Perception: Modules Information PDF

Perception =========== - The interpretation of information from the sensory system - All senses - Vision - Audition - Smell - Taste - Touch - Sensation -- receives, transmits and converts information from environment - Sensory organs -- transmit in...

Perception =========== - The interpretation of information from the sensory system - All senses - Vision - Audition - Smell - Taste - Touch - Sensation -- receives, transmits and converts information from environment - Sensory organs -- transmit information to brain - Top down and bottom up - Direct perception theories - Bottom-up processing - Perception comes from stimuli in the environment - Parts are identified and put together, and then recognition occurs - Constructive perception theories - Top-down processing - People actively construct perceptions using information based on expectations - Light / pattern / motion / colour / shape  - Recognition of (eg) dog - Perceptual processes include: -- Selection -choosing which stimuli to process. - Organization -- forming information into pattern. - Interpretation - understanding the pattern. - Perceptions can be in error - Illusions are visual stimuli that are misinterpreted. Perceptual Constancy ==================== - the tendency for the environment to be perceived as remaining the same even with changes in sensory input. - Size constancy - Shape constancy - Color constancy - Brightness constancy Interpretation - Influenced by: - perceptual adaptation - perceptual set - motivation - frame of reference Absolute threshold - Weakest amount of a stimulus that can be distinguished from no stimulus at all Detected 50% of the time Visual perception =================  **Rods** - - - - Visual perception - 'What' and 'Where' What? - Colour - Texture - Shape - Size - Where? - Location - Movement Visual perception ================= - Two neural systems - Ventral stream - Dorsal stream - Dorsal stream projects to posterior parietal cortex Ventral stream projects to inferior temporal cortex - Both project to frontal cortex - Looking, reaching and locomotion Ventral and dorsal streams ========================== Primary visual cortex ===================== - Cells respond differently to different aspects of the stimulus (e.g. orientation, size, colour) - Categorisation rather than analysis - Projects to other regions where analysis occurs - Damage to PVC leads to total or partial blindness Form perception =============== - Gestaldt -- unified whole - People organise visual elements into groups or unified wholes when certain principles are applied - Law of proximity - symmetry - Law of similarity - Law of common fate - Law of closure - Law of figure ground Law of proximity -- The closer objects are to each other the more likely they are to be perceived as a group Ehrenstein, 2004 - Law of symmetry - Law of similarity -- Objects that are similar in terms of components or attributes are likely to be organised together Law of common fate -- Objects with common movement or those that move in the same direction at the same pace or at the same time are organised as a group Law of closure -- There is a tendency to complete unfinished or partially obscured objects. Kanizsa's triangle is one example - Law of Figure Ground - Common perceptual illusions =========================== Blindsight ========== - Subjects are blind - no perception on visual information - Due to damage to area V1 BUT - can "guess" the direction of travel of a moving stimulus - can "guess" the colour of a stimulus - THEREFORE - they are able to discriminate some aspects of a stimulus - no perception of the stimulus - processing at the sub-conscious level - Visual information reaches other levels of the cortex, even when V1 is damaged Colour ====== - Trichromatic Theory - Three types of cones - Sensitive to red, green, or blue - Opponent-Process Theory - Three types of color - Red-green, blue-yellow, and light-dark Colour Blindness ================ - Trichromat - Normal color vision - Monochromat - Totally color blind - Dichromat - Partial color blindness - Discriminate between two colors (red & green, or blue &yellow) - More common in males (sex linked trait) - A person with red-green color blindness would not be able to see the 6, and a person with blueyellow color blindness would probably not discern the 12. Spatial function - Localising objects in space - Perception of movement - Depth perception - Spatial memory - Topographical orientation Perception of movement ====================== PET image of left side of brain Clinical example ---------------- - became unable to perceive continuous motion - rather saw only separate successive positions - unaffected in colour, perception, object recognition, etc - able to judge movement of tactile or auditory stimuli - difficulty crossing the street because she could not follow the positions of cars in motion. - difficulty following conversations because she could not perceive lip movement, so couldn't tell who was speaking Auditory Perception =================== - **What vs. Where system:** - Where: dorsal pathway -- Sound localization - What: ventral pathway --  Identifying sounds Perception of smell ==================== - Sensory information - about odours is sent to the brain through the olfactory nerve - Odour contributes to flavor of foods Perception of taste ==================== - Four primary taste qualities -- Sweet, sour, salty and bitter - Flavour of food depends on odour, texture, temperature and taste - Individuals have taste sensitivities Perception of touch and pressure ================================= Some areas of the body are more sensitive - Nerve endings are more densely packed - More sensory cortex is devoted to perception of sensations Temperature =========== - Receptors are located just beneath the skin - Skin temperature increases -- receptors for warmth fire - Skin temperature decreases -- receptors for cold fire - Sensations for temperature are relative Pain ==== - Nociceptors in skin are stimulated - Pain is usually sharpest where nerve endings are densely packed - Pain can be felt deep within body Phantom Limb ============ - Experiencing pain in amputated limbs - 2 out of 3 people with amputated limbs report phantom limb pain - May involve activation of nerves in the stump of missing limb - May also involve reorganization of motor and somatosensory cortex Body sensation ============== 1. Skin : touch, temperature, and pain. 2. Vestibular Sense: body orientation and threedimensional space - semicircular canals provide balance information. 3. Kinesthetic Sense: body posture, orientation and movement - Kinsethetic receptors in muscles, joints, and tendons. - Pain - Kinaesthesia - Vestibular - Kinesthesis -- Sense of position and motion of your body - Vestibular function - - Agnosias ======== - Inability to recognise objects despite having intact knowledge of the object's characteristics. - May perceive geometric features of an object but not know what it is used for. Can be present in other sensory modalities Types of Agnosia ================ - Sensory (Warrington, 1985): - colour, form, acuity, motion detection. - Apperceptive (Lissauer, 1890): -- Perception impaired - impairment is to object perception. - Associative agnosia (Lissauer, 1890): -- Perception intact and impairment is to the association of the percept with meaning. - Knowledge about objects can be impaired. - Category specificity (living versus non-living). Apperceptive visual agnosia =========================== - Visual acuity normal and perception of stimuli in both visual fields may be intact - Cannot point to named objects. - Cannot match, copy, or discriminate simple visual forms - May draw well from memory - Recognition may improve if the objects are moved around Associative Agnosia =================== - Cannot point to named objects Can match, copy and discriminate simple visual forms such as geometric shapes - Cannot process meaning: Prosopagnosia ============= - Term first used by Bodamer, 1947 - Inability to recognize familiar faces - Visual acuity is normal - Caused by lesion to right inferior temporal lobe - May be congenital - Patients compensate by using other recognition cues: clothing, gait, voice, etc **PARIETAL** Somatosensory changes **FRONTAL** Impaired spatial relations Personality changes Hemispatial neglect **OCCIPITAL** Alexia (disorders of muscle movements **CEREBELLUM** Ataxia Perception ========== PERCEPTION ========== - Senses provide information about the environment. -..stimuli to the brain from senses are recognised and interpreted in light of persons present situation and past experiences. -..impairment in recognition or appreciation of sensory stimuli in the presence of an intact sensory system\.....peripheral sensory receptors are still working. - Wide variety of deficits grouped together and referred to as \'perceptual deficits' - Usual to see a variety of deficits in same patients **Sensory-Perceptual Function** ------------------------------- - Distinction between sensation and perception: - The [senses] capture information from the environment - Subsequent elaborations and interpretations in different parts of the brain enable one to [perceive] or become aware of external stimulation - The most common perceptual deficits are: - auditory - tactile - visual **Factors Influencing Evaluation of Sensory-Perceptual Function** ----------------------------------------------------------------- - Underlying primary sensory deficit (eg. color blind at baseline, hypoacusis at baseline secondary to age-related hearing loss) - Advancing age may diminish senses and dull perception - The state of the perceiver(e.g. anxiety, physical discomfort) may influence the perception of a stimulus - Severe language problems can impair a patient's ability to respond appropriately to tests of sensory function Categorisation ============== - e.g. body image - anosognosia or denial - unawareness - unilateral neglect - inattention Categorisation ============== - localisation of objects in space - recall of spatial location - route finding - topographical memory - reading and counting - visual construction - right/left orientation Categorisation ============== - e.g. limb kinetic apraxia - ideomotor apraxia - ideational apraxia - constructional apraxia - dressing apraxia (?) Gnosia (Agnosia) ---------------- - Knowledge of......... - An inability to recognise familiar objects through the senses Agnosia ------- - Two Types - Apperceptive - Object recognition failure due to perceptual processing - Associative - Perceptual processing intact but subject cannot use information to recognize objects Agnosia ----------------------------- ### Anosognosia - Lack of awareness of impaired neurologic or neuropsychological function which is obvious to the clinician and other reasonably attentive individuals. - Difficulty performing a planned motor activity in the absence of paralysis of the muscles normally used in the performance of that act. - Can also be considered a disorder of language as many procedural tasks are verbally mediated. - Basic sequence of events and logical plan underlying a chain of simple actions is disrupted - Ideomotor apraxia - Dissociation between the areas of the brain that contain the ideas for movements and the motor areas that actually execute the movements. - Constructional apraxia - Inability to produce properly organized constructions such as drawings or simple building tasks - Motor apraxia - Not generally reported by patient, but family will often describe difficulty with using common objects (toothbrush, eating utensils). Dyspraxia --------- "Is the disorder of the execution of learned movement which cannot be accounted for by weakness, incoordination, sensory loss, incomprehension or inattention to commands " (Geschwind 1975, in Jackson (1999) BJOT 62(7) Ideomotor Apraxia ----------------- - Inability to correctly perform learned skilled movements, when this deficit cannot be attributed to weakness, sensory loss, etc. - Greatest difficulty in attempting to pantomime an action (e.g., sawing a piece of wood, using a phone); improves with imitation, and best when using actual object - Lesion: Left inferior parietal lobe Constructional Apraxia ---------------------- - Probably a heterogeneous deficit. - Spatial-perceptual problems - Motor planning - Visuo-motor integration - Sequence planning ("executive control") - Lesion: - left or right parietal (stronger association with right), but also frontal Constructional Apraxia ---------------------- Constructional Apraxia ---------------------- - Left vs. right hemisphere variants show subtle differences along a *local-global* dimension - Loss of topographical memory - Inability to find the way and tendency to become lost in familiar and unfamiliar environments - Apraxic agraphia- - poor letter formation - spatial distortions - patient/family report illegible handwriting - Alexia (difficulty reading) - may occur as a result of an inability to perform the continuous and systematic scanning eye movements necessary for reading - may also be considered a language deficit - Acalculia (difficulty with calculation) - may result from misplacement of digits, misalignment of columns, or aphasia for number symbols Disorders of Body Scheme ------------------------ Spatial Relations Deficits -------------------------- - Ability to perceive spatial relationships and distances between objects and yourself and objects. - **Figure -- Ground** - **Form Constancy** - **Depth / distance deficit** - **Position in space** - **Topographical Disorientation** - **(spatial neglect)** Disorders of Attention **Visual Neglect** - Also called [hemispatial neglect] or [unilateral] [neglect] - characterized by: - RH parietal lesions - the patient "neglects" contralateral hemi-space - may also "neglect" contralateral side of the body (even to the point of denial) Unilateral Neglect ------------------ - Failure to search for or respond to stimuli on the contralateral side of space to the lesion - It is not the same as Homonymous Hemianopia - There is no single theory also seen as an attentional disorder - Occurs in all modalities (Visual, Tactile, Auditory) Hemispatial Neglect ------------------- - Failure to report, respond, or orient to stimuli presented contralateral to the lesion when elementary sensory and motor deficits have been ruled out - Left neglect is more common than right neglect - [Extinction]: neglect symptoms are exacerbated by competing stimuli ipsilateral to the lesion (can cross modality!) Hemispatial Neglect ------------------- - More common following right hemi damage - Classic anatomy = right parietal - Can occur with left hemi damage but deficit is not as long-lasting or severe - Have trouble disengaging attention in good field   Burning House test (Halligan & ------------------------------ Anton Raederscheidt ------------------- - Peripersonal space - The immediate space surrounding the body or a body part. - Extrapersonal space -- unreachable. **unilateral multimodal** i.e. can affect all sensory modalities. Patients fail to report respond or orient to stimuli **neglect** on the affected side - failure to perceive sensations on the affected side - failure to use limb(s) on the affected side - walk / steer wheelchair towards affected side only - collide with furniture/ objects - failure to recognise people approaching from affected side - failure to find objects located on affected side - failure to eat food on one side of plate - may injure limb(s) by leaving arm dangling over side of chair, get fingers caught in spokes of wheelchair, leave foot off footplate - omit beginnings of words when reading e.g. reading \'deserve\' as \'serve\' or retire\' as \'tire\' - when writing or drawing, details are omitted from affected side of drawings /letters and work is concentrated on unaffected side of page. Hemispheric Bias ---------------- What happens to neglected information? Top-down -- goals can influence how the information is processed Some Intervention Approaches ---------------------------- - Vestibular Stimulation - Hemi-Spatial Sunglasses - Yoked Prisms ### VESTIBULAR TREATMENT ### HEMI-SPATIAL SUNGLASSES - 10 patients with unilateral left neglect - Used copying and line bisection tasks - 4 out of 10 patients showed some improvement - One patient demonstrated dramatic and lasting improvement in functional activities - Arai, Ohi, et. al 1997 Prism ----- - 12 patients, mean age 62 - All in neuro rehabilitation hospital - Moderate to severe hemiplegia and somatosensory dysfunction - 3 weeks-\>14 months post stroke - 10 degree (18 prism diopter) - Simple pointing task - Rossetti, et. al 1998 - **Positive effect was a minimum of two