Cultural Context and Development

1. Cultural Context and Development Conceptual Framework Methodology

2. Cultural context and development Maya Nelson, Raj S., Genevieve Sigaran, Zoie Tiller

3. Darwinism (Evolution and Natural Selection) Darwinism is based on five key observations and inferences: • Species have great fertility. They make more offspring than can grow to adulthood. • Populations remain roughly the same size, with modest fluctuations. • Food resources are limited, but are relatively constant most of the time. From the three observations it must be inferred struggle for survival must be considered among individuals: • In sexually reproducing species, generally no two individuals are identical. Variation is rampant. • Much of this variation is heritable.

4. Darwinism (Evolution and Natural Selection) Natural Selection • The prime motive for all species is to reproduce and survive, passing on the genetic information of the species from one generation to the other. • This causes the species to produce more offspring than it can support. The lack of resources means increased competition for them. As a consequence some organisms will not survive. • This 'weeding out' of less suited organisms and the reward of survival to those better suited led Darwin to deduce that organisms had evolved over time, where the most desirable characteristics of a species are favored and those organisms who have them survive to pass their genes on. • Changing environment would mean different characteristics would be favorable in an environment. Darwin believed that organisms had 'evolved' to suit their environments.

5. Descartes and Dualism • Descartes claimed to have discovered one fact beyond doubt: that he is a thinking thing. This famous argument - called the Cogito after the Latin phrase, “cogito ergo sum” (I think, therefore I am) – tries to establish the mind as a separate substance from the body. • The further the mind is taken away from its proper objects – logic and pure reason – the more likely it is to fall into error. Thus, for Descartes, the purpose of philosophy is to direct the mind away from the confusing images of the senses towards the indubitable truths contained within the mind itself. • He concluded that the mind was completely separated from the matter. • Matter is easily described: it is measurable, has dimensions, can be touched and seen, sometimes smelt and tasted, divided, destroyed and altered. Mind, however, can almost be defined as the opposite. It is invisible, without dimensions, immaterial, unchanging, indivisible and without limit.

6. Descartes and Dualism • Descartes was a very religious man with a sincere faith, so he connected his theories to his beliefs. • Mind so defined can be equated with the soul, which in turn can be proven to be distinct from the body and 

7. Cabanis • His ideas were based upon the context of the French Revolution, which was the changing of the Old regime to the new ideals. • Psychology is with Cabanis directly linked on to biology, for sensibility, the fundamental fact, is the highest grade of life and the lowest of intelligence. All the intellectual processes are evolved from sensibility, and sensibility itself is a property of the nervous system. • The soul is not an entity, but a faculty; thought is the function of the brain. Just as the stomach and intestines receive food and digest it, so the brain receives impressions, digests them, and has as its organic secretion, thought. • He had another theory which contradicted his first, Life is something added to the organism; over and above the universally diffused sensibility there is some living and productive power to which we give the name of Nature. • It’s impossible to avoid ascribing to this power both intelligence and will. In us this living power constitutes the ego, which is truly immaterial and immortal.

8. Plato (Nativism) • NATIVISM VS. EMPIRICISM Two views: – Nativism: Knowledge is part of our innate endowment (already “built in” at the time of birth). – Empiricism: Knowledge comes from • Plato’s (Socrates’) view: – At some unconscious level, we know everything already, but our knowledge is sometimes ‘hidden’. – Knowledge is innate: It is carried over from an earlier existence, but forgotten. – Learning: recollecting (anamnesis)

9. Plato (Nativism) • “PLATO’S PROBLEM” • How is it possible that native speakers come to know things (about their language) in conditions of sparse evidence? • In particular, native speakers know things about their language which: – they have never been taught; – they have never experienced

10. Phineas Gage • Phineas Gage was a railroad worker who, through a freakish accident, got a 3-foot-long rod through his head. The rod went through his left cheek to exited the midline ofthe skull anterior to the bregma, resulting in severe injuryto his left and, in all probability, his right prefrontal cortex. • It was seen as impossible for anyone to survive and at first Gage was the same. He remembered what happened before the accident, could immediately walk, and communicate sensibly. • Overtime his contractors noticed a difference in his attitude. He was once an efficient and capable foreman in their employ previous to his injury but he became fitful, irreverent, and indulging at times in the grossest profanity (which was not previously his custom).

11. Phineas Gage • Gage is an example for the theoryof cerebral localization which described in detail the focal mapping of thecerebral function and of how frontal lobe injury can result inchanges of personality that are not demonstrable by sensoryand motor exam.

