Language and Aphasia PDF

**Language and aphasia** **Communication and language** - Animals use several modalities to communicate (e.g., sounds or gestures) - Communication in humans is highly related to verbal language - Language is not a synonym of communication: only humans communicate through arbitrary/con...

**Language and aphasia** **Communication and language** - Animals use several modalities to communicate (e.g., sounds or gestures) - Communication in humans is highly related to verbal language - Language is not a synonym of communication: only humans communicate through arbitrary/conventional symbols, which are different between populations and in constant evolution language includes the whole set of these conventional signals and the rules to combine them - The complexity and sophistication of human language suggests that extensive regions of the brain must be dedicated to dealing with it **What is language?** Any communicative act through language implies: - a sender (encoding of a message in a linguistic sequence) - a receiver (decoding of the message = understanding of the meaning) → language production and language comprehension Immagine che contiene testo, diagramma, schermata, linea Descrizione generata automaticamente **Hemispheric dominance** - The two cerebral hemispheres (left and right) do not necessarily participate equally in each cognitive function - As for manual preference, the dominance of the left hemisphere for language is genetically programmed (= you use one more than the other) → the concept of dominance does not imply that one hemisphere governs the other, nor that one hemisphere presides exclusively over single integrative functions - Thus, perysilvian lesions that cause aphasia are usually located in the left hemisphere in almost all right-handed people and approximately 70% of left- handed or ambidextrous people → in a small % of right-handed people (between 1% and 5%), aphasia may be due to a right hemispheric lesion **The right hemisphere** - Understands words and short sentences - Deciphers written language - Weak capacity for retaining the auditory message - Does not have access to the expressive faculty - It is also responsible for knowledge of social concepts and interpretation of prosody (emotional aspects of language), so it's associated with "higher-level" language tasks → patients with right hemisphere disorders may lose the ability to comprehend and show emotion (e.g., empathy and embarrassment), interpret sarcasm, and manipulate prosody \- - \> metalinguistic features mapped onto the linguistic message Different aspects of language are related to different areas: - Seeing words: occipital area (visual cortex) - Hearing words: perisylvian area - Speaking words: frontal area **Aphasic syndromes** **Definitions** - *[Aphasia]*: general term meaning disruption/loss of language function(s) - *[Syndrome]*: a number of symptoms co-occurring (occurring together) and characterizing a particular disease; the mechanistic reason for their co-occurrence is not always fully understood; but of the etiology (= set of causes of a disease or condition) **APHASIC SYNDROME** refers to a disorder in language production and/or comprehension (which can be differently affected) following a brain lesion, in patients with fully acquired language skills → the deficits cannot be due to the inability to produce linguistic sounds (deficits in the phono-articulatory apparatus), perceive linguistic sounds (deafness) or mental confusion / disorientation / delusion \- - \> etiology: 40% following a stroke condition, but it can be present also in degenerative disorders (e.g., Alzheimer's and Pick's diseases), or related to brain inflammation, tumor or head injury **Broca's aphasia** Patient "Tan-Tan" had impaired language production but spared comprehension: patients have difficulties in producing a coherent speech as they seem to have problems in finding the words they want to use; some words are omitted (telegraphic speech); some have comprehension difficulties → after his death he discovered, through the autopsy, that he had a lesion in the left inferior frontal gyrus \- - \> conclusions: language production is localized in the left inferior frontal gyrus (sylvian fissure, frontal area) ++ usually aware of the problem **Wernicke's aphasia** Described a patient with 'opposite' symptoms as compared to Broca's - Fluent speech - Many sound errors - Use of semantically inappropriate words: non-words, made-up words, paraphasias (words that are semantically related but nevertheless inappropriate → this speech is called "word salad" because it tends to include random words and phrases thrown together - Impaired comprehension - Usually not aware of the problem Wernicke hypothesized a damage in the "storehouse of auditory word forms" and, by analyzing the autopsy of a patient showing similar symptoms, he supposed that this storehouse could be located in the posterior part of the superior temporal gyrus (STG) ↓ Wernicke (1877) Der aphasische Symptomenkomplex: the first theoretical model on language neurophysiology in which it was said that... - The