Lecture 3 Flashcards
the cranial nerves are numbered from
nose to back (anterior to posterior)
all of the cranial nerves are contained in and around the head with the exception of
cranial nerve X
polysensory
information from several senses is combined
sensory integration (multisensory integration)
process of combining different sensory signals
olfactory cortex
processes smell
auditory cortex
processes hearing
somatosensory cortex
processes touch
visual cortex
processes vision
the olfactory cortex is located in the
frontal cortex
the somatosensory cortex is in the
parietal lobe
the visual cortex is in the
occipital lobe
the auditory cortex is in the
temporal lobe
the areas considered a sensory ‘cortex’ only process
the most basic aspects of senses, any deeper processing happens outside of these cortexes
the central fissure separates the
frontal and parietal lobe, with the motor cortex on the frontal side and the somatosensory cortex in the parietal lobe.
The rate law
strength of a stimulus is represented by the rate of firing of an axon; the size of each action potential is constant.
rate of firing of an axon is limited by
the refractory period
rate law can be understood as the brain recognizing ______ in neuron firing
changes
labeled line theory
individual receptors preferentially transduce information about an adequate stimulus
in labeled line theory individual primary fibers
carry information from a single type of receptor
a good example of neurons that follow labeled line theory are
taste receptors/ taste buds.
across-fiber patterning
some sensory systems integrate information across multiple primary afferents; neurons work together to send a signal
multimodal afferent endings
more than one sensation can be evoked by their activation
Synesthesia
a condition in which people experience cross-modal sensations. This is the perception of one sense in response to the stimulation of a different sense
Electroencephalography (EEG)
a technique that, using many electrodes on a scalp, measures electrical activity from populations of many neurons in the brain
EEG is controversial because
it is imprecise and needs many trials to make it work well
Event-related potential (ERP)
a measure of electrical activity from a subpopulation of neurons in response to particular stimuli that requires averaging many EEG recordings
EEG has
decent temporal activity but poor spacial resolution
Magnetoencephalography (MEG)
a technique, similar to EEG, that measures change in magnetic activity across populations of many neurons in the brain
MEG has
high temporal resolution similar to EEG AND good spatial resolution
Computerized Tomography (CT)
uses X-rays to create images of slices through volumes of material
Magnetic resonance Imaging (MRI)
uses repsones of atoms to strong magnetic fields to form images
MRI and CT have
good spatial resolution but poor temporal resolution
functional magnetic resonance imaging (fMRI)
variant of MRI that measures localized patterns of brain activity based on the changes of oxygenated and deoxygenated blood to strong magnetic fields
in fMRI the highlighted areas represent
areas that have become MORE active than previous, not strictly where there was just activity
fMRI has
decent spacial and okay temporal resolution
Positron emission tomography (PET)
allows us to define locations in the brain where neurons are especially active by measuring the metabolism of brain cells using safe radioactive isotopes
PET has
great temporal resolution and spatial resolution but can’t be done constantly.
