Chapter 3: The Brain Flashcards
nervous system
a portion of the body consisting of neurons, nerves, and glial cells that allow different portions of the body to communicate with one another
neurons
specialized cells that can receive and transmit information
nerves
bundles of connective tissue between neurons that allow them to communicate with one another and with other parts of the body
glial cells
cells within the nervous system that provide support for neurons and overall nervous system function
two subsystems of the nervous system
central nervous system (CNS) & peripheral nervous system (PNS)
central nervous system (CNS)
the portion of the nervous system containing the brain and the spinal cord
peripheral nervous system (PNS)
the portion of the nervous system consisting of all neurons, nerves, and glial cells outside of the brain and spinal cord
where does cognition take place?
CNS (brain)
link between the CNS & PNS
The PNS provides inputs from external senses and passes them to the CNS for processing. The CNS sends a behavioural decision as an output to the PNS
autonomic nervous system (ANS)
connects most of the organs in the body and regulates unconscious bodily functions
subdivisions of the ANS
sympathetic & parasympathetic nervous systems
sympathetic nervous system
Unconsciously prepares the body for immediate action (fight-or-flight)
parasympathetic nervous system
regulates bodily functions under conditions where immediate action is not needed (rest & digest)
brainstem
a stalk-like structure at the base of the brain that connects it to the spinal cord and regulates involuntary functions like heart rate and breathing
hypothalamus
a small but highly complex cluster of neurons that lies in the center of the brain and is involved in regulating involuntary functions like body temperature hunger, thirst, fatigue, and sexual behaviour
what brain structures regulate the ANS
brainstem & hypothalamus
reflex action
when a stimulus generates an immediate behavioural action triggered by the spinal cord before the information reaches the brain
cerebrum
the largest portion of the human brain that consists of the cerebral cortex and related structures
cerebral cortex
a folded, layered structure that is the largest single structure and the most superficial portion of the brain.
the cerebral cortext is made up of
gray & white matter
gray matter
neuronal cell bodies
white matter
consists of the nerve tracts that connect neurons to each other
hippocampus
a complex structure that is involved in memory formation and is structurally an extension of the temporal lobe of the cortex
dorsal
the upwards direction
ventral
the downwards direction
caudal/posterior
the direction towards the back of the head
frontal/anterior
the direction towards the forehead
contralateral
one side of the brain controls or receives outputs from the opposite side of the body
what hemisphere does vision project to?
For vision, everything to the left of the point you’re looking at projects to the right hemisphere and vice versa
gyri
the hill-like projections of the folds of the cerebral cortex
sulci
the valley-like indentations of the folds of the cerebral cortex
fissure
a deep sulcus
why does the brain have gyri and sulci?
because it increases the surface area that can fit into the skull
lobes
the four anatomical divisions of the cortex that exist on each hemisphere
occipital lobe
responsible for vision
temporal lobe
responsible for the meaning of sensory information, language and visual memory
frontal lobe
responsible for planning and executive control
parietal lobe
responsible for attention, sensory integration, and somatosensory processing
lateral fissure
separates the temporal and frontal lobes
central sulcus
separates the frontal and parietal lobes
parieto-occipital sulcus
separates the parietal and occipital lobes
hemispheres
each of the two halves of the cerebrum, divided into left and right
left hemisphere
dominant location of language
right hemisphere
dominant location of spatial processing
neuropsychology
the study or observation of brain function and impairment due to brain pathology
Phineas Gage
suffered a serious accident when a metal bar penetrated his skull and travelled through much of his frontal cortex. He recovered most of his mental faculties, but his personality was different. Demonstrated that damage to specific regions can impair specific functions
Split-brain patients
patients (typically epileptic) who have had their corpus callosum severed, disconnecting the two hemispheres of the cortex. Most recovered normal cognitive function, but Michael Gazzaniga found that when an object is presented in their left visual, they cannot name what they saw
hemodynamic response
the blood delivers oxygen more quickly to active neurons than inactive neurons
subtraction method
used to measure brain activity when the participant is performing the task vs. a different task/no task at all to determine what brain areas are more active when the participant is doing the task
Multivariate Pattern Analysis (MVPA)
a data analysis that uses machine learning to decode what stimulus or task a participant is engaging in, based on the distribution of activity throughout the brain.
steps of MVPA
- The researcher must decide which neurons from different parts of the brain will be included
- The pattern of brain activity when participants are engaged in different tasks s measured using neuroimaging typically fMRI
- After a number of different neural patterns are gathered they are split into the training set and the test set. The training set is given o a computer with the correct labels so that it can learn which patterns of brain activity belong with which stimulus
- Testing whether the computer can correctly identify brain activation patterns from a set it has not encountered before
decoding
taking some brain activity and working backwards to figure out what stimulus or other cognitive process caused it
Functional Near-Infrared Spectroscopy (fNIRS)
uses near-infrared light to measure oxygenated vs. non-oxygenated hemoglobin, a component of blood
neuroplasticity
the ability of the brain to reorganize the spatial arrangement of its function
