Peoples Flashcards
Describe the stages of prenatal development
Prenatal development occurs in 3 stages:
- Period of the Zygote: ovulation to implantation
- Embryonic Period: implantation to 8 weeks
- Foetal Period:
8 weeks to birth
Zygote (weeks 1-2)
Embryo (weeks 3-8)
Foetus (weeks 9-42)
- The period of the zygote commences when the egg is fertilised and ends when the blastocyst is firmly embedded in the uterine wall.
- The period of the embryo is characterised by rapid development: all major organs and limbs are formed.
- The period of the foetus begins with the growth and integration of nervous/muscular system and the digestive/excretory system allowing foetus to move reflexively, to swallow and excrete, and the differentiation of the sex organs.
- nervous system matures - brain takes control of major functions - heart and movement - can see this in reflexes
- foetus develops lanugo (small fine hairs) and is covered in vernix caseosa for insulation.
- ‘age of viability’ is reached around 5-6 months - lungs begin to mature and begin to be able to be capable of breathing air - Lungs last thing to mature
- last three months are known = ‘finishing period’: increase in body fat and brain is fine tuning its regulation of functions and its interconnections. Most time is spent asleep.
List different environmental factors that may adversely impact upon the development of the foetus
- Genetic abnormalities (10-25%)
- Single environmental agents –teratogens (up to 10%)
- anything that harms the foetus/embryo - eg drugs, radiation, virus, absent nutrients
- ‘All or None’ effect at the embryonic phase (before organogenesis)
- after organogenesis it can be more specific
Remainder (majority) result of complex gene-environment interactions that could include: Teratogens Maternal Nutrition Maternal Stress Labour complications
describe foetal alcohol spectrum disorder
Foetal Alcohol Spectrum Disorder:
- Alcohol affects foetal development directly and indirectly by compromising the function of placenta
- Physical Symptoms:
- Microcephaly (small head), abnormality of the heart, limbs, joints, face
- Facial features
- Lower birth weight and lag in development
- Seizures, tremors
- Brain Areas Commonly Affected:
- Cerebellum
- Corpus Callosum
- Basal Ganglia
- Hippocampus
Behavioural Deficits:
- Executive Functioning (Prefrontal Cortex) - motor behaviour
- Cognition/Learning (Prefrontal Cortex) - lower IQ
- Language (Prefrontal Cortex)
- Social Skills (Prefrontal/Limbic)
- Memory (Hippocampus)
- Motor Skills (Cerebellum)
- Impulse Control (Basal Ganglia)
- Regulation of Emotion (Limbic System)
how was thalidomide a teratogen
1960’s
Mild, over-the-counter
tranquiliser for morning sickness
Results: Phocomelia (v underdeveloped) - Arms (25th-27th day) Legs (28th-36th day) Eyes ears (taken on 21st day) nose Heart defects 40th day on – no effects Majority of pregnant women taking drug did not show ill effects
Depends on when it was taken
Describe how environmental factors can interact with the stages of prenatal development to influence foetal outcome
Foetal development can be affected by (i) genetic factors (ii) environmental factors
and (iii) complex gene-environment interactions.
Most ‘environmental factors’ are referred to as ‘teratogens’ – diseases, x-rays, chemicals, absent nutritional factors.
Additional ‘environmental factors’ include maternal stress and labour complications.
How these impact foetal development is critically dependent on the stage of development when the ‘environmental factor’ was encountered.
Low birth weight is often predictive of future vulnerability and cognitive impairments, particularly in infants born ‘small for date’.
Describe infant reflexes and the significance of their presence and extinction in the developing infant
Vision and Olfaction:
- Senses present during the foetal stage of development
- initially eye sight very poor and then gradually improves
- Within few days, prefer odour of own mother’s breast milk
Audition and Gustation (taste)
- initially filled with amniotic fluid - then clears in 2-3 days
- preference for mums voice after 3 days
- Like rising tones spoken by females and children - “Motherese”, but more correctly “infant directed speech - slower and rising tones - infants have preference to this
- Can differentiate, milk, water and sugar water and react to bitter tastes
Describe infant reflexes and the significance of their presence and extinction in the developing infant
Infantile reflexes are tested and observed by medical professionals to evaluate neurological function and development of CNS, nerve trunk and PNS.
