For this question there could be a mention of the holistic versus the localisation theories and perhaps some reasons why they existed, one of which was the variability of language localisation between individuals. In answering this question there could also be a discussion of the argument between Broca and Marie on the isssue of whether Broca's area was actually a motor area. Also, that the crucial area of damage was subcortical. Most language disorders involve some subcortical damage but the importance of this remains uncertain, although this issue is referred to later in this chapter. Arguments were no doubt encouraged by the nature of stroke with its diffuse damage which within an individual caused impairment to more than one functional area and increased uncertainty making the localisation proposal difficult to defend at times.

Broca's area is sometimes included and at other times excluded as part of the prefrontal cortex depending on the approach of the author. It is assumed by many aphasiologists that this area plays an executive role within language, especially the organisation and sequencing of speech. Strokes that include Broca's area also often include damage to some of the neighbouring primary motor area (motor strip) and therefore such patients often exhibit an upper limb left hemiparesis and signs of motor dysfunction affecting the face (see Appendix 1). A syndrome description of Broca's aphasia includes the most obvious difficulties with the production of speech but also the signs of facial motor difficulties e.g. placement of tongue and agrammatism which is a difficulty with syntax e.g. joining words are absent. There is also a difficulty in repeating a series of words (phonological short-term memory). Cognitive neuropsychologists and others correctly argue that the syndrome is a description of many disorders rather than one and that the signs of this syndrome should be researched separately and many modern clinicians and researchers who refer to syndromes on occasions would not argue against this conclusion.

Any answer to this question must refer to the areas that affect comprehension of meaning that are outside Wernicke's area i.e. within the middle temporal gyrus (MTG). Because these patients suffer both semantic and phonological impairments this should implicate both the MTG and the superior temporal gyrus respectively.

According to some authors jargon aphasia is often described as a type of Wernicke's aphasia. This would explain their jargon because with a comprehension disorder they would not pick up the errors in their own speech. There may well be such patients, but the finding of jargon in patients who can clearly understand the questions given to them, makes this blanket explanation less likely. A distinction between an auditory monitoring of self versus others provides some solution. In this way a person might use the ventral pathway (through the posterior temporal lobe and MTG) to understand the speech of others. However, when articulation is produced this largely involves the dorsal pathway that runs through such areas as the parietal cortex including supramarginal gyrus. Damage to a separate area for monitoring speech would mean that patients would not be able to realise when they had made an error in their own speech, but they would still be able to understand the speech of others.

Broadly, if it is possible to have comprehension difficulties without the difficulty of repeating back then phonological short-term memory (phon STM) must be intact with these patients. This suggests separate mechanisms between phon STM and semantic analysis of speech. This is further supported by the findings of phon STM deficits being found in isolation within the vicinity of the perisylvian areas.

This is a difficult question to answer with any surety. There seems to be a prevalence of belief that the hypophonia, semantic paraphasias and mild difficulties in comprehension and repetition are due to reduced metabolism in the cortex in areas that are connected to the damaged thalamus. This rapidly recovers following injury. Not surprisingly, it matters which nuclei of the thalamus are effected because of the functions of the connections with that part of the thalamus. For example, the dorsomedial area might be related to attention, while the pulvinar with its cortico-to-cortico connections may influence and facilitate associations between words. The relatively quick recovery from thalamic aphasic effects suggests that this is an issue of connectivity and that such connections are rapidly compensated by alternative pathways some of which may be the cortical connections. The effect of subcortical lesions on the initiation of motor aspects of speech are more certain and some of this effect is most likely to be due to connections between the thalamus and pre-supplementary motor area and also damage to areas of the basal ganglia.

