Chapter 1 - Biology and Behaviour Flashcards
Franz Gall
- phrenology: if a particular trait was well developed, the area of the brain responsible for that trait would expand, causing bulge on head
- measuring psychological attributes by measuring or feeling skull
- phrenology generated research on brain functions
Pierre Flourens
- first person to study functions of major sections of brain
- extirpation/ablation on rabbits and pigeons: parts of brain surgically removed and the behavioral consequences are observed
- led to understanding that specific parts of brain had specific functions, removal of one part weakens whole brain
William James
- founder of American psychology
- studied how mind adapts to environment
- foundation for functionalism: how mental processes help individuals adapt to their environment
John Dewey
- important name in functionalism
- criticized concept of reflex arc (process of reacting to stimulus in discrete parts)
- he believed psychology should focus on study of organism as a WHOLE as it functioned to adapt to environment
Paul Broca
- examined behavioral deficits of people with brain damage
- first to demonstrate that specific functional impairments could be linked with specific brain lesions
- Broca studied person who couldn’t talk and discovered that his disability was due to lesion in specific area on left side of brain now known as Broca’s area
Hermann von Helmholtz
- first to measure speed of nerve impulse
- related measured speed of impulse to reaction time, providing link b/w behviour and underlying nervous system activity
- early link b/w psychology and physiology, Helmholtz credited with transition of psychology into natural science
Sir Charles Sherrington
- inferred existence of synapses
- falsely thought that synaptic transmission was electrical process when it is primarily chemical
Human Nervous System
- 100 billion cells that communicate, coordinate, regulate signals for rest of body
- mental and physical action occurs when body reacts to external stimuli using nervous system
nerve cells - SENSORY NEURONS
AFFERENT neurons - Ascend in the cord toward the brain
- transmit sensory info from receptors to the spinal cord and brain
nerve cells - MOTOR NEURONS
EFFERENT neurons - Exit the cord to rest of body
- transmit motor info from brain and spinal cord to muscles and glands
nerve cells - INTERNEURONS
- found b/w other neurons
- most numerous
- mostly in brain and spinal cord
- linked to reflexive behaviour
reflex arcs
control reflexes
1. step on nail
2. receptors in foot detect pain
3. pain signal transmitted by sensory neurons up to spinal cord
4. sensory neuron connects w/ interneuron which relays pain impulses to brain
5. interneurons don’t wait, they send signals to muscles of both legs
6. person withdraws foot in pain
7. eventually OG sensory info reaches brain but muscles have already responded to pain
divisions of nervous system
CNS and PNS
CNS into brain and spinal cord
PNS into somatic and autonomic
autonomic into symp and parasymp
CNS - central nervous system
brain and spinal cord
PNS - peripheral nervous system
- nerve tissue and fibers outside of brain and spinal cord
- 31 pairs of nerves emanating from spinal cord called spinal nerves
- 12 pairs of nerves emanating from brain called cranial nerves
- olfactory and optic nerves part of PNS
-PNS connects CNS to rest of body
somatic nervous system
- sensory and motor neurons distributed through skin, joints, muscles
- sensory neurons transmit info toward CNS (afferent fibers)
- motor neurons transmit info from CNS to body (efferent fibers)
autonomic nervous system
- regulates INVOLUNTARY MUSCLES: heartbeat, respiration, digestion, glandular secretions
- regulates body temp by activating sweating
-autonomic=automatic, no conscious control needed
AUTONOMIC split into symp and parasymp (act in opposition so they are antagonistic)
sympathetic nervous system
- accelerate heart rate and inhibit digestion
parasympathetic nervous system
REST AND DIGEST
- decelerates heart rate and increases digestion
- conserve energy, associated with resting and sleeping states
- reduces heart rate, constrict bronchi, inhibits adrenaline production, contracts bladder
- manage digestion by increasing peristalsis and exocrine secretions