12. Paul Broca • Paul Broca (1824-1880) was a well-known French surgeon-anthropologist-neurologist. Best known for his work on cerebral cortical localization and speech mechanisms, Broca also carefully worked out skull and scalp localization for underlying cortical regions. • In 1871, Broca treated a man who had sustained a scalp laceration from a blow to the head without loss of consciousness or skull fracture. The patient exhibited a not confluent aphasia about 1 month after injury and became progressively dulled and eventually lacked alertness. • In a post-mortem autopsy Broca found the patient had a lesion caused by syphilis in the left cerebral hemisphere. This lesion was determined to cover the area of the brain important for speech production. 

13. Shift from dualism to materialism • Dualism was somewhat accepted but did not add up biologically. Human beings start their lives as entirely physical or material entities and since nothing outside of the domain of the physical is added later on in the course of development, then we must necessarily end up being fully developed material beings.  • Its difficult for the dualist to explain where and why there could have intervened some non-material, non-physical event in this process of natural evolution. • Our development can be explained as the accumulation of matter through the process of nutrition. • Discoveries from people like Broca and Darwin only hurt the idea of Dualism.

14. Shift from dualism to materialism • During the Enlightenment theorists moved away from such Christian thinking and to what the world really was made up of other than what the church told them, basically to find a way to explain their existence. • Dualism was acceptable but as the times changed materialism became a basis for thought and scientifically acceptable.

15. Conceptual Framework

16. Biological Concepts that Affect Behavior • Natural Selection: Darwin argued that if a heritable trait contributes to an organism’s survival or reproductive success, organisms with that trait should produce more offspring than those without the trait and that the prevalence of that trait should gradually increase over generations. • Controversy of Darwin’s Theory: • Suggested that the diversity of life is a result of an unplanned, natural process than that of a divine creation. • Implies that humans are NOT unique and that they share a common ancestry with other species.

17. Biological Concepts that Affect Behavior (cont..) • Due to the gradual increment nature of evolution, adaption's sometimes linger in a population even though they no longer provide a survival or reproductive advantage. • Self Sacrifice explained: W.D. Hamilton proposed the theory of inclusive fitness. An organism may contribute to passing on its genes by sacrificing itself to save others that share the same genes.

18. Biological Concepts that Affect Behavior (cont…) • Theorists have focused primarily on the evolution of physical characteristics in the animal kingdom but from the very beginning Darwin recognized the natural selection was applicable to behavioral traits. • Dualism • Materialism • Thought and consciousness

19. Neurotransmitters • Neurotransmitter are chemical messengers that carry signals across the synapse (junction between two neurons where the axon bulb of one neuron comes in close proximity with specialized receptor sites on another neuron).

20. Neurotransmitters (cont..)

21. Neurotransmitters (cont..) • Action potential= neural impulses within the neuron

22. Neurotransmitters (cont..) • Neurotransmitters will cause excitation in the postsynaptic cell (receiving neuron). • Excitation occurs when the neurotransmitters make the postsynaptic cell MORE likely to fire an action potential. When the neurotransmitter binds with the receptor site, it causes Na+ to leak into the cell, thus making the inside of the cell more positive and closer to the threshold of excitation. • It depolarizes the postsynaptic cell.

23. Neurotransmitters (cont..)

24. Neurotransmitters (cont..) • Inhibition: When a neurotransmitter further polarizes the postsynaptic cell and it becomes less likely to fire an action potential. • The cell is less likely to fire an action potential. • Cause chlorine (CL-) to enter the neuron or potassium K+ to leave the neuron.

25. Neurotransmitters (cont..) • Only a sum of the signals moves the resting potential at the axon the threshold (-55 mv) will the neuron fire an action potential. • Excitation starts actions in the nervous system. Inhibition is required to slow down and stuff off certain processes. • Example: Bend your arm • Muscles contract= excited • Muscles relax= inhibited

26. Neurotransmitters (cont..)

27. Neurotransmitters (cont..) • Neurotransmitters are the brain's chemical messengers. • Inhibitory neurotransmitters balance mood and are affected by excitatory neurotransmitters, which stimulate the brain. • Within the two types of neurotransmitters are chemicals that serve to stabilize mood and regulate the fight or flight response associated with anxiety. • When the neurotransmitters are out of balance, it can lead to chronic anxiety or other anxiety disorders. Source

28. Neurotransmitters (cont..) • “Acetylcholine (ACh) is a neurotransmitter that links motor neurons and muscles. Ach has an excitatory effect on muscles. Dopamine, however inhibits muslces and helps control the voluntary movements.” • Endorphins= body’s pain relievers • Diseases due to malfunctioning chemical messengers: • Alzheimer’s disease • Parkinson’s disease • Schizophrenia

29. Neurotransmitters (cont..)

30. Localization of Functions • 1860s-Paul Broca's discovery that damage to a specific part of the brain-the left frontal lobe-was associated with speech impairment. • 1874-Carl Wernicke identified the part of the brain responsible for receptive speech (the upper rear part of the left temporal lobe), • 1870-Gustav Fritsch and J. L. Hitzig found that stimulating different parts of the cerebral cortex produced movement in different areas of the body.