brain is organized in projection pathways and associative areas - The whole left peri-sylvian region is responsible for language → they were right in a way, the problem was that they didn't understand that it was a network of regions, not just a specific one The Wernicke's arc (1874): Wernicke added the following to what Broca had said language depends on a system, including: - A storehouse (long-term store) of auditory images of words → lesion in Superior Temporal gyrus = Wernicke's aphasia - A storehouse of motor images of words → lesion in Inferior Frontal gyrus = Broca's aphasia these 2 systems are connected through an anatomical structure/pathway → the arcuate fasciculus **WERNICKE-LICHTHEIM MODEL** (1885): Localizationist model Speech input -\> auditory analysis of this input it arrives in region A (Wernicke area): now 2 different pathways 1. Comprehend the linguistic message → then go to M (Broca area) and produce speech 2. Repeat what we heard: from A to M (Arcuate fasciculus) \*M = Motor center -\> storehouse for motor representation of words \*A = Auditory center -\> storehouse for auditory representation of words \*B = concept center -\> conceptual representations (B from German "Begriffe", which means "concepts")  thanks to this model we can understand different aphasic syndromes  **Subcortical sensory aphasia/subcortical motor aphasia** = related to sensory and motor aspects, so you're not able to hear sounds or articulate speeches with your muscles ++ related to gray matter **Broca's aphasia** = deficit in production and articulation (related to gray matter: inferior frontal gyrus) → speech is: - slow - effortful - non-fluent - very simple grammatical structure → speech programming deficit: loss of the ability to execute speech movements (no facial or vocal muscle paralysis) → we have a Telegraphic and Agrammatic speech → patients: - may have similar "agrammatical" problems when writing - may be able to use well-practiced expressions ("It never rains but it pours!") and to sing a well-known song - usually have preserved comprehension - may read aloud in a relatively unaffected way **Wernicke's aphasia** Opposite pattern of symptoms to Broca's aphasia = deficit in comprehension, repetition, naming and meaningful output (related to gray matter: superior temporal gyrus) → speech is fluent speech, but with little or no meaning (word salad) → we can observe: - production of neologism and non-words - semantic paraphasias - paragrammatism - anosognosia: they're not aware of their problem because they are not aware of what they are producing **Agrammatism (Broca) vs Paragrammatism (Wernicke)** - **AGRAMMATISM** - **PARAGRAMMATISM** = refers to the inability to form grammatically correct sentences well-constructed sentences with errors in grammatical morphemes and substitution of lexical items **Transcortical motor aphasia** Similar to Broca's = aphasia but with preserved repetition and spontaneous speech is absent ++ presence of echolalia (to repeat things aloud) ++ white matter disconnections **Transcortical sensory aphasia** Similar to Wernicke's = impaired comprehension, preserved repetition and spontaneous speech ++ presence of echolalia (to repeat things aloud) ++ white matter disconnections **Conduction aphasia** = preserved comprehension, impaired repetition (especially of novel or unusual words) ++ white matter disconnections the frequency of phonological errors in conduction aphasic patients depends on the posterior extension of the lesion, i.e., how much it affects: - the posterior part of the superior temporal gyrus (BA 22) and the neighbor posterior parietal cortex (supramarginal gyrus, BA 40) - or the white matter connecting it to frontal regions (arcuate fasciculus) **Anomic aphasia** = disturbance in the production of single words, most marked for common nouns, intact comprehension and repetition disturbances of concepts and/or the sound patterns of words inferior parietal lobe or connections between parietal lobe and temporal lobe; can follow many lesions **Global aphasia** = major disturbance in all language functions: it affects both production and comprehension of language disruption of all language processing components large portion of the perisylvian association cortex **Isolation of the language zone** = disturbance of both spontaneous speech (sparse, halting speech) and comprehension, with some preservation of repetition; echolalia common disconnection between concepts and both representations of word sounds and the speech production mechanism cortex just outside the perisylvian association cortex **Summary**  **Limits of the "classical" aphasic syndromes classification** 1. Most aphasic patients show deficits in both language comprehension and language production, while the model implies a dichotomy partially replaced by the classification in fluent vs. non-fluent aphasia forms 2. The association between symptoms and lesions is not so reliable the brain regions involved in language are much more than those identified by the classical Wernicke-Lichtheim model 3. The classification does not consider the analysis of deficits in the