Chapter 1 - Brain And Behavior

Question 1

Cerebral cortex

Answer 1

Heavily folded outer layer of brain tissue composed of neurons (cortex = bark)

Question 2

Gyri

Answer 2

Bumps. A ridge or fold between two clefts on the cerebral surface in the brain.

Question 3

Sulci

Answer 3

Grooves. A groove or furrow, especially one on the surface of the brain.

Question 4

Forebrain –

Answer 4

prominent in mammals and birds,

responsible for most conscious behaviors

Question 5

Brainstem

Answer 5

source of behavior in simpler animals,

responsible for most of our unconscious behaviors

Question 6

Four Lobes of the Brain

Answer 6

1. Frontal
– “Executive” functions, decision making
2. Parietal
– Integrates sensations into body coordinates
3. Temporal
– Hearing, language, memory, smell, taste
4. Occipital
– Visual processing

Question 7

Central Nervous System (CNS)

Answer 7

• The brain and spinal cord

Question 8

Peripheral Nervous System (PNS)

Answer 8

– Somatic division: conveys sensory information
to the CNS and motor information from the CNS
to the muscles.
– Autonomic division: enables the CNS to govern
the workings of the internal organs (e.g.,
heartbeat, respiration)

Question 9

Nervous system subdivides in:

Answer 9

CNS and PNS

Question 10

Irenäus Eibl-Eibesfeldt:

Answer 10

Behavior consists of patterns in time.”
– Examples
• Movements, vocalizations, thinking

Question 11

Animals produce behaviors that

Answer 11

– are inherited ways of responding

– that are learned

Question 12

Most behaviors probably consist of

Answer 12

a mix of

inherited and learned actions

Question 13

Mentalism

Answer 13

An explanation of behavior as a function of the nonmaterial mind

Question 14

Aristotle

Answer 14

– Believed the brain cooled the blood; no role in
producing behavior
– Psyche: Synonym for mind; an entity once
proposed to be the source of human behavior

Question 15

Dualism

Answer 15

Both a nonmaterial mind and the material

body contribute to behavior

Question 16

Mind–Body Problem

Answer 16

– Quandary of explaining a nonmaterial mind in command of a material body

Question 17

Rene Descartes

Answer 17

• Mind directs rational behavior
• Body and brain direct all other behavior via
mechanical and physical principles
– Examples: sensation, movement, and
digestion
• Mind is located in the pineal gland of the
brain, which sits beside ventricles filled
with fluid 
• Mind regulates
behavior by
directing the flow
of ventricular
fluid to appropriate
muscles

Question 18

Descartes and Dualism

Answer 18

Pineal gland is involved in biological
rhythms, but not in intelligence or
behavioral control
• Fluid is not pumped from the ventricles to
control movement
• Nonmaterial influences on the body would
violate the law of conservation of matter
and energy

Question 19

Darwin and Materialism

Answer 19

• Behavior can be explained as a function of
the nervous system without explanatory
recourse to the mind
• Related to evolutionary theories of Alfred
Wallace and Charles Darwin
– Both were struck at the many similarities
among species

Question 20

Darwin’s Concept of Natural Selection:

Answer 20

• Explanation for how new species evolve
and existing species change over time
• Differential success in the reproduction of
different characteristics (phenotypes)
results from the interaction of organisms
with their environment

Question 21

How are Traits Selected Naturally?

Answer 21

Appearance of New Trait
(e.g., via mutation)

Trait Increases
Reproductive Success

Increases
Chances of
Survival

Trait Passed
on to Offspring

Question 22

Epigenetics

Answer 22

• Study of differences in gene expression
related to environment and experience
• Epigenetic factors do not change your
genes, but they do influence how your
genes express the traits you’ve inherited
from your parents
• Epigenetic changes can persist throughout
a lifetime, and the cumulative effects can
make dramatic differences in how your
genes work

Question 23

Darwin and Materialism 2

Answer 23

1.Because all animal species
are related, so too must be
their brains
2.Because all species of
animals are related, so too
must be their behavior
3.Can study and understand
human behavior and brain
function by comparing the
genes, brains, and
behaviors of different
animals

Question 24

Common Ancestor

Answer 24

• A forebearer from which two or more
lineages or family groups arise
– Example: Humans and apes are thought to
share a common ancestor
• Can trace our lineage by comparing the
genes, brains, and behaviors of different
animals

