Chapter 1: Origins of Brain and Behavior Flashcards
1
Q
Why should the study of brain and behavior be linked?
A
- How the brain produces behavior is a major scientific question
- The brain is the most complex organ on Earth and is found in many groups of animals
- A growing list of behavioral disorders can be explained and treated as we increase our understanding of the brain
2
Q
Neurons
A
specialized nerve cell engaged in information processing
3
Q
Glial Cells
A
nervous system cell that provides insulation, nutrients, and support and that aids in repairing neurons and eliminating waste
4
Q
Central Nervous System (CNS)
A
the brain is encased by the skull, the spinal cord is encased by the vertebrae
5
Q
Peripheral Nervous System (PNS)
A
neurons and nerve processes outside CNS, sensory connections to receptors in the skin, motor connections to body muscles, sensory and motor connections to internal body organs and gut
6
Q
Cerebrum (forebrain)
A
major structure o the forebrain that consists of two mirror-image hemispheres (left and right) and is responsible for most conscious behavior
7
Q
Hemisphere
A
literally, half a sphere, referring to one side of the cerebrum
8
Q
Brainstem
A
central structure of the brain (including the hindbrain, midbrain, thalamus, and hypothalamus) that is responsible for most life-sustaining, unconscious behavior
9
Q
Cerebellum
A
major brainstem structure specialized for learning and coordinating movements, assists the cerebrum in generating many behaviors
10
Q
Embodied Behvaior
A
theory that the movements we make and the movements we perceive in others are central to communication with others
11
Q
Locked-In Syndrome
A
condition in which a patient is aware and awake but cannot move or communicate verbally because of complete paralysis of nearly all voluntary muscles except the eyes
12
Q
Minimally Conscious State (MCS)
A
condition in which a person can display some rudimentary behaviors, such as smiling or uttering a few words, but is otherwise not conscious
13
Q
Clinical Trial
A
consensual experiment directed toward developing a treatment
14
Q
Deep Brain Stimulation (DBS)
A
neurosurgery in which electrodes implanted in the brain simulate a targeted area with a low voltage electrical current to produce or facilitate behavior
15
Q
Persistent Vegetative State (PVS)
A
condition in which a person is alive but unaware, unable to communicate or to function independently at even the most basic level
16
Q
Psyche
A
synonym for mind, an entity once proposed to be the source of human behavior
17
Q
Mentalism
A
explanation of behavior as a function of the nonmaterial mind, associated with Aristotle
18
Q
Dualism
A
philosophical position that both a nonmaterial mind and a material body contribute to behavior, associated with Descartes
19
Q
Mind-Body Problem
A
difficulty of explaining how a nonmaterial mind and a material body interact
20
Q
Materialism
A
philosophical position that behavior can be explained as a function of the nervous system without recourse to the mind, associated with Darwin
21
Q
Epigenetics
A
differences in gene expression related to environment and experience
22
Q
What are some characteristics of materialism?
A
because all animal species are related, their brains must be related
because all animal species are related, their behavior must be related
brains and behaviors in complex animals such as humans evolved from simpler animal’s brains and behaviors
23
Q
Eliminative Materialism
A
states that if behavior can be described adequately without recourse to the mind, then the mental explanation should be eliminated
24
Q
In what order did the nervous system evolve?
A
- Neurons and muscles
- Nerve net
- Bilateral symmetry
- Segmentation
- Ganglia
- Spinal cord
- Brain
25
Nerve Net
simple nervous system that has no center but consists of neurons that receive sensory information and connect directly to other neurons that move muscles
26
Bilateral Symmetry
body plan in which organs or parts present on both sides of the body are mirror images in appearance, for example the hands are bilaterally symmetrical, whereas the heart is not
27
Segmentation
division into a number of parts that are similar, refers to the idea that many animals, including vertebrates, are composed of similarly organized body segments
28
Ganglia
collection of nerve cells that functions somewhat like a brain
29
Chordate
animal with both a brain and a spinal cord
30
What is the central nervous system (CNS)?
most interconnections between the brain/body are made through the spinal cord
the spinal cord has input/output: nerve fibers out to muscles and organs, sensory receptors into the spinal cord
called central because it is the core of the nervous system and the core structure mediating behavior
31
What is the peripheral nervous system?
all the neurons in the body outside the brain and spinal cord
sensory and motor connections
signals from the brain and spinal cord to muscle
sensory signals from receptor to brain
32
What is the cerebrum?
major forebrain structure, two nearly identical hemispheres
prominent in mammals and birds
responsible for most conscious behaviors
33
What is the brainstem?
set of structures responsible for critical unconscious behaviors
life sustaining behaviors
34
What is the cerebellum?
learning and motor coordination
35
What is the brain?
the brain is more than just the tissue inside the skull, it is the idea itself of: the organ that exerts control of behavior, a control center
the term brain, then, signifies both the organ itself and the fact that this organ rpoduces behavior
refers to an intelligent, functioning organ that is connected to the rest of the nervous system and the body to produce behavior
36
Could the brain remain awake and conscious without sensory information and without the ability to move?
things to consider:
embodied behavior
sensory deprivation effects
locked-in syndrome
minimally conscious state (MCS)
persistent vegetative state (PVS)
the brain can be conscious in the absence of much overt behavior
in the absence of overt behavior, the brain can communicate through signals
37
What is behavior?
