Neuropsychology Flashcards
(88 cards)
1
Q
Neuroplasticity
A
The nervous system’s potential for physical or chemical change that enhances its adaptability to environmental change and its ability to compensate for injury.
2
Q
Localisation
A
The theory that different brain regions have different functions.
3
Q
Lateralisation
A
A process by which functions become located primarily on one side of the brain.
4
Q
Broca’s area
A
An area in the anterior left hemisphere that functions with the motor cortex to produce the movements that are needed for speech.
5
Q
Broca’s aphasia
A
The inability to speak fluently despite normal comprehension and intact vocal mechanisms, due to a lesion in Broca’s area. Also known as expressive aphasia or non-fluent aphasia.
6
Q
Wernicke’s area
A
An area in the secondary auditory cortex which regulates language comprehension.
7
Q
Wernicke’s aphasia
A
The inability to comprehend or produce meaningful speech, despite intact production of speech. Also known as sensory aphasia or fluent aphasia.
8
Q
Conduction aphasia
A
A type of fluent aphasia; results from damage to the arcuate fasciculus, which transports information from Wernicke’s area to Broca’s area.
The person has intact auditory comprehension and (simplified) speech production, but poor speech repetition.
9
Q
Alexia
A
The inability to read (may result due to a disconnection between the visual areas of processing and Wernicke’s area.
10
Q
Apraxia
A
The inability (in the absence of paralysis or another impairment) to make or copy voluntary movements, especially an inability to make proper use of an object.
11
Q
Agnosia
A
Partial or complete inability to recognise visual stimuli; is not explained by a defect in sensation or a reduced level of alertness.
12
Q
Ataxia
A
A difficulty/failure to properly coordinate muscle movements.
13
Q
Ventral stream
A
Visual processing pathway for object identification and perception of related movements; starts in the occipital lobe and goes towards the temporal lobe.
14
Q
Dorsal stream
A
Visual processing pathway for guiding movements relative to objects; starts in the occipital lobe and goes towards the parietal lobe.
15
Q
Parkinson disease
A
A disorder of the motor system which is correlated to a loss of dopamine. Characterised by tremors, muscular rigidity, involuntary movements, and changes in emotions and memory.
16
Q
Brain lesion
A
An area of damage to the brain. May be a result of a stroke, loss of blood flow, tumour, injury etc.
Will appear as a white area on an MRI scan, due to reduced blood flow to the area.
17
Q
Hierarchical organisation of brain function
A
Brain processes start with the ‘lower’ levels and are processed through increasingly higher levels. A loss of function in the higher will lead either to dissolution or to the lower regions taking over certain functions (this will result in simplified behaviours).
18
Q
Hindbrain
A
- includes the spinal cord, brain stem, and the cerebellum
- controls the body’s vital functions
- probably evolved first
19
Q
Midbrain
A
- includes the colliculi, tegmenjtum, and cerebral peduncles
- controls vision, hearing, motor function, alertness, and temperature regulation
- probably evolved second
20
Q
Forebrain
A
- includes the telencephalon (cerebral hemispheres) and the diencephalon (thalamus, hypothalamus, epithalamus, and sub-thalamus)
- controls complex cognitive, sensory, and motor processes
- probably evolved last
21
Q
Hebbian theory
A
Neural pathways develop based on experiences; as pathways are used roe often, they become faster and stronger.
22
Q
Biopsychosocial model
A
This model examines a person’s biological, social, and psychological wellbeing and health together, as a whole.
23
Q
Axon hillock
A
The juncture of the soma and axon, where the action potential starts.
24
Q
Neuron’s internal structure
A
- Dendrite: collects information from other cells
- Dendritic spine: a small protrusion from a dendrite which increases the surface area
- Nucleus: contains the neuron’s chromosomes and genese
- Mitochondrion: gathers, stores, and releases energy
- Endoplasmic reticulum: folded layers of membrane where proteins are assembled
- Golgi body: packages protein molecules for transport
- Lysosomes: sacs containing enzymes which break down waste in the cell
25
Temporal summation
The tendency of two or more events related in time to add. Hence, two or more temporally related postsynaptic potentials add or subtract.
26
Spatial summation
The tendency of two or more adjacent events. Hence, two or more adjacent postsynaptic potentials add or subtract.
27
Storage granule
Membranous compartment which holds several vesicles containing a neurotransmitter.
28
Ionotropic receptors
These are usually excitatory and they increase the likelihood that a neuron will produce an action potential.
