Loading
Notes
Study Reminders
Support
Text Version

Postnatal Development

Set your study reminders

We will email you at these times to remind you to study.
  • Monday

    -

    7am

    +

    Tuesday

    -

    7am

    +

    Wednesday

    -

    7am

    +

    Thursday

    -

    7am

    +

    Friday

    -

    7am

    +

    Saturday

    -

    7am

    +

    Sunday

    -

    7am

    +

Postnatal Development
Hello and welcome to the course introduction to advanced cognitive processes I am Ark Vermafrom IIT Kanpur we are in the final week of the course and we have been in this week talkingabout cognitive development.So, in the last lecture I talked to you about you know different aspects of developmentdifferent fundamental questions that have been asked about development the nature versusnurture debate.I spend a lot of time talking about how the nature aspects of you know the whole equationreally works out, what is genes heredity?How do things how do things transmit from one generation to the other?What are the kind of genetic disorders that might be there?What are the kinds of other prenatal influences like, the influences of drugs and alcoholon the developing child?So, in today's lecture actually I will take this discussion a little bit further we havetalked about the prenatal aspect of things in much detail, but let us now talk abouthow is the newborn, you know born with what are the abilities that a newborns is.You know coming with and how do these abilities develop in the course of the life.Now, I am kind of going to talk about these different aspects.So, let us begin with the perceptual processes, let us begin with visual.Newborns have poor visual acuity their ability to change focus is very limited and they arevery nearsighted.So, for example, children were just one, one and half months old they generally the fathersthey can see is very close up to 10 15 20 centimeters.So, also the other aspect is that they have very poor visual acuity you can actually lookat this figure here this is basically you know a kind of mirroring, what kind of resolutionas a newborn is really looking at on the you know.So, slightly blurred picture is what actually the newborn is really getting and the visualacuity the resolution you can actually think of visual acuity in terms of resolution theresolution that the child has you know with respect to whatever he seeing in the worldis a slightly poorer.By 7 to 8 months infants visual acuity is close to that further so, it takes around7 to 8 months for the child to actually go from a slightly hazy slightly blurry visionto more clear to you know to the proper vision that adults have.Now, newborn is spend a lot of time actively looking and this is something.So, a lot of these things I am talking about you can actually observe them yourself youcan actually observe them, when you are actually you can actually observe how children arebehaving and by being around them.So, newborns if you see they spend a lot of time actively looking around you know theyare interacting with their environment.So, they scan the world in a in a rather organizer.So, they are not really randomly just moving their heads and looking around the world theyare actually scanning the world in a very organized manner and say for example, if thereis something that catches their attention they would pause if they will try and analyzethat.So, the when the eyes encounter an object or some change in the visual field will orienttowards it and they will kind of try and understand what has really happened.So, it is not like we are just here and they are just passively seem them I mean thereactively interacting with the environment you know and this interaction becomes veryinteresting say for example, when the child is just a newborn a month, month, month andhalf old to when the child is got you know full visual acuity by 7 8 months and thenwhen a what are the kind of sense that the child is making later.Newborns are particularly attracted to areas of high contrast such as the edges of an objectsay for example, when the child is looking at particular objects is more intrigued bythe edging part because say for example, you are looking at a surface and then there isa edge there is a vast contrast difference between these 2 parts.So, the edges are regions of high contrast you can actually you know one a one the inthe surface a different kind of ah structure is there and as the surface ends the differentkind of structure is there.So, this is something which the child kind of gets attracted to a lot.Now evidence is suggests that newborns display what is referred to as facial preference.So, they like to look at faces they have this inborn innate preference for faces as comparedto other kinds of visual stimuli.So, children you would see they will be more interested in looking at people's faces ascompared to and when they are very young children as compared to you know other objection othervisual stimuli that might be available, also they would prefer looking at a normal facemuch more than a scrambled or a blank face.So, if you try and show them scrambled face pictures or something like that they willnot really you know grasp their attention, also one of the things is they would preferlooking at happy faces over fearful or you know angry faces.So, that is also something you know that the child is born with so, is preference for happyfaces is there you know when you are talking about the child.Now brains of newborns are oriented towards obtaining information from faces one of thethings is that this is something which is evolutionary also useful.So, brains of newborns are supposed to be oriented towards obtaining information fromfaces, suggesting that they come equipped to you know there is suggesting that theycome equipped to perceive the basic features of faces you know the eyes, nose, mouth, alsoslight you know some emotional information that might be there in the faces .And the child is always trying to