Unit 3B: The Brain Flashcards
lesion
tissue destruction; a brain lesion is a naturally or experimentally caused destruction of brain tissue
electroencephalogram (EEG)
an amplified recording of the waves of electrical activity that sweep across the brain’s surface. These waves are measured by electrodes placed on the scalp
CT (computed tomography) scan
a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body. Also called a CAT scan
PET (positron emission tomography) scan
a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task
MRI (magnetic resonance imaging)
a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy
fMRI (functional MRI)
a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function
brainstem
the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions
medulla
the base of the brainstem; controls heartbeat and breathing
reticular formation
a nerve network in the brainstem that plays an important role in controlling arousal
thalamus
the brain’s sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
cerebellum
the “little brain” at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance
our brain processes most information…
… outside of our awareness
limbic system
doughnut-shaped neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives
amygdala
two lima bean-sized neural clusters in the limbic system; linked to emotion
hypothalamus
a neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward
anther function of the hypothalamus
it monitors blood chemistry
reward deficiency syndrome
genetically disposed deficiency in the natural brain systems for pleasure and well-being that leads people to crave whatever provides that missing pleasure and relieves negative feelings
cerebral cortex
the intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information processing center
glial cells (glia)
cells in the nervous system that support, nourish, and protect neurons
frontal lobes
portion of the cerebral cortex lying just beneath the forehead; involved in speaking and muscle movements and in making plans and judgements
parietal lobes
portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position
occipital lobes
portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields
temporal lobes
portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear
motor cortex
an area at the rear of the frontal lobes that controls voluntary movements
Jose Delgado
experimented with people causing fists with electric shocks
what occupies the most cortical space?
parts that require the most precise control, eg. fingers
sensory cortex
area at the front of the parietal lobes that registers and processes body touch and movement sensations
association areas
areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking
aphasia
impairment of language, usually caused by left hemisphere damage either to Broca’s area (impairing speaking) or Wernicke’s area (impairing understanding)
what happens when you read out loud
- visual cortex (receives written words as visual stimulation
- angular gyrus (transforms visual representations into an auditory code)
- Wernicke’s area (interprets auditory code)
- Broca’s area (controls speech muscles via the motor cortex)
- motor cortex (word is pronounced)
plasticity
the brain’s ability to change, especially during childhood, be reorganizing after damage or by building new pathways based on experience
neurogenesis
the formation of new neurons
corpus callosum
the large band of neural fibers connecting the two brain hemispheres and carrying messages between them
split brain
a condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them
Gazzaniga’s 1967
experiment on separate hemispheres - conclusion is that the left hemisphere is the interpreter
right functions
rational, deliberation over decisions
left functions
simple requests, object perception, quick responses, copying drawings, recognizing faces, perceiving and displaying emotion
left functions (continued)
speaking/calculation, language (including sign language), quick, literal interpretation
right functions (continued)
perceptual tasks, inferences, subtleties, modulation of speech to make meaning clear, sense of self, relations with other people
consciousness
our awareness of ourselves and our environment
cognitive neuroscience
the interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language)
dual processing
the principle that information is often simultaneously processed on separate conscious and unconscious tracks
two types of seeing
perception (recognize things, plan future actions) vs. action (moment-to-moment actions)
big idea of unit 3B
much of our everyday thinking, feeling, and acting operates outside our conscious awareness
