Introducing Neuropsychology - A Summary PDF

**Introducing neuropsychology** **Cognitive neurosciences**: we study the organization of neurofunctions, so the structure and the function of the brain, the mind and the mental processes - Through animals - Through Cognitive Psychology: studies of the behavioral and functional correlates...

**Introducing neuropsychology** **Cognitive neurosciences**: we study the organization of neurofunctions, so the structure and the function of the brain, the mind and the mental processes - Through animals - Through Cognitive Psychology: studies of the behavioral and functional correlates of neurologically healthy subjects in developmental, adult and elderly age - Through Cognitive Neuropsychology: studies of the behavioral and functional correlates of brain-damaged patients with neuropsychological deficits in developmental, adult and elderly age → cognitive neuropsychologists use models to identify "modules" (i.e., processing units) and the way they collaborate to enable psychological processes, such as memory, object recognition, or attention to operate **Neuropsychology**: discipline that studies the cognitive, behavioral and emotional-motivational disorders associated with brain lesions or dysfunctions - EXPERIMENTAL: investigation of the (neuro-)functional organization of the mind and its neural correlates in relation to a cognitive (dys)function → → it tries to understand impairments to psychological processes in terms of disruptions to the information-processing elements involved - CLINICAL: diagnosis and rehabilitation of these brain disfunctions → diagnostic and prognostic purposes, patient care and planning, rehabilitation, forensic (of research) → in focuses on the effects of brain damage/disease on psychological processes, such as memory, language, and attention - Neuropsychology is based on the scientific method, fits into the fields of neuroscience and has areas of overlap with psychology, neurology, neuroanatomy, psychiatry, statistics, basic neurosciences, neural networks, etc. - Research methods in neuropsychology: a. the study of single cases (define a model of normal cognitive functioning) b. the study of groups (large case studies, standardized psychometric procedures, analysis of results using statistical methods) **Who is a neuropsychologist?** A neuropsychologist studies the relationship between the brain and Behavior: they focus on understanding how brain and/or cerebral alterations (e.g., injuries, neurological conditions, psychiatric disorders) affect cognitive functions and behavior → the neuropsychologist can be specialized on children and/or adolescents or adults and elderly - Assessment of cognitive functioning through standardized tests - Diagnosis in collaboration with other healthcare professionals (traumatic brain injury, stroke, dementia, ADHD, learning disorders) - Rehabilitation: design and implement of treatment plans to help patients regain cognitive functions and improve daily living skills - Consultation, providing guidance to patients and families, helping them understand the impact of neurological issues and offering strategies for coping and support - Research, to further understand brain-behavior relationships and to develop new assessment and treatment methods **Causes of neuropsychological disorders**  **The central nervous system (CNS)** = the brain and the spinal cord (PNS -- peripheral nervous system: it's everything else) THE BRAIN: Cerebrum, the Cerebellum, the Brainstem and the Diencephalon Immagine che contiene diagramma, Cervello, design Descrizione generata automaticamente **Nerve cells** - Nerve cells = neurons and nerve fibers - Neurons send electrical information via synaptic transmission to other neurons and muscles - Active neurons generate tiny magnetic fields - Around 86 billion neurons in the human brain, and around 16 billion neurons in the Cerebrum: the number appears to be steady in childhood, but declines in adolescence Immagine che contiene mappa Descrizione generata automaticamente con attendibilità media - A SCHEMATIC SYNAPSE: the nerve impulses arrive in the terminal region of the neuron and a series of biochemical mechanisms lead to the action potential - BIOCHEMICAL MECHANISMS SCHEME: two neurons having action potentials (APs), converge on a single "receiving" neuron. The first releases the excitatory neurotransmitter (GLU) and the other releases the inhibitory neurotransmitter (GABA). Depending on the relative influences of the two competing inputs, the receiving neuron will fire or not **The brain** - GREY MATTER: neuronal cell bodies, dendrites, and synapses (40% of the brain) - WHITE MATTER: nerve fibers (axons) covered by the myelin (which is white and gives the color to this region: the myelin sheath makes it faster to convey action potentials) - It allows communication from and to gray matter - It develops throughout the 20's and peaks in middle age **SOMATOSENSATION**: Afferent neurons (they carry nerve impulses [towards] the brain) = Sensory information from the body → towards the dorsal regions of the spinal cord → up to the Somatosensory cortex **MOTOR CONTROL**: Efferent neurons (they carry impulses [away] from the brain) = Motor output from the motor cortex → towards the ventral regions of the spinal cord → down to the innervate muscles ↓ **DECUSSATION**: nerve fibers cross their side at the level of the medulla → brain hemispheres are related to the contralateral part of the body **CEREBROSPINAL FLUID** The CerebroSpinal Fluid (CSF) is a clear, colorless transcellular fluid that circulates around the CNS FUNCTIONS: 1. NUTRITION: It allows the diffusion of nutrients and chemicals from the blood into the space surrounding nerve cells 2. CLEANING: receiving products secreted by the nerve cells themselves 3. PROTECTION: The CSF protects the brain inside the skull and the spinal cord inside the spinal canal **THE BLOOD SUPPLY** - Cerebral arteries to supply oxygenated blood - Cerebral veins drain deoxygenated blood from the brain - The blood-brain barrier protects the brain tissue from harmful elements present in the blood, while still allowing the passage of substances necessary for metabolic functions **THE CEREBRUM** - The brain is organized in two hemispheres (left and right) - Delimited by gyrus and sulcus/fissure → the ridges of brain convolutions are known as gyri (singular, gyrus), and the valleys between them are called sulci (singular, sulcus) or, if they are especially deep, fissures sulci are important because they divide the different lobes - Subdivided in 5 lobes → each divided in specialized areas: Frontal lobe, Occipital lobe, Parietal lobe, Temporal lobe, Insular lobe (according to some there's a 6^th^ lobe, the Limbic lobe) Central sulcus = Rolandic sulcus Lateral fissure = Sylvian fissure - Areas are interconnected through the white matter and create functional networks  **BRAIN DEVELOPMENT** 1. NEUROGENESIS: neurogenesis involves generating new neurons from neural stem cells, forming the foundation of cognitive abilities 2. CELL MIGRATION: cell migration is the movement of cells to their designated locations in the brain, essential for proper brain structure and function 3. CELL DIFFERENTIATION: cell differentiation transforms stem cells into specialized neurons and glial cells, creating a diverse neural network 4. CELL MATURATION: cell maturation involves neural progenitor cells developing into neurons and glial cells, forming the brain's intricate network 5. SYNAPTOGENESIS: synaptogenesis is the formation of synapses between neurons, driven by experiences and stimuli, crucial for learning and brain function 6. CELL DEATH AND PRUNING: cell death and pruning eliminate excess neurons and synapses, refining neural circuits for optimal cognitive function 7. MYELOGENESIS: myelogenesis forms myelin, insulating nerve fibers to speed up signal transmission and enhance brain communication **BRAIN MATURATION** Brain maturation is related to thinning and pruning the pre-frontal cortex is the last in maturation after adolescence we have a progressive reduction of neurons but an increase of connections **BRAINS ARE DIFFERENT IN STRUCTURE** ∗ PYSHIOLOGICAL DIFFERENCES: a. The right frontal region typically projects further forward and is wider than the left frontal region (the reverse pattern is seen in the occipital lobes) b. The Sylvian fissure extends further back horizontally on the left side than the right c. The planum temporale is larger on the left side than on the right d. The two hemispheres are different from one another: split-brain studies ∗ LATERALIZATION: The hand we use to write is usually indicative of our hemispheric dominance: who's right-handed usually has a left-hemispheric dominance for language (i.e., brain region crucial for language lateralized on the left) → left hemisphere: it lateralizes language; it has an "analytical-sequential" processing style (it sees all details) → right hemisphere: it lateralizes visuospatial skills; it has a more "holistic-parallel" processing style (it sees the object as a whole) ∗ GENDER: Studies on sex-based differences in grey matter have revealed certain patterns, although the brain's overall structure is highly individualized, and these findings reflect general trends rather than strict rules - MALES - Bigger in size - Higher grey and white matter volume compared to females - Bigger amygdala - Higher proportion of grey matter in areas related to motor and visuo-spatial abilities - FEMALES - Smaller brain → lower white matter volume but greater grey matter volume relative to overall brain size compared to men - Bigger hippocampus (hormone differences) - Bigger corpus callosum: it's the largest of the 4 nerve tracts bridging the hemispheres (that enables communication between the two), in fact we can say that females are less lateralized than males - Higher proportion of grey matter in regions associated with emotional processing, multitasking and verbal communication - During