1. Slide 1Chapter 10 - Language Chapter 10 Language

2. Slide 2Chapter 10 - Language Outline One of the things that really seems to differentiate us from other animals is our ability to communicate very complex thoughts and ideas from one person to another, even from people long since dead. We will be covering three general issues related to language in this part of the course, one a day for the next three days. 1) Speaking and listening to language 2) Reading and Writing 3) The Acquisition of Language

3. Slide 3Chapter 10 - Language Verbal Communication - Speech Our ability to communicate via speech gives our species a huge advantage by allowing us to learn things from others, instead of having to learn everything from scratch ourselves. It also allows for an enhanced ability for cooperative behaviour as one individual can precisely specify what they would like another to do. While other animals do posses some extent of auditory communication (e.g., whales & wolves), their form of communication seems much more crude, focused almost completely on hunting and mating behaviours.

4. Slide 4Chapter 10 - Language Perception of Speech Our ability to perceive speech is truly amazing … another one of those abilities that is very hard to teach a machine to do (though speech recognition devices are now OK). One of the things that makes speech perception so difficult is the challenging of parsing the speech sound into words. This seems easy to us, but try it with another language. Once we have figured out where a word begins and ends, then we have to somehow find a match for that sound in memory, then retrieve the meaning associated with the sound and fit it together with what we have already heard.

5. Slide 5Chapter 10 - Language Learning the Rules of Language In order for anyone to understand what we are saying, we must form our thoughts into sentences according to a set of rules typically called grammar. For example, the sentence “George lives in the yellow house” makes sense but “George lives in the house yellow” makes less sense and “George house lives in yellow the” makes no sense at all. In French, the second sentence makes more sense than the first, as the rules concerning adjectives and nouns are different in French. These rules are also called syntax.

6. Slide 6Chapter 10 - Language Learning and Using the Rules Although most of us can use the rules of grammar quite well, we are not generally very good at stating what the rules are. The rules seem to be learned and used automatically, without us having any explicit knowledge of what they are. In fact, one of the most famous studies attempting to show our ability to learn without awareness is a study that uses grammar learning as its base. The phenomenon it is focussed on has come to be called implicit learning, and a typical experiment goes like...

7. Slide 7Chapter 10 - Language Implicit Learning - Grammer & Stimuli F G R D X P S W L C Legal Stimuli DFXGR DWLPS DFWLCS Illegal Stimuli DFGPS DWXPR DLWXGR

8. Slide 8Chapter 10 - Language Implicit Learning Experiment & Results In a typical implicit learning experiment, subjects will first be shown a number of “legal stimuli”. They are then shown stimuli that either do or do not conform to the grammar, and are asked to categorize each stimulus as legal or not. Even when the legal stimuli shown in the second part are different from those shown in the first part, subjects can perform the categorization task at above chance levels. Despite their performance, subjects cannot verbalize the grammar at all … it is as if they implicitly learned it.

9. Slide 9Chapter 10 - Language The Role of Context We have already discussed the fact that context often exerts top-down effects that aid perception … the same is true of speech perception. In one study, Polack & Pickett (1964) found that subjects could only understand about 47% of spoken words when they were presented out of context (i.e., as isolated words), but could understand nearly all of them when presented in the original spoken context. Similarly, subjects can perceive words better in a noisy environment when the words form meaningful sentences then when they do not.

10. Slide 10Chapter 10 - Language World Knowledge Thus, we use the structure of the sentence and context to help us understand speech, but that is far more to it than that. Another strong part of our ability to understand speech (and writing) is our general world knowledge. Consider the following paragraph: Tony was hungry. He went to the restaurant and ordered a pizza. When he had finished he realized he had forgotten to take his wallet with him. He was embarrassed. Thus, much of the meaning of a sentence is not in it. Where does it come from?

11. Slide 11Chapter 10 - Language Schema Theory One theory that helps to explain where we get the additional information is something called schema theory The general idea is that we have “scenarios” stored in memory that describe the typical roles and events associated with certain situations … similar to the consciousness model? For example … when we go to a restaurant we expect certain things to happen; (1) we are seated and given menus, (2) we are given some time, then someone asks us what we want, (3) we order, then wait, (4) our food comes and we eat it, (5) they take our plates and give us our bill, (6) we pay our bill with money (in our wallet).