different areas of linguistics (phonological, morphological, lexical, syntactic level) allows a better classification of symptoms and their co-occurrence 4. The model does not explain the pattern of dissociations found in aphasic patients, e.g., dissociations between deficits in different grammatical classes (e.g., nouns and verbs) or lexical categories 5. The model does not allow explaining the behavior of some aphasic patients in tasks like reading and writing or repetition of non-words 6. The model does not provide the possibility of processing non-lexical sequences (non-words) ↓ **Non-words** Non-word = a sequence of letters or sounds that is not accepted as a word by speakers of a specific language, used especially in (neuro)psychological or linguistic experiments **Fluent vs non-fluent aphasia** This classification maintains the dichotomy between anterior vs. posterior lesions leading (most likely) to different types of disturbances (fluent vs. non- fluent aphasia), but the difference between the two does not regard production vs. comprehension: they are characterized by a qualitatively different speech this classification focuses on the quality of the speech - **FLUENT APHASIA** No articulatory deficits nor effortful speech; no agrammatism (but paragrammatism) More frequent in the elderly see Wernicke's aphasia, conduction aphasia - **NON-FLUENT APHASIA** **Psycholinguistic perspective** LINGUISTICS: The scientific study of language and its manifestations language is hierarchically organized: 1. *Phonetics* studies how humans produce and perceive sounds (phonetic tracts) 2. *Phonology* studies how languages/dialects systematically organize their sounds in words 3. *Morphology* describes the rules applied to combine phonemes in words 4. *Syntax* describes the rules applied to combine words in sentences 5. *Semantics* describes the association between words and meaning (damage: temporal pole) 6. *Grammar* describes the rules to combine units in hierarchical structures 7. *Pragmatics* studies the language in a context, how it is used in social interactions **Psycholinguistics** It's the study of the psychological/cognitive processes at the basis of language - it studies the interrelation between linguistic factors and psychological aspects; - it concerns the mechanisms by which language is processed and represented in the mind and the brain ([neurolinguistics]) analysis of symptoms of aphasic patients based on different levels of analysis (phonological units, words, sentence, discourse) **Language is hierarchically organized** - Phonological units are the distinctive units that allow the identification of words, and are composed by phonetic tracts (= how sounds are produced by the phono-articulatory apparatus and perceived by the auditory one) - Morphemes are the elementary units of words conveying information - Some morphemes combine to create words (e.g., prefix \[sub-, pre-, anti-\]) - Words combine to create sentences **Phonetics and phonology** **PHONETICS** studies how humans produce and perceive sounds (units = phonetic tracts) the physical features of verbal communication - Articulatory phonetics = how speech sounds are produced - Auditory phonetics = classification of speech sounds based on how they are perceived phonetic tracts (= how sounds are produced by the phono-articulatory apparatus and perceived by the auditory one **PHONOLOGY** studies the rules used to systematically organize sounds in words. phonological units allow the identification of words, and are composed by phonetic traits **Classification of language sounds (glossary)** **VOWELS AND CONSONANTS** - Vowels = speech sounds produced by an open configuration of the vocal tract, with vibration of the vocal cords but without audible friction (no obstacles in the flux of air), see a, e, i, o, u, y - Consonants = speech sounds articulated with complete or partial closure (obstruction) of the vocal tract Consonants are either voiced (sonant) or voiceless (surd) - Voiced consonants are pronounced with the same vocal murmur (vibration of the vocal cords) that is heard in vowels e.g., b, d, g, l, r, m, n, z - Voiceless consonants are produced without a vibration of the vocal cords and lack this murmur e.g., p, t, c (k, q), f, h, s, x Consonants can be also classified depending on the place of articulation **Disorders of phonological processing** **PHONOLOGICAL SELECTION ERRORS (PRODUCTION)** = result in the production of incorrect phonemic sequences, easily recognizable when they constitute neologisms crucial features: - They include the specific sounds of the patient's language phoneme perception is categorical (Liberman, 1967): - We can primarily distinguish (and systematically produce) the speech sounds that we have learnt through linguistic development (mother tongue) - Once these categorical boundaries are learnt, they cannot be forgotten - The neologisms follow the same phonemic rules of the patient's language (e.g., no sequences of consonants) **PHONOLOGICAL PROCESSING ERRORS** In aphasic patients, a phonological deficit is characterized by the presence of **phonemic