"behavior consists of patterns in time"
animal behavior
inherited: little or no previous experience
learned: requires experience + practice, learned behaviors depend on brain's plasticity
most behaviors consist of a mix of inherited (innate; fixed) and learned actions
38
What are inherent and learned behaviors?
animals with smaller and simpler nervous systems depend mainly on heredity
animals with complex nervous systems are more dependent on learning
39
What are the three perspectives on brain and behavior?
mentalism
dualism
materialism
40
What is Aristotle's mentalism perspective?
explanation of behavior as a function of the nonmaterial mind
psyche: where intellectual functions are created, entity once proposed to be the source of human behavior
psyche's departure from body results in death
a person's mind (psyche) controls behavior
41
What is Descartes' dualism perspective?
both a nonmaterial mind and the material body contribute to behavior
the mind receives information from the body through the brain
42
What is the mind-body problem?
whether or not mental phenomena are a subset of physical phenomena or not
43
What is the dualist hypothesis?
mind resides in the pineal gland, where it directs the flow of fluid through the ventricles and into the muscles to move the body
the pineal gland actually influences daily and seasonal biorhythms
44
What are the issues with dualism?
young children and those who are insane must lack minds because they often fail to reason appropriately
if someone lacks a mind, is this entity a machine?
45
What is Darwin's materialism perspective?
philosophical position that behavior can be explained as a function of the nervous system without recourse to the mind
behavior = brain + nervous system, no external psyche or nonmaterial entity
natural selection and inheritable factors explain how new species evolve and existing species change over time
46
What is a species?
group of organisms
47
What is a phenotype?
measurable individual characteristics
48
What is a genotype?
individual's genetic makeup
49
What is epigenetics?
gene expression related to environment/experience
the study of differences in gene expression arising from environment and experience
epigenetic factors influence how genes express the traits inherited from parents
epigenetic changes can persist throughout a lifetime, can make dramatic differences in how genes work
50
Who was Gregor Mendel?
heritable factors (genes) govern various physical traits displayed by the species
members of a species with a particular genetic makeup, or genotype, are likely to express (turn on) similar phenotypic traits
similar characteristics within or between species are usually due to similar genes
51
Cladogram
phylogenetic tree that branches repeatedly, suggesting a taxonomy of organisms based on the time sequence in which evolutionary branches arise
52
Hominid
general term referring to primates that walk upright, including all forms of humans, living and extinct
53
Encephalization Quotient (EQ)
Jerison's quantitative measure of brain obtained from the ratio of actual brain size to expected brain size, according to the principle of proper mass, for an animal of a particular body size
54
Topographic
representing all different functional areas of the CNS
55
Connectome
all pathways connecting regions of the CNS
56
Neoteny
process in which juvenile stages of predecessors become adult features of descendants, idea derived from the observation that more recently evolved species resemble the young of their common ancestors
57
Plasticity
body's potential for physical or chemical change, enhances it's adaptability to environmental change and it's ability to compensate for injury (aka neuroplasticity)
58
Species-Typical Behavior
behavior that is characteristic of all members of a species
59
Culture
learned behaviors that are passed on from one generation to the next through teaching and imitation
60
Meme
an idea, a behavior, or style that spreads from person to person within a culture
61
What are contemporary perspectives on brain and behaviors?
contemporary brain theory is materialistic
materialism argues for objective, measurable descriptions of behavior that can be referenced to brain activity
behavior and neural function are perfectly correlated
e.g. amygdala activation and fear responses
62
How do you trace the evolution of human brain and behavior?
the understand the evolution of the human brain and behavior we must consider:
animals that first developed a nervous system and muscles
how the nervous system grew more complex as the brain evolved to mediate complex behavior
how the human brain evolved it's present complexity
63
What is the evolution of brain and behavior?
our lineage can be traced by comparing the genes, brains, and behaviors of a common ancestor
forebear of two or more linages or family groups; ancestral to both groups
a humanlike brain first developed only about 6 million years ago, and our modern human brain has been around for only the past 200,00 years or so
brain cells and brains evolved only recently
64
What is a taxonomy?
the branch of biology concerned with naming ad classifying species by grouping representative organisms according to their common characteristics and their relationships to one another
65
How did neurons and muscles evolve?
brain cells and muscles evolved together, enabling animals to move
likely origin in single cell animals
66
How did the nerve net evolve?
