Ch 4 - The role of the brain in behaviour and mental processes Flashcards
- Approaches to understanding the brain - Regions of the brain - The cerebral cortex
Structural neuroimaging techniques
Computerised tomography (CT)
- 2D x-rays are stacked to create a 3D image
- used for disease/disorder detection
- black and white & aren’t as detailed
- uses electromagnetic ionising radiation
Magnetic resonance imaging (MRI)
- uses magnetic & radio fields to take detailed 2D and 3D images
- used for disease/disorder detection
- less harmful than CT scans
- produce detailed, coloured images
Functional neuroimaging techniques
Positron emission tomography (PET)
- person injected w/ radioactive glucose substance - help brain light up when active
- solution releases emissions help trace biochemical changes
- person asked to complete a task
- show colours - represent level of activity
- red = most activity, purple = least
Functional magnetic resonance imaging (fMRI)
- uses magnetic & radio fields to take 2D & 3D images
- measures activity by tracing biochemical changes in brain - traces oxygen
- activity reflected w/colours
- preferred method - higher quality images, no needle
Hindbrain
a region at the base of the brain, located around and including some of the brainstem
- responsible for coordinating basic survival functions
- in terms of evolution, was 1st to develop
- contains the medulla, pons, and cerebellum
Cerebellum
- monitor and coordinate skeletal muscle movement
- receives info about body’s position in space & planned motor movements from brain regions
- maintaining balance & posture
- controlling voluntary movement (procedural & sequential) (riding bike, tying shoe)
- forms and consolidates procedural memories (know how brush teeth etc)
Damage = difficulty coordinate muscle control for everyday activity (walking etc), problems with balance, difficulty w speech
Medulla
- connects brain & spinal cord, pathway for neural signals
- regulate autonomic processes (respiration, heart rate, blood pressure, digestion)
- controls reflexive actions (vomiting, coughing, sneezing)
- subconscious & fundamental to survival
Damage = often fatal (e.g. blow to back of head)
Pons
- located above medulla (small bundle of nerve tissue)
- regulates respiratory system & controls sleeping, dreaming & waking
- involved in involuntary behaviours (blinking)
- relays info between brain areas (cerebral cortex-cerebellum) (medulla-midbrain)
Damage = often fatal/develops locked-in syndrome (no sensory/motor function, except moving use up, down, blinking)
Midbrain
a region at the centre of the brain, between the hindbrain and forebrain, and is part of the brainstem
- relays info between hindbrain-forebrain
- process sensory info (auditory, visual, tactile
- coordinates motor movement relating to sensory stimuli (eye movement)
- regulates sleep & psychological arousal
- contains the reticular formation
Reticular formation
- network of neurons that run through centre of midbrain & hindbrain & up toward forebrain
- filters neural info that’s travelling to brain & directs them to brain areas & structures
- integrated & relays neural info relating to survival & reflexive functions
- regulates sleep, wakefulness, consciousness
- regulates physiological arousal & alertness through the reticular activating system (RAS), to higher brain areas about necessary info
Damage = disruption of sleep-wake cycle & result in coma/chronic vegetative state
Forebrain
a large and prominent brain region that is located at the top and front of the brain
- cognitions, perception, learning, language, memory
- receiving & processing sensory info, voluntary movement
- contains intricate neuronal networks - enables higher-order functions
- contain cerebrum, thalamus, hypothalamus
Hypothalamus
- maintains body’s internal environment (homeostasis)
- regulates release of hormones from vaioous glands - controls pituitary gland
- influences basic biological needs (hunger, thirst, sleep)
- part of the limbic system - involved in emotions (anger, fear)
Damage = inability to regulate internal bodily functions, problems with sleep, overwhelming urge to eat, uncontrollable ranger
Thalamus
- filters info from sense receptor sites (except nose), passes to relevant brain areas for further processing
- relays motor signals b/w higher & lower brain areas involved in motor control (relaying sensory and motor signals)
Damage = visual/hearing impairment/ inability to feel sensations when touched
Cerebrum
- occupies most of forebrain
- outer surface called cerebral cortex - 2 hemispheres (left, right), connected via corpus callosum - allows passing of info
- coordinated cognition, perception, judgement, language, problem-solving
- receives & processes sensory info, initiates voluntary motor movement
Cerebral cortex
the outer layer of the cerebrum that covers the brain
- composed of 3 functional areas: motor, sensory, association
- divided into 4 regions: frontal, parietal, occipital, temporal (FPOT)
Functional areas
motor areas - initiating & executing motor movement, made of motor neurons
sensory areas - receiving & processing sensory info, made of sensory neurons
association areas - integrate info from motor & sensory areas to execute complex processes
Frontal lobe
- largest of the lobes
- located in upper forward half of each hemisphere
Association & motor areas:
- prefrontal cortex
- premotor cortex
- primary motor cortex
- broca’s area
Prefrontal cortex, premotor cortex, primary motor cortex
Prefrontal cortex:
behind forehead
- association area
- reasoning & logic, planning, problem solving, decision making, attention, emotions, reactions, self-awareness, personality
- plans required motor sequence & sends instruction to premotor cortex
Premotor Cortex:
- motor area
- organises movement sequence
- prepare movement sequence & sends to primary motor cortex
Primary motor cortex:
- motor area
- controls voluntary movement through skeletal muscles
- PMC in left lobe controls right body (vice versa)
- sends signals to cerebellum to do movement
Prefrontal –> premotor –> primary motor
Broca’s area
- association area
- next to motor cortex in frontal lobe of left hemisphere
- coordinates muscle movement for speech & provides info to right motor areas
- production of articulate speech
Damage = broca’s aphasia - difficulty forming clear speech (no loss in comprehension)
Parietal lobe
- behind frontal lobe & upper back of brain
- association area - attention, spatial reasoning, judging position in space, info abt muscle movement
- sensor area - primary somatosensory cortex
Primary somatosensory cortex
- sensory area
- processes info from skin & body parts
- left parietal lobes receive info from right side of body (vice versa)
Occipital lobe
- back of cerebral hemisphere
- association area - visual perception & interpretation, organises & integrates info from sensory area with other info
- sensory area - primary visual cortex
Damage = serious visual impairment
Primary visual cortex
- sensory area
- back of each occipital lobe
- where visual inffo from eyes is stored
- right primary visual cortex receives info from left visual field (vise versa)
Temporal lobe
- lower centra area of brain
- association area - processing auditory info, plays important role in memory
Functional areas:
- primary auditory (sensory area)
- wernicke’s area (association area)
Primary visual cortex
- sensory area
- back of each occipital lobe
- where visual info from eyes is stored
- right primary visual cortex receives info from left visual field (vice versa)
Temporal lobe
- lower central area of brain
- association area - processing auditory info, plays important role in memory
Functional areas:
- primary auditory cortex (sensory area)
- wernicke’s area (association area)
Primary auditory cortex
- receives & processes sounds from both ears to perceive & identify different types of sounds
- left hemisphere - verbal sounds (like words)
- right hemisphere - non-verbal sounds (music)
Wernicke’s area
- only in left hemisphere
- below primary auditory cortex
