Lecture 5: Sensation And Perception Flashcards
What is Sensation? What are the 3 Basic principles?
Sensation is the detection of physical energy by sense organs (eyes or ears) which then send info to the brain. There are 3 basic principles in sensation, TRANSDUCTION, SENSE RECEPTOR, SENSORY ADAPTION.
What is Transduction?
The process of converting an external energy (light) into electrical activity within neurons
What are Sensory Receptors?
It’s a specialized cell responsible for converting external stimuli into neural activity for a specific system.
- Specialized cells in the back of the eye transduce light
- Specialized cells inside thew transfuse airborne odorant’s
What is Sensory Adaptation?
The process in which activation is greatest when a stimulus is first detected, practical and good for us cause otherwise we’d be tending to everything around us and that’s exhausting.
There are 3 types of Attention, what are they?
Inattentional blindness, Selective attention, Filter Theory of Attention
Inattentional Blindness
Failure to detect stimuli that are in plain sight when our attention is focused elsewhere
Selective Attention
Process of selecting one sensory channel and ignoring or minimizing others
Filter Theory of Attention
Mental filter that allows us to pay attention to important stimuli & ignore others, listen to messages from their left ear and ignore the right ear
Cocktail Party Effect
The ability to pick out an important message in a conversation that doesn’t involve us.
The Binding Problem
Our brains manage to combine, or “bind,” diverse pieces of information into a unified whole - different parts of our process the parts of the apple differently, so the regions aspect the pieces of info together, so as an apple.
What 4 Different Sense Systems Do We Have?
Visual system, Auditory system, Olfactory & Gustation system, Somatosensory systems.
Visual System - Light, What is it? What is the range of wavelengths?
The narrow range of wavelengths of light that we respond to, or can see.
- We can see on the same spectrum as X-Rays, UV rays, and Microwaves
- The wavelengths from 400nm purple to 700nm red
How Do We Perceive The Brightness of Objects?
So the part of the light is reflected by the object and part of it is absorbed by the object.
- White Objects reflects all the light that is shone on them
- Black Objects absorb all the light that Is shone on them, reflect none of it
What are Hues?
The colour of light…The primary colours are red, green, and blue
-> Addictive colour mixing - mixing different amount of primary colours, to get any colour.
-> Mixing equal amount of red, green, and blue light produces white light
How Does Light Enter The Eye? What controls the amount of light entered?
The light enters through the pupillary reflex - which is the closing of the pupils in response to light, to decrease the amount of light allowed into them.
- The Iris controls how much light enters the eye.
Basic Structure of Eye…Cornea, Retina, and Forea
Cornea, is a curved transparent layer that covers the iris and pupil. It bends light that comes into the eye to focus on the image in the back of the eye
Retina is located at the back of the eye and is responsible for converting light into neural activity (this is where transduction takes place)
- Contains 100million receptor cells for vision
Fovea, is the central part of the Retina and it’s responsible for acuity (sharp vision)
Good Example - you look at the laptop (Forea), and in the background you see students (Retina)
RECAP: What is the Cornea?
It’s a curved transparent layer that covers the iris and pupil
What is the Fovea?
It’s the central part of the Retina, and its responsible for the sharpness in your vision
What is Retina?
Located in the back of the eye, this is also where transduction takes place - converting light into neural activity
What are the 2 Receptor Cells?
Rods and Cones
What are Rods?
There are numerous rods, and they allow us to see basic forms and shapes.
What is Darkabaoation
The time it takes for rodes to regain their maximum sensitivity to light, usually happens when we enter a dimly lit room (movie theatre)
What are Cones?
They give us our colour vision
What is our Optic Nerve
It consists of a bundle of axons, that travels from the retina to the brain
What is the Blindspot?
The region of the retina containing no rods and totally devoid of sense receptors
What happens when optic nerve reaches optic chiasm?
Half of the axons cross in the optic chiasm, and half stay on the same side
What is it called when the optic nerve enters the brain?
Optic Tract
Where does the optic tract send mist of their info
The thalamus - primary visual cortex or v1
There are 2 major routes of vision….
- Visual information from the retina travels to the visual thalamus.
- Next, the visual thalamus sends inputs to the primary visual cortex (V1), then along two visual pathways to the secondary visual cortex (V2).
- One pathway leads to the parietal lobe, which processes visual form, position, and motion; AND one to the temporal lobe, which processes visual form and colour.
The remaining axons go to the midbrain - reflexes