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Paradigms:

Psychodynamic and humanist paradigms are important for their contribution to discipline and clinical practice

Behaviourist, cognitive and biological paradigms lay the foundation upon which much of modern experimental psychology has been built

A paradigm is a framework for understanding and investigative phenomena within a discipline

the behavioural paradigm

root metaphor of the blank slate

* behaviour are wholly determined by our environment

key concepts of history of reinforcement and learning

* law of affect (rewarded is repeated)
* rejection of unobservable processes as unscientific

question about how contingencies pairing stimuli with reward punishment effect subsequent behaviour

* studied experiment

the cognitive paradigm

root metaphor of computer

* inputs are processed and transformed into outputs (behaviour)

key concepts of mental representations and mental states

* focus on unobservable mental processes and their effects


* attention memory decisionmaking

questions about the mental processes that give rise to this

* studied experimentally often with humans

the biological paradigm

root metaphor of the biological machine

* what are the physical bases of thought and behaviour

key concepts of evolution genetics physiological functions

* focus on identifying physiological correlations of specific behaviours
* measurement of brain activity and identification of genetic contributions to behaviours or physiological disorders

questions about how mental process is realised in the brain and how it evolved

studied experimentally on humans and animals and case studies

**Placebo effect**

a beneficial effect produced by a placebo drug or treatment, which cannot be attributed to the properties of the placebo itself, and must therefore be due to the patient's belief in that treatment

**Hawthorne Effect**

the alteration of behaviour by the subjects of a study due to their awareness of being observed.

**Stereotype Threat**

Stereotype threat is a situational predicament in which people are or feel themselves to be at risk of conforming to stereotypes about their social group

**Demand Effects**

bias that occurs when participants infer the purpose of an experiment and respond so as to help confirm a researcher's hypothesis.

expectation effects

* single blind research can restrict participant knowledge of study aims (combats participant expectations)
* bias from experimental expectations (Rosenthal effect-Pygmalion/golem)
* Double blind research can restrict experiment and knowledge of participant groups (combats experimenter expectations)

the brain

2% of body weight

receives 20% of blood pumped from the heart

consumes 20% of the body's energy

100 billion neurons

1000000 billion synapses

10^1000000 possible circuits

three parts of brain

cerebrum- two hemispheres

cerebellum (hindbrain)

* cerebral cortex: outermost layer of the cerebellum= gray matter
* contains most of the neurons
* two to four millimetres thick
* highly folded to maximise surface area
* white matter underneath the grey matter is the wiring

brain stem

Primary sense

Sight= occipital lobe

Hearing= temporal lobe

Taste= parietal lobe

Touch= parietal lobe

Movement= frontal lobe

* first site of input/last site of output

frontal lobe

executive functions: reasoning, planning, problem solving, inhibitory control, working memory

motor functions:

* premotor cortex= motor planning,
* primary motor cortex= execution

speech production

Parietal lobe

Primary somatosensory cortex (touch)

sense of space and locations

spatial attention- directing attention and eye movements

linking vision to action

Occipital lobe

primary visual cortex (VI) all vision perception

higher visual areas: different regions process shape, colour, orientation, movement

temporal lobe

primary auditory cortex

language comprehension

medial temporal lobe: limbic system (learning and memory)

* amygdala: fear and arousal
* hippocampus: learning and memory (forming new episodic memory)

corpus callosum

neuron connections between left and right hemispheres

allows communication within brain

Broca’s area 1861

left frontal lobe damage

lack of speech

Broca’s aphasia: speech disorder

Wernicke’s area 1874

Left posterior temporal lobe

language comprehension

Wernicke’s aphasia: can speak fluently but it's nonsense

Wilder Renfield 1951

electrical stimulation to brain during surgery

maps of motor and sensory cortices

peripheral nervous system (brainstem)

autonomic nervous system

* involuntary
* heart rate, respiration, sweating, stress, arousal, fight or flight

Somatic nervous system

* Voluntary
* motor and sensory

central nervous system (brainstem)

brain and spinal cord

autonomic nervous system (brainstem)

two divisions

sympathetic nervous system

* emotional arousal, stressed, fear
* fight or flight
* increases heart rate, respiration, perspiration, pupil dilation

parasympathetic nervous system

* rest and digest
* lowers heart rate, respiration
* increases stomach intestine activity
* opposes sympathetic system

Medulla (brainstem)

autonomic nervous system functions

controls heart rate, blood pressure, temperature, respiration

reflex centre for coughing, sneezing, swallowing, vomiting

Low level to high level functions responsible (brainstem)

Brainstem (ANS) low.

