Week 5 Terms Flashcards
What is the Wisconsin Card Sort Test?
A neuropsychologic test of “set shifting”
Analyses of higher level cognitivie function - how well a person can adapt to changing rules
What is the Stroop Test?
a cognitive test that measures inhibitory control.
demonstrates effect that occures when there is a mismatch between name and color
What is the N-Back Test?
Cognitive test of working memory
Presents items in a sequence and must determine if a stimulus matches the stimulus n-times ago.
Parietal Association Cortex
- Critical for sensory guidance of motor behaviour and spatial awareness.
- Example: understanding where objects are in relation to each other.
- Injury results in disorders of body awareness, motor control, spatial recognition
Temporal Association Cortex
- recognition of sensory stimuli and storage of factual knowledge
- links to areas of frontal lobe concerned with emotion and cognition
Frontal Association Cortex
- Plays role in organizing and executive behaviour and working memory.
- DLPFC maintains intention. Injury to this area creates disorganized behaviour & distractability. (Phineas Gage)
Limbic Association Cortex
Emotion and Long Term Episodic Memory Formation
Orbital Ventromedial PreFrontal Cortex
- receives input from sensory
- links to hypothalamus & amygdala
- projects to DLPFC
- goal directed behaviour
- injury to this area leeds to indicision and lacking aversive emotional response
(Cht 18, Cognition, pg 406)
What are the 2 areas of the Frontal Association Cortex?
1) Dorsolateral Pre-Frontal Cortex
2) Ventromedial Pre-Frontal Area
Who were some of the first investigators to formulate the Rate Model?
Albin, 1989
DeLong 1983, 1990
Penney & Young 1983
What are the 2 Main Input Nuclei of the Basla Ganglia?
1) The Striatum
2) The SubThalamic Nuclues
What are the 2 Main Output Nuclei of the Basla Ganglia?
1) GPi (Globus Pallidus, pars interna)
2) SNr (Substantia Nigra pars reticulata)
What are some of the key components of the Rate Model?
1) Basal Ganglia form an Interconnected Network
2) Basal Ganglia are involved in Motor & Cognitivie Function
3) The Cortex generates commands, however the intergirty of the basal ganglia as a positive feedback system is essential to sustain activity
4) The network can be subdivided into 2 Main pathways (direct & indirect)
5) Dopamine acts on the 2 pathways at the Striatum
6) The Striatum selects from competing actions
7) GPi and SNr (output) inhibit or disinhibit thalamocortical and/or brain stem areas to suppress or promote actions
How does the Basal Ganglia control movement?
Movement requires disinhibition.
The Output Nuclei (GPi/ SNr) have a high level of discharge which inhibits the Thalamus > Cortex.
Decreased firing disinhibits the Thalamocortical discharge unit which promotes movement
What is one of the most important neuromodulators of basal ganglia?
Dopamine
What effect does Dopamine have on D1 receptors?
- This is the Direct Pathway.
- Results in increased spiking of neurons in Striatum
- Facilitates striatal signalling to output nuclei
- Facilitates strong, phasic inputs, suppresses weak inputs
What effect does Dopamine have on D2 receptors?
- This is Indirect Pathway
- Suppresses action (striatal inhibitory pathway)
- Inhibits motor behaviour
What is optogenetic activation & what author used this method to show effects of the indirect pathway suppressed action inhibiting motor behaviour in a mouse?
Optogenetics = biological technique using pulse of light to activate a neuron
Kravitz et al. 2010
Basal Ganglia Dysfunctions
- Motor abnormality
- Impaired Memory
- Attention Deficit
- Affective Disorders
- Sleep Disturbance
Basal Ganglia Dysfunctions
- Motor abnormality
- Impaired Memory
- Attention Deficit
- Affective Disorders
- Sleep Disturbance
Basal Ganglia Related Disorders
- Parkinsons
- Huntington’s
- Dementia
- Tourette’s Syndrome
- ADHD, OCD
- Depression
- Schizophrenia
What is the relation between Dopamine and Parkinsons Disease?
- The Nigrostriathal pathway is affected (bilateral dopaminergic pathway that connects SNc to Striatum)
- Dopamine no longer has an impact on the striatum.
- Thus, the direct pathway is suppressed and indirect pathway is facilitated.
- In absense of dopamine–> tremors, rigidity, bradykinesia, sleep disturbance
What are the 2 Reward Pathways in the Brain?
1) Mesolimbic
2) Mesocortical
Which researchers discovered the Brain Reward Pathway in 1954?
James Olds
Peter Milner