you know learn through whatever he is looking at, learnthrough the face is dynamically understanding the persons you know expressions, reactingand learning also 2 things.So, for example, when the child is looking at the face the child is doing at least 2things a is that the child is trying to understand the emotional information in the facial expression,also one of the things could be whether child is trying to you know learn to reciprocatethose emotions as well.Say for example, and I was probably talking about this in some other lecture is that oneof the things that the child learns to do is you know smile for example, or being angryfor that matter partly could be innate, but partly has also learned from looking at howpeople behave, when they have to you know how people turn their faces, when they aredisplaying particular kinds of emotions.So, that is a very interesting thing that is one of the reasons why it might be a evolutionarilyimportant for the child to look at the faces more carefully because that kind of you knowcould have survival value to it, also the child kind of it is learning it is first youknow impressions of social communication it is first aspects of you know learning howto behave in the world by looking at faces they are certainly the most important visualstimuli this child is you know coming across.Now, brains of newborns as ever same brains of newborns are oriented towards obtainingthese various kinds of information from the faces suggesting that they are kind of equippedto perceive these basic faces features and also learn through them.Now let us move to the hearing part auditory part, even 26 to 28 week old infants movein response to sharp sounds.So, if there is a sharp sound the infant would kind of get startled look around and maybemove in response to that sound.Newborn infants turn their head towards the source of the sound.So, as soon as they develop the control of the neck, they can orient their heads towardsthe, you know where the sound is coming from.By around 4 months of age infants reach starts reaching towards the source of sound in theirsuppose for example, if there is somebody calling out the child even though it is darkand the child cannot really see the person, child would try you know move towards thesource of the sound they move, they are trying to you know localize the sound by moving towardsstate.This helps infant to learn what kind of objects go with what kind of sounds say for example,it might be very useful in recognizing you know the voices of people around the child,you know the first caregivers, the parents, the you know siblings maybe relatives andso on and so forth.Now, newborns they show preference for their mothers voice over a strangers voice and theyeven show a preference for you know stories that their mothers have told their storiestheir mothers have recited why during the last weeks of pregnancy.Now this is also something which I am sure you might remember from the lectures on languageacquisition when we are doing those in the, I think in the third week.Now, this is something that the child is kind of an a hearing by the way is something veryvery important for the you know sense of for the ability of language for the cognitivefunction of language to develop so, hearing is very closely tied to that.Hearing you must remember we have talked about you know at these day things when you aretalking about child language acquisition things like you know across cultures.And that is also very important across cultures adults speak to young infants in very peculiarways you remember I have been talking about infant directed speech or mother is now theywill talk in a way that is highly exaggerated, they will talk in a way that the has too manyloud noises, they will have too many very well defined spaces or pauses which will helpthe child to grasp aspects about you know human speech .So, a good proper and a very receptive auditory function is a very much required for the childto be able to learn language that is one of the reasons by the way why a children whoare congenitally duff might have it slightly difficult in learning you know speaking andlanguage moving further.Infants as young as 6 months of age are also able to even you know they can they can distinguishor discriminate between intonations of voice indicating approval and disapproval.So, for example, if you are kind of praising the child, you know a lot of times peopletalk to children in funny ways suppose they are kind of appreciating something that thechild that over suppose they are kind of you know trying to you know in a play sort ofway scold the child that you know you should not do this.So, children as there is around 6 7 months of age they start understanding these intonations,they start understanding whether I have been praised or whether I am scolded at this moment. And this is this is very fascinating againsomething that has to do with the child having a superior ability to process prosodic characteristicsof speech.So, they will smile more in response to approval intonation and they will smile you know theywill ah less and they will kind of try and avoid get unhappy start crying when the disapprovalintonation is presented, even when this is presented in a language different from theirown.So, this is not really about them having learned language by this time they are not reallylearned language of words or anything, but they have just kind of started appreciatingthe intonations that are there.So, again I am not really talking about them having learned the language, but it is justthat the prosodic characteristics are giving certain kinds of valuable information to thechild which the child is processing and many and kind of you know ah manipulating it isown behavior in response to these auditory information.Let us move to something else let us talk about taste and smell, infants can discriminatetastes very shortly after birth they prefer sweet tasting liquids over liquids that aresalty, bitter, sour