Biopsychology AO1+3 Flashcards
Outline the Structure and Function of Sensory, Relay and Motor Nuerones
Sensory - short axon, long dendrite:
They carry nerve impulses from the PNS to the CNS
Relay - short axon, short dendrite:
Connect sensory to motor
Motor - long axon, short dendrite:
Carry impulses from CNS to receptors (muscles)
The Neurones Function together by:
1) A stimulus is presented (flame)
2) Sensory neurone detects the flame and sends a message up the PNS
3) The message reaches the spinal cord, where it is passed onto a relay Neuron
4) The message is then passed on from a Relay Neurone to a Motor Neurone to bring to receptors (muscles)
((Pulls arm away from the flame))
Outline the Process Of Synaptic Transmission
1) Nerve impulse travels down the axon of pre-synaptic neurone
2) reaches the synaptic terminal at the end of the pre-synaptic neurone.
3) This triggers the neurotransmitter to move to the edge of the membrane
4) Neurotransmitters are released into synaptic gap
5) They travel across the synapse
6) They bind to receptor sites on the Post-Synaptic Neurone
7) Triggers an electric signal to be sent down the post-synaptic neurone
8) Neurotransmitters left in the synaptic gap and took back via “Reuptake”
- Nerve Impulses travel down the axon of the pre-synaptic neurone.
- They reach the synaptic terminal, which triggers neurotransmitters to move to the edge.
- They are then released into the synaptic gap, to travel across the synapse to the Post-Synaptic Neurone.
- They bind to receptor sites which trigger new nerve impulses down the Post-Synapse.
- Remaining Neurotransmitters are absorbed by the Pre-Synapse via “Reuptake”
Outline Excitation and Inhibition
(Included in the process of Synaptic Transmission
Excitation - Dopamine causes excitation of the post-synaptic neurone by increasing its positive charge, making it more likely to fire
Inhibition - Serotonin causes inhibition in the post-synaptic neurone making it less likely to fire
Summation - adds up all the excitatory and inhibitory input to determine the effect of either firing or not.
Outline the divisions of the nervous system: Central and Peripheral
Nervous System
|—————|—————|
PNS CNS
SNS / \ ANS. Spinal Cord + brain
|
/. \
Sympathetic Parasympathetic
(Increases). (Decreases)
- The PNS transmits messages to the CNS
- SNS controls voluntary movements
- ANS governs vital functions such as breathing
E.GS:
Parasympathetic:
- Constricts pupils
- Slows Heartbeat
- Contracts Bladder
Sympathetic:
- Dilates pupils
- accelerates heartbeat
- relaxes bladder
Outline the function of the Endocrine System: Glands and Hormones
The endocrine and nervous system work together to regulate processes in the body
- The Endo uses messages (Hormones) to regulate functions
Examples include;
Glands: - Hormone(s): Function:
-Adrenal. - Adrenaline Fight or Flight
-Testes. - Testosterone. Puberty
- Pineal. - Melatonin Sleep-wake
Outline the fight or flight response including the role of adrenaline (+1 AO3)
1) a sudden fright (acute stressor) causes the hypothalamus to direct the sympathetic branch of the ANS to send messages to the Adrenal Medulla
2) results in the release of adrenaline in the bloodstream causing Fight Or Flight
3) this accesses emergency functions such as:
(Sympathetic Functions)
- increased heart rate
- Dilated pupils
- Contracted bladder
So
Stressor activates hypothalamus which activates Sympathetic branch of ANS which activates Adrenal Medulla which releases adrenaline
AO3: X
DIFFERENT IN FEMALES
Taylor found females adopt a “tend and befriend” response to stressors
Outline localisation of function in the brain (+AO3)
The idea that specific functions have specific areas in the brain
- therefore if a certain area is damaged, the function will also be effected
- the brain is divided into two symmetrical halves
Each area in the brain:
Auditory - to left of the spine
Broca’s Area - about auditory
Frontal lobe - above Broca’s
Motor Cortex - to the right of Frontal
Somatosensory cortex - Right if Motor
Visual Cortex - right of Somato
Wernicke’s Area - below Visual
- Damage to Auditory produces hearing loss
- damage to motor results in a loss of control over fine movements
- damage to visual causes blindness
- damage to Broca’s causes a loss of speech fluency
- damage to Wernicke’s causes loss of speech meaning
AO3:
+ supported by Tan
+ brain scan research — Broca’s area was active during a reading task
x lashley — removed 10-50% Cortex in rats, they could still learn the maze
Outline Hemispheric Lateralisation (+AO3) and Split Brain Research (+AO3)
The brain is contra-lateral (opposite sides) so left deals w/ right vice versa
Left Hemisphere - Language processing (because Broca’s and Wernicke’s area is In the Left Hemisphere)
Right Hemisphere - Facial Recognition
(Spatial Information)
AO3;
+ - Fink used PET scans to see which areas of the brain were active during a visual processing task (Forrest as a whole = right , Tree = left)
x - plasticity shows that when an area is damaged the brain, the brain compensates for this, suggests the brain is not lateralised
X - Lashley contradicts he found rats could learn a maze w/ 10-50% of cortex gone
Split Brain studies - Sperry
- 11 split brain Ps due ti Epilepsy, had their Corpus Callosums cut
Procedure:
Verbal Recognition: A visual image is shown to the Left Visual Field and then the Right.