paraphasias** (substitutions, omissions, additions and transpositions of phonetic units) even multiple that sometimes make the target words unrecognizable (**phonetic neologisms**) often the patient tries to correct the phonemic errors produced by means of spontaneous corrections, sometimes repeated in trials (**conduites d'approche**) \- - \> in some cases the phonemic errors can result in words that actually exist and thus simulate a lexical rather than phonological substitution Phonemic paraphasia refers to the substitution of a word with a word or a nonword that preserves at least half of the segments and/or number of syllables of the intended word some examples of phonemic paraphasias: - [Anticipatory errors]: a syllable from later in the word replaces a syllable from earlier in the word →\"papple\" for apple or \"lelephone\" for telephone - [Paradigmatic errors]: based on similarity in how the sounds are formed →\"marmer\" for barber → lips-related consonants - [Substitution errors]: involve a clear phonological substitution →\"ragon\" for wagon - [Epenthetic errors] are the insertion of a segment into the target → \"plants\" for pants - [Metathetical errors]: the full exchange of segments →\"deks\" for desk **DISORDERS OF PHONOLOGICAL PROCESSING** **Phonological decoding (comprehension)** When listening to spoken words - [Frequency effect]: higher frequency phonemes and phonological sequences are more easily identified - [Lexical status]: real VS non-words → people make more errors when listening to non-words than words and tend to interpret acoustically ambiguous phonemes in the form that is semantically congruent **Morpho-syntactic aspects of language** - Morphemes are the elementary units of words conveying information some morphemes combine to create words (e.g., prefix \[sub-, pre-, anti-\]) - Words combine to create sentences - Sentences convey relationships between the meaning of words → Morpho-syntactic aspects are the set of the propositional content of a sentence MORPHOLOGY: describes the rules applied to combine phonemes in words - Describes the class of each word (noun, pronoun, verb, adjective, preposition...) - Describes how to conjugate verbs and create derivations - (derivation = the formation of a word by changing the form of the base or by adding affixes/suffixes to it, e.g., "hope" to "hopeful") SYNTAX: describes the rules applied to combine words in sentences - Describes the order of the words, how to organize subordinates (dependent) - Describes how to use functional words (closed class words)\*, e.g., pronouns (you, them), modal verbs (could, must), determiners (a, the), prepositions (of, in), and conjunctions (and, but) MORPHO-SYNTAX: describes the relationship between morphology and syntax, e.g., rules applied to achieve agreement between nouns and verbs (singular/plural) The guy cooks Sentences convey relationships between the meaning of words propositional content of a sentence SYNTACTIC STRUCTURES: describe how individual words can be arbitrarily combined to convey propositional content → express one of several equally likely relations E.G: approximately 85% of aphasic patients have troubles in understanding/use the syntactic structure to convey/determine sentence meaning (Caplan et al., 1985) E.G: patients with Broca's aphasia show more errors in understanding sentences with reversable roles (where semantics cannot 'help') → the syntactic structure is the only source of information **SYNTACTIC STRUCTURES** Are studied by linguistics as syntactic trees (Noam Chomsky, 1928-alive) rules to describe how meaning can be derived from syntactic structures → identification of thematic roles = who does what → crucial for understanding co-reference (pronouns, reflexives), passive sentences... They divide each sentence in different types of morphemes: depending of the complexity and structure of the three, we will have different types of trees - S = sentence - NP = noun phrase - VP = verb phrase - N = noun - V = verb **DISORDERS OF SYNTACTIC PRODUCTION** = sentence production is a process including three major stages aphasic disturbances can affect: 1. The production of grammatical vocabulary elements → agrammatism and paragrammatism 2. The ability to generate syntactic forms → impoverishment of syntactic structures in spontaneous speech (simplification) 3. The ability to assign thematic roles (severely affected patients) **NEUROANATOMY OF SYNTACTIC PROCESSING** PREMISE: deficits in syntactic comprehension and production often co-occur in agrammatic patients, but they can also dissociate, and the severity of the deficit does not correlate they do not appear to depend on a single functional impairment (ONLY) Syntactic processing involves the whole left perisylvian associative cortex - Inferior frontal gyrus (BA 45, 44) (Broca) - Angular gyrus (BA 39) (integrative cortex) - Supramarginal gyrus (BA 40) (integrative cortex) - Superior temporal gyrus (BA 22) (Wernicke) EXPERIMENT Despite much research on agrammatism, the lesion correlates of paragrammatism are still unknown - Subjects: 53 right-handed patients with aphasia following chronic left-hemisphere