What is the Difference Between Sensory and Somatosensory

The key difference between sensory and somatosensory is that sensory refers to the primary somatosensory region that receives sensory information while somatosensory refers to the secondary somatosensory region that is responsible for processing sensory information.

The human brain receives signals via the nervous system across the body and processes the signals in order to create necessary actions against the received stimuli. Hence, the brain is responsible for processing all nervous stimuli generated. Sensory is the primary somatosensory region present in the ridge of the cortex. The secondary somatosensory region lies posterior to the primary somatosensory region. Both sensory and somatosensory regions follow the somatosensory pathway that involves three neurons: primary, secondary, and tertiary.

CONTENTS

1. Overview and Key Difference
2. What is Sensory 
3. What is Somatosensory
4. Similarities – Sensory and Somatosensory
5. Sensory vs Somatosensory in Tabular Form
6. Summary – Sensory vs Somatosensory

What is Sensory?

Sensory is a region of the human brain that receives sensory information such as pressure, temperature, pain, and touch. Primary somatosensory cortex (S1) is another term that describes sensory. The sensory region is located in the human brain, posterior of the central sulcus (postcentral gyrus). This region receives projections from nuclei of the thalamus of the brain. This involves receiving different sensations from receptors located throughout the body.

These sensations include pain, touch, temperature, pressure, and proprioception. The sensory region is comprised of Brodmann’s areas 1,2,3a, and 3b. Out of the four areas, area 3 is responsible for the highest amount of somatosensory input from the thalamus. The sensory region possesses the ability to locate the exact region where the specific sensations arise. This allows the individual to pinpoint the exact location of touch, pain, pressure, etc. The sensory region also helps to determine the approximate weight of an object by looking at it.

What is Somatosensory?

Somatosensory is a region of the human brain that helps to receive and process sensory information to create tactile responses and memory. Receiving signals include touch, pain, and temperature across the body. Secondary somatosensory cortex (S2) is another term that describes somatosensory. It is present posterior and adjacent to the primary somatosensory (sensory) region in the upper part of the lateral sulcus of the cortex of the brain. Somatosensory is connected to the sensory region. It also receives direct projections from the thalamus region of the brain. The somatosensory region consists of Brodmann’s areas 40 and 43.

Somatosensory or secondary somatosensory is involved in tactile object recognition and memory. Basically, the somatosensory region helps to store, process, and retain information received by the sensory region. The somatosensory region possesses connections with the hippocampus and amygdala. This is the main reason that allows the receiving of information from the environment and creates decisions on how to deal with the situation using stored information from similar incidents in the past and how the individual feels about the information related to the scenario.

What are the Similarities Between Sensory and Somatosensory?

• Sensory and somatosensory are present in the parietal lobe of the brain.
• These regions code somatosensory information.
• Both sensory and somatosensory regions possess similar neurons.
• These neural responses are of similar response magnitudes.
• Both regions possess Brodmann’s areas.

What is the Difference Between Sensory and Somatosensory?

The sensory or primary somatosensory region receives sensory information from various parts of the body and processes. The somatosensory or secondary somatosensory region is responsible for creating tactical responses to the sensory information received and storing the responses in memory. Thus, this is the key difference between sensory and somatosensory. Sensory is located in the postcentral gyrus, while somatosensory is located in the upper part of the lateral sulcus. Moreover, Brodmann’s areas 1, 2, 3a and 3b are present in the sensory region and 40 and 43 are present in the somatosensory region.

The below infographic presents the differences between sensory and somatosensory in tabular form for side by side comparison.

Summary –  Sensory vs Somatosensory

Sensory and somatosensory are two regions of the somatosensory system. Sensory is the primary somatosensory region, whilst somatosensory is the secondary somatosensory region. The sensory region receives sensory information, while the somatosensory region creates tactical responses to sensory information based on experiences. Both consist of Brodmann’s regions and similar types of neurons. So, this summarizes the difference between sensory and somatosensory.

Reference:

1. Guy-Evans, Olivia. “Somatosensory Cortex Function and Location.” Simply Psychology.
2. “Know Your Brain: Primary Somatosensory Cortex.” @Neurochallenged.

Image Courtesy:

1. “Posterior Parietal Lobe” By I, Paskari (CC BY-SA 3.0) via Commons Wikimedia
2. “BA312 – Primary Somatosensory Cortex – lateral view – with homunculus” By Polygon data were generated by Database Center for Life Science(DBCLS)[2]. – Polygon data are from BodyParts3D[1]. (CC BY-SA 2.1 jp) via Commons Wikimedia