ovulation we are less good in visual processing  **History pills** **Gall and the phrenology -- the concept of modularity/localization** He was the first one to make the hypothesis that a specific part of the brain is associated to a specific function → he looked at the skull of the brain and hypothesized that, on the basis of the physical size and shape of the skull, one could be able to describe an individual's personality and other "faculties" (not true) Freccia GIÙ con riempimento a tinta unita **Anatomo-functional correlations** The description of the functional consequences of brain damage/alterations allows inferring the functional significance of each brain region/network E.G: injuries in specific areas of the brain create highly specific functional symptoms PATIENT "TAN-TAN": the scientist Paul Pierre Broca described this patient that was only able to say "Tan-Tan": in a study post-mortem, he discovered that he had a lesion in a specific brain area (in the left inferior frontal gyrus), probably due to epilepsy, syphilis, or a stroke he understood that a lesion in this part of the brain would cause an expressive aphasia: he couldn't speak other than uttering, but could comprehend and follow complicated instructions MISTER PHINEAS GAGE: he had a work accident and an iron bar passed through his brain and his personality completely changed, in fact before the surgery he was very shy but later he became very irritable, blasphemy-prone, etc. HENRY GUSTAV MOLAISON: he had epilepsy and was not treatable with a pharmacological treatment, so they decided to make him have a big surgery and remove his hippocampus he was able to remember everything before the surgery but from that day he couldn't remember any new information (he remembered information for a maximum of 10-20 seconds): they discovered that hippocampus is a very important region for coding memory **ASSUMPTIONS OF THIS CORRELATION** Traditionally, neuropsychology studies the relationship between cognitive functions and their neurophysiological bases through the investigation of anatomo-clinical correlations - Different cognitive functions are localized in specific brain regions (localization of function) Some injuries in the brain create highly specific functional symptoms: **POST-MORTEM CORRELATIONS** Nowadays, anatomo-clinical correlations are made with more sophisticated techniques (neuroimaging), but the same logical reasoning is applied  **LIMITS OF THIS ANATOMO-CLINICAL CORRELATION** 1. Different types of lesions can be more/less difficult to be circumscribed  2. Diaschisis effects: damage to one brain area can produce, by loss of excitation, loss of function in brain regions adjacent to or remote from, but connected to, the primary site of damage, inducing a dysfunction in distant nervous system structures 3. The effect of brain plasticity: the brain compensates to regain functions thanks to all kinds of cortices = the spontaneous recovery (physiotherapy can help) E.G: phantom limb experience (residual feeling emanating from an amputated body region reducing over time) → "mirror box" remedy the functional consequences of a brain lesion are due to both the lesion and the brain plasticity processes taking place after the lesion itself It is not easy to establish the relationship between the lesion and the symptoms **Cognitive neuroscientific techniques** The enable to study the neural bases of mental processes while the brain is working - Both in patients and healthy people - With mainly non-invasive methodology -\> NEUROPHYSIOLOGICAL METHODS: - Electroencephalography (EEG) - Magnetoencephalografy (MEG) -\> NEUROIMAGINING: - Magnetic Resonance Imaging (MRI) and functional MRI (fMRI) - Positron emission tomography (PET) -\> NON-INVASIVE BRAIN STIMULATION (NIBS) - Transcranial Magnetic Stimulation (TMS) - Transcranial electrical stimulation (tES: tDCS/tACS/tRNS) Different methods addressing different questions: [Different temporal and spatial resolution]  Different methods addressing different questions: [Different nature of the inference obtained on the relationship between brain functioning and behavioral performance] -\> Neurophysiological methods: - Electroencephalography (EEG) - Magnetoencephalografy (MEG) -\> Neuroimaging: - Magnetic Resonance Imaging (MRI) and functional MRI (fMRI) - Positron emission tomography (PET) -\> Non-invasive brain stimulation (NIBS) - Transcranial Magnetic Stimulation (TMS) - Transcranial electrical stimulation (tES: tDCS/tACS/tRNS) **GENERAL PRINCIPLES APPLIED WHEN DESIGNING NEUROCOGNITIVE STUDIES** Similar to those applied in all fields of experimental psychology The more the better (group studies are preferred): many participants and many trials per participants (at least in studies with healthy participants/control groups) Comparisons between at least an experimental and at least a control condition are needed (e.g., observation of static vs. moving dots to identify V5) Construct validity: Is my behavioral measure the correct