Of course, it has been argued by some that if thalamic lesions have their effect due to their connectivity with other structures then this would explain why cortical lesions on their own may have more subtle effects compared to a case where connections with the thalamus are also undermined as sometimes happens following stroke. Lesions that disconnect language areas within the cortex may be compensated by connections with the thalamus and vice versa leading to temporary and milder symptoms. This is evident in some studies e.g. by Wilder Penfield that observe the effects of surgical tumour removal from the cortex in the language area. Typically if there are aphasic signs they pass and recover quickly.

This is a question that could potentially be both long and involved. However, a good understanding of the limitations and advantages of research measures allows a more sophisticated understanding of neuropsychology. No one technique provides all the answers and some methods of analysis are too novel to be completely trusted. The following measures might be considered for a start.

• Voxel-based lesion-symptom mapping (VLSM) to show a relationship between the volume of the lesions (number of pixels at various slices of the damaged area) with their test performance. The recent work in this area has been most theoretically useful, providing maps of areas contributing to various tests and consequently language function.
• Functional MRI allows the analysis of language in the healthy brain. However, the many different ways of analysing these results and types of tests means that careful reviews of studies are the most useful when making sense of the extensive literature in this area.
• Electroencephalography (EEG), magnetoencephalography (MEG) for temporal discrimination and fMRI for spatial discrimination. Sometimes these measures may be combined in order to compensate for each measure's shortfall.
• Intracranial EEG. There are relatively few direct measures of neural activity. However, for ethical reasons intracranial EEG can only be used with epilepsy patients and others who will benefit from such a procedure. Also, the position of the electrodes is determined by the clinical questions being asked which may not coincide with the research question. However, it is clear that this method unlike others may directly measure the speed and directional run of the neural response and therefore the order of speech analysis. However, the testing methods often have to be a little basic.
• Research looking at connectivity between language areas. This is an up-and-coming field that seems to highlight the areas that are crucial to language processing by identifying hubs (areas of  pathway convergence). However, the functional role of such hubs must be inferred. For the most part the methods used just describe where the pathways run. Unless this method is combined with other measures such an fMRI, connectivity only tells with a certain probability the pathways without an indication of their functional significance. This method allows an inspection of the pathways that may be used for a variety of language-related processes. Post-mortem analysis of such pathways may gain more credence but these are limited by the selective nature of the patients available.

The ventral pathway is associated mostly with language comprehension requiring both semantic (meaning) and phonological (sound) analysis. From Heschl's gyrus where there is basic sound analysis of auditory, information then proceeds to the sylvian parietal temporal area (Spt) according to some authors as a nexus of the start of the ventral (understanding) and dorsal streams (production) or alternatively, others propose that information transfers directly to the posterior superior temporal gyrus.

This phonological and semantic analysis is described as being serial by some authors (posterior superior temporal gyrus to middle temporal gyrus) and processed in parallel by others.

It is certain that there are patients who have posterior lesions within the temporal cortex who are described as suffering from phonological paraphasias without semantic paraphasias e.g. conduction aphasia. This seems to argue against a serial analysis otherwise the phonological impairments would undermine the later semantic analysis. Also, semantic analysis may be demonstrably faster than phonological analysis and so the author does favour the view that they are analysed in parallel although serial processing may occur in addition.

The VLSM approach allows a relationship between the area of damage and the performance of a variety of tests for each individual, the tests being chosen to represent assumed language process. There is reference in this chapter to the difficulty of relying on the degree of such a relationship given there may be other areas, even in the contralateral hemisphere, that may be compensating for the lesioned area. The author has never read this criticism being made but the reader may see that there are significant differences between studies using this same technique and this lack of consistency may be due to a number of factors e.g. time since lesion.

