6. From Signals to Sensations Flashcards
What do the senses convey specific information about?
Some source of physical energy
Each what has a ‘labelled line’ which means high level specificity?
Each sensory modality
Which receptor can only convey info to the brain when the skin is stretched?
The Pacinian Corpuscle
Each time you stretch your skin, what happens to the membrane?
It moves and opens the ion channels and triggers an AP
List 3 things that each sensory modality responds to/has
- Responds to a range of stimuli
- Has evolved to fit the animal’s need
- Has a specific set of codes
Sensory receptor organs act as filters of the environment to detect and respond to what?
Specific events
Sensory receptor organs are known as the gate between what?
The external environment and the brain
Define stimulus
Event that affects the sensory organ
Describe the task that sensory systems complete
They convert environmental signals into neural activity that can influence the motor system of the animal
What are the 3 methods of studying sensory processing?
- Psychophysics
- Electrophysiological
- Neuroimaging
Describe psychophysics
Use behavioural testing to establish the sensitivity of a sensory system and the ‘rules’ of its operation
Describe electrophysiological
Recording from single neurons or small groups of neurons along the sensory pathway to find out how the neural circuitry gives rise to the perceptual abilities
Describe neuroimaging
In humans that are doing perceptual tasks to identify the brain areas responsible
Describe qualitative features of sensory signals and what it is often referred to
Feature such as colour or odourant (often referred to as modality)
Describe quantitative features of the sensory signal and what it is often referred to
Features such as magnitude (often referred to as the intensity)
What is a common strategy of sensory systems?
Separate neural pathways specialised for estimating different types of stimulus features
What are the 2 main functions of each sensory system?
Detection and discrimination
Define detection
The detection of a signal (i.e. is the signal present)
Define discrimination
Discrimination of some aspects of a sensory input (often referred to as estimation) (i.e. is this strong)
Define adequate stimulus
Type of stimulus for which a given sensory organ is particularly adapted (essential because each organ can only detect specific stimuli)
Define transducer function of receptors
The process in which a stimulus energy is transducer into an electrical response
What type of cells does sensory processing start with?
Receptor cells
Upon exposure to a stimulus, a receptor cells can convert energy into a…
Change in electrical potential across its membrane
Define sensory transduction
Changing physical energy to electrical potentials/neural activity - when the ion channels open