Modified: 2023-09-18 8:43 PM CDST
In this chapter we will cover the vertebrate nervous system, the cerebral cortex, and research methods for studying all of those. Again, you might look at my general psychology chapter covering these topics if you want a more basic introduction.
Term |
Definition |
Dorsal |
Toward the back, away from the ventral (stomach) side. The top of the brain is considered dorsal because it has that position in four-legged animals. |
Ventral |
Toward the stomach, away from the dorsal (back) side |
Anterior |
Toward the front end |
Posterior |
Toward the rear end |
Superior |
Above another part |
Inferior |
Below another part |
Lateral |
Toward the side, away from the midline |
Medial |
Toward the midline, away from the side |
Proximal |
Located close (approximate) to the point of origin or attachment |
Distal |
Located more distant from the point of origin or attachment |
Ipsilateral |
On the same side of the body (e.g., two parts on the left or two on the right) |
Contralateral |
On the opposite side of the body (one on the left and one on the right) |
Coronal plane (or frontal plane) |
A plane that shows brain structures as seen from the front |
Sagittal plane |
A plane that shows brain structures as seen from the side |
Horizontal plane (or transverse plane) |
A plane that shows brain structures as seen from above |
Area |
Also Known as |
Major Structures |
Forebrain |
Prosencephalon (“forward-brain”) |
|
Forebrain |
Diencephalon (“between-brain”) |
Thalamus, hypothalamus |
Forebrain |
Telencephalon (“end-brain”) |
Cerebral cortex, hippocampus, basal ganglia |
Midbrain |
Mesencephalon (“middle-brain”) |
Tectum, tegmentum, superior colliculus, inferior colliculus, substantia nigra |
Hindbrain |
Rhombencephalon (literally/“parallelogram-brain”) |
Medulla, pons, cerebellum |
"On old Olympus's towering tops, a Finn and German viewed some hops." (Medical students learn this mnemonic)
Number and Name
Major Functions
I. Olfactory
Smell
II. Optic
Vision
III. Oculomotor
Control of eye movements; pupil constriction
IV. Trochlear
Control of eye movements
V. Trigeminal
Skin sensations from most of the face; control of jaw muscles for chewing and swallowing
VI. Abducens
Control of eye movements
VII. Facial
Taste from the anterior two thirds of the tongue; control of facial expressions, crying, salivation, and dilation of the head’s blood vessels
VIII. Statoacoustic
Hearing; equilibrium
IX. Glossopharyngeal
Taste and other sensations from throat and posterior third of the tongue; control of swallowing, salivation, throat movements during speech
X. Vagus
Sensations from neck and thorax; control of throat, esophagus, and larynx parasympathetic nerves to stomach, intestines, and other organs
XI. Accessory
Control of neck and shoulder movements
XII. Hypoglossal
Control of muscles of the tongue
They state:
The notion of layers added to existing structures across evolutionary time as species became more complex is simply incorrect. The misconception stems from the work of Paul MacLean, who in the 1940s began to study the brain region he called the limbic system (MacLean, 1949). MacLean later proposed that humans possess a triune brain consisting of three large divisions that evolved sequentially: The oldest, the “reptilian complex,” controls basic functions such as movement and breathing; next, the limbic system controls emotional responses; and finally, the cerebral cortex controls language and reasoning (MacLean, 1973). MacLean’s ideas were already understood to be incorrect by the time he published his 1990 book (see Reiner, 1990, for a critique of MacLean, 1990). Nevertheless, despite the mismatch with current understandings of vertebrate neurobiology, MacLean’s ideas remain popular in psychology. (A citation analysis shows that neuroscientists cite MacLean’s empirical articles, whereas non-neuropsychologists cite MacLean’s triune-brain articles. See https://osf.io/r6jw4/ for details.)
Examine Effects of Brain Damage |
|
Study victims of stroke, etc. |
Used with humans; each person has different damage |
Lesion |
Controlled damage in laboratory animals |
Ablation |
Removal of a brain area |
Gene knockout |
Affects wherever that gene is active (e.g., a receptor) |
Transcranial magnetic stimulation |
Intense application temporarily inactivates a brain area |
Examine Effects of Stimulating a Brain Area |
|
Stimulating electrodes |
Invasive; used with laboratory animals, seldom with humans |
Transcranial magnetic stimulation |
Brief, mild application activates underlying brain area |
Record Brain Activity during Behavior |
|
Record from electrodes in brain |
Invasive; used with laboratory animals, seldom humans |
Examine Effects of Brain Damage |
|
Electroencephalograph (EEG) |
Records from scalp; measures changes by milliseconds, but with low resolution of location of the signal |
Evoked potentials |
Similar to EEG but in response to stimuli |
Magnetoencephalograph (MEG) |
Similar to EEG but measures magnetic fields |
Positron emission tomography (PET) |
Measures changes over both time and location but requires exposing brain to radiation |
Functional magnetic resonance imaging (fMRI) |
Measures changes over about 1 second, identifies location within 1 to 2 mm, no use of radiation |
Correlate Brain Anatomy with Behavior |
|
Computerized axial tomography (CAT) |
Maps brain areas, but requires exposure to X-rays |
Magnetic resonance imaging (MRI) |
Maps brain areas in detail, using magnetic fields |