Principles of Neural Science

Part I

Chapter 1 The Brain and Behavior

• Explaining behavior in terms of the brain’s activities is the task of neural science.
• In each of the hemispheres the overlying cortex is divided into frontal, parietal, occipital, and temporal lobes. Each lobe has a specialized set of functions:
  
  • The frontal lobe is largely concerned with short-term memory and planning future actions and with control of movement.
  • the occipital lobe with vision
  • the temporal lobe with hearing and its deep structures, the hippocampus and amygdaloid nuclei—with learning, memory, and emotion.
• The First Strong Evidence for Localization
  of Cognitive Abilities Came from Studies of
  Language Disorders
  
  • Wernicke’s area processes auditory input for language and is important for understanding
    speech.
  • Broca’s area controls the production of intelligible speech. It lies near the region of the motor area that controls the mouth and tongue movements that form words.
  • Wernicke’s area communicates with Broca’s area by a bidirectional pathway, part of which is made up of the arcuate fasciculus.
  • Wernicke realized that different components of a single behavior are likely to be processed in several regions of the brain. (notes: 將每個問題拆分成階段性的小步小問題來思考)
  • He was thus the first to advance the idea of distributed processing
• In the visual system, a dorsal cortical
  pathway is concerned with where an object is located in the external world while a ventral pathway is concerned with what that object is.

Chapter 2 Nerve Cells, Neural Circuitry, and Behavior

The Nervous System Has Two Classes of Cells

• nerve cells, or neurons, and glial cells, or glia.
• Nerve cells are the signaling units of the
  nervous System
  
  • A typical neuron has four morphologically defined regions: (1) the cell body, (2) dendrites, (3) axon, and (4) presynaptic terminals
  • Dendrites receive incoming signals
    from other nerve cells. While the axon carries signals to other neurons. An axon can convey electrical signals over distances ranging from 0.1 mm to 2 m.
  • These electrical signals, called action potentials, are initiated at a specialized trigger region near the origin of the axon
  • The amplitude of an action potential
    traveling down the axon remains constant at 100 mV because the action potential is an all-or-none impulse that is regenerated at regular intervals along the axon
  • Here we see a key principle of brain function: the information conveyed by
    an action potential is determined not by the form of the signal but by the pathway the signal travels in the brain. The brain analyzes and interprets patterns of incoming electrical signals and their pathways, and in turn creates our sensations of sight, touch, smell, and sound.
  • principle of dynamic polarization: electrical signals within a nerve cell “ow only in one direction: from the receiving sites of the neuron, usually the dendrites and cell body, to the trigger region at the axon.
  • connectional specificity: nerve cell makes specific connections—at particular contact points—with certain postsynaptic target cells but not with others.
• Glial cells support nerve cells
  
  • Glial cells greatly outnumber(2-10 times) neurons.
  • are not electrically excitable; and are not directly involved in electrical signaling

Each Nerve Cell Is Part of a Circuit That Has One or More Specific Behavioral Functions

Signaling Is Organized in the Same Way in All Nerve Cells

Nerve Cells Differ Most at the Molecular Level

Neural Network Models Simulate the Brain’s Parallel Processing of Information

Neural Connections Can Be Modified by Experience