stroke - Task: retelling the Cinderella story - Methods: lesion-symptom mapping was used to investigate the degree to which the lesion correlates of agrammatism and paragrammatism overlap or dissociate four expert raters assessed videos - Results: damage to Broca's area was significantly associated with agrammatism but not paragrammatism, while damage to the left posterior superior and middle temporal gyri was significantly associated with paragrammatism but not agrammatism → DOUBLE DISSOCIATION paradigm picture both at clinical, structural and functional level:  **DISORDERS OF LEXICO-SEMANTIC PROCESSING** Lexical semantics is the branch of linguistics which is concerned with the systematic study of word meanings lexicon refers to the store of language labels associated with concepts \- - \> semantic lexicons are made up of lexical entries: lexical entries are semantic (not orthographic) and are interconnected with semantic relations NEVERTHELESS, deficits in the semantic system or in the lexical retrieval (lexicon) lead to similar behaviors (e.g., anomia -- not being able to retrieve specific labels) \- - \> the organization of lexicon has been studied by psycholinguistics using *computational modelling* - they are artificial systems mimicking the behavior of patients and healthy subjects - they provide hypotheses on the organization of both the cognitive and the neural systems ('artificial' neural networks) \*Lexicon labels are different from conceptual and semantic ones Immagine che contiene testo, schermata, cerchio, diagramma Descrizione generata automaticamente It allows us to: - [Phonological input lexicon] (Ellis & Young, 1988) translates acoustic to semantic representations = understanding of the meaning of words - [Phonological output lexicon] (Ellis & Young, 1988) translates a concept into a spoken word - [Lexicon] = connections between domains (coherent with a distributed view of linguistic representations in the brain) **OTHER LEXICO-SEMANTIC EFFECTS** - WORD FREQUENCY Even in the lexical-semantic domain, frequency plays a role - AGE OF ACQUISITION during early learning, connection strength changes are large **LEXICO-SEMANTIC ERRORS** Among the deficits at the semantic-lexical level: - Anomia = a difficulty in retrieving words - Anomic latency = in the case of a simple delay in recalling a target word the words not recalled can sometimes be replaced by circumlocutions - Error in the choice of words, for which there are substitutions with terms of similar meaning (*semantic paraphasias*; for example: "glass" for "bottle") or with words without a relation of meaning (*verbal paraphasias*; for example: "tablecloth" for "telephone") PARAPHASIAS = confusions of words or the replacement of one word by another real word; length of the word is not often preserved some examples: - [Categorial]: same category → tiger for lion, car for van. - [Associative]: replace the target word with one that is related to the target but is not of the same category → foot with shoe - [Superordinate]: replace a specific target word with a more generalized group to which the target word involves → pear with fruit - [Subordinate]: replace the target word with one that is more specific → rose for flower **Aphasic patients -- sum of frequent symptoms** - *[Verbal stereotypy]* = nonpropositional utterance characterized by repetition of a syllable, word, or phrase (e.g., "ba-ba-ba," "yep," "bloody hell," "wait a minute"), typically used in high frequencies and as emotional exclamations - *[Phonemic paraphasias]* = substitutions, omissions, additions and transpositions of phonemes in a word - *[Phonetic neologisms]* - *[Conduites d'approche]* = effort to correct the phonemic errors produced by repeated spontaneous corrections - *[Anomia]* = deficit at the semantic-lexical level, difficulty in retrieving words - *[Anomic latency]* = simple delay in recalling a target word - *[Circumlocutions]* = a description of the word in place of the target word - *[Semantic paraphasias]* = substitutions of the target word with another semantically related - *[Verbal paraphasias]* = substitutions of the target word with another not semantically related - *[Agrammatism]* VS *[Paragrammatism]* **Double dissociation: category-specific deficits** NATURAL OBJECTS (dog, tree, strawberry,...) → left inferior temporal lesions ARTIFICIAL OBJECTS (comb, scissors, iron,...) → left parietal lesions = we may not be able to name natural objects, but artificial objects because they are related to different brain regions 2 hypotheses: 1. Separate organization at lexical output level (Hart, Berndt and Caramazza, 1985) 2. Different organization of conceptual knowledges (Warrington and Shallice, 1984) → natural objects have visual representations (left occipito-temporal cortex), artificial objects have functional representation (left parietal cortex) ↓ in a similar way ↓ NOUN → lesions in intermediate part of the second temporal gyrus VERBS → left premotor frontal lesions for non-fluent aphasia; left posterior temporal and inferior parietal lesions for fluent aphasia 2 hypotheses: 1. Noun and verbs have different