Developmental psych Flashcards
What are some strengths and limitations of using interviews to gather data about children?
o Allows full focus on the behaviour in question
o Follow up questions can clarify an earlier response
o Can be difficult to generalise beyond the individual case
o Can be difficult to generate a causal argument – don’t have control over all variables
o Have to keep in mind the accuracy of what the child is saying (could be lying)
What are some strengths and limitations of using naturalistic observations to gather data about children?
o Observe children in their natural environment
o Has good ecological validity – similar to “real-life”
o Can be used to study a range of behaviour – e.g., things that would be unethical to replicate in an experiment (neglect etc.)
o Hard to identify causal relationships – hard to know which variables influenced the behaviour of interest
o Painstaking to administer – many behaviours occur only occasionally in everyday environments – takes huge amounts of time, resources and money to do effectively
What did Jean-Jacques Rousseau believe?
Jean-Jacques Rousseau – argued that parents and society should give the child maximum freedom from the beginning
What did John Locke believe?
John Locke was an empiricist too – saw the child as a blank slate and advocated first instilling discipline, then gradually increase the child’s freedom
What did Aristotle believe? What did he emphasise?
Aristotle however was concerned with fitting child rearing to the needs of the individual child
Aristotle was an empiricist – believed that knowledge comes from experience - nurture
What did Plato believe? What did he emphasise?
Plato emphasised self-control and discipline when raising children
Plato was a nativist – believed that children are born with an innate knowledge about the world - nature
What is Ontogeny?
The evolution of the individual organism
What is Phylogeny?
The evolution of the species
What are the strengths and limitations of using a cross-sectional design to examine development?
o Children of different ages are compared on a given behaviour/characteristic over a short period of time
o Most common design used
o Quick
o Doesn’t show development of the individual
o Can show problems with cohort effects – might have a variable embedded in lifestyle use for one age cohort compared to another, would affect results
How did Hood (1995) test young children’s understanding of gravity?
- Dropping an object and will children understand where the object will fall
- Dropping an object into a tube that moved the ball to a position that wasn’t straight down
- Child’s understanding of gravity was robust – didn’t change no matter how many errors occurred
What is a naturalistic experiment?
Naturalistic experiments – data is collected in everyday settings such as the home or in a special playroom at the testing lab
What are some strengths and limitations of using experiments to gather data about children?
o Can directly test relationships between variables
o Change one variable at a time – experimental control is relatively easy
o Can establish a causal relationship
o “artificial” technique – so lacks in ecological validity unless using “naturalistic” experiments
o Sometimes are not possible due to ethical issues
What is this issue with observational learning in infants? Does it happen at all?
- Recent work suggests that young infants cannot imitate – will stick tongue out to any interesting visual display
- Imitation in older infants does happen – can imitate in person or behaviour they see on TV by 15 months
- Implicate their intentions rather than literal actions
- Infants watch an adult try to pull the end off of a dumbbell but fail. Infant would then imitate the action but would pull the end off – imitating the intention
What is observational learning?
- Ability to imitate others may be present from early life e.g., newborns sticking out their tongues if you do too
What is instrumental conditioning (operant)?
- Learning the relationship between our behaviour and the consequences of our behaviours
- Repeat behaviours that lead to reward and give up behaviours that lead to punishment
- Behaviour must already occur before it can be instrumentally conditioned
- Conditioning occurs when an infant learns the contingency relation between their behaviour the resulting consequence
- Positive reinforcement - means behaviour is reliably rewarded by a positive experience (used mostly with children)
- Negative reinforcement – behaviour is reliably rewarded by stopping an ongoing negative experience
- Punishment – behaviour is reliably penalised by a negative experience
- Extinction – behaviour is neither reliably rewarded or punished, behaviour just stops occurring
What is Classical conditioning? Give an example related to infancy
- Association between an initially neutral stimulus with another stimulus that always evokes a reflexive response
- When bottle is presented, baby turns and sucks
- If stroked hand when presented bottle, eventually the baby will suck just to the stroking of the hand
What is statistical learning?