The overlapping lesion method has been used for many years. A collection of patients is found suffering from the same impaired language process or language disorder and the scans of their lesions are overlapped in such a way that it is assumed that the darkest area with the most overlap contributes to the language impairment. The difficulty here is that the patients who incidentally have strokes associated with a particular artery may show an overlap for the artery in areas that only eventually identify the language impairment. This might be overcome to some extent by hotspotting which removes the area of lesions of patients without the impairment. A second approach chosen by Hillis and others is to show a relationship between the function with structural damage and measures of blood perfusion. In stroke around the area of structural damage there is hypoperfusion of blood and this lesser blood flow is also associated with dysfunction. Based on the relationship between these measures and the performance, they were able to show that identification of the insular as being involved with articulation was spurious and was merely there with overlap studies because it shared an occluded middle cerebral artery with the inferior frontal gyrus.

The two methods may suffer similar disadvantagesThe Hillis method takes into account hypoperfusion while the VLSM method looks at each individual patient and the relationship with test performance. Both have their merits for different reasons.

This a straightforward question that can be answered by reading the text.

The uncinate fasiculus has a connection between the IFG and the poles of the temporal lobe poles, this being the location most associated with Centre 2 and the amodal representation of knowledge. There are also connections between the temporal poles with the ventral visual pathway (inferior longitudinal fasciculus). This is in addition to the auditory pathways that also project to the temporal lobe poles. This would allow Centre 2 to receive both visual and auditory information which is appropriate given this area is seen to be a hub providing an amodal storage of knowledge, as evidence in the disorder of semantic dementia.

Centre 1 in contrast is described as a specialised auditory processor of semantic information and is therefore more specialised.

The IFG has connections with both centres but the connective pathways between the IFG and Centre 1 seem to be primarily serving auditory comprehension (the extreme capsule and IOFF).

TMS studies suggest that Centre 1 is primarily used for language comprehension while Centre 2 at the poles of the temporal lobe seems to be an alternate access point of the IFG for use when selecting discriminations between shades of meaning or relationships between concepts.

Initially, in infancy, the main pathway articulation is between superior dorsal areas of the parietal cortex including the supramarginal gyrus and the angular gyrus. At around 7 years of age a second inferior dorsal pathway has developed which is seen as allowing more sophisticated use of syntax and complex organisation of sentences. This pathway is the pathway that is commonly associated with articulation projecting from the posterior temporal lobe through the supramarginal and on to the inferior frontal gyrus.

It appears that we may simulate what someone is saying to us in a process that includes mirror neurons within the IFG and which also activate speech motor areas. In other words as people are talking to us we are mirroring the process even to the point of simulating the same speech patterns.

It is understood that this helps anticipate the speech of others to the point that we may be able finish off their sentences. This anticipation facilitates the process of comprehension.

The two identified types of conduction aphasia are a phonological type that involves the supramarginal gyrus while another type more obviously involves errors of phonological short-term memory (phon STM) and is found following perisylvian lesions. The phonological type implicates the supramarginal gyrus that converts words into articulations. The phon STM is more likely to be a buffer store of to-be-articulated and recently-received sentences. A more comprehensive answer could be given to this question.

First there seems to be a general rule that a more complex semantic understanding of syntax requires more anterior processing in the temporal cortex. Also that the production of articulation is supported by anterior areas within the most inferior dorsal pathway which probably additionally support anterior aspects of the ventral pathway. The left inferior frontal gyrus (LIFG) is seen as playing a selective sequencing and organising syntax. One theory proposes that the more rostral areas of the LIFG supply more complex analysis required of syntax processing.

Persons with developmental dyslexia show a reduction in connectivity on the left side within the dorsal arcuate fasciculus and IFG with an increased inter-hemsipheric connectvity suggesting a less unilateral process of reading. This is typically associated with increased bilateral activation of areas associated with reading such as visual form word area (VFWA). The VFWA is an area that converts letters into the physical image of words and orthography.

Also, during reading there is a greater activation of the hippocampus suggesting a conrolled rather than an automatic retrieval of words during reading.

The conversion that occurs of reading regular words that converts letters or combinations of letters into speech sounds using rules of pronuciation.

