Biopsychology Flashcards
Nervous System
- What is the Nervous System?
- What are the two main functions of the Nervous System?
- What subsystems is the Nervous System divided into?
- Specialised network of cells in the body, primary internal communication system
- Based on electrical and chemical signals
- Two Main functions
- To collect, process respond to info in environment
- To coordinate working of different organs and cells in the body
- Two subsystems- Central Nervous System (CNS) and Peripheral Nervous System (PNS)
Central Nervous System
- What is the Central Nervous System made up off?
- What is the purpose of (1)?
- Describe the cerebral cortex
- What is the purpose of (2)?
- Made up of Brain (1) and Spinal cord (2)
- Brain, centre all conscious awareness, cerebral cortex outer layer of brain only found in mammals highly developed, distinguishes our higher mental functions from other animals, consists of left and right hemisphere
- Spinal cord extension off brain, passes messages to from brain, connects nerves to PNS, responsible for reflex actions
Peripheral Nervous System
- What is the purpose of the PNS?
- What is the PNS further subdivided into?
- What does (1) govern?
- What are the two main divisions of (1)?
- What is the difference between the two divisions?
- What does (2) govern?
- Transmits messages via neurons to and from the CNS
- Subdivided into Autonomic Nervous System (ANS) and Somatic Nervous System (SNS)
- ANS (1) governs vital functions in body (breathing, heart rate, stress responses etc)
- Two main divisions, Sympathetic and Parasympathetic Nervous Systems
- Sympathetic stimulates organs and tissues
- Parasympathetic inhibits organs and tissues
- SNS (2) governs muscle movement, receives info from sensory receptors
Endocrine system
- What is the Endocrine System?
- What is the purpose of the Endocrine System?
- What do glands do?
- How do hormones travel and get received?
- Complex network of glands and organs
- Aims to control vital functions in the body
- Slower than NS but very widespread powerful effects
- Glands produce/secrete hormones
- Hormones travel in bloodstream to any cell that has a receptor for that particular hormone (Example- Thyroxine affects cells in heart)
- Most effect cells in more than one body organ leading to diverse powerful responses
Glands and Hormones
- TOP|HAT represents glands
- What do each of these glands secrete?
- Pituitary Gland (“Master Gland”) controls release of hormones from all other endocrine glands
- Hypothalamus secretes dopamine
- Adrenal Gland secretes cortisol and adrenaline
- Thyroid Gland secretes thyroxine
- Ovaries secretes oestrogen and progesterone
- Testes secretes testosterone
Fight or Flight
- Give an example off this and systems used
- Explain stages of the response till it ends
- Endocrine system and Autonomic Nervous System (ANS) can work in parallel
- An example of this is during a stressful event
- Stressor introduced, amygdala (area of brain) associate’s situation with emotional response
- Amygdala sends signal to Hypothalamus
- Hypothalamus activates Sympathetic Nervous System, used to send signal to adrenal medulla
- ANS goes from resting state (Parasympathetic) to a physiologically aroused state (Sympathetic)
- Adrenaline released from adrenal medulla (Part of adrenal gland near kidneys) into bloodstream
- Physiological changes in body (Increased heart rate) creates physiological arousal for fight or flight response
- When threat passes, parasympathetic branch of ANS reverses changes bringing body back to normal resting state
Evaluation for Fight or Flight response
- FR|BB&A|MR
- Not just fight or flight response (Gray 1988)
- Beta bias and Androcentrism (Taylor et al)
- Fight or Flight is a maladaptive response
Not just fight or flight response (Gray 1988)
- In stressful situation, not limited to F or F, some psychologists suggest an initial “freeze” response
- Gray (1988), suggested first response to danger is to avoid confrontation altogether, demonstrated by freeze response
- During this response, animals and humans are hyper-vigilant whilst assessing situation to decide best course of action for particular threat
- Suggests that the F or F response is not complete, does not tell us all the steps taken in a stressful situation
Beta bias and Androcentrism (Taylor et al)
- Early research typically conducted on only men (androcentrism), generalised universally (including women)
- F or F response typically M response to danger, more recent research suggests F adopt a “tend and befriend” response
- Taylor et al (2000), women more likely to protect offspring (tend), form alliances with other women (befriend) rather than fighting or fleeing
- Women’s response to stress is to produce more oxytocin (love hormone), this reduces F or F and enhances tend and befriend, it is an evolved response
- Suggests that research did not take the differences between the two genders into account, beta bias, assumed they both responded in the same way to stress/danger
Fight or Flight is a maladaptive response
- Maladaptive just means an adaptation that is more harmful than helpful
- F or F may have been useful for our ancestors that had to face life-threating situations (predators), modern day life rarely requires such an intense bio response
- Stressors of modern-day life activate this response, can have negative consequences to health
- For example, individual daces a lot of stress, continually activates Sympathetic NS, increases their blood pressure, can cause damage to blood vessels, can obtain heart disease
- Suggests that this response is maladaptive in the modern day, it does more harm (blood pressure) than good because we don’t really need it anymore, more often than not its activated when it is not needed
Neurons
- What are neurons?
