A pregnant woman’s sense of “peripersonal space” tends to expand in the third trimester, according to a new study by researchers from Anglia Ruskin University and Addenbooke’s Hospital in Cambridge, England.
Peripersonal space is defined as the area immediately surrounding the body where our brain is constantly monitoring. This space is commonly described as being within an arm’s length of another person and is where the majority of interactions with the external world occur.
“Peripersonal space is considered a ‘safety bubble’ and it’s possible that the observed expansion of this at the late stage of pregnancy might be aimed at protecting the vulnerable abdomen during the mother’s daily interactions,” said lead author Dr. Flavia Cardini, a senior lecturer in psychology at Anglia Ruskin University.
“So as the mother’s bump grows, in effect the expanded peripersonal space is the brain’s way of ensuring danger is kept at arm’s length.”
For the study, published in the journal Scientific Reports, researchers used an audio-tactile test to measure the boundaries of the peripersonal space during pregnancy.
As well as testing women who were not pregnant, the researchers tested women at the second trimester (approximately the 20th week) when the abdomen is just beginning to enlarge; at the third trimester (approximately the 34th week) when the abdomen is clearly visible; and roughly eight weeks after giving birth.
The researchers found that a pregnant woman’s sense of personal space expands, but only during the third trimester of pregnancy. No changes were observed in the earlier stages of pregnancy or after giving birth, when the size and shape of peripersonal space were both comparable to that of non-pregnant women.
“Pregnancy involves massive and rapid changes to the body both externally, as the body suddenly changes shape, and internally, while the fetus is growing,” said Cardini.
“Our results suggest that when the body undergoes significantly large changes, at the stage when the abdomen is clearly expanded, the maternal brain also begins to make adjustments to the space immediately surrounding the body.”
Source: Anglia Ruskin University