Topic 5: Sensation, Perception and action Flashcards
What are cortical and sub-cortical areas of the brain?
The cortex is the 3-4 mm thick outer layer of the brain that contains the majority of the specialised cells called neurons and is responsible for higher order processes like thinking or memory. Sub cortical ares of the brain are anything below the cortex. Does contain neurons but performs functions like reflex actions or emtional response such as flight or flight. These 2 systems become increasingly integrated as a person develops.
What is the development pattern of neurons as we age?
The connectivity of neurons becomes rapidly more advanced with development. So it is better understood as a re-organisation of the brain than outright growth.
What is arborization?
Growth of dendrites, dendrites being the tree like structure that recieve communications from other cells.
What is synaptogenisis?
Formation or growth of synapses, the points of contact where information is transmitted between neurons.
What is myelination?
The production of myelin, the shielding that wraps around neuronal axons improving communication between cells.
What is synaptic pruning?
It is a degenaritive process whereby neuronal connections that are no longer used will atrophe. So over time there are fewer but much stronger neural connections.
What is the sensitive period of development?
It is vital that an infant has a normal learning environment between the ages of 0-3 years. Experience dependent learning must happen within this time or else neural connections will atrophe and an individuals abilty to learn later in life will be comprimised.
What is the role of perception?
The world is often complicated and ambigious, perception organizes, identifies and interprets sensory input into representations that the brain can use to make sense of the world.
What does habituation create?
Habituation creates a preference for novelty. Infants become used to sensory stimnuli fairly quickly and display a preference for novelty.
(Study) What did Fantz show that infants had a preference for?
In the 1950s Fantz demonstrated that infants had a visual preference for some patterns over others. He measured infant looking time and showed that babies have a preference for face shapes over any other pattern.
What is perceptual constancy?
The tendency for the human brain to make sense of ambigious sensory information by seeing familiar objects as having the same shape, size or colour regardless of changes in perspective or distance. E.g. a visual object is still understood as the same object even though the sensory information has changed.
What is perceptual categorisation?
The ability to distinguish between sensory inputs that are categorically different. E.g. Becoming habituated with a pattern of acute angles and then when presented with an obtuse angle pattern infants look for longer.
What is the cross-modal link between sight and sound?
Certain auditory and visual inputs are linked neurologically, E.g. sight of hands coming together and the sound of clapping.
Study of infants ability to match auditory and visual stimuli. (Spelke, 1976)
Using soundtracks de-
synchronized from the image reveal an infant’s sensitivity to audiovisual correspondence from at least 4 mths. Suggests infants have developed cross-modal integration from an early age.
Why do infants have reflex actions and what part of the brain are they reliant on?
Reflex actions serve obvious survival functions like making sure the baby sucks on the mother’s nipple when presented. These actions are mainly reliant on sub-cortical brain function but as the brain develops and the cortex exerts more control, these reflex actions become more controlled and intentional.