Signs of pathology occur with:
- Absence
- Abnormality - maybe weak or barely observable
- Persistence - reflex observable after the age it should become extinct
- Redevelopment - in later life
List the stages of perceptual-motor development in early childhood
Vision and Olfaction:
- Senses present during the foetal stage of development
- initially eye sight very poor and then gradually improves
- Within few days, prefer odour of own mother’s breast milk
Audition and Gustation (taste)
- initially filled with amniotic fluid - then clears in 2-3 days
- preference for mums voice after 3 days
- Like rising tones spoken by females and children - “Motherese”, but more correctly “infant directed speech - slower and rising tones - infants have preference to this
- Can differentiate, milk, water and sugar water and react to bitter tastes
Motor development milestones - wide variation: - sitting without support - 4-9 months - standing with assistance - 5-11 months - hands and knees crawling - 5-13 months - walking with assistance - 6-14 moths - standing alone - 7-17 months - walking alone - 8-18 months see slide 12 of child development lecture
Describe the stages of cognitive development identified by Jean Piaget
thinks its discontinuous - happens in stages and you progress through them
- the way in which we learn about and adapt to our world is constant across all cultures and races, and proceeds as a set sequence in all
Theory comprises:
- Stages themselves - and the age at which they occur
- Processes: how we move through stages - acquire features and abilities
- Start off with schema - basic knowledge of environment
- then progresses to hierarchical - builds on schema to form more complex structures
- Assimilation = Process of fitting an experience to existing schema - eg sees plane and calls it bird because has wings and flies
- Accommodation = Changing schema or creating new schema to account for new experiences that don’t fit existing schema - eg mum tells him its a plane and explains what a plane is, kid creates new schema and can now understand
- equilibrium - need stable internal world - schema corresponds with external world - can understand world around them and predict things that are happening - happy
- disequilibrium- new experience does not match existing schema - child needs to accommodate to restore balance - alter schema or create new one - creates feeling of discomfort
- Desire for equilibrium is innate and drives us to learn
- operation - Transformations or manipulations that occur in the mind
says cognitive development occurs in stages:
- Sensorimotor stage (0-2 years):
- lacks internal schemas or representations
- has no sense of self - don’t know they’re human being
- understands the world directly through its senses from moment to moment
- Egocentrism: unable to distinguish self from environment - lack of object permanence - when an object can’t be seen they think it doesn’t exist anymore - Pre-Operational Stage (2-7 years):
- Child dominated by the external world, rather than their own thoughts.
- simple internal schema - through increased language use
- Features:
- Animism: attribute feelings to inanimate objects
- Realism: Believing that psychological events are real -dreams
- Egocentrism: inability to see things from other people’s perspectives
- Inability to see things are the same despite looking different: conservation absent - Concrete Operations Stage (7-11 years):
- child is now able to carry out operations on their environment and develops logical thought
- still requires concrete examples, being unable to think in abstract terms
- use thought and imagination more
Features:
- Reversibility: ability to mentally picture an action being carried out in reverse
- Transitivity (e.g. A > B > C ) only possible with concrete examples - so would need to say something like harry is bigger than bob who is bigger than sally, is sally bigger than harry - if just letters then they mightn’t be able to think that abstractly yet
- Categorisation: Hierarchies of groups
- Conservation: is made possible by the ability to de-centre- give correct answer and explain why - Formal Operational stage (11 years onwards):
- Children in this stage can concentrate on the form of an argument without being distracted by the content.
Features
- Abstract thought - love, density etc
- Hypothetical thought
- Hypothesis testing
- Appreciation of values and ideals
Explain Vygotsky’s sociocultural theory of child development
- A child’s development is inseparable from social and cultural activity
- Culture and social interaction guide cognitive development
- Interaction different in every culture
- Language is essential for the communication of knowledge and ideas
- Social interaction: With language, the child has the ability to learn from those with more knowledge, especially adults. Learning occurs by active internalisation of strategies picked up by communicating with others.
- Thinking and language are closely linked
Ages 0 to 2 years: language and thought develop independently of one another.
