Part 2: Experimental Approaches to Studying Infant Development

Question 1

Experimental Designs

Answer 1

A group of approaches that allow inferences about causes and effects to be drawn

▪ Essential characteristics
* Random assignment of participants to groups

• Experimental control
• Inference about causes and effects allowed

Question 2

pros and cons

Answer 2

pros

• direction of causality no third variable problem
• have control over variables

cons

• not natural
• cannot be used in many different variables

Question 3

Correlational Design (Quasi-Experimental) infant development
before vs during Covid

Answer 3

Take advantage of existing differences in experience

*And then measure outcome/performance, e.g.

▪ Pandemic presence/absence
▪ Night light in room or not
▪ The language/languages heard at home
▪ Exposure to SRIs in utero

Question 4

pros and cons

Answer 4

**pros: **
* compares many groups of interes

• is able to establish relationship between many variables

cons
* no direction of causation
* third variable problem

Question 5

Longitudinal

Answer 5

Same participants studied repeatedly at
different ages

pros:how same children develop, allows to see individual diffference

cons: takes longer,bigg commitment,

Question 6

Cross-sectional

Answer 6

People of differing ages all studied at the
same time

pros:quick,less commitment

cons:age diference counfounded in group difference

Question 7

Longitudinal-
Cross-sectional/ cohort-sequential

Answer 7

Same groups of different-aged people
studied repeatedly as they change ages

pros:less commitment,longitudinally over long time span in less time

con:conhor may different other then age

Question 8

Microgenetic

Answer 8

Same participant studied repeatedly over a short period as they master a task

pros: observe development in real time

cons:commitment

Question 9

Challenge of Studying Infants

Answer 9

• Cannot talk
• Cannot follow instructions
• Short attention span
• Limited behavioral repertoire
• Develop rapidly, so different tasks need to be used at different ages

Question 10

Behavioral Measures

Answer 10

Dependent variables
* Sucking, head turning, reaching, surprise, looking time

Question 11

Physiological Measures

Answer 11

Dependent variables

• Heart Rate, EEG or Event Related Potentials (ERPs), Pupil Dilation, Hemodynamic response (e.g. fMRI, Optical Imaging)

Question 12

Measure: High Amplitude Sucking

Answer 12

• Can test preference
• Or Habituation

Question 13

Measure: Conditioned Head Turn

Answer 13

• Can test discrimination
• And categorization

Question 14

Psychophysiological Methods

Answer 14

Measures of autonomic nervous system activity

• Heart rate, blood pressure,
  respiration, pupilometry, stress hormones

Question 15

EEG - electroencephalography

Answer 15

• Measures electrical activity in the brain when nerve cells communicate
• EEG measures brain wave oscillatory activity
• Can be steady state or in response to stimuli
• Can reveal cognitive function (e.g. alpha waves for attention)
• Can reveal entrainment (rhythmical synchronization

Question 16

ERP – event related potentials

Answer 16

• Amplitude changes in response to an external event
• Can Reveal Discrimination
• Latency can also reveal different cognitive processes

Question 17

Measures of Brain Function

Answer 17

• Both non-invasive
• Motion artifacts
• Can reveal timing/latency
• Difficult to reveal brain localization

Question 18

MEG - Magnetoencephalography

Answer 18

• Similar to EEG, but measures the magnetic Field changes that accompany electrical activity
• Can localize where in the brain better than In EEG/ERP
• But still difficult in infant brains because their brains are changing and growing
• Noninvasive
• Very expensive
• Sensitive to movement artifacts

Question 19

Structural (MRI) and functional brain
imaging (fMRI

Answer 19

• fMRI via BOLD hemodynamic response
• Used primarily in clinical work, but
  also in some experimental work
• Minimally invasive, but the pulse
  sequence is noisy, so challenging
• Infants need to be perfectly still
• Very good spatial localization
• Not very good temporal resolution
• Easiest with sleeping infants, or children old enough to learn how to lie still in a scanner

Question 20

• Optical Imaging (fNIRS) via functional Near Infrared Spectroscopy

Answer 20

• Measures hemodynamic response
• Shine light, picked up by blood (like in a pulse oximeter)
• Can determine changes in amount of oxygenated and deoxygenated blood in response to a stimulus
• Non-invasive
• Excellent spatial localization, but not as precise as MRI
• Poor temporal localization
• Can tolerate some movemen
  t
• More expensive than EEG, less than MRI

Question 21

Ethical Research requires:

Answer 21

Informed Consent
* Parents give on behalf of children or infants
* “Assent” is still important

• Honesty & Transparency
• Full disclosure of any conflict of interest
• Random sample unless otherwise specified
• Obviously NOT manipulating the data
• Good research REQUIRES stringent adherence to ethical standards
• Ethical research REQUIRES thoughtful and appropriate
  experimental design and implementation

cost must be lower then the benifit

and cause as little harm as possible

Question 22

Is Empiricism Innate? Preference for Nurture Over Nature in People’s Beliefs About the Origins of Human Knowledge

Jinjing (Jenny) Wang

Answer 22

people belive that nurture play a bigger role then nature