Chapter 1: Introduction Animism Dualism Monism Using our own - PDF document

Chapter 1: Introduction

• Animism • Dualism • Monism • Using our own brain to explain the brain?

Can we explain consciousness? • Blindsight • Split brains--Is right hemisphere also thinking? • Unilateral neglect • Raised questions • Computer programmed to be aware of itself?

Blindsight

blindsight

Visual Pathway

Split brain

Split brain-operation

Split brain—odor task

Unilateral neglect

Physiological psychology • What does the brain do? • Generalization and reduction – Generalization-a type of scientific explanations; a general conclusion based on many observations of similar phenomena. – Reduction, a type of scientific explanation; a phenomenon is described in terms of the more elementory processes that underlie it.

Biological root • Descartes • Reflexes • Dualism, but believe that the connection between mind and body is mechanical. The pineal body.

Reflexes

Biological root • Johannes Muller • Doctrine of specific nerve energies – Because all nerve fibers carry the same type of message, sensory information must be specified by the particular nerve fibers that are active • Pierre Flourens • Experimental ablation, like modal gene knock out – The research method in which the function of a part of the brain is inferred by observing the behaviors an animal can no longer perform after that part is damaged. • Broca’s area

Natural selection and evolution • Darwin: natural selection and evolution • All of an organism’s characteristics-its structure, its coloration, its behavior- have functional significance. • Functionalism – The principle that the best way to understand a biological phenomenon (a behavior or a physiological structure) is to try to understand its useful functions for the organisms. • Natural selection • Mutation • Selective advantage

Schematic representation of how antibiotic resistance is enhanced by natural selection. The top section represents a population of bacteria before exposure to an antibiotic. The middle section shows the population directly after exposure, the phase in which selection took place. The last section shows the distribution of resistance in a new generation of bacteria. The legend indicates the resistance levels of individuals.

• Natural selection is the biological theory that explains why living creatures seem to match their environmental niches so well – the process by which individual organisms with favorable traits are more likely to survive and reproduce than those with unfavorable traits. Insofar as there is genetic variability for the trait under selection, the genotypes associated with the favored traits will increase in frequency in the next generation. • Natural selection is simply the logical result of four features of living systems: • variation - individuals in a population vary from one another • inheritance - parents pass on their traits to their offspring genetically • selection - some variants reproduce more than others • time - successful variations accumulate over many generations

• Natural Selection Requires... • For natural selection to occur, two requirements are essential: • There must be heritable variation for some trait. Examples: beak size, color pattern, thickness of skin, fleetness. • There must be differential survival and reproduction associated with the possession of that trait. • Unless both these requirements are met, adaptation by natural selection cannot occur. Some examples: • If some plants grow taller than others and so are better able to avoid shading by others, they will produce more offspring. The reason they grow tall is because of the soil in which their seeds happened to land, and not because they have the genes to grow tall, Will evolution occur? • If some individuals are fleeter than others because of differences in their genes, but the predator is so much faster that it does not matter, will evolution occur?

Evolution • Evolution • Vertebrate evolution • 360mya: Amphibian– therapsids– catastrophic series of volcanic eruptions • Cynodont—ancestor of mammals– small, nocturnal, eat insects and live in trees • 65mya: dinosaurs extinction, primates

• Evolution of human beings – 25mya: Hominids—orangutans, gorillas, chimpanzees, humans – 3.7mya: bipedalism, 2.5mya:tools – 1.7mya: Homo erectus, Africa to Europe and Asia; Homo neanderthalis, Homo sapiens

• Evolution of large brains – Human vs. chimpanzee: 1.2% difference in DNA; size 3 times larger

– Neoteny: A slowing of the process of maturation, allowing more time for growth; an important factor in the development of large brains

Ethical issues in research with animals • Research using animals are beneficial to human beings and to other animals. • We should treat animals humanely. • Animal models are very important in research, examples.

Careers in neuroscience • Physiological psychologists, behavioral phenomena • Neuroscientists, all aspects of the nervous system, anatomy, chemistry, physiology, development and functioning • Neurologist, diagnose and treat diseases of the nervous system, practice of medicine • Experimental neuropsychologist, studying subjects with brain damage using brain-scanning devices, such as fMRI, CT. • Teaching • Research • Pharmaceutical companies