Dr Alexandra Hooper
Clinical Psychologist
CAMHS





Information received through the sensory organs is vast and
constantly changing - therefore we must establish some
form of order.
We have a preference for whole objects “the whole is greater
than the sum of the parts”
Proposes the brain organises itself in regular and predicable
ways – largely innate
Perceptual grouping eg squareness
Look for organised wholes in figure ground differentiation



Rubin – visual separation of an object from its
setting
Visual field can be divided into two basic
parts; figure and ground.
Only able to focus on one at a time – the
figure and ground cant be seen
simultaneously as ground becomes figure
when the focus is shifted

Law of Closure – we fill in the blanks in order
to complete a regular figure / object:
Law of Similarity – Organised together if they
look similar. This might depend of
relationships of form, colour, size or
brightness
Law of Proximity – the closer two figures are to
each other the more we will group them
together perceptually:
Law of Symmetry – Symmetrical images are
perceived collectively:
Law of Continuity – we group with as few
interruptions as possible:
Law of Common Fate – elements seen moving
together are perceived as belonging together.
The ability to perceive an object as
unchanging and constant under changing
conditions
◦ Size / depth constancy: Object is same size
regardless of distance (as object recedes it is not
seen as decreasing in size) Appearing in infants
only a couple of weeks old, although not believed
to be innate.
◦ Shape Constancy: we perceive the shape of the
object more or less independently from the angle
from which it is viewed
◦ Brightness constancy: enable us to view object as
being the same apparent lightness and colour
despite change. Objects appear the same colour at
sunset even though proportionally there is far more
red light in the sun-light.

Example of object constancy:
http://www.youtube.com/watch?v=RyFPfsxT18&feature=relmfu




GIBSON
Perception is a sensation that occurs primarily
within the CNS with little further processing
Directly determined by the information presented
to the sensory organs.
Primary function of perception is to facilitate
interactions between individual and environment.
◦ Optic flow: the point which we appear motionless
while other parts of the optic field move more
rapidly (pilot take off/land)
◦ Textual gradients: This gives information about
depth. Objects which are closer can be seen in
greater detail than objects further away
◦ Affordances: Objects afford (offer) us information
about their function and the opportunity to use
them in some way. How we use them depends on
a combination of information from the optic
array, the physical surroundings and the person’s
psychological and physiological state.




GREGORY
Perception involves analysis of sensory
information. We only attend to some information
and then fill in the gaps according to what we know
and expect to see according to our prior
knowledge of the world
Actively construct our own perception
Problem solving – hypothesis testing when sensory
input is unusual.
GIBSONS THEORY
What is the role of
stored knowledge?
Where is visual
perception studied?
Is perception inbuilt
or constructed?
GREGORYS THEORY

Misrepresentations of external stimuli
◦ Gregory took illusions as evidence of his theory



Gregory and Allport
Directly relevant to Gregorys view that perception is an active
process involving selection, inference and interpretation
We select what we perceive and then interpret it according to
different factors
◦ context
◦ previous instructions
◦ personality
◦ previous experience
◦ cultural factors
◦ perceptual accentuation (like)/ defence (dislike)

Factors which influence or induce set include:
◦ Motivation
◦ Emotion
◦ Values
◦ Beliefs
◦ Cognitive styles
◦ E.G. Hungry people more likely to see pictures which are
neutral or ambiguous as food.
◦ Anxious people respond more quickly to the presentation
of threatening material. (clinical implications)



Babies can perceive light in the womb
Colour seen by 4/12
Depth perception is innate and develops early
but avoidance takes 4-6/12

Blind since birth – receives successful corneal transplant
◦ Certain aspects of visual perception were innate such as
detection (scanning of a shape such as a triangle, however
figural identity (recognising and naming shape as a
triangle) is learnt through experience.
◦ Patient S.B.

