The brain ch 3 Psychology

pierre flourens (1794-1867)- psychologist preformed brain surgery on animals to see what they could or could no longer do

ablation- destroy part of animal’s brain and see what function was impaired

localization of function- there are specific parts of the brain responsible for conrolling specific functions

Brain Imaging Techniques

-detect when the brain is working

• EEG Electroencephalogram: records electrical activity in the brain via electrodes on outside pf the skull. Good for sleep showing waves of sleep and wakefulness. stages of sleep determination. sleep issues sleep lab record brain activity

• fMRI Functional Magnetic Resonance imaging: detect what parts of the brain are more active. detailed 3-d image of structures & activity. aims a powerful magnetic field at the brain

• PET Positron emission tomography scans: radioactive injections. shows bio-chemical activity in the brain at a given moment.

• TMS Transcranial magnetic stimulation: magnetic pulse aimed into the brain to disrupt functioning in a specific area of the brain. strong magnetic field. see what part of the brain does what

viewing on a smaller scale-

optogenetics, hydrogel-embedding methods and neuropixels

Inside the Brain

The central core-

or “old brain” controls basic functions ex: eating and sleeping. common to all vertebrates

pons- pons means bridge. bridge between medulla and rest of the brain. transmits motor info, coordinates muscles, integrates movement between left and right halves of the body. does things you don’t need to think about

medulla oblongata- controls critical body functions ex: breathing, heart rate

Reticular formation (activating system or brain stem)- runs through the medulla and pons; its involved in changes in the body’s level of arousal. gives things a boost or calms them down when needed.

Cerebellum (”little brain”)- controls balance, coordination, movement and motor skills

Thalamus(chamber)- chamber in center of brain. is located in the central core and relays information about most of the senses. sensory information. all senses except smell

Hypothalamus- maintains homeostasis and regulates behavior critical to basic survival of the species. “thermostat” of you. ex: eating, drinking, sex

beyond central core…

The limbic system-

controls eating, aggression, reproduction (functions related to emotions & self-preservation), learning and memory.

amygdala- involves in our experience of emotion and tying emotional meaning to memories. almond shape

Hippocampus- structure associated with learning and memory. looks like a seahours. hippocampus means seahorse

olfactory bulb- smell

Cerebral Cortex-

“new brain” is responsible for the most sophisticated information processing in the brain

sulci-groove.

gyri-peak.

4 Lobes-

association areas- sites of higher mental processes, thought, language, memory and speech

• frontal lobe: motor cortex- voluntary motor control in frontal lobe. involved in planning and coordinating movement

• parietal lobe: somatosensory cortex- in paraital lobe. processes sensory information

• temporal lobe: auditory area that processes auditory information

wernicke’s area: important for speech and comprehension

broca’s area: involved in speech and language production

-injuries to association areas can produce aphasias

broca’s aphasia: difficulty speaking

wernicke’s aphasia: difficulty understanding others’ speech in producing language

• occipital lobe: primary visual cortex. interprets visual info. organized retinotropically

-motor cortex and somatosensory cortex are both organized topographically

wilder penfield (1891-1976)- did work with people undergoing brain surgery. stimulated direct part of brain of conscious person and asks what they experienced

Neuroplasticity and the brain

neuroplasticity: the brain can change throughout the life span—adding new neurons & inter-connections & reorganizing info-processing areas

Specialization of hemispheres

the brain is divided into two roughly mirror-image and symmetry

right hemisphere- controls left half of body

left hemisphere- controls right half of body

lateralization: the dominace of one hemisphere of the brain in specific functions

left handed people may have this organized in a different way

courpus callosum- connects the 2 hemispheres and allows communication between them

may be severed in rare cases in a split brain operation. specifically people who experience seziures

gazzaniga’s split-brain experiment: they don’t think they have seen anything but can pick up the object they saw by showing only a certain hemisphere of the brain