- Involves picking up info from the environment, forming associations among stimuli that occur in a statically predictable pattern e.g., knowing where the mirror is in a bathroom
- Natural environment contains high degree of regularity and redundancy
- Statistical learning is critical to language learning
What are affordances? Give an example
- The possibilities for action offered by objects and situations
- E.g., an infant must learn in a shape sorter which shapes afford being picked up and put in which hole
What is differentiation? Give an example
- The extraction from the constantly changing stimulation in the environment of those elements that are invariant or stable (Gibson)
- E.g., infants learn the association between certain facial expressions and tones of voice, even from different people
Does perceptual learning take place from birth? Elaborate
- From birth, infants can use their sense to search for order and regularity. Perceptual learning is involved in many examples of intermodal co-ordination e.g., a glass falling and a glass smashing are related events
What is habituation?
- A decrease in responsiveness to repeated stimulation – reveals learning has occurred
- The infant has a memory of representation of the repeated, now-familiar stimulus
- The speed with which an infant habituate is believed to reflect the general efficiency of the infant’s processing information
- Some continuity has been found between these measures in infancy and general cognitive ability at 18
Does learning begin before the child is born? Elaborate
- Learning begins before the child is even born
- Newborn infants show recognition of things they’ve been presented before birth
- Also prefer smells, tastes, and sound patterns that are familiar due to prenatal exposure
True or false, Rich learning environments lead to more synaptic connections?
TRUE
What is synaptogenesis?
The creation of more synapses
What must researchers do when researching children (ethical issues)
- Ensure the research does not harm the children physically/psychologically
- Obtain informed consent from parents/guardians and the child (if they are old enough to understand)
- Persevere the anonymity of the children who take part
- Counteract any negative outcomes and correct any inaccurate impressions
What is the micro genetic design?
o Used to provide an in-depth depiction of processes that produce change
o Provides insight into the process and the emotional response to it
o Children who are thought to be on the verge of an important developmental change are provided with heightened exposure to the type of experience that is believed to produce the change and are studied intensely while their behaviour is in transition
o Seigler and Jenkins – “counting on”
Can using a longitudinal vs a cross-sectional design result in different conclusions?
Yes
e.g., growth is smooth vs growth is inconsistent
What are the strengths and limitations of using a longitudinal design to examine development?
o Take one cohort of children and study them at several different times
o Time-consuming
o Suffer from attrition – drop out from ppts, could end up with bias from study. The attrition isn’t random, the people that stay in the study may depend on the very characteristics you are studying e.g., impulsivity, substance abuse
o Powerful designs because you’re studying the same individuals – no group differences
o Expensive
What are the 3 main levels of categorical hierarchies?
o A very general one – the superordinate level (living things)
o A medium one in between, the basic level (birds)
o A very specific one, the subordinate level (parrots)
What are categorical hierarchies?
o A major way in which infants figure out how things in the world are related to are another is by dividing objects into categorical hierarchies e.g., categories related by sub-set relations
Can infants attribute personality traits to inanimate objects?
- Infants can seemingly attribute personality traits to inanimate objects just by watching their behaviour
- Circle trying to get up the hill, square helps and triangle pushes circle back down
- Infants then chose the square over the triangle when given the choice
What evidence suggests that - Infants may attribute intentions and goals to inanimate entities as long as they “behave” like humans?
- 12- and 15-month-olds were introduced to a faceless, eyeless, blob that “vocalised” and moved in response to what the infant/experimenter did, thus simulating a normal human interaction (Johnson, 2003)
- When the blob turned in one direction, the infants looked in that direction. Infants didn’t behave this way with a blob whose behaviour was not contingently related to their own
What evidence suggests that infants understand intention?
- Woodward – infants who see a human arm repeatedly reach for an object in the same location assume that the action is directed toward the object, not the place
- 6-month-olds looked longer when the hand went to the new object in the old place, than when it reached for the old object, it had reached too before
What is social knowledge?
- Infants must acquire knowledge about people and their behaviour
o Distinguishing between animate and inanimate objects
o Knowing that the behaviour of others is purposeful and goal-directed - By the end of the first year, infants have learned lots about how people’s behaviour is related to goals and intentions – suggests theory of mind
What violations are detected at each stage of development?
- By 3 months – no contact between an object and its support (appears to float)
- By 5 months – type of contact is important – e.g., cannot be supported from the side
- By 6.5 months – amount of contact is important
- By 12.5 months – shape of objects is important
What is physical knowledge?
