BIOPSYCHOLOGY (NEURONS AND SYNAPTIC TRANSMISSION (Sensory Neuron
FIGHT OR FLIGHT
Acute stress (Fight or Flight)- occurs when we register a stressful event.
1) Hypothalamus is activated by amygdala (part of the limbic system).
2) this activates the Automatic Nervous System (sympathetic + Parasympathetic)
3) SNS is activated sending messaged to prepare for the whole of the body.
4)Signals adrenal medulla to release adrenalin.
5)Then the Parasympathetic nervous system is causing the body to go back to normal.
-ncreases breathing rate
-Increase heart rate
-Blood flows away from surface
-Decrease breathing rate
-Decrease heart rate
-Inhabits saliva production
Stress comes from an evolutionary defensive measure against danger.
Stress is the perceived ability to cope vs the demand of the task.
There are 2 different types of stress
- Acute stress occurs when the stressor is short lasting i.e giving a speech.
- Chronic stress occurs when stressor lasts a long period of time i.e a long-term illness.
The nervous system is a speicalised network of cells in the human body and is our primary internal communication sysrem. It has 2 main functions
- To collect, process abd respond to information in the environment.
- To co-ordinate the working of different organs and calls in the body.
Central Nervous System
-Center of conscious awareness
-Outerlayer+ Cerebral cortex, highly developed in humans.
-the brain is divided into 2 hemispheres.
- An extension of the brain
- Responsible for reflect actions ie pulling away from something hot.
- It passed messages to and from the brain and connects nerve to PNS
Peripheral nervous system (Automatic nervous system + Somatic Nervous system)
Automatic nervous system
-governs vital function in the body such as breathing, heart rate, digestion, sexual arousal + stress.
Somatic nervous system
-Controls muscle movement + receives information from sensory receptors.
-Works withe the nervous system to control vital function in the body.
-Glans produce hormones
-Hormones are secreted into the blood stream ad affect and cell in the body that has a appropriate receptor.
- Thyroid gland produces thyroxine, this affects cells in the heart, also increase metabolic + growth rates
- Pituitary glans controll release of hormones and is in the Brian.
- Adrenal gland produces adrenaline, effects whole body such as cardiovascular system.
INVESTIGATING THE BRAIN
Functional Magnetic Resonance Imaging (fMRI)-
Detects the changes in blood oxygenation and flow.
Created a 2D black and which picture of different levels in the brain
Event- Related Potentials (ERPs)
- Measure electrical activity but focus of brain, get rid of extranous variables.
These are linked to cognitive process such as attention + perception.
Electrical activity within the brain via electrode fixed on subjects scalp, recording brain waves.
Used as a diagnostic tool to detect any unusual arrhythmic patterns of activity.
Female Menstrual cycle - Time between first day of period to the day before her next period. (24-35 days)
Oestogen levels rais causing overy to release eggs.
After ovulation progesterone help the womb lining to grow thicker.
Period affected by exogenous factors (cycle of other women)
He took 29 woman with a history of irregular periods. Sampling 9 of the women's pheromones at stage of menstrual cycle via a rotten pad on their armpit. Cycles because closer.
Sleep-wake cycle- Governed by Suprachiasmatic nuclei (SCN), found in the hypothalamus. It detects levels of light (exogenous zeitgebers) and adjusts our sleepiness.
Siffre -stayed in a cave for several months, getting rid of all natural light and sound(Exogenous zeitgbers). He found that sleep cycle was 25 hours and it was regular.
Aschoff + Weaver- Got 4 participants in a ww11 bunker deprived of natural light. All but 1 displayed a circadian rhythm,
Folkard- 12 people in a dark cave for 3 weeks. They speed up the clocks displayed, by the end of 3 weeks 'a day' was 22 hours. not one of the participants were able to adjust comfortably.
All organism are subject to biologival rhythms. All Biological rhythms are governe by 2 things:
1)The bodys internal biological clock(endogenous pacemaker)
2) External changes in the environment (exogenous zeitgebers).
-Suprachaismatic nucleus (SNC) bundle of cells.
DeCoursey destroyed SCN in 3 chipmunks who were then returned and observed in habitat for 80 days, Sleep wake cycle destroyed.
Pineal gland + Melatonin-
Lack of light in optic chasm in SCN pineal gland produces melotonin (induces sleep). Light then alerts the SCN through the optic chiasm, pineal gland inhabits melitonin.
External factors in the environment that reset out biological clocks through a process humans as entrainment.
Key zeigtgeber, can reset the body but activating SCN
Cambell + Murphy, skin can detect light when eyes are covered. They shined a flashlight on a participant on the black of the knees.
Sleep wake cycle is random for baby's, at 6 w the cardian rhythm begins and by about 116 weeks most baby's are given schedules, meal + bed time.
fMRI -SUP. Doesn't use radiation.+ High spatial resolution
LIM. Can only measure blood flow, cannot hone in on individual neurons. + Person has to stay completely still (Poor temporal resolution).
EEG- SUP. High temporal resolution. + Important in diagnostic condition such as epilepsy.
LIM. Cannot pinpoint the exact source of neural activity
EPRs- SUP. Excellent temporal resolution. Has helped researchers identity types of ERP and their role.
LIM. Background noise + extraneous material much be eliminated. + Lack of standarrdiation
Post- Mortem - SUP. Built current foundation of knowledge.
LIM. Ethical issue, consent. + Observed damage may be due to decay of brain
SUP, Phantom Lim Syndrome- When brain rewires it self it have have maladaptive behavioural consequences.
Individual difference, Cognitive reserve, the idea that a better education they greater the chance of being disability free recovery. 40% patients who studies who achieved FDR had more that 16 y education.
APP. Neurorehabilitation. Pysio therapy, retrain brain.
SUP, Scientific, lab experiment, standardise procedures.
LIM, W don't know if results are due to operation on corpus callosum or due to the epilepsy.
Plasticity, - Recruitment of Homologous areas. Jody Lee
SUP. Rem sleep. Recorded(EGG) brainwaves of 9 people sleeping, controlling EV (coffee+ alcohol). REM was highly correlated with dreams. Scientific evidence.
LIM. Tucker, found individual difference in sleep cycles, but were consistent.
LIM, to many factors affecting menstrual cycle(stress). + Small sample of women.
APP. Photo-therapy. Using strong lights in evening/morning to change level of serotonin. Lights between 6,000-10,000 lux =day light. Revealed 60% of users symptoms
placebo affect 30% reported symptoms reduced.