operationalization of the cognitive process that I aim to study? **SPECIFIC FOR COGNITIVE NEUROSCIENCE** - Has my technique the correct spatial resolution to target the specific brain area of interest? - Has my technique the correct temporal resolution to capture the process I am interested in? - What are the intrinsic limits of my techniques (e.g., contraindications, movement constraints, transportability, costs)? **NEUROPHYSIOLOGICAL METHODS -- Electroencephalography** It records electric activity generated by neurons by using electrodes placed on the scalp The international 10-20 system is a commonly recognized method to describe and apply the location of scalp electrodes Clinical use: up to 16 channels; Experimental use: 16, 32, 64, or 128-channel EEGcap Higher frequency and reduced apmpliputed = neuronal desynchronization -\> cognitive task  **NEUROPHYSIOLOGICAL METHODS -- EVENT RELATED POTENTIALS** Event-related potentials (ERPs) are event-related voltage changes in the ongoing EEG activity in ERP experimental design, a large number of epochs having as onset a sensory, motor, or cognitive stimulation are averaged together. \- - \> statistical differences between stimulation and rest (or different stimulations) the ERP describes different stages of processing with extremely high temporal resolution (ms) [Experimental group]: 13 Parkinson Disease (PD) patients "on" and "off" dopaminergic medication [Control group]: 13 healthy controls (HC -without dopaminergic medication) ERP task: flanker task (see image) [Methods]: comparison of performances and ERP amplitudes between the groups and between an "on" or "off" condition in PD patients; focus on errors, usually followed by fronto-centrally distributed negativities (ERPs) if they make an error, they expect a specific error (but no difference at behavioral level with drugs and no drugs patients, but difference at neurophysiological level) [Results]: PD patients committed more errors than HC, BUT error rates were not significantly modulated by dopaminergic medication → no differences at behavioral level PD patients showed reduced Ne/ERN amplitudes relative to HC → differences at neurophysiological level  if it's congruent: left bottom; it's incongruent: right bottom **CRUCIAL ELEMENTS OF EEG AND ERPs -- to sum up** - Components: *amplitude* and *frequency* for EEG versus *amplitude* and *latency* for ERPs of each wave that represent the sum of the activity of neurons in the area of the brain closest to the recording electrode - The topographical distribution on the scalp - High temporal resolution (ms) - Low spatial resolution (the problem of source localization: no good localization of where something has happened) **PORTABLE DEVICES**  **NEUROPHYSIOLOGICAL METHODS -- Magnetoencephalography** - Same principles of EEG, but EEG is sensitive to electrical fields generated by extracellular currents, whereas MEG primarily detects the magnetic fields induced by intracellular electrical activity - High number of electrodes (60) - Magnetic fields are analyzed to find the location of the neuronal sources - The resulting source locations are superimposed on an MRI image for clinical and experimental purposes - MEG has a very high temporal resolution (msec) and excellent spatial resolution (mm) **IN VIVO BRAIN RECORDING** We put records inside the brain in vivo electrophysiology measures very precisely neuronal activity in the brain as either local field potentials or single units = invasive technique **NEUROIMAGINING -- Mri and pet scan**  MRI: Magnetic Resolution Imaging PET: Positron Emission Tomography **NEUROIMAGINING TECHNIQUES -- Positron emission tomography** Positron Emission Tomography (PET) is a nuclear imaging test that integrates computed tomography (CT) and a radioactive tracer that allows to see how body tissues absorb and use different chemicals in real time (= it assess functional brain activity) STEPS: 1. a tracer is injected into your bloodstream 2. the tracer is radiolabeled, meaning it emits gamma rays that are detected by the PET scanner 3. the radioisotopes used in PET to label tracers are 11C, 13N, 150, and 18F (carbon, nitrogen, oxygen and 18F used as a substitute for hydrogen) 4. once the tracer is absorbed in the body, subject is positioned in the scanner The computer collects the information emitted by the tracer and displays it on the CT cross-sections: these cross-sections can be added back together to form a 3D image of the brain ++ PET can measure blood flow, blood volume, oxygen usage, tissue pH (acidity), glucose (sugar) metabolism, and drug activity, useful for: a. detecting the activity of cancer. Because malignant cells grow at a fast rate, they metabolize more sugar than normal cells → how aggressive a tumor is or how its growth is slowed by therapy. b. presurgical evaluation of seizures Immagine che contiene schermata, lastra dei raggi X Descrizione generata automaticamente a. PET scan from a control subject showing high uptake of 18fluorodopa in the striatum. b. Patient with Parkinson's disease with motor signs that are mainly confined to the right limbs. 