- Knowledge of gravity begins in the first year (Hood’s tube experiment)
- Infants have been shown to longer at objects that appear to violate laws of physics e.g., ball rolling up a slope (Kim & Spelke, 1992)
- Infants also gradually come to understand under what conditions one object can support another – gradually refined
Why might infants show object permanence with VoE and not with A-not-B task?
- Memory limitations – infants may have difficulty remembering the location of the hidden item
- Problems with inhibitory control – have difficulty inhibiting an over-learned response
- Competition – between a representational system and a response system – they do understand where the object is hidden, but there is some competition/disconnection between their understanding of their perceptions and the system which programs the correct motor behaviour
What is the Baillargeon drawbridge study?
- Infants as young as 3 ½ months look longer at an “impossible” event than at a possible event. The infants mentally represented the box (understood object permanence) even when it was occluded and were surprised when the screen seemed to pass through the box
What is the A-not-B error?
A-not-B error – not simply making a mistake, is specifically returning to the original hiding location
What is the A-not-B task? What are some factors that make the A-not-B error more or less likely to occur?
A-not-B task – object hidden several times in Location A then hidden in Location B – does child look for the object in Location A or B?
- Highly replicable – basic result not in doubt
- Factors that make the A-not-B error more or less likely to occur:
o Age of child (won’t look for object before age 8 months, won’t make error after 12 months)
o Length of delay
o Number of times object hidden in location A
o Number of hiding locations – less likely to make error if there are more hiding locations
What is play in relation to Vygotsky’s theory?
- Play – play with peers is one way that children can stretch their performance into the ZPD
o Playing games involves rules and roles, allowing children to learn how to: separate ideas from objects; self-regulate their behaviour
What is guided participation?
- Guided participation – a more knowledgeable individual can organize activities in ways that allow children to engage in them in a kind of cultural apprenticeship
What is social scaffolding?
- A process in which more competent people provide a temporary framework that supports children’s thinking at a higher level than children could manage on their own (into the ZPD)
o The quality of scaffolding that other people can provide tends to increase as people become older and gain experience
What is the zone of proximal development?
- Zone of proximal development – the range of performance between what children can do unsupported and what they can do with optimal support
What is social referencing?
o Social referencing – the tendency to look to social partners for guidance about how to respond the unfamiliar/threatening events
What is joint attention?
o Joint attention – a process in which social partners intentionally focus on a common referent in the external environment
What is intersubjectivity?
- Intersubjectivity – the mutual understanding that people share during a communication
How are children products of culture? (Vygotsky)
- The content that children learn varies greatly from culture to culture and these differences shape children’s thinking accordingly
- Sociocultural theorists believe that change occurs through social interactions
- Although cultural content varies, the processes that produce development are the same in all societies
What role do teachers and learners play in a child’s development? (Vygotsky)
- Adults teach young people facts, skills, values and traditions – happens in every society and makes culture possible
- The inclinations to teach and to learn are uniquely human (controversial)
o Emerges very early
What is behaviour regulation? (Vygotsky)
- Children’s behaviour is primarily controlled by other people telling them what to do
- Then children’s behaviour is controlled by their private speech (4- 6 years)
- Eventually children’s behaviour is controlled by internalised private speech
o Speech “goes underground” and becomes thought
What is a child’s private speech?
- Piaget called this “egocentric speech”
- Vygotsky viewed this as the foundation for all higher cognitive processes. Language and thought are integrally related. E.g., a child talking themselves through what they are doing when they are playing. Eventually this private speech becomes silent
How are cultural tools useful for a child’s development? (Vygotsky)
Interactions allow a child to learn the cultural tools of their society e.g., language, values, skills
Eventually a child understands a cultural tool and can use it independently – process of internalisation
What are higher mental functions? (Vygotsky)
- Higher mental functions – consciously controlled transformations of lower functions that are developed through cultural mediation. Involve voluntary attention, conceptual thought and logical planning
- Higher mental functions develop through cultural mediation – the transmission of knowledge through social interactions
What are lower mental functions? (Vygotsky)
- Lower mental functions – regarded as basic mental abilities closely tied to biological processes that are innate and involuntary. Involve simple perception, memory and responding directly to environment
How did Vygotsky view children?
- Children are viewed as social beings, shaped by cultural contexts.
- Children develop and learn by interacting with other members of their society
- Sees development as continuous with quantitative changes
What is guided participation?
