Sensation
-the initial steps in perceiving things, converting physical features of the environment into electrochemical signals within specialized nerve cells
-Sensations can be defined as the passive process of bringing information from the outside world into the
Perception
Perception can be defined as the active process of selecting, organizing, and interpreting the information brought to the brain by the senses.
Sensation occurs:
a) sensory organs absorb energy from a physical stimulus in the environment.
b) sensory receptors convert this energy into neural impulses and send them to the brain.
Perception follows:
a) the brain organizes the information and translates it into something meaningful
B) But what does "meaningful" mean? How do we know what information is important and should be focused on?
Distal stimuli
-The thing in the world or events that are perceived.
Ex. the tree or the buzzing sound from your phone
Proximal stimuli
-the physical phenomena evoked by a distal stimuli that impinges on specialized cells of the relevant sense
-the internal representation of things, like a small movie inside your brain.
Top down info
-An observers knowledge, expectations, and goals which can effect perception
Bottom up info
-The info contained in neural signals from receptors
Neural code
-a pattern of neural signals that carry info about a stimulus and can serve as a representation of that stimulus.
Psychophysics
-a field of study concerned with relating psychological experiences to physical stimuli
-measuring the limits of your senses
Transduction
-a transformation of a physical stimulus into a chemical stimuli.
Method of adjustment
-a method used in experiments to measure the absolute threshold . The participant observes a stimuli and manipulates a control that directly adjusts the intensity of the stimulus.
Absolute threshold
-the minimum intensity of a physical stimuli that can be detected by the observer.
The stair case method
-Used to measure absolute threshold.
-When the participant is presented with a stimulus and indicates if it was detected, based on that response the next stimulus will either be one step up or one step down in intensity.
Psychometric function
- a curve that relates a measure of perceptual experience to the intensity of a physical stimulus.
The process of perception begins with 1._________ that produce physical phenomena called 2.______ that specialized 3.__________ called 4. _________ convert into 5._________ that are sent to the brain. The speed and accuracy of perception can be enhanced b
1. distal stimuli
2. proximal stimuli
3.neurons
4.sensory receptors
5. neural signals
6. top down info
Name at least 3 human senses beyond the normal five senses and list the physical dimensions of each.
-Proprioception: muscle tension, knowing where your body is in relation to the world
-Balance: head orientation
-Pain perception: tissue damage, pain quality and location in body
Neuron Doctrine
-the principle that perception depends on the combined activity of many specialized neurons, each of which responds to specific aspects of a stimulus.
What is the most important subcortical structure in the brain that is responsible for perception?
-the Thalamus: most neural signals originating in the sensory organs pass through the thalamus on their paths to the cortex.
Electroencephalography (EEG)
-a function of neuroimaging based on measuring the electrical fields associated with brain activity
What part of the spectrum can humans see?
- 370-730
***going from blues to green to yellow, organs, reds and then purple.
Brightness
- the perceived intensity of light reflected by a surface or emitted by a light source
Field of View
-the portion of the surrounding space you can see when your eyes are in a given position inter sockets.
Acuity
-a measure of how clearly fine detail is seen
Sclera
- outer membrane of eye, the white of the eye
Choroid
- the middle membrane of the eye, contains the blood vessels that supply the inside of the eye with oxygen
Retina
- inner membrane of the eye
Cornea
- a transparent membrane on the eye
Iris
-the colored part of the eye
Pupil
-the opening in the middle of eye
Perceptual grouping
-how the visual system combines separate regions of the retinal image that "go together" based on similar properties.
Perceptual interpolation
-the process the visual system uses to fill In hidden edges and surfaces in order to represent the entirety of a partially visible object.
Uniform connectedness
- a characteristic of regions of the retinal image that have approximately uniform properties.
Heuristics
-In perceptual organization, rules of thumb based on evolved principles and on knowledge of physical regularities
visual agnosia
-an impairment in object recognition
Prosopagnosia
-type of visual agnosia in which the person is unable to recognize faces, with little or no loss of ability to recognize other types of objects.