Biopsychology Flashcards
What does low levels of serotonin mean?
Depression
What do high levels of dopamine mean?
SZ (type 1)
What do high levels of melatonin mean?
Sleepiness
What does high adrenaline mean?
Stress
Parts of the brain and it’s functions (6)
Frontal lobe - thinking,memory, behaviour and movement
Temporal lobe - hearing, learning and feelings
Brain stem - breathing, heart rate and temperature
Cerebellum - balance and coordination
Occipital lobe - sight
Parietal lobe - language and touch
What is a genotype?
They only determine the potential for characteristics genetic makeup.
What is a phenotype?
The observable characteristics of an individual depend on the interaction of genetic and environment factors.
Overview of the endocrine system
- Endocrine system is separate from the nervous system, although the two work together.
- It works with the nervous system to control the vital functions in the body. The endocrine system acts more slowly than the nervous system, but has very widespread and powerful effects.
- The main aim of the endocrine system is to maintain homeostasis.
What are hormones?
- The chemicals circulate in the blood and carry them to the target sites throughout the body.
- A given hormone usually affects only a limited number of cells nearest target cells.
- There has to be particular receptors for particular hormones, so they don’t have such a receptor cannot be directly influenced by that hormone.
- When enough receptor sites are stimulated. This results in the physiological reaction to go to target cell.
Pituitary gland
- Next to the hypothalamus
- Secretes LH and FSH which stimulate the ovaries to produce oestrogen and progesterone and testes to produce testosterone and sperm.
Adrenal gland
- On top of each kidney
- Secretes adrenaline - prepares the flight or fight response
Testes
- In the scrotum
- Secretes testosterone
Ovaries
- In the uterus
- Secretes oestrogen and progesterone - controls the menstrual cycle.
Thyroid gland
- Below the Adam’s apple
- Secretes thyroxine - controls the rate of metabolism
Thymus gland
- Above the heart
- Secretes thymosin - stimulates development of T cells
- Part of the immune system and functioning
Pancreas
In the pancreas
- Secretes insulin and glucagon which regulates the blood sugar
Pineal gland
- In the brain next to the thalamus.
- Produces melatonin which helps regulate the wake-sleep cycle.
What it is the CNS
The Central nervous system consists of the brain and spinal cord.
What it is the PNS?
The peripheral nervous system is everything apart from the CNS.
Nervous system
CNS - PNS
|
SNS ANS
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Sympathetic - Parasympathetic
Localisation of function of brain:
The brain has a particular part that is in charge of a specific behaviour.
Franz Gall’s theory:
Phrenology (looking at the structure of the skull to determine a person’s character) was influential, but quickly discredited.
Phineas Gage:
- Provided evidence for localisation of function.
- Prior to accident was nice/friendly.
- After accident he was mean/aggressive, different character.
- Pole went through the top of his brain.
Corpus Callosum
Bridge between the 2 hemispheres.
Motor cortex:
- Located in frontal lobe, both hemispheres.
- Allows to produce voluntary movement, sends info out.
- Damage (stroke/accident) to this area results in loss of control over fine movements.
- Different parts of the motor cortex control different parts of the body.
- These are arranged logically - the region that controls the foot is next to the region that controls the leg.
Somatosensory cortex:
- Detects sensory events, dedicated to the processing of sensory info related to touch.
- Uses sensory info to produce sensations such as: touch, pressure, pain, temperature.
- The amount of somatosensory area devoted to a particular body part denotes its sensitivity. Receptors in our face + hands occupy over 1/2 of the somatosensory area,
Visual centres:
- Located in the occipital lobe.
- Visual processing begins in the retina.
- Nerve impulses from the retina travel to areas of the brain via the optic nerve.
- Some travel to areas of the brain involved in coordination of circadian rhythms.
- Most terminate in thalamus, this acts as a relay station passing info to visual cortex.
- Each eye sends info from the right visual filed to the left visual cortex and the other way. This means damage to the left hemisphere can produce blindness in the right visual field.
- Visual cortex contains different areas that process different types of visual info such as colour, shape, movement.
Auditory cortex:
- In temporal lobes on both sides of the brain.
- Begin in cochlea in inner ear, sound waves are converted to nerve impulses.
- These travel via the auditory nerve to the auditory cortex.
- Pit stop at the brain stem where basic decoding happens.
- Then at the thalamus which acts as a relay station and carries out further processing of auditory stimulus.
- Stops at the auditory cortex.
- Sound has already been largely decoded by this point, in the auditory cortex is recognised and may result in an appropriate response.
- Damage may produce partiL hearing loss; the more extensive the damage, the more extensive the hearing loss.
Karl Lashley, evidence against localisation:
- Taught rats to do a maze quickly.
- Started destroying parts of the cortex, the the rats still retained parietal memory of the maze.
- He concluded that memory was not localised, but lies in a number of locations.
- No area was proven to be more important than any other.
- Called this the law of mass action.
Evaluation of localisation:
• Functions such as language are too complex to be assigned to just one area and instead involve networks of brain regions.
• Issues generalising from case studies or from ‘abnormal’ patients
• Issues with generalising from studies with small participant numbers
• Lashley proposed the equipotentiality theory, which suggests that the basic motor and sensory functions are localised, but that higher mental functions are not.
• Tulving et al (1994) revealed semantic and episodic memories reside in different parts of the prefrontal cortex.
Broca’s area:
- An area of the frontal lobe of the brain in the left hemisphere (in most people) responsible for speech production.
- Production of articulate speech, clear and fluent.
- Moves the muscles that are required to speak.
- Involved in analysing the grammatical structure of sentences, helps us extract meaning from language.
Discovery of Broca’s area:
- 1880’s
- Paul Broca identified small area in the left frontal lobe responsible for speech production.
- Treated patient call ‘Tan’ and other 8 patients with similar language deficits.
- All of them agreed to give their brain to Broca to analyse post-mortem.
- Neuroscientist have found that when people perform cognitive tasks (no language/speaking) their Broca is active.
Dronkers et al:
- Conducted MRI scan on Tan’s brain, trying to confirm Broca’s findings.
- Although there was a lesion found in Broca’s area, they also found evidence to suggest other areas may have contributed to the failure in speech production.
- These results suggest that the Broca’s area may not be the only region responsible for speech production and the deficits and found in patients with Broca’s aphasia could be the result of damage to other neighbouring regions.
Wernicke’s area:
- An area of the temporal lobe in the left hemisphere responsible for language comprehension.
- Vital for locating appropriate words from memory to express meaning.
Discovery of Wernicke’s area:
- Identified patients who had no problem pronouncing language but severe difficulties understanding it.
- Wernicke’s proposed that language involves separate motor and sensory regions located in different cortical regions.
- There is a neuro pathway between Broca’s and Wernicke’s area.
Turk et al:
- Discovered a patient JW, who suffered damage to the left hemisphere but developed the capacity to speak in the right hemisphere, eventually leading to the ability to speak about the information presented to either side of the brain.
• This suggests that perhaps localisation is not fixed and that the brain can adapt following damage to certain areas.
Localisation:
How much any one function is located more in one hemisphere than the other.
Frontal lobe:
- Movement
- Consciousness
- Speech production
- Personality
Parietal lobe:
- Perception
- Sensory information (5 senses)