Neuropsychology Flashcards
Neuroplasticity
The nervous system’s potential for physical or chemical change that enhances its adaptability to environmental change and its ability to compensate for injury.
Localisation
The theory that different brain regions have different functions.
Lateralisation
A process by which functions become located primarily on one side of the brain.
Broca’s area
An area in the anterior left hemisphere that functions with the motor cortex to produce the movements that are needed for speech.
Broca’s aphasia
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.
Wernicke’s area
An area in the secondary auditory cortex which regulates language comprehension.
Wernicke’s aphasia
The inability to comprehend or produce meaningful speech, despite intact production of speech. Also known as sensory aphasia or fluent aphasia.
Conduction aphasia
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.
Alexia
The inability to read (may result due to a disconnection between the visual areas of processing and Wernicke’s area.
Apraxia
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.
Agnosia
Partial or complete inability to recognise visual stimuli; is not explained by a defect in sensation or a reduced level of alertness.
Ataxia
A difficulty/failure to properly coordinate muscle movements.
Ventral stream
Visual processing pathway for object identification and perception of related movements; starts in the occipital lobe and goes towards the temporal lobe.
Dorsal stream
Visual processing pathway for guiding movements relative to objects; starts in the occipital lobe and goes towards the parietal lobe.
Parkinson disease
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.
Brain lesion
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.
Hierarchical organisation of brain function
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).
Hindbrain
- includes the spinal cord, brain stem, and the cerebellum
- controls the body’s vital functions
- probably evolved first
Midbrain
- includes the colliculi, tegmenjtum, and cerebral peduncles
- controls vision, hearing, motor function, alertness, and temperature regulation
- probably evolved second
Forebrain
- includes the telencephalon (cerebral hemispheres) and the diencephalon (thalamus, hypothalamus, epithalamus, and sub-thalamus)
- controls complex cognitive, sensory, and motor processes
- probably evolved last
Hebbian theory
Neural pathways develop based on experiences; as pathways are used roe often, they become faster and stronger.
Biopsychosocial model
This model examines a person’s biological, social, and psychological wellbeing and health together, as a whole.
Axon hillock
The juncture of the soma and axon, where the action potential starts.
Neuron’s internal structure
- 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
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.
Spatial summation
The tendency of two or more adjacent events. Hence, two or more adjacent postsynaptic potentials add or subtract.
Storage granule
Membranous compartment which holds several vesicles containing a neurotransmitter.
Ionotropic receptors
These are usually excitatory and they increase the likelihood that a neuron will produce an action potential.
Metabotropic receptors
These are usually inhibitory and they decrease the likelihood that a neuron will produce an action potential.
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.
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.
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.
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.
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.
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.