18Fluorodopa uptake is markedly reduced in the left posterior putamen (the uptake in the area indicated by the arrow is 70% below normal) and reduced to a minor extent in the left anterior putamen and left caudate. **NEUROIMAGIONING TECHNIQUES -- Single-photon emission computerized tomography** The single-photon emission computerized tomography (SPECT) is a nuclear imaging scan that integrates computed tomography (CT: X-ray and "slice-by-slice" picture of the entire brain) and a radioactive tracer that allows to see how blood flows to tissues and organs STEPS: the same as PET, but different tracers and low resolution the radioisotopes typically used in SPECT to label tracers are iodine-123, technetium-99m, xenon-133, thallium-201, and fluorine-18 ++ a SPECT scan is primarily used to view how blood flows through arteries and veins in the brain brain injury, presurgical evaluation of seizures **NEUROIMAGINING TECHNIQUES -- Magnetic resonance imaging** The magnetic resonance imaging (MRI) scan works by using a powerful magnet, radio waves, and a computer to create detailed images: our body is made up of millions of hydrogen atoms (the human body is 80% water), which are magnetic. when our body is placed in the magnetic field, these atoms align with the field, a radio wave \"knocks down\" the atoms and disrupts their polarity, the sensor detects the time it takes for the atoms to return to their original alignment = in essence, MRI is structural technique that measures the water content (or fluid characteristics) of different tissues, which is processed by the computer to create a black and white image the image is highly detailed and can show even the smallest abnormality **Functional mri** With MRI we are recording **Blood Oxygen Level Dependent (BOLD) effect** → in functional MRI (fMRI), the magnetic field is perturbed by radiofrequencies: hemoglobin has different magnetic properties in its oxygenated and deoxygenated forms Deoxygenated hemoglobin → paramagnetic (= weakly attracted by externally applied magnetic fields) Oxygenated hemoglobin → diamagnetic (= repelled by externally applied magnetic fields) Areas of the brain that are more active tend to receive higher levels of oxygenated blood which lead to a hemodynamic response, which means that blood releases oxygen to activate neurons at a greater rate than what is actually needed (overcompensation) higher levels of oxygenated blood in a brain area are believed to correspond to a higher neural activity in that cerebral region \- - \> this change in the relative levels of oxygenated or deoxygenated hemoglobin in blood can be detected on the basis of their differential magnetic susceptibility BOLD response is slow; each point in the brain is measured every 2/3 seconds (low temporal resolution) the BOLD effect can be measured in each point of the brain (voxel): high spatial resolution \- - \> more sophisticated analyses can: - Infer functional connectivity between voxels/brain regions - Apply algorithms to distinguish between pattern of activation (multivoxel pattern analyses) The obtained results are statistical maps: this means that they are comparisons between activation maps in different experimental conditions **NEUROIMAGING TECHNIQUES -- Tractography** TRACTOGRAPHY = 3D modeling techniques that image brain pathways (tracts) using diffusion tensor imaging (DTI) or diffusion spectrum imaging (DSI), two variants of MRI diffusion imaging maps the diffusion of water molecules in the brain **NON-INVASIVE BRAIN STIMULATION (NIBS) -- Tms** TMS = Transcranial Magnetic Stimulation = application of a magnetic field on the scalp by means of a stimulator (coil): the tissue underneath the coil is subjected to a current flow that generates activation/inhibition  temporary disruption of the spontaneous neural activity: it uses strong pulses of magnetization that can be focal administered via a hand-held coil, these pulses then increase neuronal excitability → it is better suited for the investigation of superficial brain regions, as concerns have been raised about the safety of the procedure ↓ [FARADAY'S PRINCIPLE OF ELECTROMAGNETIC INDUCTION] Rapid variation in an electrical current can induce a magnetic field: - the current flows through the coil for about 1 ms - a large magnetic field is produced for about 1 ms This rapid change induces an electrical current in the area under the coil, activating neurons and generating a depolarization generation of action potentials = stimulation Importance of the neuronal "pre-activation level" → the amount of depolarization in each neuron in response to the TMS pulse depends on the activation state of the membrane (the higher the stronger). = state-dependency principle Different stimulation based on: - the position of the coil (where on the skull) - the orientation of the coil (coil inclination/angle) - frequency: - high frequency TMS (5-20 