- neurotransmitter acetylcholine plays role
sympathetic nervous system
FIGHT AND FLIGHT
- activated by stress such as school assignments or life and death situation
- rage and fear reactions
- increase heart rate, blood flow to muscles of locomotion, increase blood glucose conc, relaxes bronchi, decreases digestion, dilates eyes to maximizebn bn light intake, releases epinephrine, stimulates orgasm, inhibits bladder contraction, stimulates sweating,
organization of brain
diff parts of brain p
forebrain (prosencephalon)
COMPLEX FUNCTIONS
cerebral cortex
thalamus
hypothalamus
lymbic system
basal ganglia
cerebrum
posterior pituitary gland
pineal gland
- developed after mid and hindbrain
- complex perceptual, cognitive, behavioural processes
- functions not absolutely necessary but associated with intellectual abilities of humans
during prenatal development, prosencephalon divides to telencephalon- cerebral cortex, basal ganglia, lymbic system and diencephalon - thalamus, hypothalamus, posterior pituitary, pineal gland
hindbrain (rhombencephalon)
BASIC SURVIVAL
pons
medulla oblongata
cerebellum
reticular formation
- located where brain meets spinal cord
- hindbrain controls balance, motor coordination, breathing, digestion, sleeping, walking
during embryonic development, rhombencephalon divides to form myelencephalon - medulla oblongata and metencephalon which becomes bons and cerebellum
meninges
thick, three-layered sheath of connective tissue help protect brain by keeping it anchored with skull
meninges reabsorb cerebrospinal fluid which is aq solution that nourishes brain and spinal cord and provides and protective cushion
OUTER LAYER - dura mater which is connected to skull bone
MIDDLE LAYER - arachnoid mater which is fibrous weblike structure
INNER LAYER - pia mater which is connected to brain
cerebrospinal fluid
produced by special cells that line ventricles of brain
dura mater
outer layer of meninges connected to skull bone
arachnoid mater
middle layer of meninges which is fibrous and weblike
pia mater
inner layer of meninges connected to brain
midbrain (mesencephalon)
inferior and superior colliculi - sensorimotor reflexes
- above hindbrain
- receives sensory and motor info from rest of body
- associated with involuntary reflex responses triggered by visual or auditory stimuli
- COLLICULI: 2 prominent nuclei
-superior colliculus receives visual sensory input
inferior colliculus receives auditory sensory input
brainstem
hindbrain + midbrain
limbic system
neural structures associated with emotion and memory
- agression, fear, pleasure, pain
cerebral cortex
- most recent evolutionary development of human brain which is outer covering of cerebral hemispheres
- associated w/ problem solving, language processing, impulse control, long-term planning
prenatal life
brain develops from neural tube
start off w/ 3 swellings (fore, mid, hindbrain) then hind and forebrain split into 2 swellings creating 5 total swellings
prosencephalon
forebrain
split into telencephalon and diencephalon
mesencephalon
midbrain
rhombencephalon
hindbrain
split into metencephalon and myelencephalon
medulla oblongata
lower brain structure responsible for regulating vital functions such as breathing, heart rate, digestion
emerged from myencephalon
pons
lies above medulla and contains sensory and motor pathways b/w cortex and medulla
emerged from metencephalon
cerebellum
maintains posture and balance and coordinates body movements
emerged from metencephalon
cerebral cortex
complex perceptual, cognitive, behavioural processes
basal ganglia
movement
limbic system
emotion and memory
thalamus
sensory relay station except smell
sorts impulses to appropriate areas of cerebral cortex
hypothalamus
hunger, thirst, emotion
homeostatic fxns
detects imbalances and signals body to correct them
inferior and superior colliculi
sensorimotor relfexes
from auditory and visual input
reticular formation
arousal and alertness
neuropsychology
study of functions and behaviours associated with specific regions of brain
RESEARCH - associating specific areas of brain to behaviour
CLINICAL - evaluations of patient cognitive and behavioural functioning and treatment of brain disorders
studying human brain lesions
pro: determining the functions of the brain bc damage to one part of brain is coupled with loss of the function