Guided participation – a process in which more knowledgeable individuals organize activities in ways that allow less knowledgeable people to engage in them at a higher level than they could manage on their own
What is an overview of Vygotsky’s theory?
- Sociocultural approach
- Theory presents children as social beings, intertwined with other people who are eager to help them gain skills and understanding
- Focus on the contribution of other people and the surrounding culture to the child’s development
What are some limitations of Piaget’s theory?
- Stage model depicts children’s thinking as being more consistent than it is e.g., pass conservation of number tasks before solid-quantity tasks
- Infants and young children are more cognitively competent than Piaget recognized e.g., developing object permanence earlier
o Issues with conservation of liquid task – children may have not understood the researcher question. If they children were provided with a clear reason for making the change of glass, many passed the test (Light, Buckingham & Robbins (1979))
o Conservation of number task – pass task when given a reason for the change. This works because infants assume that when the adult does it something must have changed, but with a valid reason they understand that it hasn’t
o Suggested some tasks from Piaget where just took difficult – required other skills such as working memory - Piaget’s theory understates the contribution of the social world to cognitive development
- Theory is vague and descriptive – doesn’t give a why behind his reasoning of the stages
What is the formal operations stage of development? (Piaget)
- Formal operational stage (12+ years): can think abstractly and reason hypothetically. Can imagine alternative worlds and reason systematically about all possible outcomes of a situations
- Piaget believed that the attainment of this last stage is not universal (unlike the others) – instead depends on environment, quality of education
What is the concrete operational stage of development? (Piaget)
Concrete operational stage (7 – 12 years): children begin to reason logically about the world. They can solve conservation problems but their successful reasoning is largely limited to concrete situations. Thinking systematically remains difficult
o Inhelder and Piaget’s pendulum problem – compare different lengths of string with different weights in order to see the time it takes for the pendulum to swing back and forth. Children under 12 usually perform unsystematic experiments and draw incorrect conclusions
What is the pre-operational stage of development? (Piaget)
- Pre-operational stage (2 – 7 years): toddlers and young children start to rely on internal representations of the world based on language and mental imagery
o Symbolic representation – the use of one object to stand for another object. Makes a variety of new play possible
o Egocentrism – tendency to be selfish and only perceive the world through their own view. This was depicted by Piaget and Inhelder’s Three Mountains Task – children unable to take the perspective of another person, either describe their own POV or the whole scene. Can also be seen in egocentric conversations
o Conservation errors – where the child incorrectly believes that simply changing the appearance of an object can change its quantity – this was demonstrated by conservation tasks (pouring liquid from one glass to another and see if the child thought the amount of liquid had increased, decreased or stayed the same) - “centration” – focus on one perceptually salient aspect of the stimulus and ignore the other stimulus dimensions e.g., height of the liquid but not the width of the glass
What is the sensorimotor stage of development? (Piaget)
- Sensorimotor stage (birth – 2 years): infants get to know the world through their senses and through their actions
o OP – knowledge that an object continues to exist even though we can’t see it anymore. Typically emerges around 8 months
o After attaining OP, children make A not B error – tendency to reach to where objects were found before but are not currently hidden. Happens until around 12 months. Suggests that the child mentally represents the object after it has disappeared from view but this representation is fragile
o Children start to form enduring mental representations by the stage end – first sign is deferred imitation (the repetition of other people’s behaviour a substantial time after it occurred)
What are the discontinuities of Piaget’s theory?
- Hierarchal stages that have central properties: o Qualitative step change o Broad applicability o Brief transitions o Invariant sequence
What are the continuities of Paget’s theory?
- Three processes that work together from birth to propel development forward
- Assimilation – process by which people translate incoming info into a form they can understand. Infant learns about how objects behave and can generalise this to other objects
- Accommodation – the process by which people adapt current knowledge structures in response to new experiences. Infants’ theories about the world can be contradicted by new info. So, infant has to adjust theory of the world to incorporate this new info
- Equilibration – the process by which people can balance assimilation and accommodation to create stable understanding.
What 4 characteristics does Piaget’s theory have?
- Constructionist
- Stage theory
- Invariant sequence
- Universals
Why is Piaget’s theory labelled constructivist?
Theory is labelled as constructivist – depicts children as constructing knowledge for themselves
How does Piaget see children?
