Biopsychology Flashcards
Purpose of Nervous System
Primarily involved in taking info in from our environment and ensuring an appropriate response is carried out
Central Nervous System
Brain & Spinal Cord
Peripheral Nervous System
Nerves & Ganglion cells
Role of Central Nervous System
Where all complex processing & decision making is done
Role of Peripheral Nervous System
Brings info from the senses to the CNS & transit info from the CNS to the muscles & glands
Brain’s role in CNS
Command centre: recieves signals from sensory organs & outputs info to the muscles
4 Lobes of the Brain
Frontal, Temporal, Parietal, Occipital
Spinal Cord’s role in CNS
Sends messages to and from our brain:
- spinal cord sends messages that it has RECIEVED from our ENVIRONMENT to our BRAIN
- sends messages from our brain to tell our body HOW TO REACT
Parts of PNS
Autonomic Nervous System - involuntary actions (breathing/heart rate/digestion)
ANS includes sections: SYMPATHETIC & PARASYMPATHETIC
Somatic Nervous System - voluntary actions (muscle movement)
Sympathetic Branch
Fight or Flight - expanding energy
Parasympathetic Branch
Regular Functioning - saving and restoring energy
Endocrine System
A network of glands that release hormones into the blood stream, working alongside the nervous system to control body’s vital functions
Gland
An organ in the body that synthesises substances such as hormones
Hormone
Chemical substance that circulate in the bloodstream & only affect the target organs
Thyroid’s Main Hormone & Effect
THYROXINE - Regulates body’s metabolic rate
Adrenal Cortex’s Main Hormone & Effect
GLUCOCORTICOIDS (E.G CORTISOL) - Further release of stored glucose & fats for energy, suppression of immune system
Adrenal Medulla’s Main Hormone & Effect
ADRENALINE/NORADRENALINE - Fight or Flight response, increased heart rate & blood flow to brain and muscles
Testes’s Main Hormone & Effect
ANDROGENS (E.G. TESTOSTERONE) - development of male sexual characteristics at puberty, promotes muscle mass & growth
Ovaries’s Main Hormone & Effect
OESTROGEN - regulation of female reproductive system, menstrual cycle & pregnancy
Pineal’s Main Hormone & Effect
MELATONIN - regulation of arousal, biological rythms & sleep-wake cycle
Pituitary Gland
MASTER GLAND - as any of the hormones it secretes control the secretions of other endocrine glands (makes sure everything is working properly)
Fight or Flight Response
A response to stress, the body becomes physiologically aroused in readiness to fight or flea from an aggressor
Sympathetic NS’s effects during Fight or Flight
- slows digestion
- inhibits saliva production
- increases heart rate & breathing rate
- dilates pupils
Neurons
Nerve cells carry messages to & from the CNS
- use electrical impulses and chemical signals to transmit info between DIFFERENT AREAS IN THE BRAIN & between the BRAIN AND REST OF CNS
Sensory Neuron
Convert external stimuli from environment to corresponding internal stimuli, carrying messages from the PNS to the CNS (long dendrites/short axons)
Relay Neuron
Transmits information between neurons to allow communication between different parts of the CNS (short dendrites/short axons)
Motor Neuron
Connect the CNS to the effectors such as muscles & glands (short dendrites/long axons)
Synapse
Gap betweeen pre/post synaptic neuron
Neurotransmitter
Found in vesicles
Excitatory
More likely to fire across the synpase
Inhibitory
Less likely to fire across the synapse
Synaptic Transmission
Movement of NTs over synapse to receptor sites
Localisation
Certain parts of the brain have allocated functions
Cerebral Cortex
Outer layer of tissue in the brain, regarded the most important structure in the brain
4 Lobes’ primary cortexes
Frontal - Primary Motor Cortex
Parietal - Primary Somatosensory Cortex
Occipital - Primary Visual Cortex
Temporal - Primary Auditory Cortex
Frontal Lobe
Motor area which controls voluntary movement in the opposite side of the body
Parietal Lobe
Somatosensory areas that is separated from the motor areas by the central sulcus, area where sensory info is represented & over half of somatosensory area is for the hands and face