Question 25

Taxonomy of Modern Humans

Answer 25

``` The evolution of brain cells and the brain • Only Animalia, contains species with muscles and nervous systems • Muscles and nervous systems evolved together to underlie the forms of movement (behavior) that distinguish members of the animal kingdom ```

Question 26

Nerve net:

Answer 26

– Simple nervous system with sensory and | motor neurons

Question 27

Segmented nerve trunk:

Answer 27

– Bilaterally symmetrical (the same on both sides of the body) – Segmented (divided into a number of parts)

Question 28

Ganglia:

Answer 28

Structures that resemble and function | somewhat like a brain

Question 29

Brain:

Answer 29

– The chordate phylum display the greatest degree of encephalization: they have a true brain. – Of all the chordates, humans have the largest brain relative to body size.

Question 30

Chordate Nervous System

Answer 30

• Nervous systems vary widely among chordates, but all are/have: – Bilaterally symmetrical and segmented – Brain and spinal cord encased in cartilage/bone – “Crossed” organization: Each hemisphere receives information from and controls the opposite side of the body - Emergence of complex behavior* in chordates is closely related to the evolution of the cerebrum and cerebellum

Question 31

Features common to primates:

Answer 31

``` Excellent color vision • Eyes in front of face: enhance depth perception • Females: Usually only one infant per pregnancy; infants require more care • Large brains for skilled movements and social behavior ```

Question 32

Hominids:

Answer 32

– Evolved 5 million years ago – Primates that walk upright; includes all forms of humans, living and extinct

Question 33

Australopithecus:

Answer 33

``` Early hominids were among the first primates to show distinctly human characteristics, including walking upright and using tools • Its brain was the size of that of a modern ape, about one-third the size of the modern human brain ```

Question 34

``` Homo habilis (“handy human”) ```

Answer 34

Made simple stone tools | 2 million years ago; in Africa

Question 35

``` Homo erectus (“upright human”) ```

Answer 35

More sophisticated tools than H. habilis 1.6 million years ago; in Europe and Asia

Question 36

Homo sapiens

Answer 36

– Appeared within the last 200,000 years – Until 30,000 years ago in Europe and 18,000 years ago in Asia, coexisted with other hominid species • Example: Neanderthals in Europe, who had comparable or even larger brains than H. sapiens • Exact reason why we replaced Neanderthals is unknown

Question 37

Jerison (1973) | • Principle of Proper Mass:

Answer 37

– Species exhibiting more complex behaviors will possess relatively larger brains • Jerison developed an index of brain size to allow comparisons among different species – Used body size to predict brain size

Question 38

Encephalization Quotient (EQ):

Answer 38

Measure of brain size obtained from the ratio of actual brain size to the expected brain size for an animal of a particular body size • H. sapiens have the largest EQ

Question 39

Enlarging Hominid Brain

Answer 39

``` Relative size of the hominid brain has increased nearly threefold – Australopithecus afarensis (left) – Homo erectus (center) – Modern Homo sapiens (right) ```

Question 40

Stedman and Colleagues (2004)

Answer 40

Genetic Mutation Smaller Facial Muscles & Bones Change in Diet Increased Brain Size

Question 41

Radiator Hypothesis (Falk, 1990)

Answer 41

active brain = more heat Increased Blood Circulation Improved Brain Cooling Enabled Size of Hominid Brains to Increase

Question 42

Neoteny

Answer 42

``` • Rate of maturation is slowed – Allows more brain cells to be produced • Adults retain some infant characteristics • Newly evolved species resemble the young of their common ancestors – Adult human heads look more like the heads of juvenile chimpanzees than adult chimpanzees ```

Question 43

Evolutionary Approach

Answer 43

Make brain-behavior comparisons between different species • CAUTION: – Difficult to make brain-behavior comparisons between members within the same species • Example: Brain size and intelligence

Question 44

Fallacies of Human Brain-Size | Comparisons

Answer 44

• Brain size and intelligence do not seem to be particularly related – Research has shown that many smart people (e.g., Einstein) have average size brains – Women’s brains weigh about 10% less than men, but the two sexes do not differ in measures of average intelligence

Question 45

Culture

Answer 45

Learned behaviors that are passed on from one generation to the next through teaching and learning • Enabled by our large brains

Question 46

brain is highly flexible

Answer 46

- We perform many tasks today that our brains were not originally selected for early during evolution • Example: programming computers