29
Metabotropic receptors
These are usually inhibitory and they decrease the likelihood that a neuron will produce an action potential.
30
Cholinergic system
- Includes the frontal cortex, basal forebrain nuclei, corpus callosum, and the midbrain nuclei.
- Is active in maintaining the waking electroencephalographic pattern of the cortex.
- is thought to play a role in memory by maintaining neuron excitability.
The death of cholinergic neurons and a decrease of ACh in the neocortex is though to be related to Alzheimer disease.
31
Dopaminergic system
- Includes the substantia nigra, nucleus accumbens in the basal ganglia, and the cerebellum.
- Nigrostriatal pathways: active in maintaining normal motor behaviour; a loss of DA here is linked to muscle rigidity and dyskinesia in Parkinson disease.
- Mesolimbic pathways: dopamine release causes feelings of reward and pleasure; thought to be the neurotransmitter system most affected by addictive drugs and behavioural addiction; increases in DA activity may be related to schizophrenia, while decreases in DA activity may be related to deficits of attention.
32
Noradrinergic system
- Includes the thalamus and locus coeruleus.
- Is active in maintaining emotional tone.
- Decreases in NE activity are linked to depression; increases in NE activity are linked to mania.
- A decreased level of NE activity is also associated with hyperactivity and attention-deficit/hyperactivity disorder.
33
Serotonergic system
- Includes the raphe nuclei.
- Is active in maintaining the waking electroencephalographic pattern.
- Changes in 5-HT activity are related to obsessive-compulsive disorder, tics, and schizophrenia; decreases in 5-HT activity are related to depression.
- Abnormalities in brainstem 5-HT neurons are linked to disorders such as sleep apnea and SIDS.
34
Single-cell recording
An electrode is inserted into the brain next to or into a single cell to measure its activity. This process is very invasive and therefore cannot be used to study humans. Has high spatial and temporal resolution.
35
Electroencephalogram (EEG)
Electrodes are placed onto the scalp with then create a graph that record electrical activity and represents graded potentials of many neurons. Has good temporal resolution but poor spatial resolution.
36
Electrocorticography (ECoG)
A procedure for an intracranial EEG recording during surgery, in which electrodes are placed directly onto the brain surface, providing a more direct way of identifying the source of an epileptic seizure.
37
Event-related Potentials (ERPs)
Complex electroencephalographic waveform related in time to a specific sensory event.
38
Magneto-encephalogram (MEG)
Magnetic potentials recorded from detectors placed outside the skull. Good temporal and spatial resolution.
39
Multiple Sclerosis (MS)
- caused by damaged myelin
- cumulative damage produces brain lesions
- heterogeneous disorder = patients have different symptoms and experiences, depending on the lesion's size and location, as well as how the individual's brain is functionally organised
- affects the brain and spinal cord
40
Common symptoms of MS
1. muscle spasms
2. mobility problems
3. numbness/tingling sensations
4. pain
5. speech and swallowing difficulties
6. vision problems
7. sexual problems
8. bladder or bowel problems
9. fatigue
10. difficulties thinking, learning, and/or planning
11. depression and anxiety
Most people with MS willowy experience a few of these symptoms
41
Primary progressive (PPMS)
Symptoms onset and progressively get worse; no history of remission
42
Relapsing remitting (RRMS)
Symptoms disappear and reappear across time
43
Progressive relapsing (PRMS)
Symptoms become worse with each relapse, very are and very disabling
44
Secondary progressive (SPMS)
Occurs after RRMS; remissions stop, symptoms get steadily worse
45
DNA methylation
- methyl groups (CH3) are added to the DNA molecule; this blocks promoters from expressing the gene
- can change the activity of a DNA segment without changing the sequence
- typically acts to repress gene transcription
46
Histone methylation
- histone: a type of protein that wraps itself around DNA
- changes in histone methyl groups can induce or repress gene expression
- methylation increases density (more 'spooling', less expression)
47
mRNA modification
- mRNA = messenger RNA = dynamic regulators of gene expression
- primarily refers to 13 different chemical alterations
- affects translation or stimulates other regulatory processes like mRNA degradation or localisation
- small changes can create large outcome differences
48
Mechanisms of plasticity
1. Homologous area adaptation: opposite hemisphere takes over a sensory/cognitive process
2. Cross-modal reassignment: loss of one sensory/cognitive process heightens the remaining senses/processes
3. Map expansion: some areas take on new functions to compensate for loss
4. Compensatory masquerade: brain uses alternative pathways/strategies for processing in place of a lost ability
49
Cerebellum
A major structure of the hindbrain that is specialised for learning and coordinating skilled movements.