hours - other treatments effects lasted no more than 10-12 minutes** - **Positive effect for both sensorimotor and cognitive spatial functions** - **Replicated by several studies since** **body image** distortion of body image and ### Patient cannot - point to parts of body - point to parts of therapists body - move parts of body on request - touch one part of body with another **localisation of** inability to localise an object in **objects in space** space accurately, to estimate size and to judge distances - difficulty in transfers and locomotion - difficulty in reaching for and picking up objects and placing them in correct place - difficulty in using correct grips. - May be dangerous in community -------------------------------- -------------------------------------------------------------- **recall of spatial location** failure to recall spatial information i.e. the position of -------------------------------- -------------------------------------------------------------- - unable to describe position of furniture in a familiar room - inability to recall where bed is in ward - unable to locate objects which s/he has left down moments before route finding failure to appreciate the schema of routes - No sense of direction or of the relationship of turns to the point s/he is trying to reach - unable to learn new routes e.g. to bathroom and /or inability to remember old routes - inability to find way from one room to another - getting lost on ward - may get lost on familiar routes e.g. when at home ---------------------- --------------------------------------------------------------- topographical memory failure to retrieve long established memories of geographic ---------------------- --------------------------------------------------------------- - unable to become oriented to changes in environment - unable to describe familiar routes and places -------------------------- ------------------------------------------------------------------------------- **reading and counting** difficulty in recognising placement of words but able to comprehend letters -------------------------- ------------------------------------------------------------------------------- - \'neglect\' dyslexia - skip lines and /or words - supply words in attempt to makesense - inability to tell time - forget items already counted **visual agnosia** Inability to identify or recognise ------------------------ ----------------------------------------------------------------------------- **auditory agnosia** patient has the ability to hear sounds but is no longer able to recognise ------------------------ ----------------------------------------------------------------------------- tactile agnosia inability to recognise ### Apraxias - inability to control and regulate limb movement - clumsiness performing simple tasks such as eating, writing. Patient may be very slow and have difficulty initiating simple tasks e.g. walking, rising from a chair etc to request ### Apraxias **ideomotor apraxia** a disturbance in the ability to ### Apraxias ideational apraxia the patient is capable of carrying out the individual component of the task but cannot put these together to form a whole - e.g. toothbrushing - patient is able to remove cap from toothpaste, grip brush, place paste on brush and take brush to mouth but is unable to sequence these activities to carry out the task - Systematically evaluate cognitive function at regular intervals - Set specific goals for restoration, substitution or restructuring of environment (Lazar, 1998) - Include rehabilitative disciplines (Lazar, 1998) - Evaluate for and remediate co-morbidities, including fatigue, depression, anxiety, insomnia, and physiologic discomfort (Litofsky et al, 2004) Accommodations/Environment Modification --------------------------------------- - Task instructions - Task expectations - Supports for task completion - Physical environment - Inability to organize a task (prepares, gathers items) - Inability to sequence a task (puts bra on over dress) - Inability to identify common objects (agnosia) - Inability to use common objects (apraxia) - An inability to initiate a task - Lack of judgment (uses the burners of the gas stove to heat the house. Approaches to therapy --------------------- - Transfer of training - Neurodevelopmental - Functional - Cognitive Retraining ---------- Neurodevelopmental ------------------ - Bilateral activities - Weight bearing and movement Functional approach ------------------- - Compensation - Change to the way in which the task is approached eg training patient to turn head to scan environment - Adaptation - Alteration of the environment eg anchoring when reading Cognitive --------- Strategies ---------- - Set-up - Put all needed items in front of patient. - Verbal Cues- Use short simple phrases to prompt. - Hand over hand techniques (brushing teeth) - Demonstration- Act out what you want the patient to do (brushing teeth) - Determine patient's sensory limitations - visual field cuts or diplopia - hearing loss from aging or chemotherapy, - peripheral neuropathy - Determine patient's language ability - expressive -- providing answers - receptive -- understanding the demands of the tasks - Limit testing to 1-2 hours to minimize fatigue Links to video clips -------------------- - [https://www.youtube.com/watch?v=44fGS w7QFLc] - [https://www.youtube.com/watch?v=z4BQb b188Nk] - - - - Attention -- Brain structures - - - - - Reticular formation - - - Posterior Parietal lobe - - Posterior Temporal lobe - Right hemisphere ================ - - - Hemispheric Bias ================ Frontal lobes - Keeping track, monitoring - Allport (1993) we must ask "what is attention for?" and accept that "attention" refers to a set of cognitive/brain processes. - Selective attention may limit the subset of ***objects*** to be perceived, ***memories*** to be accessed or ***actions*** to be executed. - Attention is also necessary for awareness and memory. Involved in most tasks. - To maintain coherence of behaviour. - Search for a blue thing. - Feel the seat against your back. - Listen to extraneous noise - Prepare to tap the desk next time you hear a cough. - All require "attention" to different internal or environmental information and "setting up". **Attention-** -------------- Capacity to Detect and Orient to Stimuli - - spatial attention - - selective or focused attention - - arousal/sustained attention Attention ========= - - - - **Attention** ------------- - - - - - ### Concentration- - - - - sustained concentration - focused concentration(selective) - divided (alternating) - - environmental -- external - self -- internal Attention Impairments ===================== - - - - - Clinical Implications Rehabilitation ==================================== - - - Clinical Implications -- Rehabilitation 2 ========================================= - - - 'critical period' (see Nudo et al, Science, 1995) Vigilance & sustained attention =============================== - Vigilance requires constant monitoring for signal occurrence. - Sustained attention is required once selection has occurred and further processing is necessary to complete task. - Both involve goal maintenance over time. (More an issue of executive control.) - Related to arousal levels. Selective Attention =================== - Shape, color, size, location... (vision) - Pitch, timbre, location... (audition) Awareness and acceptance ======================== Disability resulting from attention impairment includes ======================================================= - Changes in what you do by yourself or with others - Changes in simple and/or complex activities - Changes in what you [can do] in a uniform environment and what you [do do] in your environment. Cognitive rehabilitation ======================== - - - - Berquist & Malec, 1997 - - - - - - - - - - - - - - - - - - - - - - Six Intervention Approaches - - - - - - Restoration of Attention after ABI ================================== - Attention deficits common consequence of acquired brain injury - Attention required to learn new tasks, and to perform routine activities - Predicts return to work and other functionally important activities Restoration of Attention after ABI ================================== - Restoration versus compensation - Longstanding distinction (e.g., Luria, Zangwill, Goldstein) - Restoration versus