or bland.Newborns can also distinguish between odors they turn their heads towards sweet smellsand their heart rate and you know respiration slows down indicating enhanced attention toyou know and this happy and this a sweet odors that they are you know more tuned to get.Noxious odors on the other hand suggest those of ammonia or rotten eggs so, those kind ofthings will caused the children to turn their heads away from their and their heart rateand their respiration rates generally accelerate indicating distress and indicating the factthat they want to avoid these smells.So, they already show by these physiological manifestations whether they are preferringa particular odor or they are not preferring that particular odor.Also infants are able to discriminate a very well among subtle differences in smells theyare seems to be an innate preference for the odor of mother's milk.So, one of the things that I was reading actually talks about the fact that children preferthe children start getting the sense of the mothers body, they start getting this scentof the mother's milk and this is something they would say for example, if you kind ofdip you know a cloth in the mother's milk and if you kind of move it around the childyou will see that the child kind of attains reacts to that odor very favorably and kindof try as to orient itself towards that odor.That could be one of the evolutionary things that have been built up in the child you knowbecause these are the things that are necessary for the child's survival for proper feedingand you know these kind of things and I think this may have an adaptive and also about theseodor things.So, this mean these things may have an adaptive value which would help infants avoid noxioussubstances and thereby increasing the chances of survival typically noxious odors and youknow bad taste is a kind of closely related to things like say for example, imagine thetime when we were living in jungles you know the pre evolution era.It is very common that if you are in the jungle things that taste extremely bitter, mightbe poisonous things that kind of smell very bad, might be spoil food and you do not reallywant to eat it because if you ingest it you might you know die of food poisoning.Now, this enhanced the sense of you know this extremely developed sense of both taste andsmell is in that sense having a lot of evolutionarily a evolutionary value that it has a lot ofadaptive or survival value.Now let us talk about a different kind of ability let us talk about motor abilities,now motor abilities basically refer to the stages in which children acquire these motorskills and this is their sequential stages which all the infants pass through as theyacquire the muscular control necessary for making coordinated movements.So, they basically need to get that kind of muscular control developed in order to startmoving their hands or start moving there you know neck, the lower limbs, their torso forthat matter.Now the development of early motor skills you know once the child is born generallyis supposed to follow 2 kinds of rules, I list refer to these rules briefly the proximodistalprinciple basically says that parts that are closer to the center of the infants body thatis the torso will kind of you know the movement or the control of them become comes much earlierin parts away from the body.So, activities involving the trunks are mastered first before they can actually you know startmoving their arms and legs or they start getting a control over their arms and legs.The other principle that is important is the cephalocaudal principle, now the cephalocaudalprinciple says that parts of the body that are closer to the head develop better, developbefore or develop better control, before the parts of the body that are further from thehead.So, again the first thing that the child starts to move other than the trunk is the neck,again the limb, limbs part you know basically comes is slightly later.So, infants they can kind of lift their heads before they can start you know controllingtheir trunks.So, it is kind of 2 things 2 principles that are governing the, at early development thisis a chart basically borrowed from Atkinson Hilgaard's books, Susan Molen Hoeksema's book.And this kind of shows the chronology or the pattern with which the child is acquiringthe motor skills.So, you can see that you know by the amount of 2 and half, 3 2 and half to 4, 4 and halfmonths children develops you know children can roll over they have developed the controlof the trunk months later the child can kind of you know it can bear some weight on legsand start you know if you hold the child it can kind of start putting the legs you knowin a particular fashion or move a little bit more move to 5 and 8 months the child canstart sitting without support move to close to you know starting from 5 to 9 to 10 monthsthe child start can stand up holding to furniture and so on and so forth.So, again you see that these milestones which I am referring to are not kind of situatedat just one age point they are not situated in just one month they kind of span say forexample, rolling over is can happen anywhere between 2 and a half to 5 months or say forexample, sitting with our support can have a happen anywhere between 5 months to 10 months. Now, this is basically the standard deviationwith respect to which these abilities might be achieved by different children dependingon other kinds of environmentally and physical nutritional and environmental features, butif the child is kind of missing this then there is that there can be a talk of you knowwhether the child has missed that developmental milestone.Now let us move slightly further let us start talking about some other aspects of developmentbeginning with talking about cognitive development and one of the most influential theoristswho have talked about cognitive development was the Swiss a psychologist Jean Piaget andfor those people who have done any course in psychology