50
Reticular formation
Runs through the brainstem, extending from the spinal cord to the thalamus; associated with sleep-wake behaviour and arousal
51
Tectum
Consists of the superior and inferior colliculi; these mediate whole-body responses to visual and auditory stimuli, respectively, and the production of orienting movements
52
Tegmentum
Contains a collection of sensory and motor tracts as well as nuclei with movement-related, species-specific, and pain perception functions.
53
Basal Ganglia
Subcortical forebrain nuclei (caudate nucleus, putamen, and globus pallidus) that connect to the thalamus and midbrain to coordinate voluntary movements.
54
Disorders related to the basal ganglia
Huntington disease = caused by death of basal ganglia cells; characterised by involuntary movements
Parkinson disease = associated with a loss of connections into and out of the basal ganglia, especially from the substantia nigra; characterised by uncontrollable movements such as shaking, stiffness, and a difficulty balancing.
Tourette syndrome = also associated with a loss of neurons in the basal ganglia, which may cause tics.
55
Theory of Mind
The capacity to understand another's mental state and to take it into account.
56
Double dissociation
An experimental technique by which two neocortical areas are functionally dissociated by two behavioural tests; performance on each test is affected by a lesion in one zone, but not the other.
57
Commissurotomy
Surgical disconnection of the two hemispheres by cutting the corpus callosum. This will lead to the condition known as split brain. Is usually done in severe cases of epilepsy.
58
Preferred cognitive mode
Use of one type of thought process in preference to another (e.g. visuospatial vs verbal); is sometimes attribute to the assumed superior function of one hemisphere over the other.
59
Circle of Willis
Joins several arteries at the inferior (bottom) side of the brain; supplies oxygenated blood flow to over 80% of the cerebrum.
60
Ischemic strokes (clots)
Blood clots can block arteries and cut off blood flow to the brain (this is called ischemia). High blood pressure is the main cause for this type of stroke and 87% of all strokes are ischemic. There are two types of ischemic strokes: embolic and thrombotic.
61
Hemorrhagic strokes (bleeds)
Caused y breakage (hemorrhage) or 'blowout' of a blood vessel in the brain. Van be caused by various disorders which affect the blood vessels (e.g. longstanding high blood pressure & cerebral aneurysms). There are two types of hemorrhagic strokes: subarachnoid (10% of all strokes) and intracerebral (3% of all strokes).
62
Controllable risk factors of strokes
1. smoking
2. high blood pressure
3. carotid or other artery disease
4. a history of TIAs (transient ischemic attacks/'ministroke')
5. diabetes
6. high cholesterol (240 mg/dl or higher in the blood)
7. physical inactivity and obesity
63
Uncontrollable risk factors of strokes
1. age > older = higher risk
2. gender > strokes tend to be more common in men
3. heredity > greater chance if stroke f a family member has previously has had one
4. prior stroke, heart attack, or a history of TIAs
25% of people who recover from a 1r stroke will have a 2nd one within 5 years.
64
Symptoms of a stroke
- dizziness, nausea, or vomiting
- unusually severe headache
- confusion, disorientation, or memory loss
- numbness, weakness in an arm, leg, or the face, especially on one side.
- abnormal or slurred speech
- difficulty with comprehension
- loss of vision or difficulty seeing
- loss of balance, coordination, or the ability to walk
65
Lateral outcomes of a stroke
Left side may result in: paralysis on the right side of the body, speech/language problems, slow/cautious behaviour, and memory loss
Right side may result in: paralysis on the left side of the body, vision problems, quick, inquisitive, or purposeless behaviour, and memory loss.
66
Anatomical differences - cerebral asymmetry
1. left hemisphere is larger, heavier, and has more grey matter
2. right hemisphere has more cortical surface area*
3. left hemisphere has a thicker cortex (theorised to reflect social skills and processes)
4. language and music are oppositely lateralised, as are corresponding brain regions (Broca's area has more sulci on the left*)
5. asymmetry in the temporal lobe corresponds with asymmetry in the thalamus
6. distribution of neurotransmitters is asymmetrical
7. cerebral torque: the right side of the brains slightly more forward compared to te left side
*more sulci, theorised to mean more intelligence/more advanced
67
Right-ear advantage
When different stimuli are presented simultaneously to both ears, the pathway from the right ear to the speaking hemisphere has preferred access, and the ipsilateral pathway from the left ear is relatively suppressed.
