The sense of touch is an invaluable way for any organism to get information about itself and the environment. In this advanced studies thesis MEG is used to study the primary somatosensory cortex of 12 healthy children aged approximately 6.5 years. The somatosensory activity is evoked with tactile stimulation of the fingertip on digits II and V. The MEG responses are recorded to stimulation of both hands while the test subject focuses on the tactile stimuli. Similar responses are also recorded to stimulation of the left hand while not being focused on the stimuli. The study focuses on the characteristics of the SEFT50 deflection using ECD multidipole model for data analyses.
The location, latency and strength of SEFT50 responses are compared between the different fingers and for the left hand also between the conditions of being focused and not being focused on the stimuli. Statistical testing is done by using Student's paired t-test with two-tailed distribution and with a threshold of p < 0.05 for a statistical significance.
No statistically significant differences were found on the results between different fingers. Nor did paying attention to the tactile stimuli make difference on results. These may indicate that the somatotopical organization is still underdeveloped in children and that the primary somatosensory cortex is not strongly associated with higher order information processing. Problems with the quality of the measurement data and small sample size mean that further studies are needed to validate the results.
