Biological Psychology Flashcards
What is contained in the central nervous system (CNS) ?
Brain and spinal cord
What is contained in the peripheral nervous system (PNS) ?
Everything else
Nerves - motor pathways and sensory pathways
What are the three main parts of the brain ?
Cerebrum
Cerebellum
Brain stem
What does contralateral mean ?
Opposite side of the brain
What does ipsilateral mean ?
Same side of the brain
How much blood flow does the brain receive ?
20% of the blood from the heart goes to the brain
What is the anatomical term for up/superior ?
Dorsal
What is the anatomical term for down/inferior ?
Ventral
What is the anatomical term for front/anterior ?
Rostral
What is the anatomical term for back/posterior ?
Caudal
What does medial mean ?
Toward the middle
What does lateral mean ?
Toward the side/outside
Where is the frontal plane ?
Parallel to forehead
Splits front and back
Where is the sagittal plane ?
Parallel to the wall
Splits left and right
Where is the horizontal plane ?
Parallel to the ground
Splits top and bottom
What is grey matter ?
Cell bodies and dendrites
e.g. cortex, basal ganglia, thalamus
What is white matter ?
Myelinated axons
e.g. the corpus callosum
What is the pathway that connects the left and right hemisphere called ?
Commissure
What is the corpus callosum ?
Translates to ‘hard body’
The largest fibre bundle connects the two hemispheres of the brain
What is meninges ?
3 layers of tissue that protects the brain and spinal cord (CNS)
What are the 3 layers of meninges ?
Dura mater
Arachnoid membrane
Pia mater
What is cerebrospinal fluid (CSF) ?
A clear liquid that fills the subarachnoid space
Functions: shock absorber, buoyance, prevents carrying the weight of the brain
What are ventricles ?
‘little bellies’
Hollow cavities filled with CFS
How is CFS produced ?
Filtering blood
What is the blood-barrier ?
A semipermeable barrier
Lipid soluble substances can pass through
Substances with large molecules must be actively transported through the walls
What is the purpose of the blood-brain barrier ?
Maintain stable environment
Protection from potentially disruptive/damaging chemicals
What is the cerebral cortex ?
The outer surface of the cerebrum
3mm thick
Folded to allow a bigger surface area
What are the clefs and grooves called in the cerebral cortex ?
Sulci
Major grooves = Fissures
Folds and bulges = Gyri
What are the 4 lobes of the brain called ?
Frontal
Parietal
Occipital
Temporal
Describe the frontal lobe
Front of brain
Anterior of the cortex
Rostral to parietal lobe
Dorsal to temporal lobe
Functions: motor and cognition, higher order function
Describe the parietal lobe
Near the back
Caudal to frontal lobe
Dorsal to temporal lobe
Function: somatosensory
Describes the occipital lobe
In the back of the head
Caudal to parietal and temporal lobes
Function: vision
Describe the temporal lobe
The temple
Rostral to occipital lobe
Ventral to parietal and frontal lobes
Function: hearing, vision, cognition, emotion
What are the primary areas ?
Primary somatosensory cortex
Primary visual cortex
Primary auditory cortex
Primary motor cortex
They are all contralateral
What is the role of sensory association areas ?
Receive and analyse info from primary regions
What is the Basal Ganglia ?
A collection of nuclei (a group of cell bodies)
What are the Basal Ganglia important for ?
Controlling movement, reward systems
Lesions in the basal ganglia can cause disorders such as Parkinson’s and Huntington’s
What are the 3 parts of the basal ganglia ?
Caudate nucleus
Putamen
Globus pallidus
What are the 5 things included in the limbic system ?
Limbic cortex
hippocampus
amygdala
fornix
mammillary bodies
What is the limbic system important for ?
Emotion
Learning
Memory
feel related behaviour
emotional memory
What is the hippocampus important for ?
Consolidating memory
It is located in the temporal lobe
What is the diencephalon ?
The second division of the forebrain (prosencephalon)
What is the thalamus ?
