Neurophysiology and special senses: cortical sensory processing: practice question

A Physiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Physiology · Neurophysiology and special senses: cortical sensory processing

Sample item

A man with a right parietal lesion can feel touch and vibration in his left hand but cannot identify a key placed in it with his eyes closed. Which function is impaired?

AIntegration of tactile information to recognise objects (stereognosis)BTransmission of pain through the spinothalamic tractCStrength of the hand musclesDTransmission of touch through the dorsal columns

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Integration of tactile information to recognise objects (stereognosis)

Basic touch and vibration are preserved, so the dorsal column and primary sensory pathways work. Recognising an object by touch needs the sensory association cortex of the parietal lobe, and damage causes astereognosis.

Option by option

A. Integration of tactile information to recognise objects (stereognosis) (correct)
Correct. The association cortex integrates touch to identify objects.
B. Transmission of pain through the spinothalamic tract
The problem is not pain transmission, which is not tested in this patient.
C. Strength of the hand muscles
Muscle strength is not the problem, as the deficit is in recognition.
D. Transmission of touch through the dorsal columns
Touch and vibration are felt, so dorsal column transmission is intact.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Physiology question

What is the answer to this Physiology question?

The best answer is A, Integration of tactile information to recognise objects (stereognosis). Basic touch and vibration are preserved, so the dorsal column and primary sensory pathways work.

Why is "Transmission of pain through the spinothalamic tract" not the answer?

The problem is not pain transmission, which is not tested in this patient.

Why is "Strength of the hand muscles" not the answer?

Muscle strength is not the problem, as the deficit is in recognition.

Why is "Transmission of touch through the dorsal columns" not the answer?

Touch and vibration are felt, so dorsal column transmission is intact.

What concept does this question test?

It tests Neurophysiology and special senses: cortical sensory processing in Physiology. Recognising an object by touch needs the sensory association cortex of the parietal lobe, and damage causes astereognosis.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Neurophysiology and special senses: cortical sensory processing?

For each system, sketch the key graph (pressure–volume loop, oxygen dissociation curve, nephron handling) and explain it aloud. Then use the flashcards and the other Physiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.