Unit 5 Notes: Sensation and Perception

Sensation: 

• The process by which our sensory receptors and nervous system receive stimulus from the environment. 

Perception:

• the process of organizing and interpreting information, enabling us to recognize meaningful objects and events. 

1. Bottom-up Processing: begins with sense receptors and works up to the brain's integration of sensory information.
2. Top-Down Processing: information processing got it by higher level mental processes. 

1. Absolute Threshold: the minimum stimulation needed to detect a stimulus 50% of the time. 
2. Difference Threshold: The minimum difference that a person can detect between two stimuli.

Weber's Law: 

• The idea that, to perceive a difference between two stimuli, they must differ by a constant percentage; not a constant amount.

1. Vesticular sense: tells us our body is oriented in space.
2. Kinesthetic sense: tells us where our body parts are. 

Death Perception:

• the ability to see objects in three dimensions although the images that strike the retina are two-dimensional.
• allows us to judge distance.

Binocular Cues:

• the closer an object comes to you the greater the disparity is between the two images. 

UNIT 4 NOTES:

The Nervous System:

It starts with an individual nerve cell called a NEURON.

Neurotransmitters: chemical messengers released by terminal buttons through the synapse. 

Types of Transmitters:

1. Acetylcholine (ACH): deals with motor movement and memory.
2. Dopamine: deals with motor movement and alertness.
3. Serotonin: involved in mood control.
4. Endorphins: involved in pain control.

Types of Neurons:

1. Sensory Neuron: Take information from the senses to the brain.
2. Inter Neuron: Take messages from sensory neurons to other parts of the brain or to motor neurons.
3. Motor Neuron: Take information from brain to the rest of the body.

The cerebral cortex is made up of four lobes:

1. Frontal Lobe: 

• Abstract thought and emotional control
• contains motor cortex
• contains broca's area

2. Parietal Lobe:

• contain sensory cortex
• most of the parietal lobes are made up of association areas

3. Occipital Lobe: 

• deals with vision
• contains visual cortex

4. Temporal Lobe: 

• process sound sensed by our ears
• contains wernike's area
• wenicke's aphasia: unable to understand language