earlier if you even if you havedone first year course in psychology or if you have just held a book of introductionto psychology in your hands you will find Jean Piaget name there.And Jean Piaget is one of the persons who has you know extensively worked over you knowhe is kind of worked by observing children over long periods of time and he is kind ofworked over different aspects of children's development I will talk to you about willPiaget work today.Now Jean Piaget basically he focused on the interaction between the child's naturallymeasuring abilities you know, the biological part that we have been talking about and alsohis or her interactions with the environment.Say for example, when the child is growing up see for example, we are talking about themotor development part at different ages when the child is you know acquiring these differentmotor skills.The nature of the child's interaction with the environment also changes till the pointthat the child can only roll over the child can only reach out to particular places andyou know the entire thing is just limited to that by the time that the child startscontrolling limbs where the child can reach out to things hold things etcetera.By the time that the child you know has started to stand then our started to work then theentire the scope of activity is completely changes, also during these interactions thechild is learning a lot about the world the child is kind of elaborate on that in a bit.So, Piaget basically and the whole point of the example that I was giving was that Piagetbasically sees the child he views the child as an active participant in his environmentthe child is an active participant in his environment and is also an active role playerin the entire developmental process it is not that the child is just you know a passiverecipient of whatever biological development is happening and whatever the external stimuliis are teaching external stimuli are teaching the child.So, according to Piaget and that is a very interesting thought children are 'inquiringscientists' who are constantly experimenting with objects and events in their environmentyou will see when children are growing up they say for example, they will they willdo a lot of hit and trial they will you know do something observe very keenly what is happening,how is the environment changing.Suppose for example, you touch something you know if you touch something you like the textureyou will touch it again and again you know furry objects soft objects that children youknow develop a likeness to or if the child touches a texture that is you know slightlyuncomfortable it is thorny picky or something like that which I will not try and touch itagain the child learns this is a texture that I can prefer this is a texture that I wouldnot prefer.Now, Piaget says these experiments or interactions that the child is carrying out these are usedto construct what are called schemas.Now schemas are small schemes there are small theories about the world you know about howthis works, do not touch the cup it is hot, do not you know do touch the soft why becauseit is soft and you like it . So, these kind of schemas are developed and they are beingdeveloped constantly as the child is growing up they are basically coming from the interactionof the child with the environment.So, it is not like somebody is coming and telling the child you know it is it is notcoming from the god given thing that, you know this these things you are going to preferthese things you are not going to prefer it is basically coming out from the child's interactionit itself.Now upon encountering a novel object or a novel event you know if something is donewhat will happen or a novel object how do I interact with this object, the child attemptsto assimilate it that is understand it in terms of a pre existing schema.So, for example, it could be a case of a child say for example, you know child has a petat home and the child kind of pats is paired plays with this pet and you know gain someinformation about.So, dogs say for example, dog you know is a child as a pet dog child would know dogsare harmless creatures and it is fine to pet dogs hold their tail move around with thedog etcetera, but if the child kind of comes across a new object you know a different kindof a dog you know it goes to somebody at someplace else and kind of encounters a different dog.Now, what would happen is then the child will try and [FL] this is a dog this probably isvery similar to the dog I have at home.So, it is kind of trying to understand it in terms of a pre existing schema for themost part it could turn out in the same way the dog also responds by place and you kindof you know to start developing a theory about how to interact with dogs.Now Piaget said that if the new experience does not fit the existing schema what thechild will do is it will engage in what is called accommodation, accommodation basicallyis modifying a schema to fit new information thereby extending the child's theory of theworld you know.This is what happens in the world and the child is constantly doing these experimentsand you know gaining or grass or kind of garnering evidence in order to move ahead in life.So, for example, the child knows that you know dogs are friendly creatures, they canbe patted they can be moved around and their tail can be held etcetera, etcetera, but thenthe child goes outside and it is kind of you know trying to do the same to a stray dogor trying to do the same to a dog that you know that is probably not as friendly as thedog that child is known.Now what will happen is that the child will learn the fact that not all dogs are neededto be fed if the dog kind of bars on kind of you know growl.So, the child milling is get afraid, start crying get back and make a note mental notethat this is not what supposed to be done.So, you cannot pet all dogs you can actually very easily you know fit this example thatI was trying to make assimilation and accommodation to