Piaget sees children as “little scientists”:
- Learning important lessons on their own
- Intrinsically motivated to learn
Why do children usually learn the basic level category first?
o Objects at this level share many common characteristics (unlike superordinate level categories)
o Category members are relatively easy to discriminate (unlike those in subordinate level categories)
What are reflexes?
Reflexes – innate, fixed patterns of action that occur in response to particular stimulation (not always automatic e.g., rooting reflex is more likely to occur when infant is hungry)
Some reflexes have a clear adaptive value which promotes the child’ survival (e.g., feeding reflex), others appear to be pointless (e.g., tonic neck reflex – head turned, limbs extend on correlating side and pull in on other)
What is intermodal perception? What does research suggest?
Intermodal perception – the combination of info from more than one sense to create a coherent whole. The ability to combine info from 2 or more sense is present from very early in life
- When 2 videos are presented simultaneously, 4-month-old infants prefer to watch the images that correspond to the sounds they are hearing
- Using a similar technique, researchers have found that by 5-months-old, infants associate facial expressions with emotion in voices
- Infants held 2 rings under a cloth, allowed to play until habituated
- Some rings were connected by a rigid bar and others by a flexible cord
- Were then shown the other type of rings, but not allowed to touch them. Looked longer at these rings
- Infants can combine info
What is expression of taste like in newborns?
- Newborns facial expressions when tasting different flavours are similar to those of adults, indicating these expressions are innate
What is taste and smell like in newborns?
- By 2 weeks, babies appear to be able to differentiate the scent of their own mothers from that of another woman, an ability shared by a variety of infant mammals
When does infants sensitivity to taste and smell develop?
- Develops before birth
- Newborns prefer the smell of breast milk, regardless of whether they have been breastfed or bottle-fed
How do infants perceive taste and smell?
- Preference for sweetness, may be innate:
o DeSnoo – treatment for mothers who had too much amniotic fluid
o Injected dye + sweetener vs. dye alone
o More dye present in urine of mothers injected with dye and sweetener vs dye alone
o Preference for sweetness, as they ingest more amniotic fluid when it is present - Marlier et al.:
o Newborn infants prefer the smell of their “own” amniotic fluid relative to that of another baby - Teacher & Blass:
o Amniotic fluid promotes post-birth feeding behaviour in rats
o Baby rats navigate to mother rat for feeding very soon after birth
o If rat is washed immediately after birth, pups don’t find food source
Can infants perceive music?
- Evidence to suggest biological foundation
o Heel lance procedure on premature infants, 31 weeks
o Heart rate returned to normal more quickly when played Brahms lullaby (regardless of instrument)
o Not present for infants <31 weeks GA
o Suggests by 31 weeks of pregnancy, infants have an appreciation for music and it can calm them more quickly - Corbeil et al. – singing keeps infants 7-10-months calm for twice as long as speech
- Infants share preferences for music sounds, like adults
- Infants respond to rhythm and temporal organisation in music, preferring music that had pauses between musical phrases rather than in the middle
- Infants are also sensitive to melody, showing habituation to the same tune regardless of changes to the pitch
What are infants perceptions of speech sounds?
- At 2-months:
o Infant such on dummy, presented one phoneme until habituated (seen through sucking), presented new phoneme, infant dishabituates (sucking rate increases)
What is pictorial representations research?
- Newborns can recognize the 2D versions of 3D shapes however, children must come to understand their symbolic nature
- Before they reach 19-months and have substantial experience with pictures, infants and toddlers attempt to treat pictures as though they were the real objects
What is the Ames window study?
- 7-month-old, wearing an eye patch (takes away binocular depth info), reaches to the longer size of the trapezoidal window – looking at monocular depth cue
- This behaviour indicates that the infant sees it as the nearer, and hence more readily reachable, side of a regular window
What are monocular cues?
Monocular cues – cues of depth that can be achieved by one eye alone
- 6-7-months, infants become sensitive to these
- Inc. relative size (larger is closer) , interposition (overlapping) and linear perspective (convergence of parallel lines)
What is stereopsis?
Stereopsis - the process by which the visual cortex combines the differing neural signals caused by binocular disparity (the slightly different signals sent to the brain by the two eyes)
- Stereopsis emerges suddenly at around 4 months of age
What is optical expansion?
Optical expansion - a depth cue in which an object occludes increasingly more of the background, indicating that the object is approaching
- One-month-old infants will blink defensively at an object that appears to be heading towards them
How does object segregation and gravity affect infants?