Located in the diencephalon
Inner chamber
Two lobes separated by massa intermedia
Receives info from and sends info to the cortex
What are the 3 nuclei that the thalamus is divided into ?
Lateral geniculate - receives from retina, to visual cortex
Medial geniculate - receives from midbrain, to auditory cortex
Ventrolateral
What is the hypothalamus ?
Located in the diencephalon
Important for physiological processes (PNS)
Connected to the pituitary gland
What is the mesencephalon ?
The midbrain
What is the tectum ?
In the mesencephalon
Superior colliculi
Inferior colliculi
What is the tegmentum ?
In the mesencephalon
Reticular formation
Periaqueductal grey matter
Red nucleus
Substantia nigra ‘black substance’
What is the rhombencephalon ?
The hindbrain
What is the metencephalon ?
In the hindbrain
Contains the pons - sleep and arousal, relay info from cortex to cerebellum
Contains the cerebellum - modify movement so it is controlled and smooth
What is the myelencephalon ?
In the midbrain
Contains the medulla oblongata - regulates cardiovascular system, respiration, skeletal muscles
Wat are the subdivisions of the forebrain (prosencephalon) ?
Telencephalon - end brain
(cerebral cortex, basal ganglia, limbic system)
Diencephalon - interbrain
(thalamus, hypothalamus)
What are the principle structures of the midbrain (mesencephalon) ?
Tectum and Tegmentum
What are the subdivision of the hindbrain (rhombencephalon) ?
Metencephalon - after brain
(cerebellum, pons)
Myelencephalon - narrow brain
(medulla oblongata)
What are the 3 types of neurons and their roles ?
Sensory neurons - gets info from the body
Interneurons - link sensory and motor neurons
Motor neurons - take info yo the body and control muscle contractions
What are neurons ?
They do all of the information processing and information transmitting
Many different types of neurons
86 billion neurons
What is the structure of the neuron ?
Soma - cell body containing nucleus
Dendrites - receive messages and connect to other neurons
Axon - carries info from soma to terminal buttons
Myelin Sheath - wraps around the axon
Terminal buttons - at the end of axon branches
What are the 3 glia cells ?
Astrocytes - structural support and provide nutrients, surrounding the synapse
Oligodendrocytes - produce myelin sheath
Microglia - clear away dead neurons
What is the cell membrane ?
Covers all cells
Two layers of phospholipid molecules
Tails point in and heads point out
Intracellular fluid inside the cells
The ion channel spans the membrane
What are the two types of ions ?
Cations - positively charged
Anions - negatively charged
What is the intracellular fluid ?
Fluid containing potassium ions (K+) and anions (A-)
What is the extracellular fluid ?
Fluid containing sodium (Na+) and chloride (Cl-) ions
What is the membrane potential and how is it balanced ?
The difference in electrical potential inside and outside the cell
Balanced by diffusion and electrostatic pressure
What do organic anions A- do ?
Concentrate inside the cell
Cannot cross the membrane
What do potassium ions K+ do ?
Concentrate inside the cell
Want to diffuse out
Attracted to the inside of the cell as it is negative
The forces balance so K+ doesn’t move
What do chloride ions Cl- do ?
Concentrate outside the cell
Want to diffuse in
Repelled from the inside as it is negative
Forces balance so Cl- doesn’t move
What do sodium ions Na+ do ?
Concentrate outside the cell
Want to diffuse in
Attracted to the inside as it is negative
Na+ is forced into the cell
Kept controlled by sodium-potassium pumps
What is the resting potential of a neuron ?
-70mV
The inside is negative
The outside is positive
What is action potential ?
Rapid change in the membrane potential
It is an all or none process and it stays the same size throughout transmission
What is depolarization and hyperpolarization ?
Depolarization - decrease from normal resting potential (brings membrane closer to 0)
Hyperpolarization - increases relative to resting potential (more negative)
Threshold of excitation is -40
What is propagation ?
How the action potential is transmitted down the axon
Acts like a chain of dominos
Entry of sodium ions results in it being regenerated down the axon
What are the benefits of saltatory conduction ?