things like say for example, the childis reaching out for a cup, the cup has hot milk and then the child learns you know accommodatesat not or all cups need to be touched because you need to wait and check whether the liquidthere is hot or not . So, these are some of the things there aresome examples ah which can demonstrate what Piaget was really thinking and how Piagetwas viewing this process of development.Now Piaget was basically before he you know ah became his own person and became he isyou know is started his own individual work he was working as a intelligence tester youmight have heard of the name heard of the name of Alfred Binet who was designed a famousintelligence skills . So, he was working as an intelligence testerfor Alfred Binet and work he used to do was he used to you know get these children conductthese intelligence tests on them and in you know one of the things he wondered a lot waswhy are these children making errors, what kind of errors they are making, what kindof you know ways that they can be actually taught not to do these errors .So, he was convinced during his experience being an intelligence tester is that children'sability to think and reason progresses through a series of qualitatively distinct stages.So, he thought that this cognitive development, this development of intelligence is basicallygoing through you know a variety of qualitatively distinct stages you know in one say somethingelse is happening in the other one something else is happening and so on.So, he divided this cognitive development of the child into 4 major stages, I will justtalk to you briefly about what these stages are and you know there could be some stagessub stages as well the first stage that Piaget basically talks about again you know the firstyear of the child is the you know is the sensorimotor stage.During this stage the infants interact with and learn about their environments you knowbe it about dogs or hot cups and stuff like that, the kind of you know are gaining moreand more information about the environment by relating their sensory experiences to theiractions I like to touch this I will touch this again and again till there is you knowreason not to do it.So, what they are doing is they are interacting with their environment using their limbs usingtheir you know physical senses and the kind of the experience that they are getting isdetermining whether their actions will continue on it they will change.So, this is the sensorimotor stage movement and sensory interactions are involved, duringthis stage there are interesting things that the child cannot do things like object permanence.The object permanence basically refers to the understanding that objects or events continueto exist, even if they cannot no longer be interacted with suppose; now this is againsomething that a lot of people do which in you show them a toy and then you hide thetoy behind your back.You will notice that very very young children stop searching for the toy as soon as youkind of you know take it away from them, one of the reasons that Piaget said is that childrenhave not really developed this concept of object permanence.Very young children in the first stage of development they do not really have this conceptif they if the object is not perceptible, it is not there for them to see they wouldnot have the sense of that object still exist because if they one they once they developthis sense that this object still exists they will try to look for and search for the objectand will try to ask you to bring that object because they know that it is there somewhereand you see how this behavior changes when the child is growing up .Now, so this concept of object permanence develops slowly over a period of about 9 monthsand by the end of the sensory motor stage an infant will now start searching for theobject, you know they will start looking for the lost disappeared objects indicating thatthis sense of object permanence is now fully developed.You can see this example here again from Nolen Hoeksema's book that you know if you hidethe toy using a particular kind of screen the child is not really looking for the toyanymore because there is no sense that this object actually you know exists more thanthere.The next stage is the preoperational stage; the preoperational stage is the second ofPiaget's developmental stages, during this stage, children learn start learning to useusing symbols such as words or mental images to solve problems.So, there are 2 kinds of interesting problems that you know Piaget gave the children tosolve and kind of thought how they are going to develop this first is this problem of conservation. Now, conservation basically refers to thefact that even though the shape of some object or substance is changed the total amount remainsthe same suppose for example, I am kind of lined up if I think I will show you the examplenow.If the concept of conservation suppose here you look there are 3 glasses you can see thatthe amount of the liquid is the same when you look at the shorter glasses, but if youkind of put liquid from one of the glasses into this taller, but more slender glass thelevel will rise up.Language is actually one of the things that as we have talked about in this entire coursethat it plays a role in understanding thoughts it plays a role in communicating expressingall those kind of things and so according to Vygotsky language is one of the centraltenets of how cognitive development really goes through.He says that children use their language ability language ability to guide their own actionsand to practice the new skill I mean that is one of the things that children are constantlyusing and that is something that contributes to their overall development.So, that is all from my site about cognitive development and we talked a little bit abouthow they are you know initial perceptual abilities of the child are and will continue talkingabout various aspects of development in the next lecture.Thank you