View
214
Download
0
Embed Size (px)
Citation preview
1Copyright © 2005 Pearson Education Canada Inc.
Evolutionary Psychology
The biological theory of evolution assumes natural selection is a key factor in how a species changes over time
Characteristics that help an organism survive are passed on to future generations
2Copyright © 2005 Pearson Education Canada Inc.
Evolutionary Psychology
Adaptation occurs when a trait has increased in a population
Individuals with the adaptive trait are more likely to survive and reproduce
3Copyright © 2005 Pearson Education Canada Inc.
The Genome
The genome is the total DNA blueprint of traits that can be inherited
Genetic mapping is the dividing the chromosomes into smaller fragments that can be mapped to reflect their respective locations
4Copyright © 2005 Pearson Education Canada Inc.
The Basics of Genetics
Behavioural Genetics is the study of both genetic and environmental contributions to variations in human behaviour
Heritability is the proportion of variation in a trait determined by heredity
5Copyright © 2005 Pearson Education Canada Inc.
The Basics of Genetics
Each human cell contains 23 pairs of chromosomes
Chromosomes are strands of DNA that carry genes
6Copyright © 2005 Pearson Education Canada Inc.
The Basics of Genetics
Genes are the fundamental units of heredity
Genetically determined traits are controlled by pairs of genes
7Copyright © 2005 Pearson Education Canada Inc.
The Basics of Genetics
A genotype is a person’s genetic make-up, which is fixed at birth
The phenotype is a person’s observable characteristics
8Copyright © 2005 Pearson Education Canada Inc.
The Basics of Genetics
Recessive members of gene pairs appear in the phenotype only if both members of the pair are recessive
A dominant gene is always expressed if it is inherited
9Copyright © 2005 Pearson Education Canada Inc.
The Neuron
The neuron is the basic unit of the nervous system
10Copyright © 2005 Pearson Education Canada Inc.
11Copyright © 2005 Pearson Education Canada Inc.
12Copyright © 2005 Pearson Education Canada Inc.
Types of Neurons
Afferent neurons carry messages to the brain and spinal cord
Efferent neurons carry messages from the brain and spinal cord to other structures of the body
13Copyright © 2005 Pearson Education Canada Inc.
Figure 2.2 The Action of Afferent and Efferent Neurons
14Copyright © 2005 Pearson Education Canada Inc.
Types of NeuronsSensory neurons are afferent neurons that carry information from the sense organs to the brainMotor neurons are efferent neurons that carry information from the brain and spinal cord to muscles and glandsInterneurons connect other types of neurons
15Copyright © 2005 Pearson Education Canada Inc.
Electrochemical Processes
The electrical process is created by a thin membrane around the neuron
In the normal resting state, the interior of a neuron carries a negative electrical charge
16Copyright © 2005 Pearson Education Canada Inc.
Electrochemical Processes
Activity within neurons is electrical Activity between neurons is chemical
17Copyright © 2005 Pearson Education Canada Inc.
Electrochemical Processes
The electrical process is created by a thin membrane around the neuron
In the normal resting state, the interior of a neuron carries a negative electrical charge
18Copyright © 2005 Pearson Education Canada Inc.
Electrochemical Processes
The exterior carries a positive electrical charge
The difference in interior and exterior charges creates a state of polarization
19Copyright © 2005 Pearson Education Canada Inc.
Electrochemical Processes
The action potential (or spike charge) is an electrical current that travels down an axon
It is initiated by a rapid reversal of the polarization of a neuron’s cell membrane
20Copyright © 2005 Pearson Education Canada Inc.
Electrochemical Processes
When stimulated to the action potential, gates in a neuron’s membrane open
The action potential occurs in an all-or-none fashion
21Copyright © 2005 Pearson Education Canada Inc.
Figure 2.5 Generation of an Action Potential
22Copyright © 2005 Pearson Education Canada Inc.
Electrochemical Processes
After firing, a refractory period occurs
Normal stimulation will not activate the neuron
23Copyright © 2005 Pearson Education Canada Inc.
Neurotransmitters
When an action potential moves down an axon, it causes the release of neurotransmitters
24Copyright © 2005 Pearson Education Canada Inc.
The Neural Synapse
The synapse is a small space between the axon terminals of one neuron and receptor sites of another
25Copyright © 2005 Pearson Education Canada Inc.
Figure 2.4 The Synapse
26Copyright © 2005 Pearson Education Canada Inc.
Neurotransmitters
Neurotransmitters are chemicals that move across the synaptic space
They communicate with other neurons by binding to receptors
27Copyright © 2005 Pearson Education Canada Inc.
Neurotransmitters
After communicating, the neurotransmitter may be neutralized or taken back by the neuron that released it
The process of taking neurotransmitters back in is called reuptake
28Copyright © 2005 Pearson Education Canada Inc.
Neurotransmitters
A change in the membrane of a neuron after receiving neurotransmitters is called a postsynaptic potential
29Copyright © 2005 Pearson Education Canada Inc.
Neurotransmitters
Sometimes neurotransmitters cause a neuron to fire more easily
They create an excitatory postsynaptic potential
30Copyright © 2005 Pearson Education Canada Inc.
Neurotransmitters
At other times neurotransmitters inhibit a neuron from firing
This is an inhibitory postsynaptic potential
31Copyright © 2005 Pearson Education Canada Inc.
Some Neurotransmitters
GABA Serotonin Acetylcholine Endorphins