Hz) = increase of neural excitability - low frequency TMS (1--5 Hz) = decrease of neural excitability  TMS protocols differ in the number and frequency of pulses delivered: - In single-pulse stimulation (spTMS), individual pulses are delivered separately - In multiple pulse TMS, several pulses are applied with an inter-stimulus interval of a few milliseconds: either paired pulses TMS (pTMS) or triple pulses TMS (tTMS) - In repetitive TMS, trains of pulses are applied with a fixed frequency (low frequency: 1--5 Hz, or high frequency: 5--20 Hz) - Theta-burst stimulation consists of applying bursts of several pulses, repeated at a frequency close to 5 Hz (cTBS), or each burst is applied for 2 s and repeated every 10 s for 190 s (intermittent TBS, iTBS) in a third variant, intermediate TBS (imTBS), 5 s burst trains are repeated every 15 s **EXPERIMENT** - Subjects: 17 healthy individuals (HC) - rTMS trains of two pulses (frequency 10 Hz, duration 200 ms, delay 150 ms) over left and right Extrastriate body area (EBA, black dot) and ventral premotor cortex (vPMc, white dot) - Behavioural task: a two-choice matching-to-sample visual discrimination task - form discrimination task: same action performed by two different models - action discrimination task: same model performing two different actions stimuli were expected to activate both body part representation (EBA) and the related action (vPMc) - Results: reaction times and accuracy - Accuracy: Stimulation had no effect on accuracy of responses - Reaction times: EBA rTMS selectively impaired the ability to discriminate two different forms, vPMc rTMS selectively impaired the ability to discriminate two different actions - The interference caused by EBA and vPMc stimulation was independent of the hemisphere stimulated - Conclusions: EBA may be crucial for the identification of actors, particularly when facial cues are unavailable or ambiguous (→actors' body identity) ++ causative evidence that motor representations are necessary for visuoperceptive action discriminations and vPMc may represent the observed actions without taking into account the actors' identity double dissociation paradigm **Single-pulse tms** Single-pulse TMS and Motor Evoked Potentials (MEP): the magnetic pulses induced by TMS over the contralateral primary motor cortex (M1) can pass through the scalp and induce a response known as "motor evoked potential" (MEP) in the target muscle this response can be recorded using surface electromyography (EMG) electrodes placed over the muscle of interest \- - \> the peak-to-peak amplitude of the elicited MEPs is an indication of changing corticospinal excitability (CSE) -\> smaller amplitudes indicate lower excitability, while larger amplitudes suggest higher CSE **Repetitive tms** Repetitive TMS (rTMS) for «virtual lesion» paradigms (online/offline rTMS) The problem of localizing the correct target area → neuronavigation **NON-INVASIVE BRAIN STIMULATION (NIBS) -- Transcranial electrical stimulation** Transcranial Electrical Stimulation (tES): techniques aimed to modify the excitability of a target area generating a current flow through the cortex neuromodulation Transcranial direct current stimulation (tDCS) Immagine che contiene Attrezzature mediche, testo, medico, design Descrizione generata automaticamente EXPERIMENTAL PROTOCOLS: On-line, Off-line, Sham stimulation - Offline stimulation involves a period of pre-stimulation in which a task may be completed, followed by a period of stimulation and then a post-stimulation task (A), or a period of stimulation followed by a post-stimulation task only (AB) - Online stimulation involves participants receiving stimulation during the task (C) - For sham stimulation, the task can be applied at any point during the session (D), depending on whether an online or offline protocol is undertaken **EXPERIMENT** - Subjects: Parkinson's Disease with mild cognitive impairment (PD-MCI) versus 20 healthy controls (HC) - Aim: Assessing Theory of Mind (ToM), i.e., the ability to understand and predict other people's behaviors - Methods: Anodal tDCS over the medial frontal cortex (MFC) to modulate ToM performance - Implications: mPFC has a causal role in TOM → clinical training with anodal tDCS over mPFC to ameliorate TOM in PD-MCI **NON-INVASIVE BRAIN STIMULATION (NIBS) -- TMS AND TES** - Non-invasive techniques - For assessment and training - Safe and regulated techniques - Causal inference: if you modify the excitability of a target area, and this stimulation or modulation influences the behavioral performance, then that specific area is crucial for that cognitive function **DIRECT ELECTRICAL STIMULATION** Direct electrical stimulation (DES) is an invasive tool used for example for mapping cognitive functions while patients are undergoing awake neurosurgery or invasive long-term monitoring to identify epileptogenic tissue **Summary** Each cognitive neuroscience technique has its limits and potentials It is crucial to integrate them when addressing