"nervous system" of older structures (e.g. jellyfish)
consists entirely of neurons that receive sensory information and connect directly to other neurons that move muscles
67
How did bilateral symmetry evolve?
more complex animals
nervous system is more organized and features bilateral symmetry
68
How did segmentation evolve?
similar repeating segments in the nervous system (spinal cord and brain)
69
How did ganglia evolve?
more recently evolved invertebrates
clusters of neurons that resemble primitive brains
command centers
70
How did the spinal cord evolve?
highly evolved chordates
nervous system pathway connecting brain with sensory receptors and muscles
71
How did the brain evolve?
chordate phylum
greater degree of encephalization: a true brain
evolutionary increase in complexity, function, relative size, etc.
72
What is the chordate nervous system?
the phylum Chordata (amphibians, reptiles, birds, and mammals) display the greatest degree of encephalization: chordates have a true brain
of all chordates, humans have the largest brain relative to body size
the brains of all representative species have many structures in common, illustrating a single basic brain plan
increasing brain sizes accommodate new behaviors, including new forms of locomotion on land, complex movements of the mouth and hands for eating, improved learning ability, and highly organized social behavior
73
What is the evolution of the brain and behavior of humans, apes, and monkeys?
evolutionary and brain similarities
our behaviors are linked to the behavior of some evolutionary ancestors
74
What are humans?
members of the primate order
enhanced depth perception, highly developed visual sense and hand movements, larger brains
75
What are hominids?
evolved 5 million years ago
walk upright; includes all forms of humans, living and extinct
humans are the only surviving hominid species
76
What is Australopithecus?
first primates to show distinctly human characteristics
evidence suggests that the Aus. is our common ancestor
the brain of Aus. was about the sane size as that of living nonhuman apes
succeeding members of the human lineage display a steady increase in brain size
77
What are two possible members of the human lineage?
homo habilis (handy human): 2 million years ago in Africa, made simple stone tools
homo erectus (upright human): 1.6 million years ago in Europe and Asia, more sophisticated tools than H. habilis
78
What is the encephalization quotient?
quantitative measure of brain size to allow comparisons among different species
the lower an animal's brain falls relative to the trend line, the smaller its EQ
the higher an animal's brain lies relative to the trend line, the larger its EQ
79
What is the process of counting brain cells?
need to consider the neuron's packing density
human behavior is complex due to large brains and densely packed neurons
80
What is a topographic map?
shows different functional areas
81
What is a connectome map?
connection of functional regions
82
Why did the hominid brain enlarge over time?
climate changes have driven many physical changes in hominids, ranging from brain changes to emergence of human culture
homo sapians adaptability = survival
primate lifestyle: social group size, complex food foraging, food selection, use of fire
83
What are some changes in hominid physiology that occurred over time?
cooking food fosters genetic mutation
reductions in face muscle fibers and masticatory muscles
smaller facial muscles and bones allow for changes in diet and energy-rich foods
changes in skull form, increased blood circulation, and brain cooling lead to larger brains
84
What is the human genome?
genome: a catalogue of all of a species genes
understanding of the hominid genome is incomplete, only the genomes of apes, archaic humans, and modern humans have been sequenced
85
What are human-specific gene changes?
the SARGP2 gene is active during cerebrum development
plays role in determining number of neurons in the cerebrum
its mutation during human evolution might coincide with the Homo habilis, erectus, and sapiens
86
What is the correlation between modern human brain size and intelligence?
the evolutionary approach: make brain-behavior comparisons between different species, humans have large brains relative to other species
humans with larger skulls smarter within species?: relationship between brain size and intelligence is mixed
87
What are the problems with correlating brain size and intelligence?
difficulty in brain size and measurement
no agreement when it comes to measuring volume or weight
variability: body weight, gender, age, nutrition, disease or injury, stress, neurological disorders, plasticity
88
What are some ways of measuring intelligence?
species-typical behavior
general factor intelligence (spearman's g)
flynn effect (generational increase in IQ)
multiple intelligences
89
What is culture?
learned behaviors passed on from one generation to the next through teaching and experience, enabled by our large brain
90
What is the relationship between memes and evolution?
cultural elements, ideas, behaviors, or styles that spread from person to person (memes) can also be studied within a evolutionary framework
memes exert selective pressure on further brain development
e.g. using tools lead to selective development in x populations relative to populations not using tools