Occipital Lobe
Visual area where each eye sends information to the visual cortex through either the dorsal stream or ventral stream
Dorsal Stream
Where something is, tells us about our environment and how to interact with it (planning movement) - goes to parietal lobe
Ventral Stream
What something is and recognition of objects - goes to the temporal lobe where long-term memories are stored
Temporal Lobe
Auditory area which analyses speech based info
Broca’s Area
Study of ‘Tan’ - discovered a small area in the left frontal lobe responsible for speech production, SPEECH PRODUCTION
Wernicke’s Area
Found patients could produce speech that was flawless but meaningless, SPEECH COMPREHENSION
Hemispheric Lateralisation
Idea that two halves of the brain are functionally different & that certain mental processes and behaviours are mainly controlled by one hemisphere
Split Brain Research
A series of studies that began in the 1960s involving patients with epilepsy who experienced a surgical separation of the two hemispheres
Vision Lateralisation
Vision isn’t lateralised as it appears in both hemispheres (it’s contralateral & ipsilateral)
- Each eye recieves light from the LVF & RVF (linked to depth perception)
Contralateral
In brains where the function is cross-wired
Ipsilateral
In brains where the function isn’t cross-wired, they’re the same sides
Corpus Callosotomy
Procedure that is performed to cure life-threatening epilepsy and involves severing the corpse collossum
Sperry & Gazinga
Conducted many different experiments:
- describe what you see
- tactile test (select object from a group)
- drawing task (draw object)
Sperry Findings - Describing
Found that when a picture was shown in LVF, the patient couldn’t describe it with spoken language
Sperry Findings - Tactile
Found that when patients saw something in left eye, they couldn’t talk but could identify it unconsciously
Sperry Findings - Drawing
Found that the left hand would draw clearer pictures than the right hand
Traumatic Brain Injury
Something external that causes the brain to move inside the skull or damages the skull (e.g. blow to the head)
Acquired Brain Injury
Occurs on a cellular level, most often associated with pressure on the brain (e.g. from a tumour/stroke/infection)
Plasticity
Brain can adapt/change neural pathways and functions as a result of experience and new learning
Functional Recovery
A form of plasticity where the brains ability to redistribute or transfer functions usually performed by a damaged area to another undamaged area
Maguire’s research into plasticity
Black Cabs - The knowledge
- found those who took it had a larger posterior hippocampus than controls
Hemispherectomies
Complete removal of a hemisphere, and usually the other hemisphere can take on many of the functions lost from this removal
Axonal Sprouting
The growth of new nerve endings which connect with other undamaged nerve cells to form new neural pathways
Recruitment of Homologous Areas
Areas on the opposite side of the brain to perform specific tasks
Summation
The process of coming to a decision of whether there’s more of a pos/neg charges
fMRI - AO1
Detects change in blood oxygenation & flow that change due to neural activity
Brain active = consumes more oxygen = fMRI detects activity
fMRI - Strengths
- Non-invasive & doesn’t involve radiation
- Virtually risk-free
- High spatial resolution
- Easy to use
fMRI - Limitations
- Expensive
- Poor Temporal Resolution
- Image is only clear if the person stays still
EEG - AO1
Measures brain waves through the masurement of electrical activity of the brain (electrodes placed on scalp)
EEG - Strengths
- More accessible than fMRI & helpful in understanding and diagnosing epilepsy
- High temporal resolution (unlike fMRI)
EEG - Limitations
- Not useful for exact sources of activity/lacks specificity
- Cannot distinguish between activites that started in different, adjacent areas
ERP - AO1
Use similar equiptment to EEG but uses a stimulus that is presented to the PP, with the researcher looking for brain activity related to that stimulus. Response is graphed using a statistical averaging technique that filters out extraneous brain activity
