Revision For SAC

Psychology Unit 3 SAC 1Time: 100 min 25 marksTitle: BRAIN + NERVOUS SYSTEM (No Text book)Format: Poster consisting of text 200 – 400 words and diagrams

Outcome 1Students should be able to explain the major functions of the brain including cort ical lobes and hemispheric specif icat ion and the role of the nervous system.

Instruct ions: Using the A3 Sheets provided.(1) Draw and explain the Divisions of the Nervous System – Explain the functions of each. P177 and class red handout(2) Draw and label a Neuron and explain neural transmission (include all 3 types neurons in your explanation). P207 211 and class handouts(3) (a) Label the 4 lobes of the brain. p182 (b) Explain the main functions of each of the four lobes. p196 (c) Include the Spinal Cord and its functions. P206 and nervous system f lowchart (handout)(4) Indicate the location of the Specialist Areas and explain the functions of each. p196•Draw, label and explain the Cerebral Hemispheres. P181 and 199• Explain the role of the reticular act ivat ing system in select ive attention and wakefulness: p 203 and 204----- brocas /wernickes p214 (7) THALAMUS

Divisions of the Nervous System

Fight-or-FlightParasympathetic NS Sympathetic NS

Pupils & Tears

Salivation

Heart Rate

Respiration and Blood Vessels

Digestion

Bladder

Elimination

Genitals

Constricts pupils Stimulates tears

Stimulates salivation

Heart rate & blood pressure decreases

Decreases respirationConstricts bronchi & blood vessels

Stimulates digestion

Contracts bladder

Stimulates elimination

Inhibits genitals

Dilates pupils Inhibits tears

Inhibits salivationDry mouth

Increases heart rate Blood pressure increases

Blood vessels dilate

Increases respirationBronchi dilate

Oxygen levels increase

Inhibits digestion

Adrenaline Release of adrenaline (located on top of kidneys)

Sugar Releases sugar/glucose from the liver (extra energy for muscles)

Relaxes bladder (temporary loss of bladder

control)Inhibits elimination

Excites genitals

A typical neuron consists of :a cell bodydendrites (which receive messages) &axon (which transmits messages)

In the process of axonal transmission messages travel along the surface of the neuron from the dendrites, through the cells body, and along the axon

Dendrites Cell body Axon

Axon terminals

Node of RanvierMyelin Sheath

Cell body (soma)Axon

Nucleus

Dendrites

Label the parts of the neuron and define each part (function):

Nucleus, axon, myelin sheath, dendrites, axon terminals, Node of Ranvier), cell body (soma)

Messages travel from one neuron to the next through the chemical process of synaptic transmission. For such transmission to occur, the neuron must fire

The all-or-none principle refers to the fact that neurons will fire only if the impulse they receive is above a certain threshold intensity.

The firing of a neuron causes a chemical neurotransmitter to cross the synapse between neurons, thereby exciting or inhibiting the firing of the next neuron

The FOREBRAIN is the largest region of the brain. It has many structures but the CEREBRAL HEMISPHERES are the largest. These are the grey folded and wrinkled looking parts of the brain.

CEREBRAL HEMISPHERES = the 2 halves of the brain

Cerebral HemispheresThe 2 hemispheres are called the LEFT and RIGHT

The LEFT hemisphere controls the RIGHT side of the bodyThe RIGHT hemisphere controls the LEFT side of the body

See Fig. 2.26 p86

LEFT HEMISPHERE RIGHT HEMISPHERE

Verbal tasks

Logical Thought

Language

Speech (Wernicke’s Area, Broca’s Area)

Writing

Maths

CONTROLS RIGHT SIDE OF THE BODY

Nonverbal e.g. recognition of faces

Visualisation

Musical

Spatial Skills

Artistic

Creative

CONTROLS LEFT SIDE OF THE BODY

The left and right hemispheres work together even though they have different functions.

Each hemispheres of the cerebral cortex is divided into 4 LOBES (F.T.O.P):

– Frontal– Temporal– Occipital– Parietal

FrontalParietal

Temporal

Occipital

Cerebellum

F – T – O - P

Areas of the Cerebral Cortex

Reticular Activating System p203

• Look at you diagram of the MID BRAIN there you will find the reticular formation. Read p 203

• RETICULAR ACTIVATING SYSTEM (RAS): is a network of neurons that extends in many directions from the reticular formation in the brain stem to different parts of the brain and spinal cord.

Functions include:

• -Alertness, e.g. regulates wakefulness and attention

• Arousal,e.g. regulates by increasing or dampening arousal in response to feedback from upper and lower brain areas. It influences whether we are awake, drowsy or asleep.

• Less active RAS = sleep• Damage to RAS= disrupts sleep/wake cycle

• Selective Attention,regulates what we choose to attend to; directsspecific cortical areas to focus on relevant info.

EVIDENCE FOR THESE FUNCTIONS

• Destroying the RAS causes a coma resembling sleep

• Electrical stimulation of RAS instantly awakens sleeping animals.

Thalamus p204• Located in the middle of the brain on top of

the brain stem.• It filters info from the senses and relays

the incoming sensory info( apart from smell ) to the cerebral cortex.

• Smell has a direct route to the cortex bypassing the thalamus.

• Regulates arousal through its connection with the RAS (therefore has a crucial role in influencing our wakefulness and level of alertness

THALAMUS

• Plays a role in attention by filtering incoming sensory info. More attention to important info.

