to transform the upper picture to the lower
    one
  • Subjects use visual imagery but the task is
    different.

19
The minds eye, ear and voice
  • Most people talk to themselves
  • Ask a person to tell about his private monologue
  • Or write down an internal speech as it occurs
  • Dell and Sullivan (2004) showed that internal
    tongue-twisters create very similar errors to
    regular ones
  • Try repeating Peter piper picked a peck of
    pickled peppers in internal speech as quickly as
    possible
  • Did you noticed inner pronunciation errors in
    spite of not really using your tongue?
  • Inner talk is confirmed by functional brain
    imaging

20
Sensory Functions
A functional framework.
Sensory Input
Sensory buffers
Bottom up attentional capture
Central Executive
Top-down Voluntary Attention
Action planning
Vision
Response output
Hearing
Working Storage
Touch
Verbal Rehearsal
Visuospatial Sketchpad
Learning retrieval
Stored memories, knowledge skills
Perceptual Memory
Visual knowledge
Habits Motor skills
Autobiographical Memory
Declarative knowledge
Linguistic Semantic
20
21
Sensory functions and sensory memory tend to be
in the posterior half of cortex.
Left lateral view
(Left hemisphere)
SENSORY Functions
Medial view
(Right hemisphere)
21
22
Motor and executive functions.
A functional framework.
Sensory Input
Sensory buffers
Bottom up attentional capture
Central Executive
Top-down Voluntary Attention
Action planning
Vision
Response output
Hearing
Working Storage
Touch
Verbal Rehearsal
Visuospatial Sketchpad
Learning retrieval
Stored memories, knowledge skills
Perceptual Memory
Visual knowledge
Habits Motor skills
Autobiographical Memory
Declarative knowledge
Linguistic Semantic
22
23
Motor functions and planning are frontal.
Left lateral view
(Left hemisphere)
Medial view
MOTOR Functions
(Right hemisphere)
23
24
Central Executive
  • The prefrontal lobes play an important executive
    role in the brain.
  • They are needed for voluntary control over
    actions.
  • Prefrontal also support emotional processes and
    are necessary to control ones unwanted impulses.
  • Stroop Color-naming task is used to test for
    frontal lobe damage.
  • Conflict between reading a word and
    and naming its color.
  • Highly practiced actions (reading) tend to be
    automatic, while novel and unpredictable ones
    tend to remain under voluntary control.
  • Automatic and voluntary control work
    hand in hand

24
25
Selective attention and conscious (reportable)
events.
A functional framework.
Sensory Input
Sensory buffers
Bottom up attentional capture
Central Executive
Top-down Voluntary Attention
Action planning
Vision
Response output
Hearing
Conscious event
Working Storage
Touch
Verbal Rehearsal
Visuospatial Sketchpad
Learning retrieval
Stored memories, knowledge skills
Perceptual Memory
Visual knowledge
Habits Motor skills
Autobiographical Memory
Declarative knowledge
Linguistic Semantic
25
26
Selective Attention and Conscious (reportable)
Events
  • Attention improves our ability to perceive
    stimuli.
  • In the case of executive attention, the executive
    regions of the prefrontal lobe shapes perceptual
    activity in the posterior half of cortex.
  • Conscious events seem to mobilize frontal and
    parietal regions of cortex.
  • Voluntary actions become automatic with practice
    and they do not need executive control.
  • Brain uses combination of voluntary and
    spontaneous control

27
Executive (Voluntary) and Spontaneous Attention
  • Spontaneous attention to find a target on the
    left.
  • Voluntary attention to find a target on the right

28
Voluntary Action Control
  • Motor hierarchy begins with general goals
  • The goals are represented in the prefrontal area
    and proceed to supplementary and pre-motor
    regions which triggers intention to act
  • The primary cortical motor region (M1) triggers
    movements of skeletal muscles.

The brain regions activated in pushing a button
with the right hand
29
A functional framework.
Sensory Input
Sensory buffers
Bottom up attentional capture
Central Executive
Top-down Voluntary Attention
Action planning
Vision
Response output
Hearing
Working Storage
Touch
Verbal Rehearsal
Visuospatial Sketchpad
Long term Memories
Learning retrieval
Stored memories, knowledge skills
Perceptual Memory
Visual knowledge
Habits Motor skills
Autobiographical Memory
Declarative knowledge
Linguistic Semantic
29
30
Consolidation of Events into LTM
31
Long-term Memories
Long-term memory functions are widely distributed
throughout the brain by means of long lasting
connections. Posterior half of cortex involves
perceptual regions, while executive and motor
memory, such as plans for future actions, engage
frontal regions. Hippocampus is involved
episodic memory, while subcortical basal ganglia
and cerebellum are responsible for motor learning.
32
Summary
  • We discussed broad concepts for cognitive
    neuroscience.
  • Working memory is a foundation of learning and
    cognition.
  • Immediate memory seems to depend on medial
    temporal lobe including two hippocampi.
  • Damage to this regions impairs formulation of
    long term memories.
  • The rear half of cortex is involved in sensory
    processing and in sensory-perceptual memory.
  • The from half of cortex is involved with motor
    and executive functions and long term memory for
    these processes.
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