- What does this provide to the NS?
- Million’s neurons in brain, 80% located in Brain
- Neurons are nerve cells process and transmit messages electrically and chemically through signals
- Gives NS primary means of communication
Types of Neurons
- What are the three types of neurons?
- What do they do?
- Three Types of Neurons- Motor, Sensory and Relay
- Motor Neuron- Connects CNS to effectors (Muscles & Glands), short dendrites long axons
- Sensory Neuron- Carries messages from PNS to CNS, Long dendrites short axons
- Relay Neuron- Connect sensory to motor or other relay, short dendrites short axons
Structure of Neurons
- Fill in image
- Describe each part
- Cell body contains nucleus (contains genetic material of cell)
- Dendrites carry nerve impulses from neighbouring neuron towards cell body
- Axon carries impulses away from cell body
- Covered in myelin sheath which protects, speeds up transmission of impulse
- Nodes of Ranvier are the segmented gaps between myelin sheath
- Speed up transmission because impulse jumps across gaps along axon
- Terminal buttons located end of axon communicate with next neuron in chain across synapse (Gap between neurons)
Location of Neurons
- Where are each located?
- Motor neurons in CNS may have long Axons that form part of PNS
- Sensory Neurons in PNS in clusters (Ganglia)
- Relay Neurons (97% all neurons) in Brain and visual system
Electrical Transmission (Firing of Neuron)
- What does “Firing of Neuron” mean?
- Describe the steps
- What is action potential?
- What does this do?
- When neuron in resting state, inside of cell negatively charged
- When activated, inside cell positively charged for split second
- Causes an action potential (spike in electric charge) to occur
- Action potential creates an electrical impulse, this travels down axon towards end of neuron
- Firing refers to if the electrical impulse continues down next neuron when received
Chemical transmission
- How do neurons communicate?
- How are signals transmitted with neurons?
- How are signals transmitted between neurons?
- What happens when signal reaches the end of the neuron?
- Neurons communicate within groups known as Neural networks
- Signals within neurons transmitted electrically
- Signals transmitted between neurons transmitted chemically across synapse
- When electrical signal reaches end of neuron (presynaptic terminal) neurotransmitters released from synaptic vesicles (tiny sacs)
Neurotransmitters
- Fill in the image
- What are neurotransmitters?
- How are they used to transfer signals between neurons?
- Describe Synaptic Transmission
- Where are neurotransmitters found?
- They are chemicals that diffuse across synapse to next neuron
- The following are the steps of Synaptic Transmission
- Once synapse crossed Postsynaptic receptor sites (located on dendrites of next neuron) receives them
- Postsynaptic receptor sites convert chemical message back into electrical impulse
- Process of transmission begins again in this other neuron
- Direction is one way
- Neurotransmitters have been identified in Brain, Spinal Cord and some Glands
- Molecular structure fits perfectly with postsynaptic receptor sites (Lock and Key)
- Have specialist functions (Acetylcholine causes muscles to contract)
Excitation and inhibition
- What is excitation?