compensation -- "Should we simply help the patient to regain his lost performance capacity to use it in the same way as he did before the injury, or should he learn to compensate with other performances." (p. 147) Goldstein, 1942 - Restoration versus compensation - Clinical importance -- require different treatments - Theoretical importance -- imply different cognitive and neural processes Direct Training of Attention - Repeated stimulation of attentional systems via hierarchical attention exercises - Attention divided into components that are targeted discretely Purposeful Actions ================== Evidence for efficacy ===================== - - - - Training of Specific Skills - - - - - - - (Sohlberg & Mateer, 2001) Metacognitive Strategy Training ======== - - Accommodations/Environment and Modification =========================================== - - - - - - - - - - - - - - Theories of Neglect =================== B. [Representational Theories] Neglect due to inability to form adequate contralateral mental representations C. [Attentional vs. Representational Theories] - - - Rehabilitation of neglect ========================= - - - - - - - Visual Scanning Training ------------------------ This is the most classical and popular rehabilitative approach, based on the finding that the failure in visual exploration strategy results in Neglect. Weinberg and coworkers (1977) reported a visual scanning training effect on reading-related tasks in patients with left hemispatial neglect. The patients were instructed to read paragraphs with a vertical anchoring line and numbers, which were all on the left side. At first, they needed the anchoring line and the numbers as cues. As they are improved gradually, they could get along with fewer cues. Then, they were finally led to read with no cues. The training groups improved in some tasks better than control groups. Trunk Rotation -------------- Karnath, Schenkel, and Fischer (1991) considered that an egocentric coordinate system determined a border between the neglected 'contralateral' and the nonneglected 'ipsilateral' side in patients with USN. They studied patients with left USN for saccadic reaction times (SRTs) toward stimuli in various positions of the head and trunk. A deficit in SRTs towards the left visual field in the patients could be overcome by turning the patients' trunk left so that stimuli on both fields were projected to the right, ipsilateral side of trunk space. **Eye Patching** ---------------- USN may be reduced by activating intact brain stem components of the system, including the superior colliculus, on the side ipsilateral to the lesion. Monocular patching of the eye ipsilateral to the lesion in patients reduced USN in a line bisection task (Butter & Kirsh, 1992). But in most cases, the effect was limited to the period when the patch was attached. When this approach was combined with lateralized visual stimulation, the effect was larger than that alone. The effect on daily activities was not described. Ways in which rehabilitation can - **General stimulation** - **Targeted stimulation** - **Release of inhibition** - **Arousal**/**attention** Eye patching ============ - **Right hemifield versus right eye patching** - *A right half-field patches (n = 7)* *B right monocular patch (n = 7)* - *C control group (n = 8).* - **3 months post, significantly better functional status for A compared to B and C.** - *Beis et al (1999), ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION 80: 71-76* - posterior attention system governed by the parietal lobe, which causes unilateral neglect when damaged, is modulated by the sustained attention or alerting system - goal of this training is to improve the system - vigilance tasks such as coin sorting, during which the patients have their errors pointed out to them. - On a second trial, their attention is trained with a loud stimulus reminding them to attend while performing the task. - After 5 hours of training, subjects showed lasting improvements in neglect and sustained attention that lasted 1--14 days **Robertson, I. H., Tegner, R., Tham, K., Lo, A., and Nimmo-Smith, I.,** Sustained attention training for unilateral neglect: theoretical and rehabilitation implications, *J. Clin. Exp. Neuropsychol.,* 17, 416-- 430, 1995. Cognitive Supports ================== - Determine learning style -- written, verbal, demonstration, combination. - Reduce distractions in work area - Allow for white noise sound machines or music - Divide large assignments into smaller tasks - Make daily "to do" lists - Use calendar or electronic organizer - Use watch or pager with time capability - Tape record meetings - Allow additional training time - Provide written checklists - Provide environmental cues to assist memory for location of items (labels, color coding, bulletin boards) Regulatory Supports =================== - - - - - The Practical Approach ====================== - Task adaptation: - \- reduce time pressure - \- improve structure Give task-specific training, i.e. relevant attention cues embedded in routine by learning. Stimulation can improve brain function -------------------------------------- - Abilities may not be lost completely Accessing them may be the problem.. -...or they may be inhibited by other parts of the brain -... sometimes they are simply not stimulated enough for the connections to re-establish -.. But improvement not possible in all cases **NEUROPSYCHOLOGY OF ATTENTION** ================================ 1. How to define attention. 2. Understand the models of attention. 3. Give neuropsychological examples of brain disorders in which attention is affected. 4. Recognize three or four key brain anatomical regions that sub-serve attention. **1. DEFINING ATTENTION** ========================= Definition of Attention ======================= - Definition - Experimental research on attention started in the 1950s Types of Attention ------------------ - It is a cognitive brain mechanism that enables processing of relevant inputs, thoughts or actions while ignoring irrelevant or distracting ones. - Attention may be selective. - Attention may also divided between two concurrent tasks (divided attention) - It may be covert in that it can operate without overt adjustments to sensory apparati, or overt (direction senses towards a stimulus source). - voluntary or endogenous attention - reflexive or exogenous attention  Cortical regions that play a role in attention A close-up of a human brain Description automatically generated **2. MODELS OF ATTENTION** -------------------------- - Attention allows us to **focus** on a particular stimulus while at the same time **disregarding** other stimuli. - Key research questions - How do people choose which stimuli from the environment to attend to and which to ignore? - At **which level** is information processed when we decide to pay attention to a stimulus? - Physical characteristics (tonality, loudness, brightness...)? - Not only physical characteristics but also meaning? -- What happens to the stimuli that are not attended? - **Cocktail Party Phenomenon** - In a party, you have no problem concentrating on your conversation despite all other conversations - You also have little difficulty switching your focus from your conversation to another Cherry (1953) wanted to investigate the Cocktail Party phenomenon scientifically - Dichotic listening paradigm - A different message is played to each ear. - Shadowing task - focusing of attention on the attended input - no attention on the ignored input Models of Attention =================== - Better encoding -- attended ear - Degradation of information -- unattended ear Models of Attention =================== - How much is retained from the **un**attended message? - Mostly physical properties (e.g. tonality) were noticed - Virtually **no** noticing of - Meaning of the message - Change in language (English to German) - Change in gender (male to female) - Message in reverse speech Filter Models ============= - 'bottlenecks' occur at stages of perceptual analysis that have a limited capacity - Does selective attention occur early or later in sensory processing? Broadbent Model =============== - The stimuli passing the filter become the focus of attention - The unattended stimuli are completely disregarded - It is an '**[all-or-nothing]**' filter - Which channel is attended to? - Guided