Fast conduction
More energy efficient
What is synaptic transmission ?
A chemical process of neurons sending messages
Neurotransmitters are released from one neuron and attach to another neuron
This initiates a reaction that ultimately results in postsynaptic potentials
What is the synapse ?
The junction between two neurons
Synaptic vesicles are filled with neurotransmitters
Synaptic cleft is the gap between two membranes
Synaptic cleft is 20 nanometres
What is the process of synaptic transmission ?
Ca channels open and Ca2+ enters
Vesicles fuse with membrane and pores open
Release of neurotransmitters
They diffuse and bind to postsynaptic membrane
Postsynaptic channel opens
Ions flow resulting in PSP
What causes excitatory and inhibitory postsynaptic potential ?
Excitatory - depolarization e.g. Na+
Inhibitory - hyperpolarization
What is an ionotropic receptor ?
Contains a binding site and an ion channel
This opens when molecule attaches to binding site
What is a metabotropic receptor ?
Contains a binding site
Initiates a chain reaction that eventually opens ion channels
Requires energy
PSP’s slower than those produced by ionotropic receptors
What is termination ?
Some neurotransmitters are left in the cleft and the process of removing these is termination
What is reuptake ?
A method of termination
The neurotransmitter is taken back by the presynaptic terminal via transporter molecules
What is enzyme deactivation/degradation ?
A method of termination
Transmitter is broken down by enzyme
e.g. acetylcholinesterase breaks down ach into choline and acetic acid
What does excitatory mean ?
Increases the likelihood of a neuron firing and produces action potential
What does inhibitory mean ?
Decreases the likelihood of a neuron firing
What is integration ?
The summation of PSPs in control of neurons firing
When summed, the hillock reaches threshold of excitation action potential is triggers in axon
What are 3 main neurotransmitters ?
Acetylcholine (Ach) - found at neuromuscular junctions and cause contractions
Dopamine - motor control, reward, addiction
Serotonin - regulation of mood, eating, sleeping
What is an antagonist ?
A drug that blocks neurotransmitters
e.g. botox blocks the release of acetylcholine and prevents muscle contraction
What is an agonist ?
A drug that mimics a neurotransmitter and enhances synapse function
e.g. muscarine imitates acetylcholine
What is a stroke ?
Impaired blood supply to the brain and results in behavioural deficits
Such as language production (Broca’s area) and contralateral paralysis
What is Alzheimer’s disease ?
Affects the temporal lobe (hippocampus) leading to memory impairment - spatial and episodic memory
What is Parkinson’s disease ?
Moto disorder due to degeneration of substantia nigra neurons in the brain
What is the case study of ‘tan’ ?
Man who had a stroke and damaged his motor cortex could only produce the word ‘tan’ but could still comprehend speech
What is the case study of Phineas Gage ?
Man who had an iron bar explode through his prefrontal cortex and resulted in his personality completely changing
What is the case study of HM ?
Man who suffered from epilepsy had surgery on his medial temporal lobe (hippocampus)
Resulted in memory impairments such as declarative and spatial memory but other cognitive and memory functions were unaffected
Name the 6 ways of studying the brain
Behavioural studies - case study
Manipulation of brain function
Neuroanatomy and histology - learn how the brain does something
Electrophysiology - neuron function
Imagining - MRI / PET
Computational models - recreate an area of the brain
What are examples of experimentally induced lesions and other brain manipulation ?
A method used on rats
Temporary manipulations to switch neurons on and off
Electrical stimulation of brain areas
Targeted mutations of brain areas
Good temporal resolution
What was the water maze experiment ?
Putting rats in a pool and they had to find the way out
Normal rats got faster every time they did it showing they learn
Rats with lesions were slower at finding it
What is neural tact tracing ?
A tracer is put into a region of the brain and they are naturally transported across axons to other brain regions
They will end up at the regions where they are connected to
Used diffusion MRI
What is electrophysiology ?
A method of recording the electrical activity in the brain
Recording electrical activity in a single neuron (AP)
Local field potential - recording electrical potentials generated by many neurons fields potential - recorded from rat hippocampus
What is electrophysiology in humans ?
