human centered design- cognitive theories

DECISION MAKING

We make different kinds of decisions everyday

§ How?

MAKING DECISION

§ What kinds of information you search for support? § Where do you search from? § How does the information present to you?

Design to support the decision making

From M.R. Endsley, designing for situation awareness, 2003

Situation

awareness

Distributed cognition

Information processing

WHAT IS SITUATION AWARENESS?

Being aware of •  what is happening around you •  what information is important for a particular

goal •  what that information means to you now and in

the future •  individual elements of SA can vary greatly from

one domain to another

THREE SEPARATE LEVELS OF SA

Level 1 –perception of the elements in the environment.

Level 2 – comprehension of the current

situation. Level 3 –projection of future status.

LEVEL 1 SA: PERCEPTION OF ELEMENTS IN THE ENVIRONMENT

•  Human perception of information

•  Reliability of information

•  Confidence in information (based on the sensor, organization, or individual providing it)

LEVEL 2 SA: COMPREHENSION OF THE CURRENT SITUATION

•  integrating many pieces of data to form information

•  the meaning perceived relevant to goals and objectives.

•  prioritizing information’s importance towards the goals.

LEVEL 3 SA: PROJECTION OF FUTURE STATUS

Possible to predict the future (at least in the short term) § good understanding of the situation (Level 2 SA) § the functioning and dynamics of the system § good understanding of the domain (a highly developed

mental model)

§ can be quite demanding mentally. A failure inLevel 3 SA from Level 2 SA may be due to § insufficient mental resources § insufficient knowledge of the domain.

TIME, IMPORTANT PART IN SA

•  how much time is available until some event occurs or some action must be taken

•  the temporal dynamics of various elements •  perception of time

Approximately 19% of SA errors in aviation involve problems with Level 2 SA (Jones & Endsley, 1996). In these cases people are able to see or hear the necessary data (Level 1 SA), but are not able to correctly understand the meaning of that information.

Model of situaiton awareness in dynamic decision making

Mechanisms and processes involved in SA (from Endsley, 2000)

NEUROSCIENCE AND HUMAN COGNITION

HUMAN COGNITION

Neuropsychology is the science of study the relationship between brain function and behavior

Cognitive psychology deals with how people perceive,

learn, remember, and thinking about information Engineering psychology is to specify the capacities and

limitations of the human cognition for the purpose of guiding a better design

NEUROSCIENCE

Cell body Nucleus

Dendrites

Axon End foot

THREE ASSUMPTIONS

•  There are many relatively independent modules in the cognitive system. Each module can function to some extent in isolation from the rest of the processing system.

•  There are certain reasons between how the physical brain is organized with that of the mind.

•  Investigation of cognition in brain-damaged patient can tell us much about cognitive processes in normal individuals.

NERVOUS SYSTEM

central (CNS): § The CNS is comprised of the brain and spinal cord § the CNS receives input from the senses, processes this information

in the context of past experience and inherent proclivities and initiates actions upon the external world

peripheral (PNS). §  somatic and autonomic. § the autonomic system is divided into the sympathetic and

parasympathetic. § The PNS provides the sensory input and carries out the actions

initiated by the CNS.

METHODOLOGIES

•  Electroencephalogram (EEG) •  Event-related potential (ERP) •  Magnetonencephalogram (MEG) •  Positron emission tomography (PET) •  Magnetic resonance imaging (MRI)

THE SENSORS ON HUMAN BODY

On the head • Vision • Hearing • Balance • Taste • Smell

On the skin: • Head-cold • Pain • Touch-Pressure

On muscles: •  Muscle and tendon receptors

On joints: • Changes in joint position • Speed of movement • Position of the joint • Pain sensation

RECEPTORS •  are specialized part of cells •  different in each sensory system •  perceive different kind of energy. •  act as a filter. •  They are designed to respond only to a narrow band of energy

within the relevant energy spectrum. •  receptive fields of individual receptors are overlapping •  It can detect locations •  Detection of stimulus is often determined by receptor density and

overlap •  rapidly adapting receptors: they react quickly to the changes of

the stimulated energy •  slow adapting receptors: provide the information as the

stimulated energy is still there

SENSORY SYSTEM

•  Each sensory system requires three to four neurons, connected in sequence, to get information from the receptor cells to the cortex. There are changes in the code from level to level and it is not a straight through, or point-to-point correspondence

§ A motor respond can be produced § The message can be modified § Systems can interact with one another

PERCEPTION

•  Perception is a process of receiving the outside world information by the receptors and transfers the information to the brain

•  The only message the brain receives is the discharge passed along the neurons in the various sensory pathways

•  Everything we know comes to us through our senses.