either top-down or bottom-up? - Which information is attended to? - Treisman (1964) proposed that physical characteristics are used to select one message for full processing and other messages are given partial processing (i.e. they are *attenuated*). - Deutsch & Deutsch (1963) proposed that all messages get through, but that only one response can be made (i.e. late selection for attentional resources). Treisman & Geffen (1967) tests between attenuation and late selection detection much worse in unattended channel, supporting attenuation\...if late selection, detection should be no problem since all info is getting through Posner and Petersen's model (1990) ---------------------------------- - The brain has 3 attentional systems: - **Selective** - **Alerting (Sustained attention)** - **Switching** - These are separate from 'basic' processing - Different components perform within the attention system - It is possible to have disorders of attention. - Depending on which systems are damaged, very different profiles of - Specific assessment should benefit diagnosis and better Posner and Petersen's model (1990) ---------------------------------- ### Selection -- Ability to focus on one stimulus or type of stimulus from an ### Alerting/Vigilance ### Switching/control - Determine the cost of switching attention e.g. Trails B minus Trails A. Sustained Attention - Various attempts to measure - Continuous Performance Tests - Elevator counting on TEA - SART -- Sustained attention response task - Rapid Visual information processing (RVIP) PART 2 A few drawings of different clocks Description automatically generated with medium confidence Neuropsychology is about........learning from the patient - Neurodevelopmental disorders: ADHD - Visual neglect - Concussion syndrome After this lecture you should know... ------------------------------------- 1. How to define attention. 2. Understand the models of attention. 3. Give neuropsychological examples of brain disorders in which attention is affected. 4. Recognize three or four key brain anatomical regions that sub-serve attention. **3. DISORDERED ATTENTION** --------------------------- - Inattentive Presentation - Hyperactive Impulsive Presentation Do children with ADHD show heightened distractibility during tasks that require attentional engagement? Remember from part 1: Endogenous/Exogenous cues Measured endogenous/exogenous shifts in attention using modified Posner's Cueing Task ### **Drugs and cognition** ### **Cognitive training in ADHD** ### **Alternative treatment** - evidence supports a recommendation for Cognitive Behavioral Therapy (CBT) for adults and Caregiver intervention for Children (Tourjman et al., 2022). - CBT, Mindfulness, Cognitive remediation - Therapies targeting the relationship between children and others (i.e., parenttraining on ED and depression, and social skills training for children - CBT for the improvement of emotional symptoms for - Clinical interview with parent/guardian and child -- diagnosis according to DSM-IV criteria for ADHD e.g. DISC IV (Diagnostic Interview Schedule for Children) - Rating scales (e.g. Conners ⁻ Parent questionnaire ⁻ Teacher questionnaire ⁻ Adolescent questionnaire ### Concussion syndrome +-----------------------------------+-----------------------------------+ | headache dizziness vertigo | restlessness irritability | | | | | fatigue memory problems | apathy depression anxiety | | **[trouble | | | concentrating]** | personality changes sensitivity | | sleeping problems insomnia | to noise and light | +-----------------------------------+-----------------------------------+ the executive component is partially influenced; and the orienting component is substantially affected suggests that **concussion affects the ability to move attention** from the central fixation point, search alternate locations for the target and re-engage attention at the appropriate location to respond to the target stimulus. Attention tests: Simple Clear instructions Allow practice and repeated testing Time limited Contribution of other functions (memory, knowledge, reasoning) minimised. Executive tests: Complex, unconstrained May require planning and strategy formation May require novelty Often have less time pressure May emphasise using other skills (previous knowledge etc) to achieve a goal.  The Test of Everyday Attention for Children (TEA-Ch) #### The Test of Everyday Attention for Children (TEA-Ch) The Test of Everyday Attention ============================== - Map search (Selective attention) - Tone counting (Sustained attention) - Tone counting with distraction - Lift task, visual and auditory (Shifting attention) - Yellow page search (Sel att) - Yellow page search plus tone counting - Lottery ticket task (Sustained attention) Tone counting ============= Lottery ticket task 1. Ecological validity (What demands in what environment?) 2. Other types of validity....sensitivity....reliability Lapses in Attention a. b.  September 4 2010 ================ - Christchurch, New Zealand - 10 km deep 7.1 magnitude earthquake - With epicentre 40 km from city centre Earthquake-induced cognitive disruption scale - ''I found it difficult to remember things''; - ''I felt it was very difficult to make decisions' - ''I felt my brain was working more slowly than usual''; - ''I thought about the earthquake a lot''; - ''I was frustrated by not being able to think clearly. - Emotion-induced blindness: when emotionally salient stimuli are presented in a rapid stream of stimuli, they produce impairments in the perception of task-relevant stimuli, even though they themselves are task irrelevant. **4. NEUROANATOMY OF ATTENTION** -------------------------------- - **Parietal cortex**: is specialized for processing spatial relations and are thus implicated in the deployment of spatial attention. Pathologies such as unilateral neglect arise from parietal damage - **Superior and inferior colliculi:** control eye movements and orientation to salient auditory stimuli, respectively. - **Ascending reticular activating system**: implicated in arousal and the sleep-wake cycle. Affects vigilence and orientation. - **The pulvinar region of the thalamus**: seems to play a role in filtering to be attended information, damage to the pulvinar affects selective attention and attentional engagement. - **The Cingulate Gyrus**: response selection - **Frontal lobes and frontal eye fields**: involved in directing motor responses and regulating voluntary gaze. Damage to this system results in visual attention being continually drawn to irrelevant stimuli. A close-up of a human brain Description automatically generated (a)healthy brain, activity during visual search is symmetric, and interhemispheric interactions between left and right dorsal attention and visual occipital areas are balanced. **Each side of the dorsal attention network directs shifts of attention and eye movements contralaterally**. **Balanced interhemispheric activity results in a normal eye movement search pattern, shifts of attention, and coding of stimulus** (b)patient with a ventral stroke, **direct damage of ventral regions causes a reduction of arousal, target detection, and reorienting that leads to a bilateral visual field impairment. Imbalance in the dorsal attention network and visual cortex, leading to tonic and task-dependent rightward spatial biases in attention, eye movements, and stimulus salience.** - Not activated during expectations or task preparations (selective attention), respond to behaviourally relevant stimuli - Corbetta proposed that this network acts as a circuit breaker during reorientating/switching attention - Interrupts ongoing selective attention in the dorsal system & shifts attention to a novel object **The default mode network** ### After this lecture you should know... 1. How to define attention. 2. Discuss the various models of attention 3. Give neuropsychological examples of brain disorders in which attention is affected. Recognize three or four key brain anatomical regions that sub-serve attention **&** **Dysexecutive Syndrome** 1. 2. 3. 4. 