• Closes pathways of incoming sensory information during sleep, preventing information from reaching the brain

Consciousness p96Task: close your eyes and focus your attention on:

– Thoughts in your head– Sounds around you– How you feel (tired – bored)– Feel the clothes against your skin

What is consciousness?Consciousness is not a single state but it refers to a wide range of constantly

changing states. (See Fig 2.6 pg 101. It is the awareness of objects and events in the external world and of our own existence and mental processes at any given moment.

• Contents continually change.• Attention- enables us to focus on and be aware of some stimuli and ignore others.• It is a psychological construct- it is a concept used to describe a psychological

process that is believed to exist but cannot be directly observed or measured.

Awareness: NWC occurs towards the top end of the awareness continuum that ranges between total awareness (focused attention) to lack of awareness (unconsciousness).

Rene Descartes p97-Mind and Body are separate but interconnected

•Dualism-The mind (non-physical) and the body (physical) are separate and not different things but interact via the pineal gland in the brain.

•Consciousness is everything we are aware of including our own existence. ( our senses can’t be trusted so we need to rely on thinking)

•Thinking provides evidence of consciousness- “I think, therefore I am”

William James- Streams of consciousness p100 Fig 2.4 and 2.6• Consciousness includes everything we are

aware of including our own existence.• Stream of consciousness- never ending

flow of thoughts , feelings and sensations.• Is continually changing, personal and

selective.• Evolutionary based role that enhances our

ability to adapt to the environment. p101

2 TYPES OF CONSCIOUSNESS

NORMAL WAKING CONSCIOUSNESS (NWC)- Awake and aware of internal and external stimuli.

ALTERED STATES OF CONSCIOUSNESS (ASC)- Different experience from NWC

E.G. level of awareness, thoughts, perceptions, feelings, self control, time orientation, capabilities ect

eg sleeping/daydreaming

Awareness: Normal waking consciousness occurs towards the top end of the awareness continuum that ranges between total awareness (focused attention) to lack of awareness (unconsciousness).

Characteristics of Normal Waking Consciousness(NWC) – pg 105.

NWC refers to the states of consciousness associated with being awake and aware of our thoughts, feelings, memories and sensations from the outside world.

Attention: is a concentration of mental activity that involves focusing on specific stimuli.

Eg; watching T.V and someone calls you (often you don’t hear).Selective Attention: attention can be focused (like a spotlight) either on an

internal thought or feeling of external stimuli, at the exclusion of all others.To test selective attention psychologists Neisser & Becklen (1975) conducted

an experiment – see pg 108 Fig 2.10

Factors that determine whether we attend to a particular stimulus.

Important to us If it changes in some way Unusual or noveleg; personally (new)Our name TV advertisers use this.

Cocktail party effect – pg106

Content Limitations: pg 108The type of information held.– Content in NWC is generally logical and organised.– We exercise control over what we allow into NWC (blocking things which make

us feel depressed embarrassed, hurt. . .) which makes the content more restricted and limited than in an ASC.

– ASC eg; dreaming the content is illogical and disorganised.

Controlled and Automatic Processes: pg108Controlled processes - the processing of information involves conscious, alert,

awareness – individual’s attention is focused on achieving a goal. It is also serial (only one activity that requires controlled processes can be performed).

- Controlled processes are used when the activity is difficult or unfamiliar.- Attention is focused on the task at hand preventing attention being directed to

other activities.Automatic processes – are used with familiar skills requiring minimal attention.- This frees the brain to do other tasks that are easy and different to other task.- Simultaneously completing two easy unrelated tasks is called ‘divided attention’

(parallel).Eg; stroop effect – pg111Stroop effect occurs because when the word appears our automatic response is to read the word. This interferes with our attempt to name the colour of the print.

The Stroop Effect

The Stroop Effect demonstrates artificially the confusion which can occur when sensory messages conflict. The brain has difficulty in processing efficiently competing sensory inputs

Your RIGHT hemisphere tries to SAY the colourYour LEFT hemisphere wants to READ the word

Lets try it …http://faculty.washington.edu/chudler/words.html

LETS MEDITATE

Characteristics of altered states of consciousness: p114

Awareness:• Shift in focus from external environment to internal.

Content Limitations:• Content is less restricted than NWC.• Content may be nonsensical, illogical and disorganised.

Perceptual Distortions:• Either more receptive to external stimuli, or dulls them to the extent that some

sensations are not experienced at all.• Loss of identity (feel they are someone else, or are ‘outside themselves’ looking

in)• Feeling of a loss of touch with reality.• May hallucinate (experiencing perceptions or stimuli or events that are not really

occurring)

Characteristics of altered states of consciousness. . . . .Cognitive Distortions:• Cognitive functioning becomes impaired.• Difficulties with problem solving due to illogical thinking and a tendency toward

disorganised thought.• Difficulty recalling information preciously stored in memory (memory can be

accessed in NWC).• Trouble remembering events occurring during an ASC.

Emotional Changes:• Express emotions more openly OR no emotions OR an

unpredictable/inappropriate emotional response.

Self Control:• Normal inhibition or self control may weaken.• Impaired motor co-ordination.• Increased susceptibility to suggestion.• Difficulty maintaining control of emotions.

Characteristics of altered states of consciousness. . . . .

Time Orientation:• Distorted estimation of time.• Time seems to pass at a different speed than

normal – quicker or slower.

HOMEWORK lesson 5

• READ P 114-124 and complete LEARNING ACTIVITY 2.12- Questions 1-6c p121

• Review Rene Decarte and William James p97-100

• Read p121-Methods used to study level of alertness in normal waking consciousness.*We will be going over this in class.

• Briefly summarise EEG, Heart rate, Body temp and Galvanic skin response.