Cerebral hemispheres- cortex (planning, reasoning, language,

perception) high

Cerebellum

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hind brain

sense of balance and coordination of complex movements

motor learning- fine adjustment of movement based on feedback

primary motor and sensory areas

* primary motor cortex activity leads to movements
* primary sensory cortex activity leads to sensation
* different parts control different parts of body (homunculus)
* motor programme for movement

- brain creates programmes in brain before movement

- brain retrieves programme for learned skilled actions

* feedback control of action

- sensory feedback

* sense of agency

- Brain automatically links sensory events and own-actions to infer causality

- can't tickle yourself

neurons

cell body

* contains nucleus and DNA and functional things

dendrites

* received signals
* input from other neurons

AXON

* sends signals- output from Axon hillock to axon terminals
* one per neuron
* wrapped in myelin for efficient transmission

Axon terminals

* terminal buttons
* form synapses with other neurons
* secrete neurotransmitters to send signals to other neurons

glial cells

oligodendrocytes- produce myelin sheath

astrocytes- supply nutrients from blood to neurons, maintain blood-

brain barrier

microglia- brains immune system, cleans up foreign/toxic substance

myelin

0\.3-4micro meters

Wraps around axons

Action potentials = neuron signals

Electrical signal pulse travels along the axon

Fixed size- either on or off

Cell membrane wall

Forms barrier between extra-cellular and intra-cellular fluid

Na+ and K+ ions across cell membrane

Different concentrations inside and outside cell

Gives different in electrical charge (membrane potential)

Resting potential:

AT REST MORE POSITIVE IONS OUTSIDE CELL GIVES inside cell an

overall negative potential voltage (-70mV)

Ion channels in cell membrane

Open and close to allow movement of ions across cell membrane

Changes electrical potential

Sodium potassium pump

* Pumps Na and K across cell membrane (3Na out for every 2K

in)

* Pumps positive charge out of cell
* Maintains -ve resting potential
* Uses energy- 70% of brain energy, 25% of body energy

Action potential

* Input from other neurons icreases membrane potential
* If voltage exceeds threshold, triggers action potential
* Depolarisation of cell- membrane potential goes to 0 (Na flow inside cell)
* Repolarisation of cell: membrane potential back to -70mV (K flow out of cell)

Voltage dependent ion channel

* Closed at resting potential
* Open when membrane potential reaches threshold
* Allows flow of ions across cell membrane

Refractory period

* Membrane potential is further away from threshold needed to trigger an action potential

Action Potential conduction along axon

* Starts at axon hillock

- Lowest threshold to trigger AP

* Depolarisation spreads from site of action potential to neighbouring region, triggering them

Excitatory neurotransmitters

Receptors opens channels causing depolarisation

EPSP: excitatory post-synaptic potential

Closer to threshold for action potential

Inhibitory neurotransmitters

Receptors open channels that cause hyperpolarisation

IPSP

Further from threshold for action potentials

Graded potential

Excitatory and inhibitory input combines together

* Change Membrane potential on post-synaptic cell

Graded potential depends of strength of synapse connection

* Strong connect- large change in membrane potential

Membrane potential depends on sum and timing of inputs

if enough excitatory inputs occur close in time, Membrane potential will exceed threshold triggering action potential

Brain lesions (Measuring Brain functions)

Use patients with damages parts of their brain to examine what

changes in behaviour and cognition occur

Single neuron recording (Measuring Brain functions)

Place a thin electrode into an animals brain

Record action potentials firing from a single neuron

Measure what that neuron encodes or detects

Best localisation and timing of brain function

* Directly measuring action potentials from individual neurons
* Highly invasive

EEG- electroencephalography (Measuring Brain functions)

Summed activity from action potentials of neurons in the cortex cause

electrical activity change on the scalp

Measure voltage changes from electrode

Brain activity shows oscillations

Frequency of oscillations change with alertness and sleep

ERP- event related potentials (Measuring Brain functions)

Brain activity related to a specific event or stimulus

Average together 100 trials of EEGF in response to stimulus

Early brain processing of general visual features

Functional brain imagery (Measuring Brain functions)

Change in blood flow associated with neuron activity

PET

* Used to map neurotransmitters or receptors
* Uses radioactive substance injected into blood stream

fMRI

* measures change in blood oxygen levels (active neurons use oxygen)


* studies brain function
* oxygen is carried in blood and delivered to active neurons
* change in blood oxygen levels =change in brain activity
* good localisation of brain activity’

