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Unit 2:
PERCEPTION
&
NEUROPSYCHOLOGY
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SENSATION
AND
PERCEPTION
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What is Sensory System?
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A sensory system is a part of the nervous system
that consists of sensory receptors (neurons), neural
pathways, and those parts of the brain responsible for
processing the information.
Senses are the channels through which we come to
know about the world. The 5 senses are:
 Vision
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-enables
 Hearing
 Taste
 Smell
 skin
The sensory organ senses energy and convert it to a code,
which then transfer it to the brain for further process.
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What is Sensation?
Sensation is a process of detecting & encoding energy
stimulus in the environment.
 Stimulus produces physical energy, light, sound, hot,
cold.
 In sensation process:
 Sensory organ senses energy  and convert it to
a code  transfer it to brain for further process.
 The first step in the “sensing the world” is the
task of cell receptor.
 Thus, The function of any sensory organ is to detect
environmental stimuli and start an action potential on
its way to the brain.
 i.e. we receive stimulus from our environment via our
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sensory system ( the sense organ).
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What is Perception?
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Perception is a process whereby, sensory
stimulus in the environment is converted to
mental representation (repeat).
The process of perception and sensation
cannot be altered/change
Perceptions refers to the way the world
looks, sounds, feels taste or smell.
It is what is immediately experienced by a
person  It is the first step in processing
information around us.
How sensory events are translated into
patterns of activities in the sensory channels
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& central nervous system.
Process in Perceptions
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Sensory patterns (stimulus received from the
environment) merely provide the raw data for
experience.
The sensory information is then transformed,
elaborated and combined with memories to
create what we actually experience or
perceive.
“Part of what we perceive comes through the
senses from the object before us, another
part… always comes… out of our own head”
(William James)
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“out of our own head” refers to elaborations,
transformation & combinations of the sensory inputs that
make our experience/perceptions of the world what it is.6
Process in Perceptions (Con’t…)
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We must understand the meaning of
perception  in order to understand the
relationship between environment & behavior.
Therefore, in order to understand perception,
we must understand the following
process/phases:
 detection
 recognition
 discrimination
 scaling
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4 phases in the Process of Perceptions
1. Detecting stimulus
Feel/aware
of changes in our environment, that is
changes from nothing to something (0-changes
felt).
Detection is important for living beings.
2. Stimulus Recognition
Important task in the perception system is to
recognize & identify stimulus
Normal/everyday stimulus  easy to identify
Difficulty in recognizing due to context, alternative
and perceptual set that a person have.
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4 phases in the Process of Perceptions
3. Stimulus Discrimination
 Discriminate types of stimulus received.
 Increment of stimulus intensity will enable a person
to differentiate different type & degree of stimulus.
 Thus, an organism/individual must know whether
the stimulus in his/her immediate environment is
at a comfortable level or need to be change.
4. Stimulus Scaling
 All living beings are involved in measurement.
 A person can measure the magnitude of a
response by looking at the magnitude of a
stimulus  in order to overcome a certain
situation.
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NERVOUS SYSTEM
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What is Nervous System?
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The Nervous System act as the ‘control system’
that "tells" the parts of our bodies what to do and
when to do it.
The nervous system is divided into 2 major section: The Peripheral Nervous System
 sensory neurons running from stimulus receptors
that inform the central nervous system of the
stimuli
 motor neurons running from the central nervous
system to the muscles and glands - called
effectors - that take action.
 The Central Nervous System
 The central nervous system consists of spinal
cord & brain
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Central Nervous System
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Consist of Spinal Cord & Brain
2 types of Cell :
 Neurons
 Nerve
cell that send and receive information
(information carriers of the nervous system)
 Brain have 10-12 billions neurons  inter-connected to
other neurons
 Glial
Cells
 Also
known as neuroglia
 Form the “glue” of the brain  they support & protect
the neurons.
 The ‘housekeeping’ cells of the nervous system 
essential for the nutrition of certain neurons, & the
removal of dead cells from the nervous system.
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Neurons
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Neurons or sensory neurons are nerve cells in the
nervous system, and they act as the information
carriers of the nervous system. Neurons are
responsible for converting external stimuli from the
environment into internal electrical impulses.