5. Executive function & dysfunction ================================ - Acquired brain injuries - Usually *Fast* onset: Traumatic brain injury, Stroke - Developmental brain injuries - Usually *slow* onset: Tumors, brain arteriovenous malformation \[brain AVM\]; neurodevelopmental deficits (e.g. schizophrenia)  Tumors and Brain arteriovenous malformations (AVMs) 2. Features of executive dysfunction: cognitive & Social ======================================================== Executive functions =================== - Programming, regulation and verification of activity (Luria 1966) - Goal formulation, planning, and carrying out goaldirected plans effectively (Lezak 1983) - Problem-solving behaviour, trying out hypotheses and learning from failed attempts (Shallice 1988) - May be able to work along routine lines, but have difficulties in new situations (Baddeley and Wilson 1988) Executive dysfunction & clinical symptoms Dominguez et al., Psych Bull, 2009 Lishman, Organic Psychiatry 1998 - "emotional changes include blunting, instability, apathy or euphoria. Irritability and explosive anger...a passive and childish dependence may develop, with petulant behaviour and egocentricity\... lack of foresight, tact, concern, inability to plan ahead or judge the consequences of actions, and a facile euphoric disposition.... changes which it is difficult to quantify or demonstrate objectively...the patient typically has little insight into the changes which occur" Emotional and Behavioural - Agitation - Disinhibition - Impulsivity - Mood variations - Lack of insight - Poor judgement - Immaturity - Lack of motivation Personality and Social - Problems with loss of emotions - Change of personality - Unsocial behaviour - Inability to learn from experience - Impaired control - Lack of motivation The problem of executive impairment - Impairments in executive functioning cause social dysfunction, and restrict participation in pre-injury activities. (e.g. Crepeau and Scherzer 1993) - A large number and types of difficulty have been associated with frontal lobe or executive dysfunction - Disturbed attention - Increased distractibility - Difficulty grasping whole of a complicated state of affairs - Well able to work along routine lines - Cannot learn to master new types of task - Is at a loss in new situations - Kevin (Road accident TBI): 3. Theory of executive Dysfunction ================================== A close-up of a document Description automatically generated - Planning or decision making - Error correction or trouble-shooting - Situations where responses are not well-learned or contain novel sequences of actions - Dangerous or technically difficult situations - Situations which require the overcoming of a strong habitual response or resisting temptation But what are the core cognitive requirements for 'executive' responding in non-habitual responding? - Central executive remained an undeveloped component of the WM model until Baddeley (1986) suggested it might be useful to conceptualise the CE in terms of the SAS model developed by Normal and Shallice (1986). Shallice & Burgess, 1996 ------------------------ - Two control mechanisms: - **Contention Scheduling**: Rapid triggering + selection process for familiar situations with clear rules and guidelines - **Supervisory Attentional System (SAS)**: for dealing with unfamiliar or novel situations. Slow, deliberate and monitors situations where contention scheduling fails or where there isn't an appropriate behavioural action/routine. Shallice and Burgess (1996) cont'd ---------------------------------- - - - - - - -  1\. Mental set-shifting 2\. Updating & monitoring e.g. Letter number sequencing 3\. Inhibitory control - - 'SAS' model V 'Cascade' model ----------------------------- - Online monitoring - Bias to task related processes - Developing an action plan - Biase to task relevant representations - Implementing the plan - Select relevant information - Evaluate the results  Metacognition Thinking about Thinking - **Metacognitive knowledge** - **Metacognitive Regulation** Metacognition PRIME ------------------- Metacognition ------------- **(CIRCuiTS, KCL)** 4. Assessment ============= Behavioural Assessment of the dysexecutive syndrome (BADS) ---------------------------------------------------------- - Problem solving - Planning - Organizing behaviour BADS ---- - **Temporal judgement** - This test uses four questions to assess subjects' ability to estimate how long various complete events (such as a dental appointment) last. - **Rule shift cards** - Tests the ability to change an established pattern of responding, using familiar materials. In part 1 a response pattern is established according to a simple rule. In part 2 the rule is changed and subjects have to adapt their responses, inhibiting their original response set. - **Action program** - Tests practical problem solving. A cork has to be extracted from a tall tube, a result which can only be achieved by the planned use of various other materials provided. - **Key search** - A test of strategy formation. In an analogue of a common problem, subjects are required to demonstrate how they would search a field for a set of lost keys and their strategy is scored according to its functionality. - **Zoo map** - This is a test of planning. It provides information about subjects' ability to plan a route to visit six of a possible 12 locations in a zoo, firstly in a demanding, open-ended situation where little external structure is provided, and secondly in a situation that involves simply following a concrete, externally imposed strategy. - **Modified six elements** - This is a test of planning, task scheduling and performance monitoring. It is a simplified version of the original Shallice Burgess (1991) test. Subjects have to schedule their time to work on six tasks over a ten minute period. Rule Shift Cards ---------------- 1. To dictate into the tape recorder (which will be running for the whole 10 minutes) the following: A. Describe the best holiday that you ever had B. Describe any memorable event in your life 2. To write down the names of as many pictures as you can C. Those in the left-hand booklet D. Those in the right-hand booklet 3. To solve two sets of arithmetic problems (as many as you can in order) E. Those in the left-hand booklet F. Those in the right-hand booklet 6 elements instructions Cont'd ------------------------------ - In the next 10 minutes you have three different tasks to do. You can check the time with the timer. - Each task is in two parts: A and B - You will not be able to do everything in 10 minutes, but you should try to do at least something from each of the six parts. However, you must not do parts A and B of the same task one after the other. For example, you must not do part A of the arithmetic problems followed by part B of the arithmetic problems Stroop ------ Read these words as quickly as you can starting at the top of the first column. When you get to the end of the first column, go to the top of the next column. **Read the words** aloud as quickly and as accurately as you can. If you make a mistake, just correct yourself and keep on going. Blue Tan ------- ----------- ------- Green Green Red Tan Tan Red Blue Green Green Tan Blue Red Green Tan Green Blue Green Red Class exercise... ----------------- - 3 minute test: Performance on COWAT: - One minute per letter - Write down your responses (!) 5. Rehabilitation and treatment =============================== Rehabilitation (McLellan 1991) ------------------------------ ### Rehabilitation studies - - - - - -  A diagram of a flowchart Description automatically generated  - - - ### Goal Management Training - STOP! "What am I doing? Check the mental blackboard" - DEFINE The main task - LIST The steps LEARN The steps - DO IT! - CHECK "Am I doing what I planned?" ### Goal Management Training - - - - - - Impairment specific interventions --------------------------------- - Cicerone's (1987) self-instructional training for impulsivity. - Alderman, Fry and Youngson's (1995) self-monitoring training.  - Establish structure in person's daily routine - Educate individual and family - Use a wide range of activities - Organize training hierarchically - Facilitate generalisation - Incorporate learning principles that facilitate acquisition, retention, and transfer (e.g., errorless learning) **At the end of this lecture you should know...