Aphasia: Orthographic Disorders of Acquired Nature (Sphy309)

Cognitive-Communication Overview and Aphasia

Conceptual Definitions * Cognition: Refers to thinking skills including memory, attention, problem solving, and thinking speed. * Cognitive Communication: A complex combination of thinking and communication skills required to engage in everyday life. * Cognitive-Communication Disorders: Difficulties with communication where the underlying cause is a cognitive deficit rather than a primary language or speech deficit. An impairment results from dysfunction in one or more cognitive processes.
Cognitive Processes Involved * Attention: Selective concentration. * Memory: Recall of facts, procedures, and past, future, or present events. * Perception: Interpretation of sensory information. * Insight and Judgement: Understanding one's own limitations and their implications. * Organisation: Arranging ideas in a useful order. * Orientation: Knowing where, when, and who you are, as well as why you are there. * Processing Speed: Quick thinking and understanding. * Problem-solving: Finding solutions to obstacles. * Reasoning: Logically thinking through situations. * Executive Functioning: Making a plan, acting it out, evaluating success, and adjusting as needed. * Metacognition: Thinking about how you think.
The Continuum of Communication * Intention to Communicate: Related to ideation (Cognitive-Communication Disorders). * Message Formulation: Related to symbolisation (Aphasia). * Linguistic Encoding: Related to symbolisation (Aphasia). * Motor Planning: Related to translation (Apraxia of Speech). * Motor Programming: Related to translation (Apraxia of Speech). * Motor Execution: Related to execution (Dysarthria).

Research and Testing of Cognition in Aphasia

Prevalence and Evidence * Fonseca et al. (2016): Conducted a study of $47$ studies involving a total of $1710$ aphasic patients. They found that $61.3\%$ of these studies showed that patients with aphasia following a stroke tend to obtain lower scores than healthy subjects on most nonverbal cognitive tests. * Marinelli et al. (2017): Highlighted several studies indicates the presence of deficits in memory, attention, recognition abilities, logic skills, and executive functions in patients with aphasia. * Recovery Correlation: A high level of cognitive ability is predictive of better and faster recovery of language abilities (Marinelli et al., 2017).
Assessment of Cognitive Domains * Testing cognitive abilities in People With Aphasia (PWA) is difficult because many tests rely on language. * Recommended Batteries: * Butt Test of Nonverbal Reasoning: Useful for nonverbal assessment (Butt & Bucks, 2004). * Cognitive Linguistic Quick Test (CLQT): Certain components are advisable to extrapolate cognition from language (Helm-Estabrooks, 2001). * MMSE: Mini-Mental State Examination. * CAT: Comprehensive Aphasia Test. * Brisbane EBLT Cognitive Screen.

Definitions and Foundations of Alexia and Dysgraphia

Alexia * An acquired impairment of reading affecting oral production and/or comprehension of written language. * Distinct from developmental dyslexia. * Divided into peripheral and central alexias. * Treatment is informed by understanding the nature of the reading impairment via psycholinguistic models.
Dysgraphia * An acquired disorder of spelling following focal brain damage. * Caused by an impairment of the lexical and/or sublexical spelling route. * Ranges from physical writing issues to difficulties in organising and expressing letters, words, sentences, and thoughts in written form. * Uses linguistic procedures to retrieve orthographic forms of familiar words (lexical memory) and assemble plausible spellings for unfamiliar words/nonwords.
Brain Mechanics * Familiar words use "whole word reading." * New/unlearned words use "phonetic reading" (sounding out letters).

The PALPA Model: Information Processing of the Lexicon

Abstract Letter Identification (ALI) * Function: Letters must be recognised before the word itself can be recognised. Decides if a string of letters is a real word independent of font or case (e.g., "a" vs "A"). * Impairment: Pure alexia, neglect dyslexia. * Parallel Partner: Auditory Phonological Analysis (APA).
Orthographic Input Lexicon (OIL) * Function: Recognises visually presented words. It is an internal dictionary of word spellings without meaning or pronunciation information. * Impairment: Surface dyslexia. * Parallel Partner: Phonological Input Lexicon (PIL).
Semantic System (SS) * Function: Contains meanings of known words (e.g., knowing a piano is a musical instrument). * Status: This system is shared across all modalities (reading, writing, speaking, listening). * Impairment: Deep dyslexia.
Orthographic Output Lexicon (OOL) * Function: Store of written forms (spellings) for all known words. Used for spontaneous writing (SS to OOL). * Impairment: Surface dysgraphia. * Parallel Partner: Phonological Output Lexicon (POL).
Letter-to-Sound (L2S) and Sound-to-Letter (S2L) Rules * L2S: Used for sounding out words. Parallel to Acoustic-to-Phonological Conversion (A2PC). * S2L: Used for spelling unknown words or nonwords (e.g., /krut/). * Impairment: Inability to decode or encode nonwords.
Orthographic Output Buffer (OOB) * Function: A temporary storage system. It holds the spelling specification of a word while it is being written (e.g., holding the $10$ letters of "rhinoceros" in sequence). * Impairment: Affects all writing (words and nonwords) and often demonstrates a "length effect." * Parallel Partner: Phonological Output Buffer (POB).