Invasive single unit LFP only conducted rarely for pre surgical evaluation of epilepsy
Surface EEG records neuronal rhythms e.g. sleep stages and poor spatial resolution
Magnetencephalography measures magnetic field changes due to brain activity and has good spatial resolution
What is an MRI ?
Images generated from magnetic resonance signal
When hydrogen nuclei align with the magnetic field they are excited by the magnetic pulse
fMRI - non invasive, changes in blood oxygen level (BOLD), when oxygen goes to a part of the brain the MRI picks it up
What is a Positron Emission Tomography (PET) ?
Involves an injection of radioactive tracers that resemble compounds of biological interest
Using detectors, the tracers can be followed in the brain to monitor activation
Can be used to detect changes in Parkinson’s
What was the research with a robot ?
Researchers generated a circuit model of the hippocampus based on what we know and they put it into a robot
Robot then did the spatial memory task
Robot showed similar findings and correctly navigated the place
What is the path of the primary visual pathway ?
Goes from the eye, to the lateral geniculate nucleus, then to the visual cortex
How does visual information get into the brain ?
Runs from photoreceptors in the back of the eyes to the back of the brain
Info from the left eye goes to the right side and visa versa
The bit of the field of view where right and left overlap is called the fovea
Information is carried via the optic nerve to lateral geniculate nucleus and this relays the information
What is the main experimental strategy to reveal the mechanisms of visual perception ?
Use microelectrodes and electrophysical recordings when presenting visual information to the field of view
It is invasive so only used on non-human primates
Non-invasive ways include EEG, MRI to use on humans
What are rods ? (photoreceptors)
Abundant (120 million in the retina)
No colour discrimination
Sensitive in low levels of light
Higher density in periphery - when it is dark you may see better with peripheral
Track high rate change - can see flicker from corner of eyes, not centre
What are cones ? (photoreceptors)
Less abundant (6 million in retina)
3 types of colour discrimination (S, M, L)
Less sensitive to low level light
Higher concentration in fovea
Cannot follow rapid changes
What are retinal ganglion neurons ?
Receive input from multiple photoreceptors via bipolar cells
Their receptive fields are bigger than photoreceptor receptive fields
What are on-off centre surround receptive fields ?
Light in ON regions excite cells and light in OFF regions inhibit cells
ON and OFF regions are organised in centre surround fashion
Response rate of cells is based on the sum of stimulation in ON fegions minus stimulation in OFF region
Enhancement of contrast at boundaries
What is the functional significance of centre surround fields ?
The luminance of features is represented relative to their surround
Helps preserve the appearance of objects
Newspapers look the same in dark room and in sunlight, despite difference in light levels
Can also result in illusions
What are simple cells ?
Fields have inhibitory and excitatory regions
Can be thought of as combining inputs from ON and OFF cells
Excited if the stimulus is in the right orientation
What are complex cells ?
Fields have no discrete ON and OFF regions
Best response to moving stimuli
Can be thought of as combining inputs from simple cells
What is a retinotopic map ?
Orderly mapping of retinal/ visual field onto visual cortex
What are modules ?
V1 is divided into small columnar modules that combine neurons sensitive to different aspects of stimuli
What are the simple features of visual stimuli ?
Light intensity and wavelength
2D position in the visual field
What are the complex features of visual representation and memory ?
Integrated information concerning form, surface, spatial relations and movement
Integrating with other sensory modalities
What is the dorsal stream of information processing ?
Concerns visuo-spatial (where) and visuo-motor (how) processing
Aids visually guided actions
What is the ventral stream of information processing ?
Object analysis (what)
What is the visual stream - what/where ?
Inferior temporal lobe lesions impair object recognition (what) but not object location (where)
Posterior parietal lesions impairs object location (where) but not discrimination (what)
What is the visual stream - what/how ?
Ventral stream processes visual information for object perception (what)
Dorsal stream processes visual information for visuo-spatially guided actions (how)
What was the evidence for patients with occipital-temporal brain damage ?
