Sensation

Sensation: the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. 

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

Bottom-up processing: analysis that begins with the brain receptors and works up to the brains integration of sensory information. 

Top-down processing: information processing guided by higher level mental processes, as when we construct perceptions drawing on our experience and expectations.

Psychophysics: the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them. 

Absolute Threshold: the minimum stimulation needed to detect a particular stimulus 50% of the time.

Subliminal: Below ones absolute threshold for conscious awareness. 

Difference Threshold: the minimum difference that a person can detect between 2 stimuli.

Weber's Law: the principle that, to percieve their difference, 2 stimuli must differ by a constant minimum percentage. 

Sensory Adaptation: diminished sensitivity as a consequence of constant stimulation.

Transduction: conversion of one form of energy to another. Transforming of stimulus energies into neural impulses.

The Eye

Wavelength: the distance from the peak of one light or sound wave to the peak of the next.

Hue: the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green and so forth. 

Intensity: the amount of energy in a light or sound wave.

Pupil: the adjustable opening in the center of the eye through which light enters.

Iris: ring of colored muscle tissue that forms the colored portion of the eye around the pupil and controls size of pupil opening.

Lens: the transperent structure behind the pupil that changes shape to focus images on the retina.

Accommodation: the process by which the eyes lens changes shape to focus the image of near objects on the retina,

Retina: the light sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.

Acuity: the sharpeness of vision.

   

Central Nervous System (CNS) Brain and Spinal Cord


Peripheral Nervous System (PNS) All nerves that are not encased in bones, everything but the spinal cord. Divided into 2 categories, Somatic and Automatic.
 
Somatic Nervous system controls voluntary movement. 
Autonomic Nervous system controls automatic functions of the body. Divided into 2 categories, Sympathetic and Parasympathetic.
Sympathetic Nervous System is the Fight or Flight response accelerates heart beating (ect) 
Parasympathetic Nervous System automatically slows the body down after a stressful event. Heart rate and breathing slow down pupils constrict and digestion speeds up. 

Reflexes (neurons) Normally sensory neurons take into up through spine to the brain. 

Lesions, cuts made to the brain to look for change. 

Brain Structures  

Hindbrain- medulla oblongata, controls heart rate, blood pressure. Pons, connect hindbrain, mid and forebrain together, controls facial expressions, the cerebellum, located int he back of the head, called the "little brain", coordinates muscle movement. 

Midbrain- Coordinates simple movements with sensory information, contains reticular formation, controls arousal and ability to focus. 

Forebrain- Thalamus recieves sensory information and sends them to appropriate areas of forebrain. The Thalamus is like a scoreboard.

Limbic System, controls emotions, made up of hypothalamus, the hypothalamus is pea sized but plays an important role, controls body temperature, hunger, set body temperature.

Hyppocampus- processes memories

Amygadala- linked to both fear responses and pleasure.

Cerebral Cortex is the top layer of the brain, contains wrinkles called fissures. Fissures increase surface size of the brain. laid out it would be about the size of a pizza.

Hemispheres 
Divided into a left and right side hemisphere. The left side of the brain controls the right side of the body and vice versa. Lefties are logical, right are artistic.
The corpus callosum attaches the 2 hemispheres of the cerebral cortex. 

The Cerebral cortex is made up of 4 lobes

The Frontal lobe controls thought, movement, emotion, the motor cortex sends signals to the body controlling muscle movements. Brocas area is responsible for controlling muscles that produce speech. 

Parietial lobe contains sensory cortex, receives incoming touch sensations from the rest of the body, made up of association areas. Information and coordinating muscle movements.

Occipital lobe deals with vision, contains visual cortex, interprets messages from our eyes into images we can understand. 

Temporal lobe processes sounds sensed by our ears, contains Wernike's Area, interprets written and spoken speech.