•  Our sense sometimes can deceive us, so we must have some innate knowledge about the world to be able to distinguish between real and imaginary sensations

SENSORY MODALITY

•  Cortex is fundamentally an organ of sensory perception and related processes

•  The recognition is happened in cortex

MULTIMODAL CORTEX

•  some areas in the cortex were identified that had functions in more than one modality, for example the vision and touch are in the same area.

•  presumably function to combine characteristics of stimuli across different modalities

•  there is probably more than one process that requires multimodal information, although it is not know exactly what this processes might be

CORTICAL CONNECTION

•  There is no a single area in the cortex that could represent entire perceptual or mental states.

•  All cortical areas have internal connections that connect units with similar properties.

•  There is a re-entry of the connection, which means that when a given area A sends information to area B, area B reciprocates and sends a return message to area A.

DISTRIBUTED HIERARCHICAL SYSTEM

Primary sensory cortex

Level 2

Level 2

Level 3

Level 3

Level 3

Level 3

Level 4

Level 4

Level 4

Level 4

Level 4

LEARNING AND MEMORY

•  Learning is a process that results in a relatively permanent change in behavior.

•  Memory is the ability to recall or recognize previous experience;

•  certain neural structures and circuits are associated with different types of learning and memory

•  every part of nervous system is able to learn

LEARNING THEORY •  a learning theory contains five components

§ Experiences: § Schemata: § Habits: § Reinforcement: § Interference:

MEMORY

•  Short-term memory: memory for things that are retained only for a short period of time.

•  Long-term memory: memory for things that are remembered for a long period of time.

•  Working memory: refers to events that can happen on a trial

THE MECHANISM OF MEMORY

There is no specific brain location that holds one specific type of memory

Hebb’s (Hebb 1949) cell assembly theory has been almost the

only theory from neuron level to explain the mechanism of the memory

INFORMATION PROCESSING

Long-Term Memory

Response Execution

Response Activation

Feedback

Attention and emotion

Out

put

Environment

Sensory Store:

visual

auditory haptic

movement

Perception Working memory

Recognition Reasoning Problem solving Decision making

PERFORMANCE LIMITATIONS

Performance problems related to processing limitations in any of the stages:

§ Data-limited § Input degraded (e.g. visual stimulus briefly flashed)

§ Resource-limited § system not powerful enough (e.g. working memory)

§ Structurally limited § system cannot perform simultaneous operations § e.g. limbs, but also perceptual focus

ATTENTION

Auditory divided attention Focus auditory attention Cross-modality attention

ATTENTION

Selective attention § Visual sampling § Pursuit – eye follows a target moving at a constant speed

across the visual field § Saccadic – jumped view § Location § Supervisory § Target search

§ Optimality of selective attention § Select the relevant stimuli to attend at the appropriate times

ATTENTION

•  Paralle processing and divided attention §  Several items within the view field might be processed together

•  Focus attention

BOTTLENECK THEORIES

Sensory register

Selective filter

Perceptual processes

Short-term memory

Input Broadbent’s Filter theory

Sensory register

Attenuation control

Perceptual processes

Short-term memory

Input Teeisman’s Attenuation theory Limited

capacity Sensory register

Perceptual processes

Selective filter

Short-term memory

Input Deutsch & Deutsch Late filter model

MODALITY COMPATIBILITY

•  Reaction time depends in part on compatibility between stimulus and response modality

§ If stimulus visual, then quicker pointing response § If stimulus aural, then quicker voice response § Tasks using verbal working memory served best by auditory inputs and vocal outputs § Spatial tasks best served by visual inputs and vocal outputs

DISPLAY MODALITY AND WORKING MEMORY CODE

speech!

print!Analog!pictures!visual!

auditory!

verbal! spatial!

Display format code!

Mod

ality

!

Sound!Loclization!And pitch!

verbal! Spatial!

Working memory!

MULTPLE RESOURCES THEORY

•  Any two tasks demand separate rather than common resources on any of the three dimensions, three phenomena will occur

§ Time-sharing will be more efficient § Changes in the difficulty of one task will be less likely to influence performance of the other § The resources are not interchangable.

MULTPLE RESOURCES THEORY

Processing stage (working memory and cognition)

Perception Responding

Spatial Verbal

Sens

ory

mod

ality

Vis

ual

Aud

itory

HICK-HYMAN LAW

More complex decisions or choices require longer to initiate

RT=a+bHs

THEORY BEHIND DISTRIBUTED COGNITION

•  The traditional view of cognition limits it the individual processes within a mind

§ This limits us to think of only a user level and how he/she will interact with a system

§ This model is insufficient to really examine today’s complex systems because they do not take into account interaction between individuals

THEORY BEHIND DISTRIBUTED COGNITION

•  When systems become larger and more complex, an individual will no longer have complete control over it, rather, it requires multiple individuals to collaborate in order to accomplish a goal

•  Distributed Cognition tries to extend the concept of what is cognitive beyond the individual

THEORY BEHIND DISTRIBUTED COGNITION

T R A D I T I O N A L

§ Boundaries: § an individual.