relative weight of perceptual features (Bird, Howard and Franklin, 2000) verbs have less sensory information 2. Based on a peripheral lexical level, where lexical labels are represented separately (Caramazza and colleague, 2002) **How to test a patient with language impairments** - General medical history and history of language - left-handed or right-handed - bilingual - reading and writing - evolution of the linguistic disorder - Spontaneous speech (during the clinical interview) = the general ability to interact and communicate is tested while asking the patient to provide details related to pathology, disturbances, family situation, habits... it allows evaluating - the speech content: is it informative? - the pragmatics: is language appropriate to the situation? - comprehension: does the patient understand my questions? During spontaneous speech it is also possible to identify: - articulatory disturbances - phonological, lexical/semantic, morphological, syntactic errors - perseverations and automatisms (e.g., repetition of brief lexical idiosyncratic sequences or even meaningless syllables) - Systematic evaluation of language abilities in the different areas (phonological, lexical/semantic, morphological, syntactic errors) can be done at very different degrees of precision/detail **International language batteries** NEUROLINGUISTIC APPROACH - Boston Diagnostic Aphasia Examination (BDAE) \[Goodglass e Kaplan, 1972, 1982\] - Aachener Aphasie Test (AAT) \[Huber e coll, 1983\] - Western Aphasia Battery (WAB) \[Kertesz, 1982\] PSYCHOLINGUISTIC APPROACH - Psycholinguistic Assessment (PALPA) \[Kay e coll, 1992\] PRAGMATIC APPROACH - Communicative abilities of daily living (CADL) \[Holland, 1980\] **How to test a patient with language impairments** **Systematic evaluation of language abilities in the different areas (phonological, lexical/semantic, morphological, syntactic errors)** can be done at very different degrees of precision/detail **Object naming or object picture test to assess lexical retrieval ability** possible presence of anomia, anomic latency, circumlocutions generally, the non-retrieved word is not lost at all; it is not accessible to the patient at that moment, but it can be facilitated through more automatic sentences or expressions, or be found on other occasions **Repetition tasks** → phonemic paraphasias, phonemic neologisms and conduites d\'approche to test repetition ability, stimuli of different length and complexity are used: starting with bisyllabic words with a simple structure (alternation consonant- vowel) and continues with progressively longer and more complex words **Oral comprehension** 1. Execution of verbal orders: it is best to avoid the most obvious ones, which are part of a medical examination and can get randomly correct answers (e.g. \"Open your mouth\"); it is more appropriate to give \"artificial\" orders (e.g. \"Knock the table three times\"), to be sure that the patient has actually recognized and understood the command 2. Recognition of objects: the patient is presented with a series of common objects; the examiner names one and asks the patient to indicate it (e.g. \"What is the key?\", \"What is the pen?\") 3. Repetition of words and phrases, said by the examiner **Other related syndromes** - Alexia - Agraphia - Acalculia **Treatment** Please note: in the different phases of stroke and related aphasia disorder (acute versus chronic), a different therapeutic approach is suitable due to the different neurophysiological mechanisms underpinning each phase different disorder -\> different treatment plan (if the patient is the same) 1. **Behavioral protocols for Speech and Language therapies** a. PHONOMOTOR TREATMENT: aims to boost word retrieval through the training of phonological skills b. SEMANTIC FEATURE ANALYSIS: lexical retrieval is supported by strengthening semantic networks c. VERB NETWORK STRENGTHENING TREATMENT: lexical retrieval, sentence production and discourse are facilitated by working on verbs, which have a central role in semantics and syntax d. SOUND PRODUCTION TREATMENT: articulatory--kinematic treatment e. TREATMENT OF UNDERLYING FORMS: based on generative syntax and targets deficits exhibited at the sentence level in people with agrammatic aphasia by training the production of grammatically complex sentences f. CONSTRAINT-INDUCED LANGUAGE THERAPY: a treatment approach for expressive language difficulties g. MELODIC INTONATION THERAPY: first developed to recruit right hemispheric brain regions related to the awareness of melody and rhythm to improve expressive language in individuals with non-fluent aphasia 2. **Computerized aphasia therapies derived via computers, smartphones, or tablets** allows for long-term and low-cost therapy options 3. **NIBS: Non-invasive brain stimulation** a. [Upregulate neural activity in perilesional brain areas of the affected hemisphere through excitatory stimulation protocols] (i.e., high frequency rTMS or anodal tDCS) b. [Downregulate neural activity in contralesional brain regions through inhibitory stimulation protocols] (i.e., low frequency rTMS or cathodal tDCS)