Ages 2 to 7 years: language has two functions:
- Monitor and direct internal thoughts (inner voice we talk to ourselves with)
- Communicate thoughts to others (talk out loud)
Age 7 onwards: The child distinguishes between the two functions of language. As our ability to use language improves, this increases our ability to think and vice versa.
Zone of Proximal development:
3 diff areas that describe how child can problem solve
- what child can do, can’t do and what they can do with help
- scaffolding - the zone is the bit that they can do with help - where learning occurs
what are some of the criticisms of Vygotsky’s sociocultural theory of child development
Motivation: child’s desire to learn?
Vague: what social interactions help us to learn best?
Social interactions: counter-productive?
Individual differences: sometimes help isn’t good enough. Genetics?
List factors that can influence the development of a child with a motor or sensory disability.
- Stage at which impairment was acquired
- Stage at which impairment was identified - could have early treatments
- Degree/selectiveness of impairment - if impairment is restricted to single thing or wider
- Circumstances & environment of child - home environment, resources available, time family has to spend getting healthcare
- Interventions: Medical, Educational, Social etc.
Describe how we detect stimuli in our environment.
scanning for changes in its environment
any changes in stimulus - intensity and characteristics
Explain how we perceive quantitative differences between stimuli.
The ability to detect physical differences in a stimulus declines as the magnitude of the stimulus increases - more intense the stimulus - needs to be a bigger difference between them to be able to detect it
Weber-Fechner Law: the smallest detectable (i.e. perceived) difference in stimulus energy (called the difference threshold or just-noticable difference [JND]) is a constant fraction of the intensity or amount of the stimulus (I).
The constant fraction [K] is different for different types of sensory inputs (sensitivity determined by evolutionary importance of sense to organism).
Weber’s Law: JND=KI
define perception
Perception:
The mind’s interpretation of sensations – i.e. how we make sense of what we see, hear, taste, touch, and smell:
Combines knowledge and understanding of the world, so that sensations become meaningful experiences
Personal experience of the world.
Influences our thoughts, feelings, actions.
Describe how we organize the perceptual world with reference to Gestalt Theory.
Gestalt roughly means ‘whole figure’.
Posits that:
- The whole figure is greater than the sum of its part
- The inherent properties of a stimulus leads us to group them together
These were expressed as a series of laws/principles:
Law of Proximity:
things that are near each other seem to be grouped together.
Law of Similarity:
things which are similar in some way appear to be grouped together
Law of Closure:
Gaps are closed in alignments of elements - adding info and meaning to raw sensation
Law of Continuity:
Contours follow the smoothest path - brain sees pathways as following the smoothest flow
Law of Pragnanz:
Reality is organised/reduced to its simplest form -
Describe depth and distance perception in terms of monocular and binocular stimulus cues.
Images are perceived in the cerebral cortex, not on the retina of the eye
- Distal Stimulus: 3D Physical Object
- Proximal Stimulus: 2D ‘Image’ on Retinal Surface
- Percept: Mental Representation (i.e. Perception)
Contributors to depth perception:
- Stimulus cues (monocular cues: only one eye needed) - cues in the image itself
- Cues based on properties of visual system (binocular cues) - require intro from both eyes - info processed together
Static stimulus cues:
- Relative size
- Interposition or occlusion
- Reduced clarity
- Textural gradient
- Linear perspective
Depth Cues from the Visual System:
- Accommodation: lens changes shape to bring an image into focus on the retina. Muscles surrounding lens must tighten or relax. Proprioceptive information is relayed to the brain.
- Convergence: muscles of the eye must rotate inward to project image onto retina. Proprioceptive information is relayed to the brain.
- Binocular Disparity: differences between the two retinal images as a result of their different spatial locations. Disparity reduces with increasing distances.
(Proprioception: the sense that indicates whether the body is moving with required effort, as well as where the various parts of the body are located in relation to each other. Stimuli from within the body)
Describe the phenomena of blindsight with reference to the neural basis of perception.
Blindsight: people cannot consciously see a certain portion of their visual field but still behave in some instances as if they can see it - this means that they can’t consciously see it but there is some subconscious processing going on
