General Psychology (PY110) Chapter 2 Neuroscience

Neuroscience and Behavior All sensory organs – Receptors Muscles and Glands – Effectors Neurons – Communication channel

The Structure of a Neuron

How Neurons Communicate Communication within a neuron is electrical Communication between neurons is chemical

Types of Neurons Interneurons exist only in the central nervous system Sensory neurons carry information to the central nervous system from sensory receptors in the eyes, muscles, and glands Motor neurons carry movement commands from the central nervous system to the rest of the body

Neurotransmitters, Drugs, and Poisons Key terms: Agonists Antagonists Drugs and poisons that increase the activity of one or more neurotransmitters Drugs and poisons that decrease the activity of one or more neurotransmitters

Neurotransmitters 1. Acetylcholine (ACh) is involved in both learning and memory and muscle movement 2. Dopmaine impacts our arousal and mood states, thought processes, and physical movement 3. Serotonin and norepinephrine are neurotransmitters involved in levels of arousal and mood, and play a major role in mood disorders such as depression 4. GABA is the main inhibitory neurotransmitter in the nervous system; glutamate is the main excitatory neurotransmitter 5. Endorphins are a group of neurotransmitters that are involved in pain perception and relief

Dopamine Low levels are associated with Parkinson’s disease, and excessively high levels are associated with schizophrenia L-Dopa is an agonist that increases production of dopamine Anti-psychotic drugs are antagonists that block the receptor sites for dopamine so that this neurotransmitter cannot send its messages Amphetamine acts as an agonist by stimulating the release of dopamine from axon terminals Cocaine is an agonist that blocks the re-uptake of dopamine

Nervous System Subdivisions

The Central Nervous System Consists of the spinal cord and the brain The spinal cord has two functions Conduit for incoming sensory data and outgoing movement commands Provides for spinal reflexes, which are simple automatic actions not involving the brain The brain is the control center for the entire nervous system

The Peripheral Nervous System Consists of two parts: The somatic (or skeletal) nervous system carries sensory input from receptors to the CNS and relays commands from the CNS to the skeletal muscles to control their movement The autonomic nervous system regulates our internal environment and consists of two parts The sympathetic nervous system is in control when we are very aroused and prepares us for defensive action (such as running away or fighting) The parasympathetic nervous system is in control when the aroused state ends to return our body to its normal resting state

Components of Emotion An emotion is a complex psychological state that involves three components: Physical Behavioral Cognitive A physiological state of arousal triggered by the autonomic nervous system An outward expression including facial expressions, movements and gestures An appraisal of the situation to determine which emotion we are experiencing and how intensely

Emotion Theory Comparison James-Lange Theory Cannon-Bard Theory Schachter-Singer Theory Stimulus: Sight of bear Physiological Arousal Emotional Response (Fear) Emotional Response (Fear) Stimulus: Sight of bear Physiological Arousal Stimulus: Sight of bear Physiological Arousal Cognitive Appraisal Emotional Response (Fear)

The Central Core Brain Structures

The Limbic System

The Four Lobes and the Sensory-Motor Processing Areas

The Case of Phineas Gage Phineas Gage was railroad worker who survived when a metal tamping iron flew through his left cheek and head, exiting through his frontal lobes He became irresponsible, impulsive, disorderly, indecisive, and cursed, leading neuroscientists to think the frontal lobes are important in such behaviors

Language Fluent speech production Comprehension of speech & reading

What we know… Left hemisphere Right hemisphere Language Math and logic skills More analytical, analyzing wholes into pieces Right hemisphere Spatial perception Solving spatial problems Drawing Face recognition A band of neurons called the Corpus Callosum joins the two hemispheres Allows communication and coordinates functions

Five Stages of Sleep Brain wave taken by Electroencephalogram (EEG)

Sleep Cycles Cycles last about 90 minutes. 4-6 cycles each night

Nature of Sleep & Dreams Stage Wave Form Remarks Non – REM 1 Alpha & Theta ‘Falling’ asleep 2 Theta Light sleep 3 Delta Deep Sleep - Night terrors, Sleep walking, Sleep talking, Etc. 4 Paradoxical Sleep - Dreaming occurs Sleep (Hrs) Awake (Hrs) % REM Adults 8 16 Babies 2 Types of Sleep – REM and Non-REM Non-REM = Quantity REM = Quality REM Sleep reduced by alcohol and sleeping pills Sleep Deprivation (or Dream Deprivation) Moderate – Sleep rebound Severe – depression, impaired memory, decreased immune response Circadian cycles – Biological clock