Neurons are cell bodies with nucleas, composed
of DNA, which contains the cell’s genetic
programming. All neurons have cell body, dendrites
and axon.
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Dendrites is usually short and have many branches which
receive stimulation from other neurons.
Axon, usually quite long. Its function is to conduct nerve
impulses to other neurons or to muscle or glands.
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Cells in the central nervous system increases
rapidly between the 25th week of gestation and the
first few months after birth.
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Neurons are cell bodies with nucleas, composed
of DNA (which contains the cell’s genetic
programming).
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As the brain grows  the cell migrate to various
parts  spread out to perform different functions 
they sprout axons & dendrites.
Through axons/dendrites  send signals to other
neurons & receive incoming message through
connection called synapses.
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Nervous System
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Function of
Nervous System:
The control system
that "tells" the
parts of our bodies
what to do and
when to do it.
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What is synapses?
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Synapses is the
nervous system
connection link  ie
the connection
between nerve cells.
Connections  made
through the stimulus
 sending signals to
the brain.
The brains define
what is it/who we are?
With proper
stimulation, the
synapses become
stronger.
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Synapses allow
nerve cells to
communicate with
one another
through axons and
dendrites,
converting
electrical signals
into chemical ones.
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Neurotransmitters
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Neurotransmitter is a chemical that transmits
information across the junction (synapse) that
separates one nerve cell (neuron) from another nerve
cell or a muscle.
Neurotransmitters are stored in the nerve cell's
bulbous end (axon).
When an electrical impulse traveling along the nerve
reaches the axon, the neurotransmitter is released
and travels across the synapse, either prompting or
inhibiting continued electrical impulses along the
nerve.
There are more than 300 known neurotransmitters.
For examples, Acetylcholine (Ach), Dopamin, Endorfin,
Norepinephrin, Serotonin, GABA (gamma amino butyric acid)
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BRAIN
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What is brain?
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Weights only 3 lb.
Looks like a gray, unshelled walnut.
The most complex structure in the world.
Body most vital organ.
Each person is born with over 100 billions brain
cells (neurons).
Brains can send signals to thousands of other
cells in the body at speed of more than 200
miles per hr.
Brain growth before &after birth is fundamental
to future development.
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In the uterus  an estimated 250,000 brain cells
form every minute.
By birth  almost 100 billion nerve cell are formed,
but not fully develop.
At birth baby brain weight is about 25% of an adult.
By first year  70% and by end of 2nd year  80%
It then continues to grow slowly  by aged 12 
almost the size of an adult.
The volume & weight of a brain can be
measured by using: Before birth ultra sound
 After birth  Measure circumference of baby’s
head.
First 3 years of life is critical to baby’s brain
development.
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1 organ with 3 mini
brains:
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Brainstem (inner core
 Breathing,
heartbeat
muscle movement,
reflex behavior
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Limbic system
 Covers
the brainstem
 Motivation, emotions,
& long term memory
 Cerebellum – control
automatic movements
& balance
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Cerebral cortex
Higher
mental
process.
 Learning, memory,
Thinking, Language
 Last to develop
Structure of the
Brain
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Cerebral Cortex
Thin layer on the
brain’s surface
that include lobes
or sections:
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Occipital lobe
Process
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Temporal Lobe
Process
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vision.
hearing
Parietal Lobe
Proces
sensory
stimuli
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Frontal Lobe
Critical
thinking
& problem
solving
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Consciousness
and
Information
Processing
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Consciousness
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Awareness
Knowledge
State of wakefulness
Much of human information processing
seems to involve awareness such as
perception, imagery and emotion.
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Information Processing
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Cognitive psychology developed around late
1950’s.
Primary focus of cognitive psychology is on memory
(the storage & retrieval of information)
A group of information theorist used computer as a
model for the way human think.
They look at:
 The way people take in, process & act on
information  focusing on attention, perception &
memory.
Information processing model are used to describe
and explain cognitive (mental) process, such as
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thinking & problem solving.
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Human mind is like a computer:
 Takes information
 Organizes information
 Store information for later use
 Retrieve information when necessary
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Types of Memory Sensory register
 Short term memory
 Long Term memory
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Types of Memory
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Sensory register
 Part
of memory that receives all the information
a person senses.