ERP - Strengths
- Addresses EEG’s lack of specificity with more exactness to the measurements of neural processes
- High temporal Resolution
ERP - Limitations
- Lack of standardisation between different reserach studies
- Studies require complete removal of background noise & extraneous material, as they could lead to errors & flaws in ther measurement
Post-Mortems - AO1
Study of the physical brain of a person who displayed a particular behaviour that suggested possible brain damage when they were alive
Enables researchers to examine deeper regions of the brain & find the possible cause of death
Post-Mortems - Strengths
- Detailed anatomical & neuroichemical examinations
- Can access areas like the hypothalamus and hippocampus which other techniques cannot access & provide greater insight
Post-Mortems - Limitations
- Requires informed consent
- Damage to the brain may not be linked to deficits under review but other unrelated trauma/decay (innacurate)
- Invasive
Types of Biological Rhythms
Circadian Rhythms
Ultradian Rhythms
Infradian Rhythms
Circadian Rhythms
A cycle which lasts for 24 hours
SLEEP-WAKE CYCLE
Sleep-Wake Cycle
The pattern of when someone is awake and when they are asleep, usually following a pattern of 16 hours awake, with 8 hours asleep
Is influenced by Internal & External Factors
Internal Factors of SW Cycle
- Lowered Body Temperature
- Lose energy
- Melatonin released by the pineal gland
External Factors of SW Cycle
- Light
- Noise
- Location
- Temperature
Light in SW Cycle
Provides the primary input to this system - acting as the external cue for sleeping or waking.
- Light is first detected by the eye, which then sends messages concerning the level of brightnmess to the suprachiasmatic nuclei (SCM)
- SCN uses this info to coordinate activity oif the entire circadian system
Homeostasis in SW Cycle
When an individual has been awake for a long time, homeostasis tells the body that there is a need for sleep because of energy consumption.
- This homeostatic drive for sleep increases throughout the day, and reaches its maximum in the late evening, when most people fall asleep
Ultradian Rhythms
Rhythms that take place for less than 24 hours
Nasal Cycle
Cycle of alternating breathing through each nostril over a length of up to 4 ours. The purpose is to help our sense of smeel, as the nostril that is breathing less allows for scents to be better detected by receptors
Sleep Cycle
Sleep is split into cycles of approx. 90 minutes in length that are composed of 5 stages
Infradian Rhythms
Cycles that occur over a period greater than 24 hours
Menstrual Cycle & SAD
Menstrual Cycle
Lasts approximately 28 days, this cycle occurs in all cultures and is controlled by hormones suggesting it’s biological in origin.
Seasonal Affective Disorder
Yearly cycle where some people become depressed as a result of the change in seasons
- Suggestred that melotonin, secreted by the pineal gland during the night is partially responsible. The lack of light in winter months results in a longer period of melotnin secretion which is linked to depressive symptoms
Endogenous Pacemakers
Internal mechanisms that govern biological rhythms, particularly the circadian sleep-wake cycle
- Can be altered and affected by the environment
Suprachiasmatic Nucleus
The master clock
- Tiny bundle of nerves located in the hypothalamus in each hemisphere of the brain
- Lies just above the optic chaism where it recieves info about light directly
- even when our eyes are closed it continues enabling the bio clock to adjust to changing patterns of daylight whilst we are asleep
EP: SCN’s Role in stages
- Eye detects low light levels
- Melanopsin carries signals to SCN
- SCN alerts the pineal gland to secrete melatonin
- Melatonin levels increase, inducing sleep
Exogenous Zeitgebers - light
Light can reset the endogenous pacemaker, the SCN and thus plays a role in the maintenance of the s/w cycle
- Has an influence on key processes that control functions such as hormone secretion & blood circulation
Exogenous Zeitgebers - social cues