Relevant clinically
◦ E.g. Depth perception may be abnormal in those with
schizophrenia
◦ Illusions are real objects or stimuli that have been distorted (e.g.
dark shadow in a bush)
◦ Hallucinations are perceptions which are not related to any
external stimuli and are internally generated
 But are perceived as actually external
 Can be found in schizophrenia, personality disorder and
epilepsy
 Also in Charles Bonnet Syndrome in which patients with visual
loss and a lack of normal nerve impulses reaching the brain,
have complex visual hallucinations – when the brain attempts to
interpret the signals it may generate spontaneous nerve activity
which causes the hallucinations.
http://www.youtube.com/watch?v=vJG698U2Mvo
http://www.youtube.com/watch?v=lHd_L7dg3U4

Information Processing
◦ Information is any input – tactile, visual, auditory
etc.
◦ Processing refers to any action or function carried
out on this information.
 E.g. visual information is processed to provide
derivative information about depth, contour etc.
 Information processing is mostly automatic

“It is the taking possession by the mind, in
clear and vivid form, of one out of what
seems several simultaneously possible
objects or trains of thought. Focalisation,
concentration of consciousness are of its
essence. It implies withdrawal from some
things in order to deal effectively with
others.”

To cope with the vast amount of information, we
must selectively attend to only some information
and somehow ‘tune out’ the rest.
◦ Focussed attention: Attending solely to one source of info
whilst being distracted by another (e.g. cocktail party
phenomenon – listening to one of two voices in a hubbub
of others)
◦ Divided attention: Attending to two or more sources of
attention simultaneously (E.g. driving and answering your
phone)

1.
2.
3.
Eyesnck & Keane (1995) identified 3 factors which
affect our ability to perform two tasks at one:
Difficulty - Generally the more difficult the task
the less successful dual task performance is
(subjective)
Practice – Practice improves dual task
performance. This could be because people
develop new strategies for performing each task
minimising interference between them
Similarity – When people are asked to attend to
two different stimulus modalities it is more
successful

Broadbent’s (1958) Filter Model


Schizophrenia: Attention difficulties due to the
lack of early filtering and a consequent overload at
the late stage of processing
Attention focus: anxious subjects search for
threat-congruent material, detecting it more
quickly than controls – which is maintenance factor
in anxiety disorders

“Without the capacity to remember and to
learn it is difficult to imagine what life would
be like, whether it could be called living at all.
Without memory, we would be servants of the
moment, with nothing but our innate reflexes
to help us deal with the world. There would
be no language, no art, no science, no
culture. Civilisation itself is the distillation of
human memory.”

Refers to the way in which we record the past and utilise it for
later so it can affect the present:
◦ The SENSORY STORE: very brief store for the first level of
observation including visual iconic (up to 0.5 second) and
auditory echoic memory (up to 2 seconds)
◦ The SHORT TERM MEMORY: Suggested to be 0-18s long
where information that is processed is either sent to the
long term memory or lost. The short term memory is
proposed to have a capacity of 7 (+/- 2)
◦ The LONG TERM MEMORY: ‘indefinite’ storage consisting of
episodic and semantic memories.
1.
DECLARATIVE (EXPLICIT) MEMORY: Refers to memories which can be
consciously recalled such as facts and knowledge:
1. Semantic Memory: Stores factual information – memory of
meanings, understandings and other concept based knowledge
unrelated to specific experiences. (E.g. Are wrenches pets or
tools? – you can answer without remembering any specific
event in which you learnt that wrenches are tools.
2. Episodic Memory: Stores specific personal experiences –
Memory of autobiographical events that can be explicitly stated.
Events that are recorded in episodic memory may trigger
episodic learning (e.g. bitten by a dog results in fear of dogs is
episodic learning)
Conscious, intentional recollections of previous experiences and
information – use explicit memory throughout the day e.g.
remembering time of appointment or recollecting an event from
years ago.
2. PROCEDURAL (IMPLICIT) MEMORY: The memory of
how to do things. Guides the processes we
perform without the need for conscious control or
attention. Automatically retrieved and used for
the execution of the integrated involved in both
cognitive and motor skills (e.g. tying your shoes
or reading)
Implicit memory in which previous experiences aid
in the performance of a task without conscious
awareness of these previous experiences.

Encoding: Refers to the registration of the information. The
information processing system codes the new/incoming
information – can be affected by the ‘serial position effect’
(primary and recency effects) which means information
presented first is remembered best and information
presented last is remembered second best.
◦ Coding affected by characteristics of the individual – an
unknown language will be coded as sounds (phonemically),
while one familiar with the language will code it as
language – extracting meaning from the sounds.