Brain plasticity and learning

Brain plasticity

* How the brain changes with learning
* The capability of the brain to alter its functional organisation as a result of experience

Neurogenesis and synaptogenesis

* Generation of new neurons and synapses

Integration of signals

* Neurons receive many inputs- has only one output
* What combination of outputs will cause neuron to fire

Grandmother cells

* Neurons could represent a specific concept
* Billions or neurons can encode billions of concepts
* Memory may be represented by groups of neurons each encoding specific concepts or objects
* Jennifer Anniston cells- found in hippocampus

Connections

Spreading activation model

* Neurons represent specific concept
* Share connections with neurons that represent related concepts
* Activation of one neuron leads to the spreading activation to related or connected neurons

Learning and memory

* Making and strengthening connections between neurons that represent associated concepts

Motion aftereffect

Sensory after effects

Usually the opposite experience relative to the adaptor

Associated with reduced responding in the brain to the adapted input

Can enhance the salience of new inputs, relative to old inputs, because the brain is more responsive to new inputs

Troxler fading

* When starring at a static scene
* New input appears brighter

Perceptual after effects

Demonstrate that we do not have veridical experiences of sensory input

Our experiences are a product of activity in our brains, and that activity can promote experiences that differ from sensory input

Sensory adaption helps to ensure that perception is useful but it isn’t accurate

McGurk Effect

People do not have a veridical sense of input from any single sensory modality

Out brains tend to create perceptual experiences that sum together all the sensory information that is given to us

We can experience an averaging of audio and visual information, which is different to the audio and visual experiences we would have if those inputs were experienced in isolation

Sense organs

* Transduce environmental energy into electrochemical signals sent to your brain.
* Perception is your brains best running hypothesis about what is probably happening in the real world.

Hearing

Relies of transformation of sound waves – vibrations that propagate through a medium into signals that can be sent to the brain.

Alternations in pressure on air molecules creates a sound wave with frequency (how often air pressure increases and decreases over time) and amplitude (Big changes = loud sounds, small = quiet)

How soundwaves are transformed

* Cochlea (inner ears) > Hair cells > Have bundles of “hair-like” stereocilia which extends into surrounding liquid and move back and forward when the liquid is vibrated by sound waves.
* Bending of stereocilia bends, ions rush to top of hair cells which releases chemicals at the base.
* These chemicals bind to auditory nerve cells creating an electrical an signal that propagates along auditory nerve

How eyes transfer light into signals that can be sent

Photoreceptors - contain light sensitive chemicals called pigments which absorb photons of light.

Process that changes membrane conductance of photoreceptor causing a wave of depolarization.

Ganglion cells gather signals from back of photoreceptors and these converge to form the optic nerve.

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Important characteristics of photoreceptors:

* Pigment that absorbs light contained in outer segment positioned on back of retinae, away from light.


* Limits human eye as an optical instrument as light must pass through a no. of cellular layers which retract light and blur image before reaching photoreceptors

Blind spot

Optic nerve must pass through surface of retina to carry signal - No photoreceptors here = blind spot

Perceptual filling - Brain assumes what is on either side of blind spot

Naïve realism

Mistaken notion veridical images reach retinae

Colour vision

Colour is associated with different wavelengths of light.

Range of colours an animal can see is determined by range of wavelength their photoreceptors can process. (Humans, 400nm (blue) > 700nm (red)

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Cones - Types of photoreceptors.

Humans rely on 3: trichromats

1\. Short – 430nm (blue)

2\. Medium – 530nm

3\. Long – 570nm (red)

Colour vision is detection of ration of the above 3 colours.

* Grey = All equal, White = All max, Black = All none

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Colour consistency

Physical objects refract a range of different wavelengths and this is

affected by lighting. E.g the dress

* Our visual systems strive to subtract the impact of lighting away

from our impressions of colour

Primary visual cortex

Signals leave eye via optic nerve

Optic chiasm – signals cross so info from other side of visual space travels to 1 side of the brain.

LGN – subcortical brain structures

Primary visual cortex at back of brain first to receive stimulus.

Diagnosing problems:

Problem specific info in 1 eye = eye

1 side of visual space regardless of which eye = damage to brain

V1

* 2 V1’s, 1 in each hemisphere
* Responds to input from 1 side of visual space
* Responses to input at bottom of visual field mapped toward top of V1 and vice versa.
* Portions of V1 damaged = report being blind to regions of visual field.

V1 responds to inputs we cannot see

* Necessary for normal conscious visual experiences, without it, people report blindness. But we cannot see all V1 activity

Blindsight

People think they are blind when they are not.