- What is inhibition?
- How does this relate to the firing of neurons?
- Neurotransmitters has either excitatory of inhibitory effect on neighbouring neuron
- Serotonin inhibition in receiving neuron, neuron more negatively charged, less likely to fire
- Adrenaline excitation of postsynaptic neuron, increases its positive charge, more likely to fire
Summation
- What is this process determining?
- Describe the process
- When is the action potential of the postsynaptic neuron triggered?
- Whether postsynaptic neuron fires (sends electrical impulse down neuron) decided by this process
- Excitatory inhibitory influences summed; net effect calculated
- Net effect excitatory more likely to fire (Inside of postsynaptic neuron momentarily becomes positive)
- Net effect inhibitory less likely fire
- Once electrical impulse created it travels down neuron
Lateralization VS Localisation
- What is Lateralization?
- What is Localisation?
- Localization is the idea that different areas of the brain are responsible for certain actions and behaviours
- Lateralization is the localization of a function on one side of the body
Localisation Vs Holistic Theory
- What research argues for localisation?
- What is the holistic theory of how the brain functions?
- Broca and Wernicke argued for localisation of function (cortical specialisation)
- Idea that different parts brain, different tasks involved different parts body
- If area damaged function associated with area also affected
- Before this scientists supported the holistic theory that all parts of the brain are involved in processing thoughts and actions
Hemispheres of the brain
- What does the Left Hemisphere control?
- What does the Right Hemisphere control?
- What is the Left Hemisphere linked to?
- What is the Right Hemisphere linked to?
- Left side of body controlled by right hemisphere
- Right side of body controlled by left hemisphere
- Physical, psychological functions controlled by particular hemisphere (Lateralisation)
- Language linked to left hemisphere
- Image processing linked to right hemisphere
The Motor, Somatosensory, Visual and Auditory Centres
- What are the four “lobes”?
- What areas are located at these “lobes”?
- What do these areas do?
- Cortex subdivided into four centres (“Lobes”)
- Frontal, Parietal, Occipital, Temporal Lobes
- Lobe associated different functions
- Back of Frontal Lobe- Motor area, controls movement in opposite side of body
- Front of Parietal Lobe- Somatosensory area, where sensory info from skin represented
- Occipital Lobe located back of brain, visual area (visual cortex), sends info from left visual field to right visual cortex vice versa
- Temporal Lobe-Auditory area, analyses speech-based info
Language centres of brain
- What is the area located in the left frontal lobe?
- What is the area located in the left temporal lobe?
- What are these areas responsible for?
- What are the effects when these areas are damaged?
- Language restricted to left side of the brain
- Broca identified “Broca’s Area”, located left frontal lobe responsible for speech production
- When damaged speech is slow, lacks fluency, difficult to come out
- Wernicke identified “Wernicke’s Area”, located in left temporal lobe, responsible for language understanding
- When damaged individual gets Wernicke Aphasia
- Produce nonsense words, fluent speaking that’s meaningless
Evaluation for Localisation
- Evidence from neurosurgery (Scientific Credibility)
- Evidence from Brain Scans (Scientific Credibility)
- Counterpoint (Distributed not localised)
- Language localisation questioned
- Case Study Evidence
- Counterpoint (Generalisation)
Evidence from neurosurgery (Scientific Credibility)
- Damage areas of brain linked to mental disorders
- When specific area of brain targeted, procedure successful
- Suggests behaviours associated with serious mental disorders may be localised
Evidence from Brain Scans (Scientific Credibility)
- Evidence everyday brain functions are localised
- During procedures, Wernicke’s area active when doing listening task (understand what they are being told)
- Broca’s area active during reading task
- Review of LTM revealed episodic semantic memories stored different parts of prefrontal cortex
- Objective methods for brain activity provide scientific evidence brain functions localised
Counterpoint (Distributed not localised)
- Some Psychologist removed areas of cortex (10% to 50%) in rats that were learning route of maze
- Learning seemed to require every part of cortex rather than particular area
- Higher cognitive process not localised, distributed (Holistic)
Language localisation questioned
- Language may not be localised to just Broca’s and Wernicke’s Area
- Advancement in brain imaging (fMRI) gives us more clarity
- Language function distributed more holistically
- Language streams identified across cortex
- Language may be organised more holistically contradicts localisation theory
Case Study Evidence
- Gage, had rod through most of his left frontal lobe
- Went from calm and reserved too quick-tempered and rude
- Suggests Frontal lobe responsible for regulating mood
Counterpoint (Generalisation)
- Case Study difficult to become generalised
- Subjective interpretation of researcher
Hemispheric Lateralisation
Definition- Idea hemispheres functionally different, certain mental processes behaviours controlled mainly by one hemisphere
Left and Right Hemispheres
- Where are the language centres located?
