• Neurolinguistics: the study of the relationship between language and the brain 

• The part shown as (1) is technically described as the “anterior speech cortex” or, more usually, as Broca’s area. 

• Language ability must be located in the left hemisphere 

• Broca’s area is crucially involved in the generation of spoken language. 

• The part shown as (2) is the “posterior speech cortex,” or Wernicke’s area 

• The left hemisphere location of language ability 

• Led to the view that Wernicke’s area is part of the brain crucially involved in the understanding of spoken language. The Motor Cortex and the Arc 

• The part shown as (3) is the motor cortex, an area that generally controls movement of the muscles (for moving hands, feet, arms, etc.). 

• The part of the motor cortex that is close to Broca’s area controls the articulatory muscles of the face, jaw, tongue and larynx and hence the physical articulation of speech 

• By applying small amounts of electrical current to specific parts of the brain, they could identify areas where the electrical stimulation would interfere with speech production. 

The Arcuate Fasciculus

• The part shown as (4) is a bundle of nerve fibers called the arcuate fasciculus.  

• This was also one of Wernicke’s discoveries and is now known to form a crucial connection between Wernicke’s and Broca’s areas. 

• To conclude specific aspects of language ability can be accorded specific locations in the brain.

• => This is called the localization view 

• It has been used to suggest that the brain activity involved in hearing a word, understanding it, then saying it, would follow a definite pattern. 

• In a sense, we are forced to use metaphors mainly because we cannot obtain direct physical evidence of linguistic processes in the brain 

• Most of these methods involve attempts to work out how the system is working from clues picked up when the system has problems or malfunctions. 

• We have all experienced difficulty, on some occasion(s), in getting brain and speech production to work together smoothly. 

• Minor production difficulties of this sort may provide possible clues to how our linguistic knowledge is organized within the brain. 

• The tip-of-the-tongue phenomenon in which we feel that some word is just eluding us.

• Studies of this phenomenon have shown that speakers generally have an accurate phonological outline of the word get the initial sound correct and mostly know the number of syllables in the word

• When we make mistakes in this retrieval process, there are often strong phonological similarities between the target word we are trying to say and the mistake we produce

• Malapropisms: the mistaken use of a word in place of a similar-sounding one, often with an amusing effect

• Misuse of a word for another one 

=> a speech error in which one word is used instead of another with a similar beginning end and number of syllables 

• ~ an incorrect word that sounds like the correct one 

=> has the same number of syllables and metric pattern and is the same part of speech as the correct word. 

• E.g: distinguisher instead of extinguisher, medication instead of meditation

• -A slip of the tongue is a speech error in which a sound or word is produced in the wrong place

• Unintentionally saying something not meant.

• “A long shory stort” instead of “make a long story short” –> slips of this type are sometimes called spoonerism

• Spoonerisms: a transposition of usually initial sounds of two or more words 

-> a slip of the tongue in which two parts of words are switched/swapped 

E.g: 

• Is it kisstomary to cuss the bride? ( It is customary to kiss the bride ) 

• The Lord is a shoving leopard ( The Lord is a loving shepherd ) 

• You have tasted the whole worm ( You have wasted  the whole term )  

• One other type of slip may provide some clues to how the brain tries to make sense of the auditory signal it receives. These have been called slips of the ear 

• A processing error in which one word or phrase is heard as another, as in hearing a great ape when the utterance was “gray tape” 

• Some of these humorous examples of slips may give us a clue to the normal workings of the human brain as it copes with language. However, some problems with language production and comprehension are the result of much more serious disorders in brain function. 

• Those people suffer from different types of language disorders, generally described as “aphasia.” 

• Aphasia: an impairment of language function due to localized brain damage that leads to difficulty in understanding and/or producing language 

• The most common cause of aphasia is a stroke (when a blood vessel in the brain is blocked or bursts), though traumatic head injuries from violence or an accident may have similar effects. Those effects can range from mild to severe reduction in the ability to use language. 

• Someone who is aphasic often has interrelated language disorders, in that difficulties in understanding can lead to difficulties in production, 

• Broca’s Aphasia (motor aphasia): a language disorder in which speech production is typically reduced, distorted, slow, and missing grammatical markers

• Broca’s Aphasia is characterized by: Difficulty in producing speech 

• The effect of Broca’s Aphasia: speech production is typically reduced, distorted, slow, and missing grammatical markers

• Broca’s Aphasia has led to the characterization of this type of aphasia speech as lacking grammatical forms, or “agrammatic”. In agrammatic speech, the grammatical markers are missing

• Agrammatic speech: the type of speech without grammatical markers, often associated with Broca’s Aphasia ( functional and inflectional morphemes ) 

• The characteristics of speech in Broca's aphasia: It consists mostly of lexical morphemes  

• The typical relationship between comprehension and production in Broca's aphasia: Comprehension is better than production 

• Wernicke’s aphasia: a language disorder in which comprehension is typically slow while speech is fluent, but vague and missing content words

• Wernicke’s aphasia is characterized by: Difficulty with comprehending language 

=> Individuals with this disorder can produce very fluent speech, but the speech is often difficult  to understand  

• E.g: I can’t talk all of the things I do, and part of the part I can go alright, but I can’t tell from the other people.

