Braina And Behaviour Lateralisation Summary Flashcards
(42 cards)
What is the definition of the somatosensory system?
The somatosensory system allows the brain to detect touch, pressure, pain, temperature, and body position.
What are the subcomponents of the somatosensory system?
- Exteroceptive system – senses from the skin (touch, pain, temp)
- Proprioceptive system – monitors body position
- Interoceptive system – monitors internal states (e.g. blood pressure)
What is the function of the primary somatosensory cortex (S1)?
Receives direct input from the thalamus (postcentral gyrus).
What does the secondary somatosensory cortex (S2) do?
Further processes somatosensory info.
What is the role of the posterior parietal association cortex?
Integrates visual, auditory, and somatosensory input → sends to motor areas.
What is the function of the dorsolateral prefrontal association cortex?
Evaluates external stimuli and initiates voluntary movement.
What is somatotopic mapping?
Sensory info is organized in a homunculus map.
Which body parts occupy more cortex in somatotopic mapping?
- Lips
- Hands
How does selective attention affect somatosensation?
Selective attention affects what sensory input we consciously perceive.
What is endogenous attention?
Directed by internal thoughts (top-down).
What is exogenous attention?
Captured by external stimuli (bottom-up).
What is the definition of the corticospinal tract?
A major descending pathway from the motor cortex to the spinal cord that controls voluntary movement.
What is the function of the lateral group of motor control pathways?
Independent limb movement (e.g. fingers, face).
Which pathways are included in the lateral group?
- Corticospinal
- Corticobulbar
- Rubrospinal
What is the function of the ventromedial group of motor control pathways?
Posture and whole-body movement.
Which pathways are part of the ventromedial group?
- Vestibulospinal
- Tectospinal
- Reticulospinal
- Ventral corticospinal
What is corticospinal decussation?
~90% of corticospinal fibers cross over (decussate) at the medulla.
What does contralateral control mean in terms of the corticospinal tract?
Left brain controls right body, and vice versa.
What is apraxia?
Inability to carry out purposeful movements on command.
What causes apraxia?
Not due to muscle weakness or sensory loss; often due to left parietal cortex damage.
What is contralateral neglect?
Failure to attend to stimuli on the opposite side of a brain lesion.
What are common behaviors of patients with contralateral neglect?
- Eat from only one side of the plate
- Shave only one side of their face
- Dress only one side of the body
What are the key functions of the left hemisphere?
- Language (speaking, reading, writing)
- Logic, reasoning
- Mathematics
- Analytic, detail-oriented
What are the key functions of the right hemisphere?
- Facial recognition
- Spatial awareness
- Art & music
- Holistic, “big picture” thinking