Subtypes of Alexia

Peripheral Alexias (Early Visual Processing Stages) * Pure Alexia: Impairment in identifying and processing letters within a word. Result is "letter-by-letter" reading. Impairment is at the level of visual orthographic analysis/abstract letter identification. * Neglect Alexia: Impairment in identifying initial or final letters (e.g., reading "cat" as "bat" or "book" as "look"). Spatial consistency is usually present. * Attentional Alexia: Impairment due to interference from other letters (e.g., "riverbank" becomes "biverbank"; "butterfly" becomes "flutterfly"). * Visual Alexia: Errors represent real-word substitutions (e.g., "house" for "horse") without the spatial consistency seen in neglect alexia.
Central Alexias (Later Stages: Phonologic or Semantic Processing) * Surface Alexia: Impaired reading of irregular words (e.g.) yacht) with intact reading of regular words (e.g., bike) and pseudowords. Known as the "regularity effect." Errors include visual errors or regularisations (e.g., "pint" as /p\ɪnt/). * Deep Alexia: * Severely impaired nonword reading (e.g., Cannot read $/blik/$ ). * Semantic errors (e.g., "apple" → "banana"). * Visual errors (e.g., "table" → "cable"). * Morphological errors (e.g., "baking" → "baked"). * Imageability effect: Better success with concrete words (e.g., "horse") vs. abstract words (e.g., "freedom"). * Part-of-speech effect: Better success with content words (e.g., "bee") vs. function words (e.g., "be"). * Phonological Alexia: Impaired nonword reading in the absence of semantic reading errors. Shares visual and imageability effects with deep alexia.

Subtypes of Dysgraphia

Surface Dysgraphia: Difficulty spelling irregular/ambiguous words due to lost/degraded orthographic representations. Errors are usually phonologically plausible (e.g., "oshen" for "ocean"). Demonstrates a high-frequency effect.
Phonological Dysgraphia: Marked impairment of nonword spelling with preserved real-word spelling. Impairment is in the non-lexical route (S2L rules).
Deep Dysgraphia: Semantic errors are prominent (e.g., writing "clock" for the target $TIME$ ). Features similar to phonological dysgraphia plus semantic deficits.
Semantic Dysgraphia: Damage to the lexical-semantic route. Difficulty with homophones (e.g., "pear" vs "pair") because the writer cannot rely on semantic context. Writing to dictation is often preserved because it can bypass the semantic system.
Graphemic Buffer Impairment: Errors in grapheme identity and order affecting all writing tasks (spontaneous, copying, dictation, naming). Not affected by frequency or imageability, but strongly affected by word length.

Assessments for Alexia and Dysgraphia

Linguistic Variables to Consider * Real words vs. Nonwords (Lexicality). * Regularity: Regular (e.g., "cat", "drink") vs. Irregular (e.g., "yacht", "psychic"). * Imageability: High-imageability (e.g., "jury") vs. Low-imageability (e.g., "justice"). * Length: Long vs. short words. * Error Patterns: Semantic (e.g., "APE" → "monkey") vs. Visual (e.g., "DOOR" → "doom").
Alexia Assessment Materials * Standard aphasia batteries: Comprehensive Aphasia Test (CAT), Boston Diagnostic Aphasia Examination (BDAE-3), Western Aphasia Battery-R (WAB-R). * PALPA subtests: $18$ to $36$ , $38$ (reading aloud), and $48$ (matching written word to picture). * Reading Comprehension Battery for Aphasia, 2nd ed (RCBA). * Gray Oral Reading Test-5 (GORT-5). * The Gates-MacGinitie Reading Test (GMRT). * Kempler Sentence Comprehension Test. * Arizona Battery for Reading and Spelling (ABRS).
Dysgraphia Assessment Materials * Spontaneous Writing: Evaluated via standard stimuli in the WAB-R or CAT. * Single-Word Writing: PALPA subtests assessing frequency, length, imageability, and regularity. * Johns Hopkins University (JHU) Dyslexia and Dysgraphia Batteries.

Summary of Cognitive Neuropsychology Features

Core Realisations 1. The performance of the individual is the primary focus. 2. The nature of errors (e.g., semantic vs. regularisation) is always informative. 3. Performance is explained via cognitive neuropsychological models rather than just brain lesions or stroke locations.
Diagnostic Markers * Deep Dyslexia/Dysgraphia: Characterised by semantic errors (e.g., reading $NEPHEW$ as "cousin", writing $CITY$ as "town"). * Surface Dyslexia/Dysgraphia: Characterised by regularisation errors (e.g., writing $LISTEN$ as "liston", reading $ISLAND$ as "izland").

Perspectives on Lived Experience

Quotes from People with Aphasia (PWA) * Eva: "I'm a bit, I feel a bit disabled in writing and, that I can't write properly or write with my name properly." * Monica: "I think I'm saddest about the language, because… it's like… I think it's like a child when I'm writing, oh God I think, like an idiot, myself, annoyed that I can't get it down." * Andrew: "I don’t know what it says. I’m lost." * Barbara: "I know nothing anymore. Before, I add the numbers in my head, now shopping is nightmare. Numbers are gone." * Lars: "When I’m going on the tram, I can't read the signs as they pass me, because I have to read more slowly, read two or three times before I remember, you know."