Ps were asked to describe what they had seen
Touch Recognition: hands were screened / Ps were asked to pick up an object and describe what they had felt
FINDINGS:
Verbal Recog:
Right Visual Field: EASY
Left Visual Field: Couldn’t describe
Touch Recog:
Left Visual Field: they could select a matching object from a grab bag
AO3:
+ supports lateralisation as it is well controlled
x limited sample, can’t be applied to everyone as they are 11 unique Ps
Outline the methods of studying the brain
fMRI - a method of detecting changes in blood flow in the brain
- when an area in the brain is most active it consumes oxygen so detecting blood flow to an area says it active
- it gives a moving picture of the brain
AO3:
+ - less Invasive
+ - good spartial resolution
x - expensive
x - low temporal resolution, 1-4 seconds after it has happened
EEGs and ERPs
EEGs measure electrical activity in the brain via electrodes (fit on the persons scalp)
- is a real time record of brain activity
ERPs - these are short segments of EEG data, they are averaged over many trials of an experiment - can tease out motor responses
AO3:
+ - EEGs and ERPs are less invasive, they don’t use radiation or insertion
+ - they are cheaper
+ - high temporal resolution - happens in “real time”
x - poor spartial resolution- can’t show the deeper areas of the brain
Post-Mortem Exams
Examining a brain after death, can be compared to a “normal brain”
AO3:
+ - detailed exams, which other can’t achieve
x - can’t see process as the brain is inactive (can’t determine CAUSATION)
x - ethical issues
Outline Plasticity and Functional Recovery
(+ Factors that effect recovery)
(+AO3)
Plasticity is the brains ability to change it adapt due to brain trauma
Functional Recovery is when the brain compensates for lost functions
What happens in the brain after recovery?
1) Axon Sprouting - the growth of new nerve endings that connect with other Undamaged nerve cells to form new neuronal pathways
2) Recruitment of Homologous(Similar) Areas - For example, if Broca’s area was damaged on the left, a similar area on the right will perform its function
3) Neuronal Unmasking - some of the brains neurones are Dormant, the idea of unmasking is that it takes over the dormant areas to open connections to inactive areas in the brain
Factors that effect recovery after trauma
- Age:older patients have worse recovery
- Gender: women recover better
- stress: can effect the ability to use a function that has been regained
AO3:
+ - Maguire used MRI scanner on LONDON CAB DRIVERS
+ PAs - treatment and rehabilitation of Brain Injury Patients
x - Effected by individual differences
Adults require more training than children
Outline Biological Rhythms
Circadian - Occurs Once Every 24 Hours
E.G: Sleep-Wake Cycle
Hormone Production - Hormones such as Melatonin can encourage feelings of sleep
Infradian - Lasts more than 24 Hours
E.G: Hibernation, Menstruation
Menstrual Cycle is a monthly Infradian cycle which includes monthly changes in hormones that regulate ovulation
Ultradian - lasts less than 24 hours
E.G: heartbeats, Digestion
Stages Of Sleep…
Outline and Evaluate Endogenous Pacemakers and Exogenous Zietgebers
Endo + Sleep-Wake Cycle
The SCN (Super-charismatic Nucleus)
- Is a tiny bundle of nerve cells in the hypothalamus.
- It lies above the Optic Chasm and so receives info about light.
- It uses entrainment based on information on light to synchronise sleep
The Pineal gland and melatonin
The SCN passes info on day length and light to the pineal gland,
- In turn the pineal gland increases production of melatonin during the night. (Induces sleep)
AO3:
+ - Morgan found if the SCN was removed in hamsters, the Sleep-wake cycle disappeared
x HOWEVER - can’t apply to humans as we have social cues
+ - Siffre lived in a cave for 6 months (no daylight), he found he could maintain a normal SW cycle despite no Zietgebers
x Folkard found that when a volunteer stayed 25 days in a lab w/ no Zietgebers her SW cycle extended to 30 hrs
Weakness because it lowers validity
Exogenous Zietgabers
Light - Resets the SCN and so the internal biological clock
Social Cues - such as bedtimes and mealtimes
AO3
+ - Campbell found shining a light on the back of a persons knee shifted the Circadian rhythm.. Implies natural light keeps SW cycle in synchrony
x - Miles studied a man who was blind from birth, despite exposure to social cues, he maintained an ABNORMAL SW cycle
