Lecture 8 Flashcards
Briefly discuss the two hemispheres
There are two hemispheres in the cerebral cortex, most functions are bilateral and use both halves. The two halves are connected to each other and to other brain areas. The hemispheres are connected via the corpus callosum and various commissures.
Define contralateral control
The fact that the left side of the brain controls the right side of the body and vice versa. The happens with the ears and eyes. Therefore one hemisphere is more responsible for one stimuli but not fully responsible.
Define lateralisation
When certain processes are more highly developed on one side of the brain/area of the brain. The left hemisphere is more dominant in language and the right in emotions.
Do we perceive emotions differently depending on the visual field we view it from?
Some theories suggest so. The right hemisphere hypothesis; the right hemisphere is dominant for emotion recognition so when viewing from your left visual field, the emotions should be interpreted as more extreme, this coincides with the idea of lateralisation. There is also the valence hypothesis; the right hemisphere is dominant for negative emotions and left for positive (the lateralisation of emotions). These are contradicting.
Discuss right hemisphere dominance and spatial ability
Research suggests there is dominance for spatial ability. For example, when there is damage to the right parietal cortex, you neglect the left side of your body. Also, when there is damage to the right temporal cortex, you neglect your surroundings on the left side. However, it always seems to be on the left side. Although, when there is damage to the left side, there isn’t much neglect.
Discuss split brain patients
People become split brain patients when their corpus callosum is cut. Communication between the hemispheres doesn’t occur so only one side interprets particular information. If a patient is shown two words, e.g. hat and band, one in each visual field. If they were asked what they read and they were right handed, then they would only write down the word band in the right visual field as it uses the left hemisphere and the two don’t communicate. Some people with severe epilepsy, have the surgery for a split brain as it reduces seizures but doesn’t severely impact day to day life. This can cause self contradictions, for example: saying you don’t know the answer, whilst pointing at it with the left hand.
Why do humans speak?
So we can communicate long distances, so we can communicate without seeing and so you can get someone’s attention quick.
What is the source filter model of speech production?
Source; There are vocal folds in the larynx, this transforms aerodynamic energy to sound waves.
Filter; Supralaryngeal cavity filters the sounds which is important for vowel productions. This is similar to non-human animals.
Why do non-human animals have limitations in speech sound production?
Because of their larynx position, our larynx is lower which allows more flexibility. They also have less advanced and less voluntary vocal, motor and breathing control. This means they can’t speak. Also, our brains are adapted to produce language and new signals.
What are the three components of speech?
Semantics aka significance/meaning, syntax aka rules and principles/grammar and prosody aka rhythm, stress and intonation/melody.
What are the two specific areas of the brain associated with language?
Broca’s area; producing language and comprehending complex sentences.
Wernicke’s area; overall comprehension and finding the correct words.
Discuss speech perception in terms of the visual field
This is the McGurk effect; seeing them mouth far and hearing far when they are actually saying bar. This shows that it’s involved in the interpretation of language. It’s called syllable fusion. Children are better at hearing the right word which shows it’s a developmental thing.
What’s the traditional view of language evolution?
It’s advantageous because it allows you to exchange information which can benefit survival, for example referential vocalisations like animal calls.
What is the recent view of language evolution?
It’s advantageous because of the social aspect, it allows you to exchange social information. It can promote social cohesion. It could have developed from modified existing systems.