** 1. Types of injury leading to executive difficulties (dysfunction) 2. Features of executive dysfunction -- ***[Cognitive]*** and ***[Social]***) 3. Theories of executive function (SAS model, Cascade model) 4. Assessment of executive dysfunction 5. Rehabilitation and treatment Neuroplasticity... Merzenich et al., 1983 -- reorganisation of cortical maps following nerve transections in monkeys ### Examples of frontal lobe dysexecutive impairment - Kevin (Road accident TBI): [[https://www.youtube.com/watch?v=qvyNhssMQpE]](https://www.youtube.com/watch?v=qvyNhssMQpE) - Jerry Harper (Non-malignant tumor): [[https://www.youtube.com/watch?v=UWHg002x\_38]](https://www.youtube.com/watch?v=UWHg002x_38) Memory ====== - Sensory (short term) memory - Working memory - Long term memory Hierarchy ========= Memory ====== **Encoding**: Converting information into a useable form **Storage**: Holding this information in memory Sensory memory ============== - Large capacity - Storage duration -- 250-3000 milliseconds - Visual and auditory information - Example -- reading successive letters and remembering them long enough to capture the word Working memory -------------- - Capacity -- approx 7 'chunks' - Duration of storage -- 20 seconds - Organises information from sensory memory - Example -- as an experienced reader it is not necessary to read every letter to recognise a word Long term memory ================ - - - The hippocampal formation - - - - - HM (Scoville and Milner 1957) ============================= - Age 20, intractable epilepsy - Bilateral medial temporal lobe resection - Removal of uncus, anterior hippocampus and hippocampal gyrus - Immediate reduction of seizures - No deterioration 'in intelligence or change in personality' HM == *(Scoville and Milner, 1957, P12)* Hebbian theory ============== - Based on work by Hebb (1949) - Present subject with stimulus - Network of neurons respond (cell assembly) - Neural activity continues while stimulus is present - Resonation - Repeated exposure -- activation (Hebbian modification) - Engram is represented by a neural network - Stored in different parts of brain depending on sensory memory - Multiple sources of sensory information Relevance ========= - Explains ability to recognise degraded information - Multiple neural networks support memory - Identification of preserved aspects / modalities Declarative Memory ================== - - - - - - - - Hippocampus =========== - Consolidation -- transfer of memory from WM/ STM to LTM - Hippocampal formation receives processes and categorises sensory information during learning - Long term potentiation Long Term Potentiation ====================== - A change in synaptic strength as a result of synaptic plasticity - Mechanism whereby brain adapts in response to a change in use - Produced by stimulation of neurons that make excitatory connections with hippocampal pyramidal cells LTP === - Short bursts high frequency leads to increased efficiency in CA1 pyramidal cell response - Possible cellular mechanism through which learning occurs - Glutamate dependent, NMDA receptor - Suggests memory also linked to amygdala - Impact of emotion on memory -- evolution and survival Procedural memory ================= - - - - - - Forgetting ========== Cognition should not be divorced from emotion, motivation and other non-cognitive functions (feelings affect how we think and how we behave). need to focus on real life problems. need a dialogue with other disciplines (misunderstanding can occur with use of different terminology) need a broader theoretical base - or several theoretical bases. Approaches to rehabilitation ============================ (these are not mutually exclusive) Improving encoding ================== Improving storage ================= Improving retrieval =================== Anatomical reorganisation ========================= Environmental adaptations ========================= Useful if there are severe intellectual deficits (avoid the need for memory) Labelling, signposts, alarms, positioning etc. Environmental control systems (e.G.Used for people with physical disabilities) "SMART HOUSES" (use computers and videos to monitor and control the living environments of people with dementia) External memory aids/functional adaptations =========================================== Using memory aids requires memory! So may need to ============== Better use of residual skills ============================= PQRST ===== **P**review **Q**uestion **R**eview **S**tudy **T**est Implicit learning/ memory ========================= PROVE TRITE LURCH ----------------- Stem completion =============== and asking for first -------------------- word that comes to mind ### FREQUENCY WORD IN ENGLISH.IF GUESSING BY ### Can disrupt this learning ### Stem completion procedure three groups a) 16 amnesic people b. c. ### errorful and errorless I am thinking of a 5 letter word beginning with "TH" please guess what it might be "Think" "no, good guess, try again" after 4 guesses or 25 seconds told correct word and asked to write this down I am thinking of a 5 letter word beginning with "TH" and the word is "Thumb" Please write that down ### Conclusions (Baddeley & Wilson 1994) #### Clinical applications (Wilson et al 1994, Wilson & Evans 1996 etc) ### Clare et al 1999, 2000 **Phase of intervention** #### PROVE TRITE LURCH ### What types of memory aids Electronic Devices Memory book/planners ### Characteristics   ### Introducing External Aids involves teaching... ### Evidence from Special Education ### Direct Instruction (DI) ### Strategy Based Instruction #### TEACH-M (Ehlhardt et al., 2005) ### TEACH-M TEACH-M Clinician Skills Checklist **T** Did I use a task analysis? **E** Did I prevent errors from occurring while the client was learning the skill? Did I provide a sufficient number of models before the client attempted the step(s)? (Unless conducting an assessment, I didn't let them figure it out by trial and error.) Did I fade my support carefully (i.e., cues/prompts)? If the client made an error, did I provide immediate, corrective feedback? Did I keep my instructional wording simple, clear, and consistent? TEACH-M Clinician Skills Checklist #### Feelings and emotions of people with memory problems Managing these problems -- Carers and relatives ◦ why does he ask me the same thing over and over again? Dr. Ciara Egan School of Psychology, Ollscoil na Gaillimhe =========================================== Language & language disorders lecture aims ------------------------------------------ 1. Spoken Language (production & comprehension) 2. Acquired language disorders 3. Reading 4. Developmental language disorders (dyslexia) - **Communicative signals:** *Intentional* and carry meaning - Language ======== Language & language disorders lecture aims ------------------------------------------ 1. Spoken Language (production & comprehension) 2. Acquired language disorders 3. Reading 4. Developmental language disorders (dyslexia) What is a word?  Interactive models with dual-stage lexical retrieval and componential semantics (e.g., Dell, 1986; MacKay, 1987), figure adapted from (Farrell et al., 2012) Speech Production ================= - Speech production & articulation - Crucial in the accurate use of words in written & spoken language Speech Production ================= Language Comprehension (Speech) ===============================   N400 ERP component (Kutas & Hillyard, 1980) Time (ms) I like my coffee with cream and... sugar I like my coffee with cream and... dog Language & language disorders lecture aims ------------------------------------------ 1. Spoken Language (production & comprehension) 2. Acquired language disorders 3. Reading 4. Developmental language disorders (dyslexia) Causes of Aphasia ================= Causes of Aphasia ================= Acute: Aphasia Variability =================== - **Quantitative**: Severity. Related to lesion size, location, and recovery time - **Qualitative**: Which aspects of language are affected and how? - - - - **Error types:** - **Phonological**: Phonemes are deleted, added, substituted or misplaced but the intended word can still be identified. TEAMS -\> KEAMS. - **Neologism**: Made up words; cannot be recognised. - **Verbal**: Real word related in form but not in meaning: HOOK -\> BOOK. - **Semantic**: Real word related in meaning. TABLE -\> CHAIR. Language vs Speech Disorders ============================ - Some lesions affect the motor execution of speech but not language itself. - Speech and language disorders are often seen together. - Speech disorder example: Spastic dysarthria  - **Global aphasia:** - The most