Newborns: sleep/wake cycle is random
6 weeks: circadian rhythms begin
16 weeks: babies rhythms have been entrained by the schedules imposed by parents (like adults determining meal times and bedtimes)
JET LAG - research suggests that adapting to local times for eating and sleeing is an effective way of entraining circadian rhythms and beating jetlag when trabelling long distances
5 Stages of Sleep
1&2: light sleep: brain wave patterns become slower & more rhythmic (alpha waves > theta waves)
3&4: deep sleep: quite difficult to wake someone up (slower delta waves)
5: REM: body is paralysed and brain activbity resembles that of an awake person, where majority of dreaming takes place
Strengths of Localisation
- OCD Research (found activity in lateral frontal lobes & left hippocampal gyrus)
- Phineas Gage
Limitations of Localisation
- Lashley removed areas of cortex in rats (no area was more important to learn a route through a maze)
- Disk & Tremblay found that only 2% of modern researchers believe B&W’s areas are solely responsible for language
Strengths of Lateralisation
- Sperry’s research was one of the first of its kind & led to future groundbreaking research
- Uses highly specialised equipment & standardised procedures
- Fink used PET scans to identify brain area activity during a visual processing task. When looking generally, their RH was more active, when looking at specific areas their LH was more active
Limitations of Lateralisation
- Causal relationships are hard to establish as all ppts had epilepsy
Strengths of Plasticity & Functional Recovery
- ## Practical Application (neurorehabilitation)
Limitations of Plasticity & Functional Recovery
- Negative Consequences (phantom limb syndrome)
Strengths of Circadian Rhythms
- Siffre spent 6 months in a cave (24.9 hours)
- Miles et al. studied a blind man (24.9 hours)
- Silver et al. found hamsters circadian rhythms disappear when their SCN is damaged/removed
Limitations of Circadian Rhythms
- Duffy et al. suggest there are morning & evening people (innate differences in circadian rhythms)
Strengths of Ultradian Rhythms
- Controlled Lab Research
- Research suggests sleep patterns are adaptive (babies need more sleep)
- Uses EEGs & ERPs
Limitations of Ultradian Rhythms
- Assume dreams happen in REM (wrong)
Strengths of Infradian Rhythms
- Reinberg examined women in separate caves w/ only small lamp (shortened to 25.7 days)
- Russell et al found synchrony w/ sweat sampled (due to pheromones)
- Terman found the rate of SAD is more common in northern countries (where winter months are longer)
Limitations of Infradian Rhythms
n/a
Strengths of the Role of Endogenous Pacemakers
- DeCoursey destroyed the SCN connections in the brains of 30 chipmunks & returned them to their natural habitat, finding their s/w cycle disappeared & most died
Limitations of the Role of Endogenous Pacemakers
- Reductionist (can’t be studied in isolation, interactionist approach is required)
- Ethics (causes high levels of harm to animals used & can end up with them being killed)
Strengths of the Role of Exogenous Zeitgebers & S/W Cycle
- Crowley studied nightshift workers & found that bright lights during the night & sunglasses during the day can be used to alter rhythms
Limitations of the Role of Exogenous Zeitgebers
Miles studies a blind man w/ an abnormal circadian rhythm & found that despite his exposure to social cues, his s/w cycle couldn’t be adjusted
Strengths of Fight or Flight
n/a
Limitations of Fight or Flight
- Less useful for modern day
- Has negative effects on physical/mental health
- Androcentric Research
- Oversimplistic
Fight or Flight Process
- Threat is percieved by sensory receptors
- Amygdala sends a distress signal to the rest of the body & hypothalamus
- Hypothalamus releases CRH & switches from the PNS to the SNS
- Pituitary gland releases ACTH which triggers the adrenal medulla to release adrenaline
- Triggers fight or flight
Synaptic Transmission Process
- Impulse arrives at end of presynaptic terminal
- Triggers release of NTs from vesicles
- NTs diffuse across synapse & bind with receptors on postsynaptic neuron
