F1- Somatosensory System

The size of an area on the body's surface where a single sensory afferent neuron is activated by a stimulus.

The region in the spinal cord that carries sensory information from the body to the brain.

The pathway for sensory information from the face to the brain.

The part of the thalamus that receives sensory information from the body and face.

The area of the brain that receives sensory input from the Ventral Posterior Complex (VP) in the thalamus.

A subregion of the primary somatosensory cortex responsible for processing tactile information from the skin, including details of surface texture.

A subregion of the primary somatosensory cortex that integrates tactile and proprioceptive information to determine the size and shape of objects.

The ability to sense the position and movement of the body in space.

The sense of internal bodily states, such as hunger, thirst, and pain.

Neurons responsible for integrating sensory information from different sources, especially when a goal-directed action is planned or executed. They receive input from motor areas and respond to the intention to move before actual contact with the object.

A region in the parietal lobe that receives input from multiple sensory modalities (touch, proprioception, vision) and integrates this information to guide movement. It is involved in complex tactile tasks like identifying objects by touch.

A type of neurological deficit where a person has difficulty recognizing objects by touch alone, even though they have normal sensation. It often occurs after damage to the posterior parietal cortex.

This refers to the ability to perceive and recognize objects by touch alone. It is also known as tactile discrimination or haptic perception.

These types of neural responses are characterized by brief, sharp changes in activity that coincide with the occurrence of a specific stimulus. They often indicate the immediate detection of a sensory event.

The somatosensory system is a network of nerves and receptors that allow us to sense the world around us. It's responsible for sensations like touch, pressure, temperature, pain, and proprioception (awareness of our body's position).

Somatosensory afferents are the nerves that carry sensory information from the body to the brain. These nerves are specialized to transmit different types of sensations, like touch, pressure, pain, and temperature.

The diameter of a somatosensory afferent's axon (the long, thin part of the nerve) is related to the type of information it carries. Larger diameter axons typically carry information about touch and position, while smaller diameter axons carry pain and temperature signals.

The receptive field of a somatosensory afferent is the area of skin or body where stimulation causes a change in its activity. Larger receptive fields mean the nerve is less precise in its response, while smaller receptive fields allow us to feel finer details.

The phenomenon where stimulation of one area of the skin inhibits the activity of neighboring areas, enhancing tactile acuity.

Neurons in the somatosensory cortex are organized into vertical columns, each specialized for processing a specific type of sensory information.

The arrangement of the somatosensory cortex where different body parts are mapped out in a specific order, reflecting the density of sensory receptors and the importance of those areas for touch.

The phenomenon where areas of the somatosensory cortex dedicated to certain body parts are disproportionately larger, reflecting the density of sensory receptors in that area.

The secondary somatosensory cortex is involved in higher-level processing of sensory information, playing a role in object recognition and manipulation.

The ability to process sensory information while actively interacting with the environment.

A complex area involved in higher-level somatosensory processing, located in the dorsal bank of the lateral fissure. It includes the SII proper and the Parietal Ventral area (PV).

A sub-area of the secondary somatosensory cortex, receiving input from the primary somatosensory cortex and thalamus, involved in processing deep somatic sensations.

A sub-area of the secondary somatosensory cortex, receiving input from different thalamic nuclei, involved in processing both deep somatic and proprioceptive information.

Two tendencies of RF convergence in SII: distal parts of limbs (hand, foot, mouth) are interconnected, and trunk RFs extend towards distal parts and head.

Area PV receives inputs from non-sensory thalamic areas like Area 3B, Area 3A, Mediodorsal nucleus, and Centrolateral nucleus.

Strong connections between area PV and premotor area, frontal eye field, and the mediodorsal nucleus suggest its involvement in memory and attention.

Experiment showing area PV's role in tactile memory: Monkeys were trained to associate frequencies to actions, and PV neurons discharged during the delay, suggesting memory encoding.

Located anterior to PV, the Parietal Rostral Area (PR) receives input from somatosensory regions and is activated only during active touch.

Area 5 (SPL) receives input from sensory and non-sensory thalamic nuclei, while Area 7 (IPL) receives mainly from non-sensory nuclei like LP, PuA, and PuM.

These non-sensory nuclei connect to higher-order areas like the temporal, cingulate, and prefrontal cortex, suggesting complex information processing in PPC.

Areas 5 and 7 are called 'somatosensory association areas' because they combine information from multiple sources to interpret the meaning of touch.

Some neurons in the posterior parietal cortex respond to stimuli in more than one sensory modality, called bimodal neurons.