February 1, 2011 Julie A. Kable, Ph.D. Ukraine Nutrition Project Update: Infant Neurodevelopment (Cardiac Orienting Responses) February 1, 2011 Julie A. Kable, Ph.D.

Attentional Models of Infant Cognitive Development Attention is a multi-faceted system rather than one thing Models are driven by theory and data Underlying belief that individuals strive to encode environmental stimuli, process it, and then generate adaptive responses

Predictive Validity Studies Traditional Infant Tests (McCall, 1979) Age in Infancy Later Age 1-6 mo 7-12mo 3-4 .21 .32 5-7 .09 .20 At-Risk Sample 2-4 .35 .30 Info Processing Tasks (Colombo, 1993) Measure Correlation IQ (2-7) Fixation Duration -.49 Novelty Preference +.49 Retention +.42 Reaction Time -.46 Rose & Wallace, 1995 IQ (11) Novelty Preference .41

Problems with Information Processing Tasks Information processing task have high attrition rates Maintaining inter-rater reliability These tests also have poor internal consistency Data from the Fagan Test-2nd edition Test Cronbach’s alpha One .28 Two .38 Three .43 Four .48

O’Connor’s Work (1980, 1984) Primarily done to establish continuity 4-month HR responses to auditory stimuli were related (r=-.63) to 18-mo Bayley (1969) scores 4-month HR responses to same auditory stimuli were related (r=-.60) to 5-year Stanford Binet IQ

Why HR as an Index of Attention? Has the potential to reduce the ambiguity of overt behavioral response Sensitive to small and rapid changes needed to assess the different components of attention ORs believed to adaptively gate oxygen to the brain to increase central processing of information Attrition rates are lower (85- 95% completion) Heart rate responses highly consistent (Cronbach’s alpha: .82-.88)

Neurophysiological Encoding Refers to using physiological responses in a learning context to index integrity and efficiency of the CNS Can be used across stages of development and across species

Information Processing Tasks Placing infants into a car seat Mothers seated out of sight of infant Attaching 3 physical sensors on the chest and lower abdomen to assess heart rate Rests for a minimum of 1-minute Started when child was awake & alert 30-sec baseline followed by stimuli

Protocol for Stimulus Presentation Auditory stimuli: Habituation: 400-1000 hertz pure tone pairs presented contiguously for 12 sec each Dishabituation: 700-1000 hertz pure tone pairs presented contiguously for 12 sec each Visual stimuli

Indices of Cardiac Orienting Responses Measure Direction of Optimal Responding Average HR Lower scores Average HR Difference Higher scores Average Latency (Speed) Average Slope Lower scores (more negative slopes) Average Peak

Average HR Trough over Trails-Phonemic Stimuli (/ba/-/da/

Cardiac Orienting Responses to Over Repeated Trials (tones and faces)

Cardiac Orienting Response to Phonemic Stimuli (/ba/-/da/)

OR in Average vs. Delayed/Intellectually Deficient Range at 4 OR in Average vs. Delayed/Intellectually Deficient Range at 4.5 years of age Average Delayed

Orienting Responses to Speech Stimuli (/ba/ -/da/) in Infants who Varied as a Function of Maternal Smoking Status

Orienting Responses to Speech Stimuli (/ba/ -/da/ in Infants who Varied as a Function of Maternal Smoking Status

Cardiac ORs Sizes by Design for Auditory Baseline Alcohol Group No Supplements PNV PNV +Choline Exposed 16 13 14 Non-exposed 25 12 7 Minimum preferred is 10 per cell

Percentage with ORs on Habituation Trials

Frequency of ORs by Group Status on Auditory Dishabituation Trials T3 Trend in nonexposed for an intervention effect Visual trials not significant but a trend for an intervention effect in the non-exposed samples T1-Exposed, no intervention-lower than nonexposed, no intervention (X=4.4, p < .04) Significant intervention effect in exposed groups (T1-χ=7.7, p < .02; T3- χ -8.3, p < .02) Among PNV, exposed less likely than the nonexposed (T3-χ=4.7, p < .03)

Baseline HR Group Differences Auditory stimulus Significant intervention effect (F (2, 81)=5.3, p < .007). PNV+choline had higher overall HR Significant interaction between exposure group status and intervention effect (F (2, 81)=3.1, p < .05). The above effect was strongest in the non- exposed groups Visual stimulus Exposure group status* intervention effect (F (2, 78)=3.1, p < .05). Same as above Differences values (Baseline HR-OR HR)

Design Analysis of Auditory Habituation Data Repeated measures ANOVA Significant linear trend for trial (F (1, 80)=4.4, p < .04)-ORs diminish over time Exposure by intervention by trial effect (F (4, 160)-2.6, p < .04). Among exposed, greater magnitude of deceleration relative to those who received no micronutrients or PNV alone on trials 2 and 3.

Average HR Difference by Trial for Each Group on Auditory Habituation Trials

Other findings Auditory Dishabituation Trials-trend for trial effect, intervention effect (F (2,71-3.7, p < .03) with the greatest deceleration in PNV+choline, trend for exposure group status Visual Habituation Trials-trial*intervention group effect trend T1& T2-PNV+choline had a greater magnitude of response and T3 PNV had greater magnitude of response than those without intervention Visual Dishabituation Trials-trend for trial effect, trend for exposure group status* trial

Summary Data represent a preliminary analysis of the cardiac ORs relative to the exposure group by intervention status. Results are promising but need larger n within each cell to improve power to detect effects, particularly the interactions effects Some evidence that choline supplementation improves neurophysiological encoding but maybe for both exposure status groups.