- Older infants can use other cues for object segregation
- E.g., understanding of concepts such as gravity to determine if it is a single object or two objects
- Wouldn’t expect this until at least 5-months-old
How does object segregation affect infants?
- Infants see perceive a rod moving behind a block, habituate to display
- Look longer at two rod segments than at a single rod
- If they see a display with no movement, look equally long at the two possibilities – without movement, are unsure if rod and block are one or two objects
- Movement is important for object segregation
What is perceptual constancy? How does it relate to infants?
Perceptual constancy – the perception of object as being of constant size, shape, colour etc. in spite of physical differences in the retinal image of the object (know the object is the same size even if it is placed in different areas that might make it appear a different size)
- If an infant looks at the larger, but further away cube, researchers will conclude the child has size constancy
- Supports nativist position, visual experience does not seem to be necessary for perceptual constancy
When do children develop pattern perception?
- 2-month-old infants can integrate separate elements of a visual display into a coherent pattern
o Subjective contour – perceive a shape but it is not actually there
o 7-month-olds can also see this overall pattern and detect the illusory shape - Infants were habituated to different varieties of the subjective contour so that it didn’t actually form a square and the dishabituated when presented with a square – suggests that they were habituated to the actual shape not just the angles
- Effect not present in newborns – possible due to acuity (too fuzzy for them to effectively see)
Do infants look longer at faces that adults find more attractive?
Yes
- Attractiveness affects behaviour – infants interact more positively with people with attractive faces
o 12-month-old children
o Very attractive/unattractive woman (same woman, different makeup)
o Play with child – child more responsive to attractive woman
o Woman did not know how she looked on each occasion
When do infants develop face expertise?
- Adults and 9-month-old children have difficulty distinguishing between monkey faces but not human faces
- 6-month-olds just as good at distinguishing between monkey faces as human faces
- Prefer females faces by around 3-months, unless primary caregiver is males
- With experience, infants not only develop a preference for the type of face they see most often, but also come to understand the significance of different facial expression (4-5-months)
What is scanning and tracking in infants like?
- Scanning
o One-month-olds: scan perimeters of shape
o Two-month-olds: scan both perimeters and interiors of shapes - Tracking
o Infants cannot track even slowly moving objects smoothly until 2-3-motnhs-old
What is colour vision in infants like?
- Very young infants have limited colour vision but by 2-3-months their colour vision is similar to adults’
- Infants can discriminate between two bright, vivid colours better than between two faints pastel colours
What does the immaturity of children’s cones cells mean? What do they help us to see?
- help us to see colour
o Light sensitive neurons concentrated in the fovea in the retina
o Different size and shape and further apart than in adults
How can contrast sensitivity be tested? When does it develop?
- Can use habituation techniques in the same way as before to test this
- Young infants up to 2-months per to look at patterns of high visual contract because they have poor contrast sensitivity
- This is because the cones of the eye, concentrated in the fovea (central region of retina) aren’t as well developed
What is contrast sensitivity?
Contrast sensitivity – the ability to detect differences in light and dark areas
How does visual acuity develop? How can it be estimated?
- The sharpness of infant’s visual discrimination develops so rapidly that it approaches that of adults by 8-months and reaches full adult acuity by 6 years
- Infant’s visual acuity can be estimated by using habituation to a striped patterned and then showing them a plain grey square – if they don’t dishabituate then they think they are still seeing the same thing
What is visual acuity?
Visual acuity – sharpness of visual discrimination
How can operant conditioning be used to measure sensation and perception in young children?
o E.g., reward infant with a particular sound according to their sucking pattern
o Measure which patterns the child responds to with to ascertain which reward is preferred
o Experimental check – don’t always associate the same pattern with the same re-enforcer for every child
o Can be used to test things like parental listening
What is preferential looking?
- Preferential looking – involves showing infants two patterns/objects at a time to see if the infants have a preference for one over the other (measure time spent looking, see which they prefer)
How did later research measure sensation and perception in young children?
o Later research with newborns revealed that infants could discriminate between stimuli using the preferential looking and habituation techniques
How did early research measure sensation and perception in young children?
- Early research simply measured how long infants would look at visual stimuli
o Using this simple technique, Fantz demonstrated that infants had visual perceptions