- What does the right hemisphere contribute?
- Which functions are lateralized?
- Which functions are not lateralized?
- Language centres only in left hemisphere
- Language therefore lateralized (One side/hemisphere of body)
- Right hemisphere can produce basic words and phrases, contributes emotional context
- Vision, Movement, Somatosensory not lateralized (On both sides/hemispheres of body)
Split Brain Research
- What does this research show us?
- What disorder is this linked to?
- Which part is severed?
- Corpus callosum severed, reduces epilepsy
- Epilepsy electoral activity travels one hemisphere to other, to reduce this, connections cut
- Brain “split” two halves, study shows us how hemispheres function without communicating with each other
Sperry’s Research
- Procedure
- Findings
- Conclusions
System to study how separated hemispheres deal with speech and vision
Procedure
* 11 People who went through split brain surgery studied using special setup
* LVF had image or word projected (RH would process) vice versa
Findings
* Picture shown in RVF (Processed in LH) could describe what they saw
* Shown in LVF (Processed in RH) could not do this
* Instead, could select matching object or in close relation (Ashtray–>Cigarette) using left hand
* Could draw image with left hand when seen in LVF (Processed in RH)
* Emotional Reaction (Giggle) when shown picture in LVF (Processed in RH)
* However, reported not seeing anything, “Flash of light”, “Nothing”
Conclusions
* Certain functions lateralised
* Supports view LH verbal RH “silent” but emotional
Evaluation for Lateralization
- Lateralisation in the connected brain
- Left or Right Brained people notion incorrect
- Lateralisation Vs Plasticity
- Research Support (Recent split-brain research)
- Generalisation Issues
- Ethics
Lateralisation in the connected brain
- Fink et al (1996)
- Strength, two hemispheres process information differently
- PET Scans used identify what part brain active when looking at picture of forest
- Looking at whole picture RH more active
- Focusing on finer detail (Individual tree) LH tended to dominate
- Suggests as far as visual processing concerned hemispheric lateralisation is a feature of a connected and split brain
Left or Right Brained people notion incorrect
- Nielsen et al (2013)
- Limitation, LH analyser RH synthesiser may be wrong
- Research suggests no dominant side which creates different personality
- Analysed Brain scans 1000 people, 7-28 (Good sample size and age range)
- Certain hemispheres were used for certain tasks (Evidence for Lateralisation)
- No evidence for dominant side (Maths Brain, Artist Brain)
- Suggest right left brained people is wrong
Lateralisation Vs Plasticity
- Rogers et al (2004)
- Lateralisation adaptive, two tasks performed simultaneously, greater efficiency
- Lateralised chickens, find food, watch for predators, “normal” could not
- Plasticity adaptive functions taken over non-specialised area opposite hemisphere
- Lateralization first preference (worth having if you can) but ultimately plasticity is more important
- This is the case because it deals with brain damage
Research Support (Recent split-brain research)
- Split brain performs better than connected on certain tasks
- Identify anomaly faster
- In normal brain, LH better cognitive strategies watered down by inferior RH
- Supports Sperry’s earlier findings, Left and right brain distinct
Generalisation Issues
- Casual relationships hard to establish
- Compared to neurotypical control group
- Nobody in control group had epilepsy (Confounding variable)
- Differences / Unique functions of cognitive abilities could be epilepsy not split brain