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Short term memory
 Also
known as working memory
 A part where new information is held
temporarily, until it is either lost or placed into
long term memory
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Long Term memory
 Part
of memory which has unlimited capacity &
can hold information indefinitely.
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When people pay attention to an information the
sensory register will pick the information  goes into
the working memory.
Once in working memory  information is
processed/ practiced within 5-20 sec  then transfer
to the long term memory.
If people don’t pay attention  the information is lost.
New information will be transferred to Long term
memory when :
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it is linked in some way with prior knowledge already in the
LTM.
Information is translated into meaningful form (encoded)
Information in the LTM is retrieve through a
process of identification & recall for a particular
purpose.
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Strategies in encoding/ memorizing
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Chunking
Rehearsal
Imagery
Mnemonics
Schema activation
Level of processing
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Strategies in encoding/ memorizing
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Chunking
 Breaking the information into manageable
chunk.
 eg. OFHRTJUDYCX  OFH RTJ UDY CX
Rehearsal
 Simple repetition
 Elaboration  when info to be remembered is
linked to other information
Imagery
 Conjured image of an object/related meaning.
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Strategies in encoding/ memorizing
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Mnemonics
 Memory strategy to help remember information
 Eg. A rhyme or pairing of to-be-learned
information with well learned information.
Schema activation
 Strategy to use with encoding complex info. 
relates new information to prior knowledge.
Level of processing
 Material that is only skimmed will not be as
deeply processed as material that is studied in
detail.
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Information Processing Model: The Stage Theory
(Atkinson & Shiffrin, 1968)
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Information is
processed &
stored in 3
stages:
1 Sensory
memory
(sensory
register)
2 Short term
memory
3 Long term
memory
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Sensory Memory
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Memory starts with a sensory input from the environment.
Sensory as a source of information (vision, light, sound,
smell, heat, etc)
In the sensory register  input are held for a very brief
time  several seconds.
Sensory receptor (neurons) send this message (receive
from sensory organ)  as a form of energy to the brain.
Through the process of transduction (change from one
form of energy to another), a memory is created.
Memory in the sensory register is very short  less
than ½ second for vision and about 3 sec for hearing.
Sensory memory is a very important stage  learner
must attend to the information receive at this initial stage
in order to transfer it (info) to the next stage.
Individual are more like to pay attention to a stimulus if:
 It has an interesting features
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 It activates a known pattern
Short Term Memory (STM)
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Also known as the working memory  Relates to
what we are thinking about at any given moment in
time.
STM is created through:Attention to an external stimulus
Attention to internal thoughts
Both external stimulus and internal thoughts.
STM will last for 15-20 sec unless is repeated
(known as maintenance rehearsal)  can last for
up to 20 min.
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Short Term Memory (STM)
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Process of rehearsal:
Attention  focused on items of information
repeated over & over (silently/loudly) processed
in such a way & link it to other prior information
that has already been stored in the memory.
Elaborative rehearsal: giving the material
organization & meaning as it is being rehearsed 
use strategies that give meaning & organization to
material  so that the to-be-remembered
information can be fitted in with the existing
organized long term memories.
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Long Term Memory (LTM)
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Information that is not being processed will be lost/ forgotten.
When information are placed in LTM, they are put into
organized categories  where they reside for days, months,
years, life time.
When you remember something  a copy of the item is
withdrawn (retrieve) from the LTM.
Some theories believe  there is no true forgetting from the
long-term memory  because once information is stored, it is
there for good.
If/when we seem to forget  it is because we have trouble
retrieving or getting access to what has been stored
(information stored in unorganized way).
Thus, information in the Long Term Memory must be
encoded, stored and placed in memory in organized way 
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for easy retrieval.
Where does
consciousness enter
into human information
processing?
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Situation when consciousness enters in
human information processing:
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We may be conscious of the stimuli that we
analyzed.
When we select more detailed attention.
When we are conscious of what we learn.
When we commit to memory.
When we are conscious to the response we
make to such stimuli.
When the required responses are complex or new
 we may be aware of devoting effort to
planning, monitoring & executing the information.
In reflective thoughts or problem solving we may
have some awareness of internal processing in
the form of thoughts, emotions, images, etc.
