About 98% of sensory perception is processed by the thalamus and relayed to the cerebral cortex, giving the thalamus a crucial role in the perception of body position, touch, pain and temperature. Riding a bicycle, stroking a cat, playing the piano or making a cup of tea would require processing of all the sensory perception sent down the motor pathways to coordinate the control of the muscle groups required for these activities. The thalamus also plays a significant role in arousal, awareness and alertness. The only sensory information not relayed by the thalamus is that related to olfaction. Dementia induced necrosis causes thalamic degeneration and inhibits processing and transfer of sensory perceptions. Significant damage to the thalamus presents a serious risk of coma and death.