They show severe forms of visual agnosia (deficit in visual perception)
They have intact visually guided actions
What was the evidence for patients with posterior-parietal lobe lesions ?
Optic ataxia (deficit with guided reaching)
In tact visual functioning
Who is patient DF ?
He had extensive bilateral ventral-stream lesions and has profound agnosia
In tact visually guided reaching
What are face cells ?
Some neurons in the inferior temporal lobe show selective responses to individual faces
This has been shown in humans using fMRI
What is the medial temporal lobe ?
At the end of the visual processing hierarchy, combining inputs from ventral and dorsal stream and receives input from other sensory modalities
It can generate multi-modal representations
What is the case study of patient HM ?
Following surgery he showed severe deficits in remembering new and recent experiences, facts and places
Other cognitive functions including procedural learning was intact
What are genotypes and phenotypes ?
Genotype - underlying biological makeup
Phenotype - observable traits that are inherited
What are dominant traits and recessive traits ?
Dominant - easily expressed in the organisms phenotype
Recessive traits - expressed in the absence of an overshadowing dominant trait
What are Mendelian inheritance laws ?
- Segregation - traits are either dominant or recessive
- Independence - varieties of each trait sort independently of each other and are not influenced by anything else
What does DNA stand for ?
Deoxyribonucleic acid
What is DNA ?
Can be found in the nucleus of a cell
Composed of two chains of nucleotides that coil to form a double helix
Bases are A&T, C&G
What are chromosomes ?
Typical humans have 46 chromosomes (23 pairs)
All pairs are XX - females XX males XY
Humans have 20,000 to 25,000 genes
How do genes work ?
Some phenotype traits may be programmed by a single gene (pleiotropic) and some are programmed by a combination of genes (polygenic)
What are X-linked genes ?
Males have a much shorter Y chromosome so they may miss out on essential alleles meaning they may have recessive traits
What are sporadic mutations ?
The result of errors in cell division, can happen naturally or due to environmental factors such as radiation
What are polygenic traits ?
Rely on coding from multiple genes so may not follow Mendelian rules, many genetic disorders are considered to be polygenic
What are the 3 X-Linked disorders ?
Turners syndrome - females with XO chromosomes and effects 1/2500
Kleinfelder’s syndrome - males with XXY and effects 1/750
Fragile X syndrome - repeat gene FMR1 and effects 1/4000 males and 1/6000 females
What are the two main sporadic mutations ?
Downs syndrome - effects 1/100, extra version of chromosome 21, some symptoms from birth and some develop
Williams syndrome - effects 1/18,000, microdeletion of chromosome 7, some symptoms from birth and some develop
What is the main polygenic trait ?
Schizophrenia - effects 20million worldwide, they are considered genetically predisposed to schizophrenia but an environmental factor sets it off
What are targeted mutations ?
Lab produces genes and insert them into chromosomes
Can be defective and fail to produce a specific functional protein (knockout gene)
Can produce new protein (knockin gene)
What is genetic engineering ?
Technology (CRISPR) may allow us to directly edit our own genome
It is being used to tackle diseases such as HIV or cancer
What are the general ethical principles to follow ?
Animals are allowed
There has to be no other option available
Minimum number required to obtain valid use
Any pain = anaesthesia
If appropriate animal should be killed
Well homed
What are the benefits of biological research ?
Medical advancements - understand anatomy and the nervous system
Psychological advancements - understand memory, sensorimotor system, treat disorders
What are the rules for using human participants in biological research ?
Minimum number required to obtain valid use
Any pain = anaesthesia
No long term damage
Reward needs to be worth the risk
What is the longitudinal fissure ?
Deep grove that separates the left and right hemisphere in the parental lobe
What are the boundaries and anatomical subdivisions of the parental lobe ?
Central Sulcus - boundary with frontal lobe
Parietal-occipital fissure - boundary with occipital lobe
Lateral sulcus - boundary with temporal lobe
What is the post central gyrus ?
In the parental lobe bordered by central sulcus and postcentral sulcus
What are the three main subdivisions of the parental lobe ?