* Damage to primary visual cortex V1

Perimetry

Determining extent of blindness following damage to visual systems.

Patients fixate a point and we flash spots of light at different areas in visual field - yes and no response.

Something interesting happened to patients when asked if the flash occurred left or right or was green or red - patients reporting blindness due to V1 damage performed well above chance.

* Shows some visual operations can occur without primary visualcortex activity

Signal detection theory

Describes how to measure sensory sensitivity in conditions of

uncertainty

* To measure sensitivity, you measure hit rate and false alarm

rate.

* =1, participant displayed 0 sensitivity
* If has any sensitivity – hit rate > false alarm rate

Functional Modularity and the blinding problem

Response selectivity - type of input to which cell will respond

* Visual cells in eye and LGN respond well to simple spots of light
* Cortical cells do not and respond to more complex units - respond to oriented inputs instead of spots of light.

Refers to the fact our brains contain multiple regions that are specialized for processing different visual properties - colour, motion and faces

Human vision

Processing hierarchy wherein cells at progressive stages of processing respond to increasingly complex features.

V1 – responds to simple things e.g bars of light with colour, moving particular direction. Cells in V1 project to other cortical brain regions for increasing complexity.

V4 – Large no. cells tuned to colour, very few directions based.

V5 – Cells are direction tuned; none respond well to colour

Facial recognition

Whole network of cortical brain regions responds to faces - Temporal lobe

* Superior temporal sulcus (STS)
* Optical face area (OFA)
* Fusiform face area (FFA)

Prosopagnosia - Face blindness

Cerebral akinetopsia - Means without motion vision

Hemisphere

Lateralised functions – some brain functions rely more on one side than the other.

* Crossed (contralateral - opposite) functions - movement, sensation, vision
* Left - Right body movement, sensation and vision (Not left eye/right eye - Left visions from both eyes go to right hemisphere)
* Right - Left body

NO DOMINANT HEMISPHERE

Left Hemisphere

Language (Usually), comprehension, speech, reading

Right Hemisphere

Tone of voice/prosody

Face perception

Perceptual grouping

Corpus callosum

Connects hemispheres through axons of nerve fibres and allows

transfer of info

Inter-hemispheric communication

Stimuli presented in left field of vision will be processed in right but

must cross to left hemisphere to report what was seen

Brain laterality “Split-brain”

“Split Brain” – severed corpus callosum - Last resort treatment for epilepsy as stops seizure spreading to another hemisphere.

These patients were used in many experiments and found that the hemispheres were able to work independently of each other.

Hippocampus (memory)

Limbic system - Medial temporal lobe

Memory forming new episodic memories

Spatial navigation - mental map of familiar environment

* Memory is not 1 thing, but different components mediated by different parts of brain.

Short-term Memory

Lasts several seconds

Can mentally rehearse to remember things - H.M who had has

hippocampus removed

Long-term Memory

1\. Declarative – conscious recall (Things you can declare) - Hippocampus

* Episodic – memory of past events
* Semantic – Facts and basic knowledge

2\. Procedural – Not for conscious recall

* Skills you have learnt (H.M could learn new skills but could not recall learning them)

Long-term memory requires encoding (laying down new memories) and retrieval (retrieving memories for conscious recall)

Epilepsy

Hippocampus is common onsite for seizures - Seizures damage hippocampus (decreases neurons) and increase amnesia.

* Epilepsy piggy backs off memory mechanisms - Consolidation of certain synapses and connections in the brain.


* Brain abnormally discharges = consolidated = increase frequency of abnormality = epilepsy

Top-down processes (Perception and Behaviour)

Cognitive control or volitional choice, modulation by prior knowledge and experience

CHOICE, CONSCIOUS - Selective prioritising

Bottom-up processes (Perception and Behaviour)

Driven by external stimuli or unconscious states

BIOLOGICAL URGES - Attention captured, things that stand out -

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Attention (Parietal lobe)

Directing attention (eye movements) to explore visual world

Spatial neglect = parietal lobe damage

Selectivity (Parietal lobe)

Select and prioritise stimuli based on location or features (whatever is relevant).

