Somatosensory cortex

Definition

The somatosensory cortex is a region of the brain located in the parietal lobe, responsible for processing sensory information from the body, including touch, temperature, pain, and proprioception. This area plays a vital role in tactile acuity, allowing us to discern fine details through our sense of touch, and is also crucial for haptic perception, helping us understand the texture and shape of objects. Additionally, it integrates information related to proprioception, which involves awareness of body position and movement, and can be involved in phenomena such as phantom limb sensations when a limb is lost.

5 Must Know Facts For Your Next Test

1. The somatosensory cortex is organized somatotopically, meaning that different parts of the body are represented in specific areas of the cortex, often referred to as the 'homunculus'.
2. Damage to the somatosensory cortex can lead to deficits in sensory perception, affecting one's ability to feel or accurately interpret touch and pressure.
3. The somatosensory cortex is involved not only in sensing stimuli but also in interpreting these sensations for decision-making and motor control.
4. Phantom limb sensations arise from changes in the somatosensory cortex after an amputation, demonstrating how this area can still generate sensations in a missing limb.
5. Research has shown that areas of the somatosensory cortex can be reorganized through experience and learning, highlighting its plasticity in response to changes in sensory input.

Review Questions

• How does the organization of the somatosensory cortex contribute to tactile acuity?
  • The organization of the somatosensory cortex plays a crucial role in tactile acuity by mapping different body parts to specific areas within the cortex. This somatotopic arrangement means that areas with higher densities of sensory receptors, like the fingertips, occupy larger regions of the cortex. As a result, this allows for finer discrimination between points of contact on these sensitive areas, enhancing our ability to perceive detailed textures and shapes.
• Discuss the relationship between haptic perception and the functions of the somatosensory cortex.
  • Haptic perception relies heavily on the functions of the somatosensory cortex as it integrates sensory feedback during active exploration of objects. When we touch an object, receptors send information about texture, shape, and temperature to this region of the brain. The somatosensory cortex then processes this data, allowing us to identify and recognize objects through touch alone, showcasing its essential role in our interaction with our environment.
• Evaluate how changes in the somatosensory cortex can lead to phenomena like phantom limb sensations after amputation.
  • After an amputation, changes in the somatosensory cortex can cause phantom limb sensations because the cortical representation of the missing limb remains intact. When adjacent areas of the cortex are stimulated or experience heightened activity due to lack of input from other body parts, it can lead to sensations that feel as if they are coming from the absent limb. This phenomenon highlights not only the persistent neural pathways associated with the lost limb but also demonstrates how adaptable and plastic our brain's representation of body parts can be even after significant physical changes.

Related terms

Tactile acuity: The ability to discern two points of touch on the skin as separate, which is influenced by the density of sensory receptors and the representation in the somatosensory cortex.

Haptic perception:

The process of recognizing objects through touch, which involves active exploration and the integration of sensory feedback from the somatosensory cortex.

Proprioception: The sense that informs us about body position and movement, which is processed by the somatosensory cortex along with other brain regions.