Storage: Refers to the holding of information
◦ Storage is unlimited and permanent where any
‘memory loss’ is likely due to retrieval problems.
The information must be consolidated from the
short term memory to the long term memory.

Retrieval: Process of returning information from the
long term memory to the short term memory.
◦ Most retrieval is unconscious such as from social behaviour
and object recognition
◦ Retrieval is not necessarily the same as recall – e.g. ‘tip of
the tongue’ phenomenon, where a word has failed to be
retrieved properly from memory, combined with partial
recall .
◦ Retrieval easier if cues are present.
◦ Retrieval and Emotion: Mood (especially low mood) can
affect retrieval. Depressed participants tend to recall more
negative personal events and recall more negative words
from a word list.

Anterograde Amnesia: Refers to sufficient memory for any
information before accident, but severe deficits with learning
new information.
◦ Normal short term memory, but cant transfer information
to long term (or is it a deficit with retrieval?)
◦ No knowledge of current affairs, time of day or family
events
http://www.youtube.com/watch?v=Vwigmktix2Y
◦ Retrograde Amnesia: Refers to a loss of information /
forgetting what happened prior to accident.
◦ Induced with clinical use of electric therapy (ECT)


Central Executive: Controls attention and coordinates the
actions of the other components, briefly stores information
but has limited capacity.
Phonological Loop: Consists of two parts:
◦ Articulatory Control System (The inner voice) Rehearses
information verbally and has time based capacity of about 2
secs. Mentally rehearses the information by repeating it
over and over again.
◦ Phonological Store (The Inner ear) Sound based code to
store information, decays after 2 seconds, unless rehearsed
by articulatory control system. Receives its input either
directly from the ears or from long term memory – if you
imagine your favourite piece of music you are using your
phonological store.


Visuo-spatial Sketchpad: Stores and manipulates
visual information, from the eyes or long term
memory. If you imagine an object then picture it
rotating you are using your visuospatial sketchpad
Episodic Buffer: More recent addition to the WMM
(Baddeley, 2000) – purpose is to bind together all
the information from the other components of
working memory with information about time and
order. This prepares the memories for storage in
episodic long term memory.



Semantic Memory: Refers to memory for meanings and may
be described as ‘knowing that’, as opposed to ‘knowing how’
Episodic Memory: Memory explicitly recalled and described –
this is memory for places, events and so on. Memory for
these episodes tend to be fairly sharp
Procedural Memory: Often difficult or even impossible to
recall explicitly. Memories of this type include ‘knowledge of’
e.g. how to ride a bike. The series of steps required to
perform this act may not be explicitly known, but the action
may be performed. Another example is language – which is
performed according to a set of grammatical rules which
most individuals would not be able to articulate and yet
clearly follow.


Decay Theory: Refers to memory fading merely over the
course of time – the memory itself as well as the strength of
the memory fades.
Interference Theory:
◦ Proactive interference – refers to when previous learning/memories may
impair an individuals ability to retain new memories (e.g new phone
number)
◦ Retroactive interference –refers to a phenomenon which occurs when
information recently learnt interferes with and impedes the recall of
previously learnt information
◦ Output interference – refers to when the initial act of recalling specific
information interferes with the retrieval of the previous, original
information (e.g. creating a list of items to purchase but then forgetting to
take the list – it would be proposed that the act of remembering a few
items of the list would decrease the probability of remembering the other
items.



Amnesia: either anterograde or retrograde. Impairment of the
ability to form and store new memories.
Dementia: serious impairment in cognitive abilities in terms
of language, attention and memory, compared to what may
be expected at that age. May be the result of a unique,
global brain injury or a progressive decline due to damage or
a disease in the body.
Psychogenic fugue: sometimes referred to as dissociative
fugue – refers to a rare psychiatric disorder characterised by
reversible amnesia for personal identity including memories
and personality and other characteristics of individuality.
Often precipitated by severe psychological or social stress.
Lasts hours to days.


Hippocampus and amygdala involved in the
transition between S/T and L/T stores
Also used for regulating different hormones
and emotional and physical reactions to
situations, including emotional stress or
trauma
◦ Repressed memory
◦ Intrusive memory