(7) From signals to sensations Flashcards
What do the senses do?
The senses convey specific information about some source of physical energy Each sensory modality has a “labelled line”
What are Labelled lines?
the concept that each nerve input to the brain reports only a particular type of information
What does each sensory modality have?
- Each sensory modality has specialised receptors for transduction
- Very specific receptors that can transform information
What do sensory modalitys respond to?
- Each sensory modality responds to a range of stimuli
- Response to stimuli which are specific range, not just one
What does each sensory modality have a set of
Each sensory modality has a set of codes
What type of codes do sensory modalitys have?
- Intensity coding - Location coding - Coding for specific object (colours, shapes, pitch)
- Codes for different types of information
What are Sensory Receptor Organs?
act as filters of the environment: they detect and respond to some events and not others (skins, eyes, ears)
What is a Stimulus?
- event that affects the sensory organ
- Taking information from the external environment to the brain
What do animals have?
All animals have specialised body parts that are sensitive to some forms of energy
What do sensory systems do?
Very diverse, yet they all solve the same task: They convert environmental signals into neural activity that can influence the motor system of the animal
How do Psychophysics study sensory processing?
use behavioural testing to establish the sensitivity of a sensory system and the “rules” of its operation.
How does Electrophysiological recordings study sensory processing?
Electrophysiological recording from the single neurons or small groups of neurons along the sensory pathway to find out how the neural circuitry gives rise to the perceptual abilities.
How does imaging in humans study sensory process?
- Imaging in humans that are doing perceptual tasks to identify the brain areas responsible.
- Taking information to the brain from external environment helps interaction and survival
What must be estimated from the sensory signal
qualitative features, quantitative features, temporal features, spatial location of the stimulus
What qualitative features need to be considered when looking at sensory signals?
Qualitative features such as colour or odorant often referred to as modality- what is it? (touch vision, modality of signal)
What quantitative features need to be considered when looking at sensory signals?
Quantitative features such as magnitude often referred to as the intensity of a stimulus
What temporal features need to be considered when looking at sensory signals?
Temporal features such as duration or frequency of a signal
What spatial location of stimulus need to be considered when looking at sensory signals?
Spatial location of a stimulus - where is it?
What is a common strategy of sensory systems?
A common strategy of sensory systems is to have separate neural pathways specialized for estimating different types of stimulus features.
What do visual systems analyse?
Visual system analyses colour, shape and movement in different brain regions
What are the two main functions of each sensory system?
detection and discrimination
What is detection?
Detection: The detection of a signal. Weak signals can be detected without the animal being able to finely discriminate any of its features (whether the stimulus is present)
What is discrimination?
Discrimination: Discrimination of some aspects of a sensory input. This is often referred to as estimation (what type of stimulus it is)
What is a Adequate stimulus?
type of stimulus for which a given sensory organ is particularly adapted
What is Transducer function of receptors?
The process in which a stimulus energy is transduced into the electrical response, which triggers an AP
Where does sensory processing start?
- Sensory processing starts with receptor cells
- A give receptor cell is specialized to detect particular energies or chemicals
