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Pregnancy Timeline by SemestersDevelopmental TimelineFertilizationFirst TrimesterSecond TrimesterThird TrimesterFirst Thin Layer of Skin AppearsEnd of Embryonic PeriodEnd of Embryonic PeriodFemale Reproductive SystemBeginning Cerebral HemispheresA Four Chambered HeartFirst Detectable Brain WavesThe Appearance of SomitesBasic Brain Structure in PlaceHeartbeat can be detectedHeartbeat can be detectedFinger and toe prints appearFinger and toe prints appearFetal sexual organs visibleBrown fat surrounds lymphatic systemBone marrow starts making blood cellsBone marrow starts making blood cellsInner Ear Bones HardenSensory brain waves begin to activateSensory brain waves begin to activateFetal liver is producing blood cellsBrain convolutions beginBrain convolutions beginImmune system beginningWhite fat begins to be madeHead may position into pelvisWhite fat begins to be madePeriod of rapid brain growthFull TermHead may position into pelvisImmune system beginningLungs begin to produce surfactant
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Executive power — developes from the nursery

A baby's cry not only commands our attention, it rattles our executive function — the exact cognitive thinking we use to make everyday decisions, according to a new University of Toronto study.

According to David Haley, Associate Professor of Psychology at U of T Scarborough, director of the lab and study co-author: "Parental instinct appears to be hardwired, yet no one talks about how this instinct might include cognition. If we simply had an automatic response every time a baby started crying, how would we think about competing concerns in the environment or how best to respond to a baby's distress?"

The study looked at the effect an infant voice had on adults trying complete a cognitive/conflict task using the Stroop test. Adults were asked to rapidly identify printed words by their color — while ignoring their meaning. Each adult's brain activity was measured by wearing an electroencephalography (EEG) cap worn during each task. And each task was preceeded by a two-second audio clip of an infant either laughing or crying.

Brain scan data revealed that infant cries reduced adult attention to thinking tasks, triggering greater cognitive conflict than after hearing an infants' laugh.

Processing cognitive conflict is important as it controls our ability to pay attention. And paying attention is one of the basic executive functions we need to complete mental tasks and make decisions.

The study is the first to examine the effects of infant vocalizations on adult neural activity during a cognitive task, and is published in the journal PLOS ONE.

"Parents constantly make a variety of everyday decisions and have competing demands on their attention
. They may be in the middle of doing chores when the doorbell rings and their child starts to cry. How do they stay calm, cool and collected, and how do they know when to drop what they're doing and pick up the child?,"  adds Joanna Dudek, graduate student in Haley's Parent-Infant Research Lab and lead author of the study

A baby's cry has been shown to cause aversion in adults. But, adds Haley, it could also be "switching on" the cognitive control parents need to respond effectively to their child while addressing other demands of everyday life.

"If an infant's cry activates cognitive conflict in the brain, it could also be teaching parents how to focus their attention more selectively. It's this cognitive flexibility that allows parents to rapidly switch between responding to their baby's distress and other competing demands in their lives — which, paradoxically, may mean ignoring the infant momentarily."

David Haley PhD, Associate Professor of Psychology, University of of Toronto, Scarborough, Canada.

There is a growing body of research suggesting infants occupy a privileged status in our neurobiological programming, obviously deeply rooted in our evolution. But as Haley points out, it also reveals an important adaptive cognitive function in the human brain.

Haley's next steps will be to examine individual new mother's neural activation of attention and conflict processing. Such differences may help or hinder her capacity to respond sensitively to her own infants' cries.

The attention-grabbing quality of the infant cry is well recognized, but how the emotional valence of infant vocal signals affects adult cognition and cortical activity has heretofore been unknown. We examined the effects of two contrasting infant vocalizations (cries vs. laughs) on adult performance on a Stroop task using a cross-modal distraction paradigm in which infant distractors were vocal and targets were visual. Infant vocalizations were presented before (Experiment 1) or during each Stroop trial (Experiment 2). To evaluate the influence of infant vocalizations on cognitive control, neural responses to the Stroop task were obtained by measuring electroencephalography (EEG) and event-related potentials (ERPs) in Experiment 1. Based on the previously demonstrated existence of negative arousal bias, we hypothesized that cry vocalizations would be more distracting and invoke greater conflict processing than laugh vocalizations. Similarly, we expected participants to have greater difficulty shifting attention from the vocal distractors to the target task after hearing cries vs. after hearing laughs. Behavioral results from both experiments showed a cry interference effect, in which task performance was slower with cry than with laugh distractors. Electrophysiology data further revealed that cries more than laughs reduced attention to the task (smaller P200) and increased conflict processing (larger N450), albeit differently for incongruent and congruent trials. Results from a correlation analysis showed that the amplitudes of P200 and N450 were inversely related, suggesting a reciprocal relationship between attention and conflict processing. The findings suggest that cognitive control processes contribute to an attention bias to infant signals, which is modulated in part by the valence of the infant vocalization and the demands of the cognitive task. The findings thus support the notion that infant cries elicit a negative arousal bias that is distracting; they also identify, for the first time, the neural dynamics underlying the unique influence that infant cries and laughs have on cognitive control.

Joanna Dudek, Ahmed Faress, Marc H. Bornstein, David W. Haley

• Marc Bornstein is a Senior Investigator at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), Bethesda, Maryland, USA,

Funding for this research was from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), Bethesda, Maryland, USA; the Canada Foundation for Innovation (CFI); and the Natural Sciences and Engineering Research Council of Canada (NSERC)
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May 31, 2016   Fetal Timeline   Maternal Timeline   News   News Archive   

This study is the first to examine the effects of infant vocalizations on
adult brain activity when the adult is working on a computer quiz.
Image Credit: Public Domain



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