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ENVIRONMENTAL
PERCEPTION
&
ENVIRONMENTAL
COGNITION
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Environmental Perception
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The initial gathering of
information through our
sense organs (sight,
sound, touch, taste,
smell) that leads to an
interpretation of the
external stimuli and
assignment of meaning
“It’s a tree” (identification)
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Environmental Perception (EP)
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Environmental Perception is an initial gathering of
information.
It includes:the ways & means by which we collect information
through all our senses.
 aspects of how we appraise & assess environment
(initial information gathering phase process).
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Individual perception of an environment may differ.
WHY?
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This could be due to:
 Personal
Variation
 Physical Variations
 Combinations of personal & physical variations
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Differences in perception
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Personal Variation
Culture differences
 Perceptual ability
 Sex
 Training/education
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Physical Variations
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Degree of visual complexity
However, no single influence (factor) by itself
determines what an observer perceives.
Any given perception is determine by the force of
many influences, each delivering its own large or
small push towards shaping the overall perception. 43
What is COGNITION?
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The mental process of knowing, including
aspects such as awareness, perception,
reasoning, and judgment.
Thus, Cognition involves the mental processes
used in perception, memory, communication,
thinking
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What is Environmental Cognition?
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Environmental
Cognition:
 Concerns
the way
we acquire, store,
organize and
recall information
about locations,
distances & the
arrangements in
buildings, streets
and the outdoors
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How we store an image
of that tree, its size,
location, the surrounding
context, etc in our head
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Environmental cognition includes Spatial Cognition
– ie. The thinking process that help us:
 “wayfind”
 Estimate distances
 Recognize route cues
 Read maps
 Understand the relative location in space
Spatial cognitions includes the concept of cognitive
maps.
What is Cognitive map?:
 A pictorial and semantic images in our head of
how places are arrange.
 E.g: evidence of cognitive mapping is in
advertisement, road maps, road sign, in every
person’s memory & thinking etc.
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What influences our thinking about our
everyday setting?
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Many factors & among others are: Stages
of life
 Spatial ability
 Familiarity with the place
 Sex
 Personal characteristics (personality, intelligence,
emotion, etc)
Environmental
Perception
Environmental
Cognition
Not a distinct concepts but a continuum
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Differences between object
perception and environmental perception
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Environmental perception studies more
complex stimuli
Perceiver is part of the scene (may have
multiple perspectives)
Perceiver is connected to the scene by a clear
goal or purpose
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Goal States in Perceiving the Environment
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Utilitarian purposes – we want to do
something in the environment, e.g.,
wayfinding, safety, etc.
Aesthetic purposes – enjoyment of the
environment’s beauty
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Perception is an active process
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We “construct” our perceptions of the world.
Our “constructions” of reality are influenced by
our expectations, goals, etc.
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Brunswik’s Lens Model Theory
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Egor Brunswik
Both perceiver (observer) & environment are
important.
The environment offers lots of cues — perceiver
needs to make sense out of key ones to function in
the environment.
No single cue is perfectly reliable, but each has a
certain probability of being an accurate clue to the
environment
Prior knowledge is important
The development of mental image of a place (eg
home) involved environmental cognitive process 
linked to our evaluation of the environment.
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Brunswik’s Lens Model
•Ecological validity
•Relation between
information (X) and
environment
•(MISLEADING)
INFORMASI
(Cues)
• Utilization
• Information
processing
X1
X2
ENVIRONMENT
X3
PERSEPSI
X4
Xn
• Functional validity
• Relationship between perception and
environment checked through action
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Brunswik differentiate between distal cues (distal
stimulus) variables and proximal cues (proximal
stimulus) variable:
 Distal cues
 Source of incoming sensory pattern (traffic
light is red, lights in the store)
 Cues that give a meaning to the observer for
him/her to make certain decision.
 Proximal cues
 The actual pattern of light on the retina of an
observer’s eye ( car must stop at the traffic light,
the shopkeeper is in)
 The conclusion that you actually make from the
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cues that you observe.
Example:
Driving up to an intersection with a
traffic light that has just turned green
Goal: Driving through the intersection
Distal Cues
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Proximal Cues
traffic light is green
“safe to go”
people walking on sidewalk
street”
“no one about to cross
buildings at side of road
“ignored”
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