research questions E.G: combination of fMRI + EEG to get both high temporal and spatial resolution E.G: combination of fMRI + TMS to obtain good localization and causal inferences **Clinical neuropsychology -- assessment** AIMS - Diagnostic: - discriminate between different conditions - provide diagnostic information in cases of negative neuroradiological data (e.g., dementia, mild trauma) - Prognostic: provide information on the outcomes of certain pathologies (e.g., post-traumatic coma) - Patient care and planning: - inform the patient of his cognitive state to understand the alterations resulting from the disease - inform family members so they can understand and adapt to the condition - evaluate the effects of medical therapies on the patient\'s cognitive efficiency - evaluate their degree of daily autonomy - evaluate the opportunity of a rehabilitation intervention - Rehabilitation: provide the starting point for a therapy, planning and managing a therapeutic program and evaluate its short and long-term effectiveness - Medical legal: - diagnostic: (is it a consequence of...? Is there reason to suspect that brain damage...?) - description of the patient condition: (will it prevent him from working?) - For research: single evaluation during a protocol or pre- and post-treatment 1. Demographic data and cognitive-behavioral history: a. obtain information on why and to whom the patient was sent (general practitioner, hospital, assistance center operators, clinical psychologist, personal request of the patient or family members, for expert/insurance purposes) b. Know the disease onset and its evolution c. Know the type of life the patient leads or led before the pathology d. Understanding the premorbid personality e. Know the health of close family members f. Know the outcome of the examination of elementary neurological functions performed by the neurologist (know of peripheral hearing or vision deficits) g. Know the outcome of the main instrumental investigations (e.g., MRI, EEG, PET) and other medical tests (e.g., blood tests and hormonal values) h. Know any premorbid cognitive difficulties (even developmental) 2. Patient interview: - Speech and comprehension skills - Mood tone - Attentional skills - Awareness of deficits or illness - Explain the purpose of the exam and what it consists of 3. Administration of standardized tests/test batteries 4. Interview with caregivers/families - Know the patient\'s family environment - Know how the patient behaves when he/she is at home - Make family members aware of the situation and its evolution - Provide them with the correct interpretation of the patient's test and behaviors Possible second visit with more ad hoc and ecological tests, to better define the diagnosis **Cognitive assessment -- test** - Single test or test battery (series of tests) → neuro-cognitive profile - Profile = cognitive areas of strength and weaknesses - Tests are standardized (i.e., uniformity of procedure) + norm-referencing process = comparison between the person's performance and scores generated by age- and/or sex-matched responders - First assessment = person's cognitive profile/picture repeating assessment over time enable to assess changing in cognitive functioning (recovery or progression) **Clinical neuropsychology -- treatment** Cognitive rehabilitation: assumption of the plastic nature of our brain = functional reorganization and (re)learning after a cerebral lesion the term "brain plasticity" refers to the property of the brain to vary structure and function along development and during adult life, in constant interaction with the outside world (environment) \- - \> plasticity concerns the changes in the nervous system organization that underlie various forms of short- and long-term behavioral modification: they include the processes of maturation, adaptation to changes in the environment, specific and unspecific learning, and the compensation Mechanisms -\> there can be positive plasticity (resource) or negative plasticity (maladaptive) **Mechanisms of neuroplasticity**  - STRUCTURAL NEUROPLASTICITY - FUNCTIONAL NEUROPLASTICITY - Long-term potentiation (LTP) is defined as a persistent (= lasting hours or longer) strengthening of synapses based on recent patterns of activity - Long-term depression (LTD) is defined as a persistent (= lasting hours or longer) decrease in synaptic strength depending on specific stimulation Rehabilitation capitalizes on brain positive plasticity (resource) to reduce the negative effects of a brain damage Cognitive remediation: based on a restorative model that attempts to reduce or eliminate impaired cognition re-gain the cognitive function Compensatory techniques: compensate for, or circumvent cognitive deficit, with reliance on intact cognitive skills and strategies and supports for working around cognitive deficits reduction of the disability through: 1. internal self-management strategies, 2. external strategies/environmental modification, 3. errorless learning