Superior parietal lobe SPL
Intrapareital sulcus IPS
Inferior parietal lobe IPL
What are the two functional subdivisions ?
Primary somatosensory cortex S1
Posterior parietal cortex
What are the four parts of posterior parietal cortex ?
Intraparietal sulcus and superior parietal lobule
Right inferior parietal lobule
Left anterior parietal lobule
Left posterior inferior parietal lobule
What is the main role of the primary somatosensory cortex ?
Touch
Pain
Proprioception
Doesn’t do heat
What is the input and output and evidence for primary somatosensory cortex ?
Input - thalamus and motor cortex
Output - motor cortex and posterior parietal cortex
Research - inserted electrodes in epileptic patients just before operating and recorded sensations
Why are we interested in the somatosensory cortex ?
Learn about brain reorganisation e.g. after injury - phantom pain
What is the intraparietal sulcus and superior parietal lobule ?
Vision for action
Dorsal visual stream
Motor anterior areas - coding in hand centred coordinate system
Motor posterior areas - coding in vision centred coordinate system
What is balint syndrome ?
Optic alexia - deficit in visually guided reaching movements
Oculomotor apraxia - inappropriate fixation of gaze and difficulties in voluntary fixation
Simultanagnosia - impaired ability to perceive multiple items in a visual display
What are three rudimentary mechanisms ?
Visuospatial working memory - link to the location of objects
Mental rotation / imagery - link to manipulating objects
Arithmetics - moving eyes, spatial layout
What is the left posterior inferior parietal lobule ?
Detect salient events internally
Semantic processing
Reading and comprehension
Default mode processing
Memory retrieval
What is the left anterior parietal lobule ?
Imitation of gestures
Communicative gestures
Real tool use
What are the three main subdivisions of the frontal lobe ?
Primary motor cortex
Pre-motor cortex
Prefrontal cortex
What is the function of the motor cortex ?
Control of skeletal muscles
Roughly somatotopically organised
What is the function of the pre motor cortex ?
Movement planning
Movement selection
Movement sequencing
Inhibit control of motor cortex
What are the 4 tests used with patients with frontal lobe lesions ?
Verbal fluency
Wisconsin card sorting test
Strip task
Tower of London
What are the main issues with the traditional approach ?
Poor sensitivity and specificity
Not all patients with lesions have difficulties
Some patients without lesions have difficulties
What is the evaluation of Struss and Alexander 2007 basic approach ?
Lesion symptom mapping is interesting
Exact processing is still unclear
General problems with patient studies
What is the difference between emotions and mood ?
Emotions are short, intense and have a target
Mood is long, in the background and have no target
What is Ekmans approach to emotions ?
Facial expressions provide insight into cognitive-affective states
There are 6 main emotions
Emotions are universal
What are the criticisms to Ekmans approach ?
They aren’t really universal
Happy and fearful we’re constantly recognised but the others weren’t
They fail to describe the richness of human emotional experience
They are replicable within the same lab and method but failed to replicate when there are no leading questions
What is the difference between complete specialisation and complete dispersion ?
Complete specialisation - one part of the brain for one emotion
Complete dispersion - all emotions come from everywhere
What is the papez circuit ?
Cingulate gyrus
Cingulum
Parahippocampal region
Subirulum
Fornix
Mammillary bodies
MTT
Anterior thalamic nuclei
Why are animal studies used ?
Problems with human ethics
No neuro imaging technique has high spatial resolution and temporal resolution and whole brain coverage
Animal research fills in gaps
Why study non human animals ?
Similarities across species in brain structure and function allow the use of animals
Comparative studies - particular species have advantages
What is the Darwinian theory ?
The characteristics of an organism have a precise function and these are selected to reproduce
What is functionalism ?
The principle that the best way to understand a biological phenomenon is to understand it’s useful functions
What is natural selection ?
The process by which inherited traits that confer a selective advantage become more prevalent in a population
What is mutation ?
A change in the genetic information in the chromosomes which can be passed on to offspring
What is selective advantage ?
