Following sensory impairments occur in extensive damage to somatosensory area of cerebral cortex.EXCEPT-
## Core Concept
The question tests understanding of the role of the somatosensory area of the cerebral cortex in processing sensory information. The somatosensory cortex, located in the parietal lobe, is crucial for processing sensations such as touch, pressure, temperature, and proprioception (awareness of body position).
## Why the Correct Answer is Right
Extensive damage to the somatosensory area of the cerebral cortex can lead to impairments in the ability to perceive and interpret sensory information from the body. This includes difficulties with localization of touch, discrimination of sensations, and perception of the body's position in space. However, **stereognosis**, the ability to perceive the form and nature of objects by touch, and **graphesthesia**, the ability to recognize numbers or letters drawn on the skin, are specific functions that can be impaired. On the other hand, **pain perception** is primarily mediated through other pathways and structures, including the spinothalamic tract, and is not solely dependent on the integrity of the somatosensory cortex.
## Why Each Wrong Option is Incorrect
- **Option A:** Impairment in localization of touch is a consequence of damage to the somatosensory cortex, as this area is involved in processing the spatial aspects of touch.
- **Option B:** Difficulty in temperature sensation can occur with damage to the somatosensory cortex, although crude temperature perception is often preserved due to the spinothalamic tract's role in transmitting basic temperature and pain information.
- **Option D:** Impairment in proprioception (awareness of body position) can result from damage to the somatosensory cortex, as this area processes information about body position and movement.
## Clinical Pearl / High-Yield Fact
A key clinical point to remember is that while the somatosensory cortex plays a critical role in processing and interpreting sensory information, **pain perception** is primarily mediated by the spinothalamic tract and other subcortical structures. Therefore, extensive damage to the somatosensory cortex may not significantly impair the perception of pain.
## Correct Answer: D. proprioception