§ Range of mechanisms § Manipulation of

symbols within an individual,

D I ST R I B U T E D

§ Boundaries: § cognitive processes

§ Range of mechanisms § a broader class of

cognitive events

§ Cognitive processes may be distributed across the members of a group

§ Cognitive processes may involve coordination between internal and external (material or environment) structure

§ Processes may be distributed through time in such a way that the products of earlier events can transform the nature of later events

THEORY BEHIND DISTRIBUTED COGNITION

A DISTRIBUTED COGNITION APPROACH|

•  Socially Distributed Cognition •  Distributed cognition encompasses the group

members • their interactions with other people, with their

environments •  Cognitive processes involve information transmission

and transformations, •  Social organization may itself be viewed as a form of

cognitive architecture

SOCIALLY DISTRIBUTED COGNITION

EMBODIED COGNITION

•  what helps the body and mind to function? •  Tools and work materials become part of the

system itself

•  A tool can be integrated in the way people think, see, and control activities and part of the distributed system of cognitive control

CULTURE AND COGNITION

•  People live in complex cultural environments •  Culture emerges out of the activity of human

• their historical contexts, • mental, • material and • social structures interact

•  Culture in the form of history of material artifacts and social practices, shapes cognitive processes, particularly cognitive processes that are distributed over agents, artifacts and environments

CULTURE AND COGNITION

•  Cognitive sciences traditionally view culture as a body of content on which the cognitive processes of individual persons operate

•  From distributed cognition’s perspective, culture shapes the cognitive processes of systems that transcends individuals

CULTURE AND COGNITION

•  The connection between culture and cognition is in that culture, • learning, • problem solving • Reasoning

•  Culture is a process that accumulates partial solutions to frequently encountered problems

CULTURE AND COGNITION

•  Culture allows us to learn from our ancestor’s experiences

•  Culture may limited our way of thinking!

CLASSICAL COGNITIVE SCIENCE

•  Thinking about thinking § Mental processes § Individual human agent § How information is represented

§ Transformed § Combined § Propagated

•  Nature of knowledge

DISTRIBUTED COGNITION

•  Unit of analysis •  Processes within system •  Representations

§ External § Internal

COGNITIVE SYSTEMS

•  Organizations •  Role of material media •  Physical processes

§ Human actors § Material media § Interactions

•  Explicit nature of environment

CONTEXT IN COCKPIT

•  Representations inside cockpit system •  External to pilots •  Procedure = behavioral properties •  Constraint-based

TASK: MEMORY TASK

Remembrance of speeds § For subsequent use § For proper & safe § Initial descent § Approach to land § Instrument landing

ARTIFACTS: WING SHAPE

ARTIFACTS: SPEED CARD & FUEL

ARTIFACTS: ASI & SPEED BUGS

ACTORS: PILOT ROLES

Two pilots/stations § Complete dual-flight instrumentations § Pilot Flying (PF) § Pilot Not Flying (PNF)

PROCESS DESCRIPTION

Prepare landing data (20 - 30 min. out) § Determine gross weight (Fuel Qty) § Find correct speed card (2000 lb. incr) § Post speed card § Set speed bugs on both ASIs

Descent - slow plane & configure wings Final approach to land - Vref

[Cross-checks & verbal communication]

COGNITIVE DESCRIPTION-EXTERNAL

•  How are speeds represented? •  How are representations

§ Transformed, § Processed, § Coordinated?

•  How does the system’s memory work?

ADDITIONAL REPRESENTATIONS

•  Memory of each pilot § Individual considered as part of system

§ Media in the cockpit § Task environment forms memory § Internal representations

EXTERNAL REPRESENTATIONS

•  Speed bugs § Resource for later processes § Durable working memory

•  Coordinated representations § Verbal § Speed card/fuel qty § Configurations

•  “System memory”

COGNITIVE DESCRIPTION-INTERNAL

•  Cognitive tasks of pilots •  Task specification

§ Not procedural recount § Provide constraints on useable § Representations § Processes

•  Interpretation not recall § Function in system memory

NOTION OF MEMORY

Traditionally a psychological function A series of tasks in a functional system § Recognition & recall § Pattern matching § Cross-modal transformations Distributed § Among human agents § Between human agents § Transformed external representations

COCKPIT AS COGNITIVE SYSTEM

•  Unit of analysis •  Transforms & propagates information •  Use of representations •  Notion of memory task •  Redundant & robust