68
Tests showing a right ear advantage
- digits
- words
- nonsense syllables
- formant transitions
- backward speech
- morse code
- difficult rhythms
- tone used in linguistic decisions
- tonal sequences with frequency transitions
- ordering temporal information
- movement-related tonal signals
69
Tests showing a left-ear advantage
- melodies
- musical chords
- environmental sounds
- emotional sounds & hummed melodies
- tones processed independently of linguistic content
- complex pitch perception
70
Positron Emission Tomography (PET)
An imaging technique that detects changes in vlood flow by measuring changes in the uptake of compounds such as oxygen or glucose; used to analyse the metabolic activity of neurons.
71
Magnetic Resonance Imaging (MRI)
A technique that produces a static, three-dimensional brain image by passing a strong magnetic field through the brain, followed by a radio wave, and then measuring the radiation emitted from hydrogen atoms.
72
Magnetic Resonance Spectroscopy (MRS)
A modification of MRI to identify changes in specific markers of neuronal function, including all macro molecules (DNA, RNA, most proteins, and phospholipids), cell membranes, organelles (such as mitochondria), and glial cells, not imaged by MRI.
73
Diffusion Tensor Imaging (DTI)
An MRI method that, by detecting the directional movements of water molecules, can image fiber pathways in the brain. DTO tractography maps the brain pathways and connectivity.
74
functional Magnetic Resonance Imaging (fMRI)
MRI I which changes in elements such as iron or oxygen are measured during the performance of a specific behaviour; used to measure cerebral blood flow during rest of behaviour.
75
Optical tomography
A noninvasive, dynamic imaging technique in which the image of an object is constructed by measuring the intensity of light transmitted through it.
76
Apoptosis
Genetically programmed cell death.
77
Stages of brain development
1. cell birth (neurogenesis; gliogenesis)
2. cell migration
3. cell differentiation
4. cell maturation (dendritic & axon growth)
5. synaptogenesis (formation of synapses)
6. cell death & synaptic pruning
7. myelogenesis (formation of myelin)
78
Radial glial cells
Cells that form minature 'highways', providing pathways for migrating neurons to follow to their appropriate destinations.
79
Effects of early brain lesions on brains structure
1. changes in the organisation of the remaining intact circuits in the brain
2. generation of new circuitry
3. generation of neurons and glia to replace at least some lost neurons
80
Amblyopia
A deficit of vision without obvious impairment of the eye
81
Athetosis
Slow, involuntary movement
82
Principles of Plasticity
1. Plasticity is common to all nervous systems, and the principles are conserved
2. Plasticity can be analysed at many levels
3. The two general types of plasticity derive from experience
4. Similar behavioural changes can correlate with different plastic changes
5. Experience-dependent changes interact
6. Plasticity is age-dependent
7. Plastic changes are time-dependent
8. Plasticity is related to an experience's relevance to the animal
9. Plasticity is related to the intensity or frequency of experiences
10. Plasticity can be maladaptive
83
Diaschisis
A show subsequent to brain damage in which areas connected to the damaged area show a transitory arrest of function.
84
Constraint-induced movement therapy
A procedure in which restraint of a healthy limb forms a patient to use an impaired limb to enhance recovery of function.
85
Stages of cognitive development - Piaget
1. Sensorimotor stage
a. 0 - 2 years
b. children are learning about their environment through sensory experiences
2. Pre-operational stage
a. 2 - 7 years
b. children develop mental abstractions; also, this is when the earliest conscious memories may occur
3. Concrete operational stage
a. 7 - 11 years
b. children develop knowledge and systematic thinking (e.g. the ability to classify, compare, etc.)
4. Formal operational stage
a. 11 - 17 years (continues into adulthood)
b. children develop the ability to form theories and test hypotheses about the world
86
The adolescent brain
- ages 10 to 17 (girls), and 12 to 18 (boys)
- rapid synaptic pruning
- growth of prefrontal connections
- heightened neural plasticity
- dual systems model > cognitive control and rewards system develop at different rates
87
Dual systems model
- rewards system (striatum): sensation seeking, sensitivity to rewards, and a preference for immediate rewards
- cognitive control (PFC): impulse control strategic planning, anticipation, and delayed gratification
In adolescents, the striatum develops earlier than the PFC and is more involved in signalling; additionally the connection from the striatum to the PFC is more mature than the connection from the PFC to the striatum.
88
