ch. 4: sensorimotor functioning Flashcards
What are the three levels of brain processing?
Primary (initial signal processing), Secondary (advanced processing, unimodal association cortex), Tertiary (integration of multiple senses, prefrontal association cortex).
What does the unimodal association cortex do?
Forms motor programs, goals, and ideas before sending signals to the primary motor cortex.
What area integrates sensory information across multiple modalities?
Tertiary processing areas
What are the two types of somatosensory processing?
External (touch, pain, temperature) and internal (body position, internal temperature)
What are the five types of somatosensory receptors?
- Mechanical receptors (touch, vibration)
- Chemical receptors (respond to external chemicals like smell/taste)
- Thermoreceptors (temperature)
- Nociceptors (pain)
- Proprioceptors (body position)
What is the homunculus?
A cortical map showing the amount of brain space dedicated to sensory and motor functions in different body parts.
How does taste information travel in the brain?
From the tongue → thalamus → multiple brain regions (contralateral processing).
What are the three types of gustatory dysfunctions?
- Ageusia (loss of taste)
- Dysgeusia (impaired taste)
- Phantogeusia (perceiving taste that isn’t there)
Where does olfactory information travel?
Olfactory bulb → limbic system → frontal cortex.
What are three olfactory dysfunctions?
- Anosmia (loss of smell)
- Dysosmia (impaired smell)
- Phantosmia (smelling something that isn’t there)
Where is somatosensory information processed?
Thalamus → contralateral primary somatosensory cortex
What is astereognosis?
The inability to recognize objects by touch.
What is finger agnosia?
The inability to identify which finger was touched or shown, independent of numbness
What is paresthesia?
Unusual sensations like numbness and tingling
What is phantom limb pain?
When the brain generates sensations of a limb that has been amputated.
What is proprioceptive disorder?
the inability to sense limb position in space
What is tactile extinction?
When tactile information is blocked, preventing full sensory perception.
How is motor information transmitted to the body?
internal capsule → spinal cord → muscles (contralateral projections)
What are the three motor planning areas before the primary motor cortex?
- supplementary motor area (SMA)
- premotor area (PMA)
- cingulate motor area (CMA)
Supplementary motor area (SMA)
Motor sequencing, timing, initiation (internal cues)
Premotor area (PMA)
Motor sequencing, timing, initiation (external cues)
Cingulate motor area (CMA)
Motor decision-making, evaluating movements
What is apraxia/dyspraxia?
A disorder of purposeful movement; difficulty forming or executing motor plans
What are the types of apraxia?
- Limb-kinetic apraxia
- Ideomotor apraxia
- Conceptual apraxia
- Ideational apraxia
Limb-kinetic apraxia
Fine-motor coordination deficits (clumsiness)
Ideomotor apraxia
Cannot connect an idea to a movement
Conceptual apraxia
Lost knowledge of movement purpose
Ideational apraxia
Difficulty sequencing complex multi-step movements
How does visual information travel from the eye to the brain?
Retina → optic nerve → optic chiasm → optic tract → thalamus (LGN) → optic radiation → primary visual cortex (V1)
What are visual field deficits?
- heminanopia
- quadrant anopia
- L Homonymous hemianopia
L Homonymous Hemianopia
loss of the left visual field in both eyes
What is visual agnosia?
The inability to recognize objects, faces, or symbols despite intact vision.
What is achromatopsia?
A condition where a person loses color vision but is not colorblind.