con: lesions of brain are rarely isolated to specific brain structures so pinpointing specific link b/w brain structure and function becomes difficult
studying brain lesions in lab animals
advantage: precisely defined brain lesiosn can be created in animals by extirpation or inserting tiny electrodes inside brain and selectively applying heat, cold, or electricity to specific regions
this has helped our understanding of comparable neural structures in humans
electrically stimulating brain +recording brain activity
- stimulate cortex with small electrode, causing groups of neurons to fire, activating the behavioral or perceptual processes associated with those neurons
- electrode stimulates neurons in motor cortex –> muscle movements triggered
- electrode stimulates visual cortex –>patient may see flashes of light not really there
cortical maps
created for patients when electrical stimulation is used
patient must be awake and alert, no pain receptors in brain so only local anesthesia required
electrodes in lab animals all used to elicit sleep, sexual arousal, rage, terror
electrodes off –>behaviours cease
EEG (electroencephalogram)
placing several electrodes on the scalp to detect, record, and study large groups of neurons and their electrical activity
noninvasive (doesn’t cause damage) so can be used with humans
research on sleep, seizures, and brain lesions relies heavily on EEgs
rCBF (regional cerebral blood flow)
- noninvasive
- detects broad patterns of neural activity based on increased blood flow to diff parts of brain
- rCBF relies on assumption that blood flow increases in regions of brain engaged in cognitive fxn
- measure blood flow: patient inhales harmless radioactive gas, and special device that detects radioactivity in bloodstream correlates radioactivity levels with regional cerebral blood flow
CT or CAT scan (computed tomography or computed axial tomography)
multiple x rays raken at diff angles and processed by computer to produce cross sectional images of the tissue
PET scan (positron emission tomography)
radioactive sugar injected and absorbed into body, and its dispersion and uptake throughout the target tissue is imaged
MRI (magnetic resonance imaging)
magnetic field that interacts w hydrogen atoms is used to map out hydrogen dense regions of the body
most modern and largest portion of brain by weight and volume
forebrain
hypothalamus subdivisions
lateral hypo
ventromedial hypo
anterior hypo
lateral hypothalamus (LH)
hunger center, triggers eating and drinking
when LH is destroyed, one lacks hunger
ventromedial hypothalamus (VMH)
satiety center, provides signals to stop eating
when VMH is destroyed, one is very much hungry
anterior hypothalamus
controls sexual behaviour
posterior pituitary
site of release for hormones ADH and oxytocin
pineal gland
secretes melatonin with regulates circadian rhythms
receives direct signals from retina for coordination with sunlight
basal ganglia
coordinate muscle movement and relay info to brain and spinal cord
plays role in Parkinson’s, schizophrenia, and OCD
extrapyramidal system
gathers info about body position and sends to CNS but doesn’t fxn through motor neurons
Parkinson’s disease
destruction of portions of basal ganglia so jerky movements, uncontrolled resting tremors (involuntary quivering movement)
limbic system
loops around central portion of brain
emotions and memory
parts of limbic system
septal nuclei
amygdala
hippocampus
anterior cingulate cortex
septal nuclei
primary pleasure centers
plays role in addictive behaviour
amygdala
plays role in defensive and aggressive behaviours such as fear and rage
damage to amygdala –>aggression and fear reduced, hypersexual, docile (submissive)
hippocampus
learning and memory
long term memories
fornix
long projection used by hippocampus to communicate with other portions of limbic system
anterograde amnesia
memory loss characterized by not being able to establish new long-term memories
retrograde amnesia
memory loss of events that happenedant before brain injury
anterior cingulate cortex
fxns in higher order cognitive processes such as impulse control and decision making
cerebral cortex
outer surface of brain
most recent region to evolve
has many bumps and folds called gyri and sulci - increases surface area
