The ordinate axis shows the shift of the soft starter under the influence of reading. Colored bars are the arithmetic mean, light bars are the standard error. Only reliably changing SCP parameters are presented ( p <0.05)
As can be seen from fig. 6.6, when reading, SCPs increase in the central and left temporal monopolar leads. An analysis of local potentials also revealed an increase in SCP in the central and left temporal regions, and a decrease in SCP in the right temporal region. When reading, there is a noticeable increase in the difference in SCP between the left and right temporal regions.
After reading, there was a tendency to decrease SCP in monopolar leads, but the initial level of potential was not restored. When retelling the text, the AMR increased again. The shift of the SCP was statistically significant compared with the previous level in the central region (2.11 + 0.72mV), in the occipital region (1.8 + 0.69), as well as in the left temporal region (2.04 + 0.8mV ) The absence of the contribution of the actual skin potentials to the dynamics of the SCP was indicated by the stability of the skin resistance.
An increase in SCP in the left temporal and central regions indicates a selective decrease in pH in these parts of the head when reading. A decrease in pH occurs due to increased energy metabolism upon activation of the corresponding cerebral structures. Changes in extracranial blood flow and a decrease as a result of this extracranial pH during exercise can also affect SCP. Such vasomotor reactions during reading may be the result of activation of the autonomic nervous system. However, changes in extracranial blood flow during autonomic reactions develop symmetrically, so it is unlikely that selective increase in SCP in the left hemisphere is of extracranial origin. The left temporal and central regions, in which the reading loss increases, correspond to those parts of the brain (temporal and precentral regions of the left hemisphere), where an increase in local cerebral blood flow and an increase in glucose consumption were detected using PET.
An additional study was carried out to study the possible effect of extracranial vascular reactions on changes in SCP when reading. For this purpose, changes in SCP were recorded in 5 subjects during abduction from the surface of the head and lobe of the left ear. The dynamics of SCP in the ear and head has a certain similarity, which indicates the role of the extracranial factor in the genesis of shift of the SCP in reading. At the same time, in the majority of the subjects, SCP in different areas of the head significantly changed in relation to the ear, although these changes could have different directions. Most naturally, SCP increased when reading aloud in the central region with respect to the ear. This is consistent with PET data on increasing energy metabolism in pre- and postcentral areas when reading.
So, according to PET, SPECT, and SCP, reading and mnemonic processes increase the energy exchange of the occipital, temporal, and prefrontal cortices of the predominantly left hemisphere. Changes in extracranial blood flow due to autonomic reactions also contribute to the overall, non-localized increase in AMR. Analysis of AMR, as well as other methods for assessing energy metabolism, may be useful for studying the neurophysiological organization of reading and memory processes.