Psychology: sensation and perception Flashcards
Define sensation.
A passive process during which the brain receives info from the environment.
Define perception.
Actively choosing info from sensation, organizing it and interpreting it to make subjective meaning of the world.
Explain the process of sensation and perception.
1) Energy signals in the environment reach the specialise receptor cells in eyes.
2) These specialised cells turn the energy signal into an electrochemical impulse as a part of a process called transduction
3) The impulse is then sent to relevant brain regions and sensation occurs.
4) The brain makes meaning of the messages and perception occurs.
What energy signals go with vision, hearing, taste, smell, touch, kinesthetic sense and vestibular sense
- vision - light waves
- hearing - sound waves
- taste - chemicals
- smell - chemicals
- touch - temp and pressure
signals - kinaesthetic sense - pressure
signals
What goes first, second and third: perception, transduction and sensation?
Sensation, transduction and perception.
Put this in order: neural impulses, stimulus, brain energy, sensory receptors.
stimulus, sensory receptors, neural impulses and brain energy.
Define psychophysics.
A special field in psych that studies sensations, their limits and how they are perceived.
What is the first law of psychophysics?
Noticing a change on the proportion by which the stimulus has changed.
What is signal detection theory.
A framework used to understand how people make decisions about detecting the presence of a signal against background noise or other competing signals.
When does adaption occur?
When we are constantly surrounded by a stimulus and so we start to block it out.
Define thresholds.
The level of energy required by a stimulus for it to be percieved.
Define absolute thresholds.
Minimum intensity of a stimulus required for a person to detect its presence accurately at least 50% of the time.
Explain difference threshold.
‘the line one has to cross’ in order to recognise that stimulus A is different from stimulus B.
Explain Just Noticeable Difference.
The minimum amount of change in a stimulus is needed for a person to detect that a change has occurred.
What do visual sensation and visual perception involve?
An energy signal, namely light, hitting the receptors in the eye.
What is the route that light travels to reach the photoreceptor cells at the back of the brain?
- cornea - protects eyes and keeps its shape.
- Pupil - opening; contracts or relaxes depending on light.
- Lens - refracts light to the back of the eye which allows the image to focus.
- Retina - contains all the cones and rod cells (photoreceptor cells) that pick up light.
What are rod cells?
Enables you to see in low light and they are all over the retina.
What are cone cells?
photoreceptor cells that pick up colour and they are mainly in the fovea.
Explain the blind spot.
It is a spot in the eye where all the axons of the receptor cells bundle together, which leads to lacking photoreceptor cells. However, the brain fills in the space.
Explain how vision works when we gaze upon something.
Signals from the right visual field cross the optic chiasm and are transmitted to the left hemisphere and vica versa
What are the hue, saturation and brightness and what are the needed for?
Hue: Determined by the wavelength of light.
Saturation: Determined by how pure colour appears or ow much it has been combined with white.
Brightness: Determined by the amplitude of the light wave.
These allow us to see colour.
Define Trichromatic theory.
The trichromatic theory states that color vision is based on three types of cone cells sensitive to different wavelengths: short (blue), medium (green), and long (red), allowing us to perceive a wide range of colors. Thus the presumption of there only being three types of cone cells.