A study has found more bilateral activation and activation between the frontal and posterior areas of the right hemisphere. This has been interpreted as the failure of the grapheme to phoneme conversion rules and with dyslexic persons having to read regular words as if they were irregular, in other words learning the speech sound for each word and not using the easier rules of pronunciation. Some of the activation of the right hemisphere is seen to be related to the use of working memory which would be required when learning words for the first time.

These two Japanese terms refer to different types of script. Kana refers to phonetic driven writing while kanji are the ideographics (each ideograph of lines representing a word or concept). It is assumed that they may represent the reading requirements of regular versus irregular word reading respectively. In the case of kanji, like some dyslexic reading, there is a tendency for bilateral involvement (left and right hemisphere) especially in the medial fusiform area (BA 37).

This question may be answered by direct reference to the text.

Because it is unlikely that we have evolved to read it is understood that some structures have been taken over for the purpose of reading. The VWFA is a unit that provides the visual representation of the word, but this structure also provides for the perception of faces and other stimuli and so it is likely that this has been "hijacked" for word reading. The role of the left VWFA is seen as providing the initial orthographic representation of the written word. The plasticity is required with VWFA's interaction and feedback with areas that serve phonological analysis so that a relationship can be made between the physical form of the word (orthography provided by VWFA) and its phonological representation. In this way pathways may be set up to represent the relationship between orthography and phonological features required for initially learning to read.

Each irregular word has to be learned in relation to its meaning. It is assumed that the associated meaning is then stored within the anterior temporal lobe in the same or similar area to the atrophied area that is associated with semantic dementia. There are pathways beween the VWFA and the anterior poles of the temporal lobe that would allow for this storage acccording to experience. Part of this explanation assumes that regular words would have redundant storage which is stored elsewhere within the phonological lexicon and perhaps the semantic Centre 1. Does this mean that regular words are not stored in Centre 2? It is not possible to say at present, but the author suspects that regular words are also stored in Centre 2 and the only reason that these are relatively preserved following atrophy to Centre 2 is that they are compensated by a second storage in Centre 1.

This a question that relates to the three possibilities mentioned in the text. The additional phonological dyslexia may be understood in terms of the understanding of the two locations within the language area and their juxtaposition, that may increase the probability that they are coincidentally damaged.

Second the idea that with extreme phonological dyslexia it might not be the deep dyslexia that is at fault in reading so much as the need to have phonological analysis to differentiate between words that are semantically similar e.g. curtains and blinds or clock and time.

Third is that the right hemisphere takes over the reading and so bothphonological and deep (semantic) dyslexia might occur. This last proposal is less attractive given that in adulthood language is not obviously transferred to the opposite hemisphere as easily as in childhood. Also, this would dispute the pure alexia theory of the right hemisphere being involved in letter-by-letter reading.

Finally, it might be an issue as to when the deep dylexia with or without phonological dyslexia is acquired. There is a described alternate route for automatic reading pathway that seems to involve semantic Centre 2 (this is uncertain). With two alternative semantic centres this might explain the rarity of this disorder since in this instance one centre would compensate for the other.

While it might be difficult to describe a standard phonics treatment for the remediation of dyslexia, describe the components of a phonics training that might be expected to improve grapheme to phoneme conversion.

While training might include letter identification, letter-sound knowledge, and phonological output phonics training might take a phoneme such as "sh" and train the person using a variety of words which contain that phoneme. Also, choose perceptual training, articulation and meaning of words containing such sounds. Practise using words and non-words.

The patients should first be assessed in the retrieval of verbs and nouns individually, then in the construction of sentences (simple to complex) and finally in the production of sentences. Any one of these may be impaired without the other and require extra training. There is some evidence that each of these stages must be applied since it is possible to have one of these areas more impaired than the other. For example, a person may be able to retrieve verbs which are more important than nouns because they concern syntactical information. However, being able to retrieve verbs may not mean that the same patient is able to apply such verbs to make sentences. Retrieving verbs within the context of a sentence may encourage more appropriate application of verbs towards syntax.