A characteristic of an organism that permits it to produce relatively more offspring
What is evolution ?
Gradual change in the structure and physiology of species, generally producing more complex organisms as a result of natural selection
What is neoteny ?
The slowing of the process of maturation, allowing more time for growth, an important factor in the development of brains
What are positive properties of schizophrenia ?
Something you have/ add
Hallucinations
Thought disorders
Delusions
What are the negative symptoms of schizophrenia ?
These take away/ inhibit
Flattened emotional response
Speech poverty
Social withdrawal
What are the cognitive symptoms of schizophrenia ?
Difficulty in sustaining attention
Low psychomotor speed
Deficits in learning and memory
Poor problem solving
What is chlorpromazine ?
A dopamine antagonist
It diminishes positive symptoms
Why do dopamine agonists induce positive symptoms ?
Activity of dopamine neurons in the accumbent
strongly reinforce behaviour
Snyder - schizophrenics report elation at the start of an episode
Fibiger - paranoid delusions caused by activity in Amygdala
What results did Davis 1995 find about concordance rates in twins ?
Monochromatic concordance - 60%
Diachronic concordance - 10.7%
Shared environment seems to play a role in development
What is depression and mania ?
Depression - low energy, loss of appetite for food and sex, sleeping problems
Mania - euphoria, delusional, poor attention span, lack of sleep, self-important
What is bipolar disorder ?
alternating periods of mania and depression
1% of the population afflicted at some point in their life
Equally frequent in men and women
What is unipolar disorder ?
Depression without mania
2 or 3 times more likely in women
Some cases of mania without depression
What is the heritability of affective disorders ?
Rosenthal - 10 times more likely to suffer if a close relative has it
Gershon - MZ 69% and DZ 13%, even if they were raised apart
What are MOA ?
Monoamine oxidase enzyme that destroys monoamines in the post synaptic neuron e.g. serotonin, dopamine
What is lithium used for ?
Used to treat mania
Side effects - hand tremors, weight gain, thirst
What is the link between depression and sleep deprivation ?
Preventing REM sleep acts as an antidepressant
All antidepressants reduced REM sleep and increased slow wave sleep
What are three ways of measuring stages of sleep ?
Electro-encephalogram EEG - head
Electro-oculogram EOC - eyes
Electro-myogram EMG - neck
What are pre-sleep alpha waves ?
Bursts of 8-12Hz in low amplitude / high frequency waves
What are the four stages of sleep EEG ?
Progressive - increase amplitude, decrease frequency
Sleep spindle - 1-2 second bursts of 12-14Hz waves
K complex
REM sleep
What is the recuperation theory of sleep ?
Being awake disrupts homeostasis
Sleep restores this
What is the evolutionary theory of sleep ?
Sleep is not a reaction to homeostatic disruption
Sleep evolved in humans to prevent accidents and predation at night
Sleep is like sex, we don’t need it but we are motivated to have it
What is sleep like in animals ?
Large species differences in sleep but not related to body size or temp
Not consistent with recuperation theories
e.g. Sloths hardly move but need 20hrs a day, lions sleep for 2 days after a kill
What are the effects of sleep deprivation in humans ?
Increases in physiological and behavioural disturbances
After deprivation, missed sleep must be regained
It influences mood and physiological function
What are the effects of sleep deprivation in animals ?
After several days they died
But post-mortem show ulcers and internal bleeding
Stress and physical damage
How is the hypothalamus involved in sleep ?
Victims who had difficulty sleeping had damage to anterior region
Victims who had difficulty staying awake had damage to posterior region
How is the reticular system involved in sleep ?
Brenner 1939
Regulates sleep wake cycle
Slow wave pattern
What are the two main sleep disorders ?
Narcolepsy
REM sleep without core muscles atonia
What is the set point theory of eating ?
Hunger is a consequence of lack of energy
Each individual has an optimal level of energy (a set point) and we seek to return to this point
What are the problems with set point theory ?