severe form - Right after a large stroke - All aspects of language are impaired - Usually recovers to some degree - Different aphasia type may follow - **Anomia:** - ***Pure anomia***: good articulation, good phonology, good syntax, good understanding but difficulty in finding nouns (lexical access deficit). - ***Anomia*** (word finding difficulties) is the most common symptom of --- ------------------------------------------------------------------------------------------------------------- --- ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **Example of pure anomia:** A stroke patient, formerly a business executive, asked to describe this picture *First of all this is falling down, just about, and is gonna fall down and they're both getting something to eat\... but the [trouble] is this is gonna let go and they're* --- ------------------------------------------------------------------------------------------------------------- --- ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Note the lack of nouns (4/134 words). - **Broca's aphasia:** - an acquired language disorder where the patient has trouble producing speech but less trouble in comprehending speech - "expressive"/ "non-fluent" aphasia - Lesion usually in inferior frontal gyrus on the left - Agrammatism/telegraphic speech - - A stroke patient describing his former job in a paper mill: - Note the low proportion of function words and the contrast with anomia. - **Broca's aphasia:** - **Wernicke's Aphasia:** an acquired language disorder where comprehension of speech is most impaired while the patient can still produce "speech"(but often just a "word salad") - - **Lesions typically include posterior part of the superior temporal gyrus** (classically Wernicke\'s area is besdie to primary auditory cortex--- more or less equal to Heschel\'s gyrus) left - Good articulation and syntax but incoherent speech with many made-up words (neologisms). - **Conduction aphasia:** an acquired language disorder, **largely restricted to problems with repetition** - Good comprehension - fairly fluent speech but with ^ ^ paraphasias, etc. Lesion classically thought of as disconnection of Broca\'s and Wernicke\'s by lesions of the arcuate fasiculus; supramarginal gyrus) The role of the arcuate fasciculus in conduction aphasia (Bernal et al., 2009) - Perhaps **a verbal short term memory disorder?**  Alexia & Agraphia ================= - **Alexia:** Acquired reading disorder, characterised by deficits in reading aloud, understanding the meaning of written words, or both -- "word blindness" - **Agraphia:** Acquired writing deficits Alexia with agraphia is also one of the core deficits of Gerstmann syndrome (following angular gyrus damage) - Alexia with agraphia - Acalculia - Finger anomia - Left-right confusion A close-up of a brain Description automatically generated Language & language disorders lecture aims ------------------------------------------ 1. 2. 3. 4. Reading ======= - The process of deriving sound & meaning from a series of arbitrary written symbols - A uniquely human process - "Children are wired for sound, but print is an optional accessory that must be painstakingly bolted on" -- S.Pinker Cognitive and behavioural demands ================================= -- ----------- Behaviour -- ----------- - ***Audiovisual mapping, phonological awareness - Decoding (and spelling)*** - *Paired Associate Learning* A close-up of a name tag Description automatically generated - ***Automatization (incl. learning/ memory) - Reading fluency*** - *Rapid Automatized Naming* **PAL**: Hulme et al., 2007; Jones et al., 2018, **RAN**: Denckla & Rudel, 1976l Jones et al., 2008, 2010, 2012, 2013, 2016 Reading Network ===============  **Temporo-parietal (dorsal) region** - Integrating ortho-phono, lexical-semantic dimensions **Occipito-temporal (ventral) region** - Memory-based word form area Anterior region --------------- Reading Network =============== - language: APPLE /ˈæ.pəl/ - Consistency: Variations in mappings between grapheme (letter(s)) and phonemes and vice versa. - - GAVE \< ɡeɪv\> or \< gav (like have) - For inconsistent words we apply our statistical knowledge of the pattern learned from other words: - PAVE \< peɪv \>, SAVE \< seɪv \> - Word reading involves learning connections/mappings between orthography, phonology, and meaning at different levels. - Knowledge of patterns weights connections and allows us to: - - - - Single word reading (decoding) is crucial for broader reading development. - Dual Route Models of Reading Aloud (DRC; *Coltheart et al., 2001*)  Chinese Katakana Logographic Syllabic - A note on consistency across alphabetic languages (orthographic depth) - **Orthographic depth:** the degree to which a written language deviates from simple one-to-one letter--phoneme correspondence Transparent Opaque (Shallow) (Deep) - **Psycholinguistic Grain Size Theory *(Ziegler & Goswami, 2005)*:** - When learning to read, children reading an **inconsistent** orthography (such as English): - - - - - - - How does this work in bilinguals? - Egan et al (2019)  English: She looked inside the **bag** for her purse Welsh: Edrychodd yn y **bag** am ei phwrs - Bilinguals alter their decoding strategy according to the language context - More fixations for cognates in the more consistent orthography (Welsh) than in the less consistent orthography (English) Language & language disorders lecture aims ------------------------------------------ 1. 2. 3. 4. Developmental delay of oral Bishop & Snowling (2004) language without apparent cause Affects 3-10% of children  Developmental delay of oral Bishop & Snowling (2004) deficit (Hulme & language without apparent Snowling, 2011) cause Have preserved Affects 3-10% of children phonological/decoding Brain bases of dyslexia ======================= **Temporo-parietal (dorsal) region** - Integrating ortho-phono, lexical-semantic dimensions **Occipito-temporal (ventral) region** - Memory-based word form area Anterior region --------------- Maisog et al., 2008; Richlan et al., 2009; Paulesu et al., 2014 -- Meta-analyses Arcuate Fasciculus ================== - White matter pathway that has been extensively studied in dyslexia - **Van der Auwera et al., 2021:** 1. Differences in fractional anisotropy (FA) between children with and without dyslexia are present before the age of reading instruction 2. There is a predictive relationship between AF FA and reading skills throughout development Theories of Dyslexia ==================== Phonological Theories -- --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **The Phonological Deficit Hypothesis -- most widely accepted theory:** Dyslexia is a core phonological deficit, resulting from degraded phonological representations *(Snowling, 1998; Snowling, 2000; Stanovich, 1988; Snowling & Nation, 1997)* Phonological deficit in dyslexia: problems with phoneme awareness, verbal short-term memory, and lexical retrieval (cognitive foundations of reading; *Hulme & Snowling, 2015)* *Criticisms:* Deficient Phonological Access Hypothesis (*Ramus & Szenkovits, 2008)* The Phonological Recoding Self-Teaching Hypothesis (PRST; *Share, 1995, 1999)* Theories of Dyslexia ==================== Sensory Theories -- ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Auditory deficit hypothesis; *Tallal, 1980*) Visual perception *(Livingstone et al., 1991; Lovegrove et al., 1980)* Visuo-spatial attention *(Vidyasagar & Pammer, 2010)* Magnocellular theories *(Livingstone et al., 1991; Milner & Goodale, 2008; Vidyasagar & Pammer, 2010)* -- recent formulations see sensory deficits as being due to impairment in temporal processing of sequences, regardless of modality *(Stein, 2019)* *Criticisms:* Inconsistent results regarding magnocellular deficits; existence of sensory deficits that do not rely on magnocellular system Attentional Theories Sluggish attentional shifting hypothesis *(Hari & Renvall, 2001; Shaywitz & Shaywitz, 2008)* Anchoring-deficit hypothesis *(Ahissar, 2007)* Criticisms: Individuals may have attentional deficits in the absence of reading deficits, which suggests that attentional deficits are not sufficient to cause dyslexia *(Ahissar, 2007)* Dyslexia Across Writing Systems =============================== - Dyslexia may manifest differently across different writing systems (dependent on orthographic depth) - However RAN remains vestibular fiunct