Information in sensory systems is transmitted from the periphery to cortical representations. Which of the following statements about cortical somatosensory representation is correct?

Question

BlackTom AI · Accepted Answer

The primary somatosensory cortex contains a map of the body surface that is magnified for regions with high density of mechanoreceptors.

1) Relevant knowledge points and concepts
- Somatotopy: neurons in primary somatosensory cortex (S1; Brodmann areas 3a, 3b, 1, 2) are arranged so neighboring skin regions project to neighboring cortical locations, producing a body map (the sensory homunculus).
- Cortical magnification: regions with high receptor density and fine discrimination (fingertips, lips, tongue) occupy disproportionately large cortical territory.
- Plasticity: cortical maps can change with experience, injury, or training across development and into adulthood.
- Organization is by body region, not by peripheral receptor class; multiple S1 subareas each contain similar somatotopic maps rather than separate maps for each mechanoreceptor type.

2) Step-by-step reasoning
- The question asks which statement about cortical somatosensory representation is correct. Compare each option to established neurophysiology.
- Option stating a map with magnification for high receptor density matches classical findings (Penfield maps; single regions like fingertips/lips are overrepresented).
- Other options make claims inconsistent with known anatomy/physiology (see below).

3) Intermediate steps / evidence
- Electrophysiology and imaging show contiguous representation across S1 with exaggerated cortical area for digits and face.
- Lesion and training studies demonstrate adult plasticity (e.g., expansion of hand area after increased use; reorganization after amputation), contradicting the “no plasticity in adulthood” claim.
- S1 contains multiple adjacent somatotopic maps (areas 3a/3b/1/2) but these are not segregated by mechanoreceptor class; receptor types converge onto single maps.
- S2 exists and has representations, but the face is not confined to S2 while rest of body is in S1; face has representation within S1.

4) Why the correct answer is correct
- It states the fundamental somatotopic organization and cortical magnification that reflect peripheral receptor density and functional importance — a core, well-established principle.

5) Why other options are incorrect
- Option A: false — cortical maps are plastic in adulthood (training, injury-induced reorganization).
- Option C: false — although multiple S1 subareas exist, they are not four separate maps each dedicated to one receptor class.
- Option D: false — the somatotopic map is continuous in S1 and the face is represented in S1, not exclusively in S2.

6) Conclusion
Therefore, the correct statement is: “The primary somatosensory cortex contains a map of the body surface that is magnified for regions with high density of mechanoreceptors,” which matches the provided answer.

Information in sensory systems is transmitted from the periphery to cortical representations. Which of the following statements about cortical somatosensory representation is correct?Single choice

Similar Questions

Name the cortical region that the blue arrow is pointing to in this image. [input]

Which part of the brain is responsible for processing sensory information from the body?

Sensations like vibration and touch are integrated in which lobe of the cerebrum?

Which functional area of the cerebrum is responsible for perception of touch, coldness and warmth?

The primary somato-sensory cortex is located on the:

The surface area of the brain’s sensory cortex corresponding to the hand is larger than the area corresponding to the upper arm because the skin on the hand

More Practical Tools for Students Powered by AI Study Helper

Homework AI Solver

Stylized AI Paper Writer

Plagiarism Checker Assistant

Citation AI Academic Writing Tool

In-Class Translation Assistant

AI Note Generator

AI Quiz Answers

Past Exam Questions from University Test Bank

Smart Practice Assistant

Adaptive Practice

Making Your Study Simpler