• Difficulty in finding the correct word, sometimes referred to as anomia, also happens in Wernicke’s aphasia

• Anomia: A language disorder in which it is difficult to find words, often associated with Wernicke’s aphasia 

=>  trying to describe objects or talking about their purpose.  

• Conduction aphasia: A language disorder associated with damage to the arcuate fasciculus in which repeating words or phrases is difficult 

• These language disorders are almost always the result of injury to the left hemisphere 

• The left hemisphere dominance for language has also been demonstrated by another research method. 

• Dichotic listening test: An experimental technique that has demonstrated a left hemisphere dominance for syllable and word processing 

• The dichotic listening test is demonstrated in the left hemisphere processing 

• Right ear advantage: the ability to perceive language better in the right ear than the left ear. 

• Left ear advantage: the ability to perceive language better in the left ear 

• In this process, the language signal received through the left ear is first sent to the right hemisphere and then has to be sent to the left hemisphere (language center) for processing and it take more time than received through the right ear which called the right-ear advantage. 

• In contrast, the right hemisphere appears to have primary responsibility for processing a lot of other incoming signals that are non-linguistic. 

• In the dichotic listening test, it can be shown that non-verbal sounds (e.g. music, coughs, traffic noises, birds singing) are recognized more often via the left ear, meaning they are processed faster via the right hemisphere. 

• The right hemisphere is first choice for non-language sounds (among other things) and the left hemisphere specializes in language sounds (among other things too). 

• The essential distinction seems to be between analytic processing, such as recognizing the smaller details of sounds, words, and phrase structures in rapid sequence, done with the “left brain,” and holistic processing, such as identifying more general structures in language and experience, done with the “right brain.” 

• The apparent specialization of the left hemisphere for language is usually described in terms of lateral dominance os lateralization (one-sidedness)

• Lateralization:

• During childhood, there is a period when the human brain is most ready to receive input and learn a particular language it is called the critical period 

• In 1970, a girl who became known as “Genie” was admitted to a children’s hospital in Los Angeles 

• Genie had spent her whole life in a state of physical, sensory, social and emotional deprivation 

• As might be expected, Genie was unable to use language when she was first brought into care. However, within a short period of time, she began to respond to the speech of others, to try to imitate sounds and to communicate 

• Such a finding, supported by other studies of right brain function, raises the possibility that our capacity for language is not limited to only one or two specific areas, but is based on more complex connections extending throughout the whole brain. 

1. Wernicke's area 

2. Wernicke identified patients who had difficulty comprehending language, often speaking fluently but without meaning. This is known as Wernicke's aphasia. 

3. This is a malapropism. A malapropism is the use of an incorrect word, often with a similar sound, in place of the correct word. A spoonerism is a speech error where the initial sounds of two words are switched 

4. This is a Freudian slip. Freudian slips are unintentional errors in speech or action that are believed to reveal underlying thoughts or desires. 

5. Aphasia is a language disorder that affects a person's ability to communicate. It can affect their ability to understand, speak, read, or write. 

6. Damage to the arcuate fasciculus, a bundle of fibers that connects Wernicke's area and Broca's area, results in conduction aphasia. This type of aphasia is characterized by difficulty repeating words or phrases, even though the person can understand and produce language independently. 

7. his speech pattern is indicative of fluent aphasia, specifically Wernicke's aphasia. As mentioned earlier, people with Wernicke's aphasia often speak fluently but have difficulty comprehending language, leading to nonsensical or incoherent speech. 

8. In a dichotic listening test, different auditory stimuli are presented simultaneously to each ear. This test is used to assess lateralization of brain function, particularly auditory processing. Subjects are typically asked to report what they heard in each ear or to identify target stimuli presented to one or both ears. 

9. The critical period is a time during development when the brain is most susceptible to environmental influences and learning. During this period, the brain is particularly receptive to acquiring new skills or knowledge. For example, there is a critical period for language acquisition, during which children are most easily able to learn a language. 

10. Researchers discovered that Genie, a child who was isolated and neglected for most of her childhood, had difficulty with dichotic listening tasks. This suggests that her language development was impaired due to the lack of early stimulation and exposure to language during the critical period.