A 2016 experiment by researchers at UC Irvine established a link between autonomic nervous system activity during sleep and memory consolidation. Participants in the study were given Remote Associates Test (a creative word association test) which was followed by the treatment: either a nap or quiet wake time. Following the treatment, a second Remote Associates Test. Individuals who napped showed improved performance on the second test compared to those who did not. The researchers found that heart rate variability and time spent in each sleep stage accounted for 73% of the improvement observed. Regarding the experiment, which of the following is essential for consolidating the creative word test memories?
A. Brainstem
B. Cervical spinal cord segments
C. Thoracic spinal cord segments
D. Lumbar spinal cord segments