- Evolutionary unlikely - food isn’t always available so it can’t just respond to hunger
- Not supported by evidence - drinking a high calorie drink doesn’t remove hunger so can’t just be about energy
- Ignorance of environmental factors - does not take into account lots of other factors such as learning, preference and social factors
What is the positive Incentive Theory ?
Anticipation - animals driven to eat by the pleasure of eating (incentive)
Craving - eating is initiated by cravings enabling you to take advantage of good food when available
Multiple factors - Flavour, knowledge of food, time since last meal, blood glucose etc
What is conditioned taste preference ?
You can learn what to eat
Flavour A - glucose
Flavour B - nothing
Rats prefer flavour A
What is conditioned taste aversion ?
You can learn to avoid food
Flavour A - LiCl
Flavour B - nothing
Avoid flavour A
What are the two things that initiate a meal ?
Pre-meal hunger - signals for meal time releases insulin into the blood, decreasing the body glucose
Huger is preparing for homeostasis disruption
Conditioned hunger in rats - Buzzer and lights = food
What is VMH syndrome ?
Dynamic phase - excessive eating and weight gain
Static gear - body weight maintained, overweight state returns following diet
VMH rats won’t work for food and become picky eaters
What is LH syndrome ?
Aphagia is often accompanied by adipsia (stop eating and drinking)
Recovery is possible - tube feeding, milk soaked cookies, food pellets
What did Cannon and Washburn find about hunger and the stomach ?
Contractions caused by an empty stomach caused hunger
But patients without a stomach also felt hunger
What was Koopmans study with rats on hunger ?
Transplanted an extra stomach into rats
When food was put into the second stomach they stopped eating even though the brain doesn’t know its full
Satiety signals must have diffused into the blood and went to the brain
What is Leptin ?
Discovered as a spontaneous genetic mutation
When injected into mice they ate much more and converted fat more efficiently
When injected into fat rats it made them stop eating and lose weight
What is cognitive neuropsychology ?
The study of the relationship between brain function and behaviour
What brain regions are responsible for what function
What are specialised areas ?
Certain regions are specialised in their role and there is no strict line
They can recover as nearby regions can pick up the slack
What is launched phrenology ?
The study of skull structure as indications for mental faculties
Studying the lumps and bumps on peoples skulls
Limited data
What did Flourens find about recovery ?
Lesioned parts of the cortex at first caused lots of damage
Later on recovery of function to the point of appearing normal
Akin to specialisation
What is Broadmann’s brain mapping ?
The appearance of the cortex under a microscope (cytoarchitectonics)
Supports localisation
Function can be passed onto another region
What is Broca’s area?
The speech region nearer the front of the brain
Broca’s aphasia - damage to this area resulting in struggle to get any words out
What is Wernicke’s area ?
The speech region in the temporal lobe
Wernicke’s area - damage to this area resulting in talking makes no sense
What is conduction aphasia ?
The consequence of Arcuate fibres being damaged
Speech impaired (difficulty repeating what is said to them)
What are the 4 types of memory ?
Episodic - specific events
Semantic - factual memory
Working - short term rehearsal
Procedural - motor memory
What is anterograde amnesia ?
Poor ability to acquire new information
Impaired explicit memory (episodic and semantic)
Preservation of implicit memory
What is the case study of HM ?
Removal of hippocampal areas
Could not learn new episodic memories - but old memories were fine
Frozen language
Intact working memory
Can learn new motor tasks
What is retrograde amnesia ?
Forget the old - can only learn since lesion
What is the role of the hippocampus ?
Does not store memories
Consolidate memories
What are double dissociations ?
Two patient groups with different lesions
What is visual agnosia ?
Inability to recognise objects - name an object through touch
What is apperceptive agnosia ?
Intact low level perception
Can’t perceive the full image
What is associative agnosia ?
Intact ability to draw from verbal instruction
Can perceive global placement
Can not identify objects
What is prosopagnosia ?
Inability to recognise faces visually but can identify through voice etc
What is the inversion effect ?
Upside down faces are hard to recognise
Hard to process the configuration of features
What is FFA ?
Fusiform facial area