* Moving “spotlight” looking for relevant features - colour, shape

Capacity limited - Resources for attention are limited – we can’t attend to all incoming sensory info; we use attention to filter and prioritise sensory info

Spatial awareness (Parietal lobe)

Linking vision to action

* Represents spatial location of objects around us for guiding actions

Map reading and maths ability

Spatial neglect (Parietal lobe)

Damage to parietal lobe in 1 hemisphere. Completely unaware of one

side of space. (Lesions commonly caused by stroke)

* Normal vision

Stimultagnosia – can’t perceive multiple objects simultaneously

Frontal lobe

Executive functions:

* Reasoning, planning, problem-solving
* Inhibitory control - Behaviour regulation, selection of appropriate behaviours (ADHD, OCD and reward addictions associated with problems here)
* Working memory

Frontal temporal dementia (FTS)

Degeneration/loss of neurons in frontal and temporal lobes

* 2nd most common after Alzheimer’s

Effects:

* Disinhibition - Increasingly inappropriate behaviour
* Apathy - Lacking motivation, withdrawal, emotionally distant
* Loss of empathy
* Deficits in executive functions
* Speech, language and motor deficits

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Behavioural variant- Main difficulty in social department

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Language variants

* Non-fluent primary progressive aphasia - Speech is effortful (Damage to brocas area - frontal lobe at back)


* Non-fluent logopenic progressive aphasia - words come out well when they come out but effortful and long pauses (Damage to left hemisphere coming more frontal/parietal into temporal)

\*Both have good understanding and comprehension

* Semantic - Speech sounds fluent, but content is empty/nonsense (temporal lobes affected)

Habituation

Initially strong response is weakened by repeated exposure

Shows how relatively unimportant stimulus comes to be ignored (to not waste energy)

Sensitization

Initially weaker response is strengthened by repeated exposure

Shows how organism becomes more vigilant about stimulus.

“Better safe than sorry principle”

Classical conditioning

Associations learned through experience

Previously neutral stimulus elicits same response after being paired with another stimulus.

Conditioned response elicited through associations between conditioned stimulus and unconditioned stimulus

Operant conditioning

Learning based on whether an action is followed by satisfying or unsatisfying consequences. Learning depends on:

1\. Behaviours of organism

2\. Consequences of behaviours

Therdike’s Law of effect

Behaviours that are followed by a satisfying outcome are more likely to be repeated.

Reinforcement – outcome that increases strength, frequency

Punishment – Out come that decreases

Schedule of reinforcement

Type of consistency matters

1\. Continuous reinforcement - Every instance

2\. Partial reinforcement - Some instances

Varieties of partial reinforcement

Schedules

* Interval – Time based reinforcement
* Ratio – response-based reinforcement - Unlike interval, frequency of behaviour is considered (not just did it or did it not happen within this time interval

Type

* Fixed – Reinforcement provided regularly
* Variable – Reinforcement is irregular

Multistore model of memory

Memory is usually referred to as a single entity - Really an umbrella term.

* 3 types: Sensory, short-term and long-term

The retention of information over time

Encoding > Storage > Retrieval

Sensory memory

Sensory memory store for each sense modality

* Must be attached and transferred to short-term memory to

avoid being forgotten.

Responsible for storing “raw” modality-specific sensory information

* Eye > iconic memory > capacity:12+ items >

Short-term memory

* Not modality specific

Contents aligned with current state of awareness

A bottleneck for which information must pass through if it wants to be repeated or reported.

* Capacity: 7+- 2 items
* Persists for 20-30 seconds
* Time-based decay

Rehearsal improves likelihood of transfer to long-term memory otherwise forgotten

Long-term memory

* Capacity: Massive (maybe unlimited)

Once encoded in long-term memory, retention is permanent

* Memory becomes increasingly robust to forgetting as information passes through successive stores.

In order to demonstrate memory for any event, one must engage in selective attention, awareness and recognition

Interference (memory)

Adding distractor items = makes it harder to pinpoint appropriate information and takes up space in short term memory.

Free recall and serial position

Ability to recall information is dependent on the order it is given

Recency effect

End of list items. In STM

Primary effect

Start of list items. Items maintained in STM by rehearsal which facilitates transfer to LTM to free up STM space. The middle items are unlikely to have experienced enough rehearsal to be transferred into long-term memory and are therefore, forgotten when new words are added

Cues and retrieval

Improved likelihood of success by adding cues to “trigger” retrieval of target information.

While associations between cues and memory can be helpful, changes to context can result in retrieval of inappropriate information > Interference

Encoding specificity principle

Retrieval is facilitated when cues that are presented at encoding are

also present at retrieval

* Incidental features of our environment (and our mental state) can become associated with target information

Depth of processing

Deeper encoding and processing = superior memory performance

Forms of interference

1\. Proactive interference – older information disrupts retrieval of more recent information

2\. Retroactive interference – more recent information disrupts retrieval of older information

Not possible to predict in advance which form interference will take  Is dependent on task, context and other situational factors unique to individuals.