Biomedical Engineering Reference
In-Depth Information
resulted in 149 movement segments. In each segment, we collected neuronal channels that were
selected at least for two consecutive bins. Figure
4.16
displays this analytical result. From this figure,
we can observe which neurons were consistently selected through the entire set of reaching move-
ments. For instance, neurons indexed by 5, 7, 23, 29, and 93 are shown to be selected in most seg-
ments. On the other hand, neurons indexed by 19, 45, 70, 71, and 84 are partially selected in some
segments. In particular, neuron 71 seems to be consistently selected in the late segments.
This observation is further demonstrated in Figure
4.17
. In this figure, we displayed neuronal
subset examples in the early movement segments (485, 509, and 600 sec from the beginning of sub-
set selection) and the late movement segments (1666, 1713, and 1781 sec). It can be observed from
this figure that there are neurons that are consistently selected such as 5, 7, and 93 for both early and
late segments. However, some neurons selected in the early segments are not selected in the late seg-
ments. For instance, neuron 70 is no longer selected in the late segments. Also, other neurons (such
as 71) are not selected in the early segments but selected in the late segments. It is interesting to see
this transition of a correlation with kinematics from the neuron 70 to 71 through time, because the
activities of those neurons are collected from the adjacent electrodes in the PMd area.
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Movement Segments
FIgURE 4.16:
Temporal patterns of neurons selected during 3D food reaching movements. Black dots
represent selection of neurons for each movement segment (see text). The segment indices are sequen-
tially ordered in time.
