In its simplest terms, sensory stimulation refers to the impact the environment has on our minds and bodies as we receive information through our five senses.
This form of stimulation is vital for brain development (zero-to-five).
Years of research has proven that children who receive adequate stimulation achieve higher IQ scores than those who lack or receive improper stimulation.
So, what is proper stimulation? At birth, an infant's brain is immature and requires stimulation to fully develop.
However, this stimulation requires dosification.
Too much stimulation will cause an overload of information, which in turn will hinder the ability of the brain to learn and make new connections.
 For example, you may have noticed how easily babies can become irritated if over-exposed to music, lights or even touch.
This emotional reaction signals that they feel overwhelmed by the amount of information and cannot cope with this stimulation.
How much is too much? Age, development, and individuality, all play a role in identifying the optimal stimulation threshold in a particular child.
As a general guideline, stimulation activities should be limited to three sessions per day and not to exceed fifteen minutes per session.
 Your child will tell you when 'too much' is 'too much'.
Does he become irritable after ten minutes? Does he push away the toys? Learn to read his cues and remember that sensory-stimulation should always be enjoyable for both parents and infants.
Also, consider alternating toys and activities so that your infant is exposed to new and less likely to become bored or irritated.