12. Slide 12Chapter 10 - Language Some Relevant Neuropsychology Findings Speech Production An area of left frontal cortex located just in front of the motor cortex controlling the mouth, throat and tongue appears critical for allowing us to produce speech - Broca’s area. If this area is damaged, it leads to a condition termed Broca’s Aphasia … a difficulty or inability to produce speech. This area may contain the “motor memories” that control the fine motor movements needed for accurate speech. There is also a problem with grammer that occurs, both in production and comprehension.

13. Slide 13Chapter 10 - Language Some Relevant Neuropsychology Findings Speech Comprehension The recognition of spoken words appears to be performed in the upper part of the left temporal lobe - Wernicke’s area If this and surrounding areas are damaged, the comprehension of speech is impaired, and the production of speech is fluent but completely meaningless - Wernicke’s Aphasia. If just Wernicke’s area is damaged, patients show something called “pure word deafness” … an inability to understand words despite fine hearing and recognition of other sounds.

14. Slide 14Chapter 10 - Language From the Brain-Cam

15. Slide 15Chapter 10 - Language Reading The ability to read (and write) extends our communication abilities beyond both space and, especially, time. It also allows us to slowly intake information, at our leisure The “Steve hates phones” example We will not talk much about writing in this class but, instead, will focus on the question of how it is we are able to read. > Is there one strategy of reading? Two? More? > What parts of the brain are involved?

16. Slide 16Chapter 10 - Language How do we read? There is still considerable controversy over the exact mental processes involved in reading, but one popular theory is called the dual-route hypothesis. This hypothesis was inspired by the fact that we must use different processes to read items from the two stimulus classes presented below: Pronounceable NonwordsIrregular Words blagid yacht ulker aisle gulgerhaun pneumonia

17. Slide 17Chapter 10 - Language The “Dual-Route” Hypothesis of Reading Printed Word whole word reading (lexicon) letter recognition phonological recoding speech control muscles yachtbonkun

18. Slide 18Chapter 10 - Language Surface Dyslexia Printed Word whole word reading (lexicon) letter recognition phonological recoding speech control muscles yachtbonkun

19. Slide 19Chapter 10 - Language Phonological Dyslexia Printed Word whole word reading (lexicon) letter recognition phonological recoding speech control muscles yachtbonkun

20. Slide 20Chapter 10 - Language Semantics - The Meaning of Words Typically, when we are reading words or listening to someone speak, our ultimate goal is to understand what they are trying to communicate to us. This involves going from the word or speech sound to its meaning (or semantics). How is “meaning” represented by the brain, and how do we access these meanings? For many years, the standard assumption was that the meaning of words was represented in a form of mental dictionary called a lexicon. This view was largely supported by the priming phenomenon that we discussed previously in this class.

21. Slide 21Chapter 10 - Language Example of a Priming Experiment Task: Simply name the following words as quickly as possible Subject 1Subject 2CARPET COUCHDISKSOFA HAMMERTRUCKCARPICTURE Subjects can name the items that occur in a related context faster than they can name the items that appear in an unrelated context

22. Slide 22Chapter 10 - Language The Lexicon View of Semantics and Priming sofa couch chair lamp disk table floppy music bed sheet

23. Slide 23Chapter 10 - Language The Lexicon View of Semantics and Priming sofa couch chair lamp disk table floppy music bed sheet

24. Slide 24Chapter 10 - Language The Lexicon View of Semantics and Priming sofa couch chair lamp disk table floppy music bed sheet

25. Slide 25Chapter 10 - Language The Lexicon View of Semantics and Priming sofa couch chair lamp disk table floppy music bed sheet

26. Slide 26Chapter 10 - Language Distributed Representations More recently, a new view has become popular. This view assumes that meaning is represented in the brain by the simultaneous activation of neurons that represent the features of a concept. Priming effects can be accounted for within this distributed view by assuming that related items have similar meaning patterns. “couch” man-made has fur furniture four legs swims