Autism

Hi everyone, I hope you liked my last post on how children develop a theory of mind – this post follows on, and talks about children with autism (if you haven’t read that post, find it here https://freudforthought.wordpress.com/2015/08/06/theory-of-mind/).

Autism is a neurodevelopmental disorder, which has a prevalence of 60 per 10,000 children under 8 in the UK (Baird et al, 2000). Characteristics of autism include impairments in social interactions, communication, and imaginative behaviours. Also, individuals with autism tend to like to stick to routine, and can become distressed if their routine changes. However, autism is a spectrum, and sufferers can have a range from very mild, to severe impairments. For example, the disorder formerly known as Asperger’s Syndrome had all the characteristics of autism, but without the language difficulties (however this is now no longer recognised as a separate disorder).

Criteria for social impairments include lack of eye contact during interactions, and the lack of voluntarily sharing interests and enjoyment with others. Communication impairments include a delay of language development, and a lack of varied pretend play. Finally, examples of repetitive behaviour include sticking to rituals, and a preoccupation with the parts of objects. As mentioned in my last post, some of these behaviours can be explained by deficits in a theory of mind, which is a theory proposed by Baron-Cohen et al.

As well as the traditional theory of mind tasks, they also carried out more advanced experiments, called ‘reading the eyes’ tasks. In these, adults with autism were shown pictures of people’s eyes, and had to work out the emotion the eyes were showing. They found that autistic participants made more errors than controls without the disorder. However, it is worth noting that this task is challenging to normally developed adults – see how you get on from the picture below!

eyes

One other interesting thing about autism is that it is more common in males than females, with a 3:1 ratio. Baron-Cohen (2003) therefore outlined his theory that autism is an extreme form of the male brain. This theory states that everyone has either a male or female brain, regardless of their actual gender, with the male brain being better at systemising, and the female brain better at empathising. As autistic individuals can struggle showing empathy, and are generally interesting in how things work, he hypothesised that autism reflects the male brain. Despite the terms ‘male’ and ‘female’, he found that about 17% of men had a ‘female’ brain, with the same percentage of women having a ‘male’ brain. Many people also have a balanced brain, showing aspects of both.

I kind of get why he came to this conclusion, but I think that this theory is very oversimplified, and that there is actually no need for the terms ‘male’ or ‘female’ at all – especially as people can have aspects of both, and that the brain type has nothing to do with gender! Might be one theory to take with a pinch of salt…

But what do you think? Let me know in the comments and thanks for reading!

The McGurk Effect

Here’s the first post in a new section of my blog called ‘Brainteasers’.

This section will be made up of short posts with videos which will show you things you can amaze your friends and family with. They will also fit in with the other sections of my blog, and will show the practical applications of some of the theories I’ve discussed. I hope you will find these demonstrations as fun as I do 🙂

So first up – the McGurk Effect!

Unsurprisingly, this was first identified by someone called McGurk in 1976. It shows the interaction between vision and hearing, and illustrates that what we see overrides what we hear.

When we see a speaker mouth the phoneme ‘ga’ while the sound ‘fa’ is played into our ears, we perceive the sound as ‘ga’. In other words, we believe what our eyes are suggesting is being spoken rather than our ears. This shows the importance of vision in language perception.

Try it for yourselves:

I hope you enjoyed this post – check back soon for more brainteasers and thank you for reading 🙂

How do infants learn language?

If you think about it, it’s pretty impressive that, given the complexity of language, infants learn to speak their first word by the time they are about a year old, and are able to talk in sentences by the age of 2. It takes us years to become fluent in a second language as adults, but infants manage to do this within just a few years. So how do they manage it?

You’ve probably noticed the strange way adults speak to babies. Kind of cooing and repetitive, this type of talking is known as infant-directed speech, or mothereseThis talking actually has a purpose – it is higher in pitch than normal speech, and has more exaggerated intonation contours. It also has longer pauses between words and is made of shorter sentences. These characteristics make it easier for infants to recognise, and so helps them to learn the properties of language.

There are other characteristics of language which are thought to help babies learn words. One example of this is phonemic categories: for example ‘b’ and ‘p’ are phonemes that are very similar, but can be recognised by infants as young as 1 months old. This was shown by Eimas et al (1971) who got infants to suck on a dummy to hear sounds, and found they sucked more to the ‘new’ phoneme they hadn’t been played before.

It has been shown by Werker and Tees (1984) that young infants are able to discriminate between phonemic contrasts that older children and adults are not. This graph shows the decline in ability as they get older:

http://web.uvic.ca/~lalonde/psyc335/notes/lecture04.html

This suggests that infants become less able to discriminate between phonemic contrasts that they don’t need to know in their native language, and so helps them focus on this language.

Identifying single words in a sentence is more difficult than it would seem, as silences don’t always come between words. Infants are thought to learn word boundaries by categorical perception – the probability that one syllable will follow another. For example, Saffran et al (1996) showed that in the phrase ‘pretty baby’, there is a higher probability that ‘ty’ will follow ‘pret’ than ‘ba’ would follow ‘ty’. They suggested that babies use this method to work out the gaps between words.

Not surprisingly, infants learn words faster if they are exposed to more language. Hart and Risley (1995) found that in the USA, a familys’ social economic status affects the amount of language they are exposed to: high SES families = 487 utterances per hour, while for low SES families, it is 178 utterances per hour. This shows the importance of environment in language learning.

Hope you found this post interesting, check back soon for more 🙂