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Psychology of Human Growth and Development
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cognitive development part 2
Psychosocial development
Development of emotions
Depression
Language development
Cognitive development part 1
Perceptual development part 2
Memory
Development of attachment
Introduction
Nature versus nature
Introduction to developmental theories
Prenatal development and chromosomal abnormalities
Prenatal development and teratogens
Brain development
Motor development
Physical growth
Perceptual development

Development of hearing, taste, touch and smell


Development of hearing perception

 

 

THe human auditory system consists of

 

        the ears

         the outer ear (which consists of the external ear)

         the auditory canal

         the middle ear (which consists of the

        several parts of the brain

        various neural pathways  connecting them

 

auditory Perception of prenatal

o    before birth fetuses can hear noise from outside and may hear complex sounds that are presented outside the mother’s body

o    infants may learn and remember what was read to them before they were born.

         E.g.: DeCasper and Spence (1986)

         prenatal auditory experience can influence postnatal auditory preferences.

o    fetuses can learn to distinguish their mother’s voice

o    fetuses can learn to distinguish sounds and rhythms of the material mother is reading.

 

auditory perception of infant

 

differences in ears of infants and adults

o    Size

o    Structure

 

newborns hearing ability

o    volume

o    Pitch / frequency

      less sensitive to low pitched sounds compared with adults

      a high pitch voice more likely to capture the infant’s attention

      between birth and 2 years, infants rapidly improve their ability to discriminate sounds of different pitch until they reach adult levels of discrimination

o    Sound Location

      newborns can locate where a sound comes from and judge how far away it is.

o       Between 1-3 months infants turn their head less towards a sound source

o       After 3 months orientation towards sound picks up again

o    Sound Distance

      newborns quite good at gauging a sound’s distance particularly when the sound is getting closer.

o    The sound of human voices

      Newborns as young as 2 days old prefer to hear the human voice

o       Especially a voice that is high pitched with exaggerated pitch contours. Known as infant directed speech

o    Sound preferences

      newborns prefer their mother’s voice

     e.g.: DeCasper et al (1980)

     infants learned how to produce the mother's voice and produced it more often than the other voice.

         The neonate's preference for the maternal voice suggests that the period shortly after birth may be important for initiating infant bonding to the mother.

 

Functional significance of early auditory skills and preferences

 

-     significance for the social development

 

-     significance for the development of language

 

 

Development of smell perception

 

        smell has a more direct route to the brain than any other sense.

        Receptors in the nasal cavity are connected without synapse to the brain

 

Researchers have proposed that there are at least 6 basic odor qualities that humans can smell

 

o       Spicy

o       Fragrant

o       Putrid

o       Ethereal

o       Resinous

o       Burned

 

what can infants smell?

 

        newborns olfaction ability

o    well developed at an early age

o    can discriminate between odors

      newborns show appropriate facial expressions in response to odors that adults rate as either pleasant or aversive

o       (e.g.: Steiner 1979)

 

Functional significance of early odor ability and preferences

        provides an early guide to the people and things in their world.

 

Development of taste perception

 

        gustatory system includes:

        the receptor

o       located on the tongue

         occur in clusters called taste buds

        several parts of the brain

        various neural pathways  connecting them

 

        Researchers have proposed that there are at least 4 basic tastes – any taste can be described as a combination of these four.

o       Sweet

o       Sour

o       Salty

o       bitter

 

development of sense of taste

 

  • genetic makeup and past experience affect taste.

 

what can prenatal  infants taste?

 

o    discriminate tastes

      prenatal respond selectively to different tastes

o       e.g.: Mistretta and Bradley 1985

o       studies of fetal lambs

o       suggest that taste perception present before birth.

o       preference for sweet over bitter substances may be present even before birth.

 

 

what can newborn  infants taste?

 

o    discriminate tastes

      Newborns respond selectively to different tastes

o       Eg. Rosenstein and Oster(1988)

o       Findings demonstrate that Ss differentiated sour and bitter from each other and from salt,

o       as well as discriminating sweet vs nonsweet tastes.

 

o    infant tastes can be modified as a function of experience

1.      eg: Menella and Beauchamp (1996) infants exposed to vanilla flavoured milk were more accepting of the flavor of vanilla later on

 

Development of touch

 

        consists of three distinct skin senses:

 

        pressure

o       this stimulus sense for pressure is physical pressure on the skin

         passive pressure(when we are being touched)

         active pressure (when we are touching and exploring our environment)

 

        temperature

o       this stimulus sense for temperature is the temperature of our skin

         cold  receptors generate a neural impulse when there is a decrease in skin temperature

         warm receptors generate an impulse when there is an increase in skin temperature.

 

        pain 

o       any stimulus that is intense enough to cause tissue damage is a stimulus for pain

         e.g.: pressure, temperature, electric shock, irritant chemicals.

         Effect of such a stimulus is to cause the release of chemical substances in the skin which in turn stimulate distinct high-threshold receptors. The receptors are neurons with specialized free nerve endings.

 

development of sense of touch

 

        Prenatal 

      present before birth

o       E.g.  Dieter, Field, Hernandez-Reif, Eugene and Redzepi (2003)

o       Preterm infants do better when touched

 

        newborns sense of touch

o    Touch / being touched

      sense of touch is present at birth

      Skin to skin contact with the mother directly after birth claimed to be an important contributor to mother – infant bonding.

 

o    Touch / doing the touching

      Before the end of their first year they can discriminate among objects using only their sense of touch

 

o    Pain

      Evidence of infant’s sensitivity to pain comes from infants stress reactions

      Gender differences:

o       Females are more sensitive to pain than males.

o    Temperature

 

Development of body senses

kinesthesis, orientation and movement

 

kinesthesis

 

        consists of our ability to:

o       sense of the position and movement of the limbs and head relative to the trunk

o       receptors are located in the muscles, tendons, joints and skin.

o       The receptors send messages about their activity to the cortex.

 

 

        Development of kinesthesis

 

o       Messages from the muscles etc are sent automatically

o       But what they are understood to mean depends on experience

         E.g. infants spend a long time watching their hands and learning to correlate visual and kinesthetic information

         Deliberate and skilled movement requires the use of kinesthetic feedback

         Kinesthetic awareness and skilled precise motor action take practice as a major contributor to development.

        Clumsy children / poorly coordinated have particularly poor awareness of their posture and movement

 

 

THe human sense of orientation and body movement

 

        consists of our ability to sense the orientation of our body with respect to gravity and to sense the movement of our body through space.

        Receptors for both are in the vestibular apparatus adjoining the inner ear

 

 

intermodal perception

 

        consists of how infants transfer learning from one sense to another

        present in 4 week old infants.

 

 

 

 

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