Location of the Stimulus

The somatosenory system is built in a way that allows it to "know" the location of stimulus.

A key idea is "a receptive field."

A receptive field is the part of the world to which a sensory neuron pays attention. You can always find the receptive field of a neuron by following a simple rule:
Find the sensory receptors that ultimately feed information to that neuron. The site of those sensory receptors is the neuron's receptive field.

The diagram below shows the receptive fields of each of three different neurons in a sensory system.

When a stimulus is applied to its receptive field, a senory neuron has a chance to respond. When a stimulus is applied outside its receptive field, that same neuron isn't much interested.

Here are two views of the same network of neurons showing the patterns of activity that occur with two sensory stimuli in different locations. ("X's" denote the location of the stimuli.)

Three question for Problem #2.

Location
1) Where is the receptive field of a neuron in the "hand" region of the somatosensory cortex in Tom's left cerebral hemisphere?
a) somewhere in his right hand
b) somewhere in his left parietal lobe
c) somewhere in his spinal cord or thalamus
2) When a neuron in Tom's somatosensory system fires a burst of action potentials, his nervous system "knows" that:
a) a stimulus was delivered at a point well outside the neuron's receptive field.
b) a stimulus was delivered at a point at a precise location inside the neuron's receptive field.
c) a stimulus was delivered at a point somewhere inside the neuron's receptive field.
3) If a small group of neurons in Tom's somatosensory cortex were activated (by electrical stimulation via an electrode or by the "electrical storms" of epilepsy), he can be expected to say that:
a) he feels touch or temperature or even pain in a certain part of his body depending upon what region of his somatosensory cortex was activated?
b) he feels some kind of sensory stimulation but we can't begin to predict where because the inputs from different parts of the body are all mixed up in the somatosensory cortex and there's no consistent map of the body.
c) he feels a somatory sensation in a particular part of his body, but the sensation is much more imaginary than real because the neural activity was not initiated by a normal kind of stimulation.