Chapter 8 Consciousness, The Brain and Behavior 識 行
I. States of Consciousness 識 狀 (I) Electroencephalogram The electroencephalogram provides one means of defining the states of consciousness. 了 識 狀 Electric currents in the cerebral cortex due predominantly to summed postsynaptic potentials are recorded as the EEG.
Rhythm generators in the thalamus are probably responsible for the wavelike nature of the EEG. The amplitude of the EEG indicates the degree of synchronous firing of the thalamic neuronal cluster. 律 度
Alpha rhythms and beta rhythms characterize the EEG of an awake person. α β
NREM sleep progresses from stage 1 (faster, lower-amplitude waves) through stage 4 (slower, higher-amplitude waves) and then back again, followed by an episode of REM sleep. There are generally four or five of these cycles per night. ( ) ( ) 行
( )
(II) Neural Substrates of States of Consciousness 識 狀 狀 力 力
II. Conscious Experiences Awareness and Attention 識 力 Conscious experiences may occur because a set of neurons temporarily functions together, the neurons comprising the set changing as the focus of attention changes. 識 力
III. Motivation and Emotion Behaviors that satisfy homeostatic needs are primary motivated behaviors. Behavior not related to homeostasis is a result of secondary motivation. 行 行 行 The mesolimbic dopamine pathway, which goes to prefrontal cortex and parts of the limbic system, mediates emotion and motivation. 葉 路 來
葉 藍
The limbic system integrates inner emotions and behavior. 了 行 葉
IV. Altered States of Consciousness 識 (I) The Mood Disorders The mood disorders (depressions and bipolar disorders) are caused, at least in part, by disturbances in transmission at brain synapses mediated by dopamine. ( )
(II) Psychoactive Substances, Dependence, and Tolerance Many psychoactive drugs, which are often chemically related to neurotransmitters, result in substance dependence (psychological dependence), withdrawal (physical dependence), and tolerance. The mesolimbic dopamine pathway and the nucleus accumbens are implicated in substance abuse. ( 理 ) ( 理 ) 參 濫
(PCP) K 類 (BZDs) 藍
(V) Learning and Memory Declarative memories are involved in remembering facts and events. Nondeclarative memories include procedural memories, which are memories of how to do things.
Memory encoding involves cellular (structural changes in the synapses) or molecular changes (changes in second-messenger systems and protein synthesis) specific to different memories. 不 不 ( ) ( ) Prefrontal cortex and limbic regions of the temporal lobe are important brain areas for some forms of memory. 葉 葉
(VI) Cerebral Dominance and Language The left hemisphere is superior at producing language. / 羅
The development of language functions occurs in a critical period that closes at puberty. 力 了 了 After damage to the dominant hemisphere, some language function can be acquired by the opposite hemisphere-the younger the patient, the greater the transfer of function. 年