3 - sensation and perception Flashcards
where on the pyramid of learning is sensation?
bottom layers - low level concept
sensation
the detection of simple properties of stimuli that occurs via sensory organs
how many sensory modalities are there?
5
what are the 5 different sensory modalities?
- gustation/taste
- oflaction/smell
- vision
- audition
- somatosensation - mixed sensory categoru
what 5 body senses are categorised as somatosensation?
- detection of touch
- thermoception
- vestibular sense (balance)
- proprioception
- nociception
what are the 2 chemo senses?
gustation and olfaction - both detect chemical systems
sensory transduction
energy from the environment is converted into neural activity
what are the two types of sensory coding?
anatomical
temporal
what is anatomical sensory coding?
when different nerves represent different modalities and stimuli from the same modalities are distinguished depending on location
anatomical coding is when different nerves from different parts of the body travel to different parts of the primary somatosensory cortex. what determines how much of the cortex is devoted to different body parts?
how richly innervated the region is with nerve fibres
what is temporal sensory coding?
when the rate of firing of axons represents/encodes the stimulus intensity
absolute threshold
the minimum level of a stimulus that can be detected
absolute threshold (signal detection theory)
the level at which a stimulus will be detected a specific percentage of the time
difference threshold
the minimum detectable difference between two stimuli
perception
our interpretation of what is represented by sensory input
what is form perception?
how we differentiate between figures and grounds
boundaries
sharp distinct changes in brightness, colour and patterns
what is gestalt psychology?
- a set of laws to outline the natural compulsion to find order in disorder
- foundation for modern study of perception
what are the 6 gestalt principles?
- figure-ground principle
- similarity principle
- adjacency-proximity principle
- good continuation principle
- the law of closure
- the principle of common fate
figure ground principle
people instinctively perceive objects as either being in the foregorund or the background
similarity principle
similar elements are perceived as belonging together
adjacency-proximity principle
elements of a visual scene that are close to each other appear to form groups
good continuation principles
elements that smoothly follow a line are perceived to belong together
the law of closure
missing information is supplied to close or complete a figrue
principle of common fate
elements on the same movement trajectory belong together
list 3 ideas about how the brain recognises objects so quickly?``
- templates - brain uses templates of objects to find an exact match
- prototypes - patterns of visual input are compared with prototypes to find similar object
- feature distinct models - visual system encodes images of familiar patterns in terms of distinct features
geons
the simple 2D or 3D forms such as cylinders, bricks, wedges, cones, circles and rectangles corresponding to the simple parts of an object in Biederman’s recognition-by-components theory
what ‘top-down’ influences can affect perception?
knowledge, motivations, experiences, context
perceptual set
selectivity bias with respect to what we perceive
attention
the allocation of awareness to a stimulus
how does attention affect our perception?
- enhances signals and perception of relevant stimuli
- inihibits signals and perception of irrelevant stimuli
our capacity for conscious processing is limited - how does the brain combat this?
we use selective attention - responsible for allocating the limited resource of awareness
inattentional blindness
the observation that when we fixate of something, we can fail to notice otherwise obvious events
change blindness
a person can be oblivious to changes in the visual scene, if our attention is directed somewhere else
how can unattended stimuli affect us?
we can still produce memories of these stimuli, even though we were not consciously aware of them
