Key points
■ Sensory information is received from exteroceptors, interoceptors and proprioceptors and is projected to specific regions of the forebrain for conscious perception. Proprioceptive input is also projected to the cerebellum for subconscious processing.
Most sensory inputs are also projected to the brainstem ascending reticular activating system for arousal (see Chapter 11).■ Projection to the cerebral cortex utilises a three-neuron pathway between the peripheral receptor and the somatosensory cortex.
■ General proprioception is the sense of the relative positions of body parts.
■ Conscious proprioception projects to the contralateral cerebral cortex; subconscious proprioception projects to the ipsilateral cerebellum.
■ A deficit in general proprioception results in ataxia due to loss of spatial awareness of the body, limbs and/or head. It may also cause a change in the rate, range and force of movement.
A wide variety of sensory modalities are projected to the cerebral cortex. The stimuli are collected by a plethora of sensory receptors that are classified as exteroceptors, interoceptors and proprioceptors.