20.7 Sensory Integration Flashcards
Where in the brain does auditory-visual integration occur?
Superior colliculus
What is the role of the superior colliculus?
Receives inputs from several sensory modalities (visual, auditory, somatosensory) - and integrates them to control innate behaviours such as head, eye and body movements
What allows sensory integration in the superior colliculus?
Layering of several modalities
What does this area show?
Posterior parietal cortex
What are the inputs to the posterior parietal cortex?
- Visual areas
- Somaesthetic areas (all types of touch)
- Auditory cortex
- Motor areas
- Limbic system
- ‘Where’ (dorsal) visual stream
What are the outputs from the posterior parietal cortex?
- Frontal cortex
- Premotor cortex, supplementary motor cortex (SMA)
- Basal ganglia
- Cerebellum
What is the function of the posterior parietal cortex?
Integrates information on position of the body and other objects
–> It is the multimodal sensorimotor association area for direction of attention, movement, speech and reading.
What do lesions to the posterior parietal cortex result in?
- Neglect syndromes (impaired attention)
- Acquired dyslexias
- Impaired perception and memory of spatial relationships
- Impaired movement - reaching, grasping, eye movements
What area does this image show?
Prefrontal cortex
What is the basic main function of the prefrontal cortex?
Orchestration of thoughts and actions in accordance with internal goals
- or evaluation of external stimuli and initiation of voluntary responses to those stimuli
What are several smaller roles of the prefrontal cortex?
- Planning, decision making
- Short-term (working) memory
- Personality expression
- Moderating social behaviour (remember Phineas Gage)
- Controlling aspects of speech and language
What are the inputs to the prefrontal cortex?
- Limbic system (via thalamic nuclei)
- Visual systems: dorsal ‘where’ stream from parietal/occipital cortex, ventral ‘what’ stream from inferotemporal cortex
- Basal ganglia
What are the outputs from the prefrontal cortex?
- Frontal eye fields
- Premotor cortex, supplementary motor cortex (SMA)
- Posterior parietal cortex
- Basal ganglia (e.g. NAc)
- Cerebellum
LIP = lateral intraparietal cortex, for eye movement
Overall, what is the difference in function of the posterior parietal cortex and prefrontal cortex?
- Posterior parietal cortex: body and space representation
- Prefrontal cortex: decisions, planning, initiative, motivation, conscience, moral sense, social skills
What is the function of the supplementary motor cortex (SMA)?
- Internally generated/guided movements
- Sequencing of actions
What is the function of the premotor cortex?
Sensory guidance of movement
E.g. how do I do this movement? More basic, mechanistic, integrating sensory stuff.
What is the function of the motor cortex?
Fine control of fingers and face
What is the function of the frontal eye fields?
Important for control of visual attention and eye movements
- stimulation elicits saccadic eye movements