31. Localization of Functions (cont..) • Three main parts: brainstem, limbic system, cerebral cortex.

32. Localization of Functions (cont..) • Brainstem (HINDBRAIN): contains the • Medulla - which controls vital involuntary functions (breathing), heart rate. • Pons - involved in sleeping and arousal. • Reticular Formation- network like group of cells that filter sensory information and help control sleep, arousal and attention.

33. Localization of Functions (cont..) • Brainstem (HINDBRAIN)= SO IMPORTANT YOU WOULD DIE WITHOUT IT. NO LIE. • The medulla sits at the top of the spinal column at the point where the spinal cord enters the base of the skull. There are no such things as MINOR DAMAGES to the medulla, a “minor damage” can lead to death from heart or respiratory failure. • Sneezing, coughing, vomiting, swallowing and digestion.

34. Localization of Functions (cont..) • The pons is located above the medulla, where the brainstem bulges inside the skull. CRUCIAL TO LIFE. • Plays a role in respiration, consciousness, sleep, dreaming, facial movement, sensory processes and the transmission of neural signals from one part of the brain to another. • Sensory information coming from the right and left sides of the brain will have to cross through the pons before they can move on to other parts of the brain.

35. Localization of Functions (cont..) • Cerebellum is the large deeply grooved structure at the base of the brain. NOT AS CRUCIAL TO SURVIVAL as the medulla and pons. • It is necessary for the balance of the body, muscle tone, and performance of motor skills. Some researches believe it plays a role in learning motor skills. • ALCOHOL impairs the functioning of the cerebellum structure because (in part) it produces the familiar symptoms of staggering, clumsiness and slowed reaction time.

36. Localization of Functions (cont..) • The Midbrain structure connects the hindbrain with the more detailed forebrain. Primarily for psychologists the most interesting structure is the Reticular Activating System (RAS). It is located near the pons, composed of a network of neurons that extends from the hindbrain regions into the midbrain. • It regulates arusal levels in the forebrain, and takes an important role in sleeping, attention and consciousness. • It also is believed by some that it plays a role in regulating the cardiovascular activity, respiratory functioning and body movement.

37. Localization of Functions (cont..) • The forebraincontains several groups of structures that ultimately works as subsystems. • The Limbic system governs emotional and motivational process. • The diencephalon contains structures important to sensory processing and motivation. • The cerebral cortex is responsibly for cognition and language. • It is divided into the right and left cerebral hemispheres.

38. Localization of Functions (cont..) • Limbic System- helps govern motivation, emotion and memory. • Amygdala- linked to fear, anger and aggression • Hippocampus- performs a key function in memory formation.

39. Localization of Functions (cont..) • Diencephalon • Hypothalamus- regulates autonomic nervous system, emotions and basic drives. It also serves as a point of connection between the nervous system and the endocrine system. • Interestingly, it can also change the hormone levels in the bloody stream by communicating with the endocrine system. • Example: If the body needs water, it “makes” you feel thirsty. • Thalamus- relay station for sensory information. Most of the information our brain collects is first sent to the thalamus before being sent to the cortex.

40. Localization of Functions (cont..) • Cerebral Cortex- controls higher-order mental processes. Composed of two hemispheres and four lobes. • It is said to give us our humaness. • Sensory areas specialize in receiving sensory information. The somatosenory cortex receives information from the touch receptors in the skin. • Motor Cortex-controls voluntary muscles. • Association Cortex- communicates with the sensory and motor areas and house higher mental processes. • Two areas that specialize in language: • Brocas’s area- production of speech • Wernick’s area- involved in language comprehension

41. Localization of Functions (cont..) • Cerebral Cortex

42. Localization of Functions (cont..) • Frontal Lobe- (lies closest to the forehead). • Broca’s area (production of speech). • Plays a role in cognitive processes such as problem solving, judgement, planning and executing behavior, and certain parts of personality. • At the back of the frontal lobe is the motor cortex (execute motor movements). On the right side of the brain it affects movement on the left side of the brain, and vice versa. • SPECIFIC POINTS along the motor cortex corresponds to particular points in the body.

43. Localization of Functions (cont..) • Parietal Lobe (not much is known in comparison) • Is involved with reading. • Damages to the parietal lobe is associated with deficits in reading ability. • Sensation: a thin strip of the lobe plays a role in our sense of touch, pressure and pain= somatosensory cortex (behind the motor cortex). Specific points along the somatosensory cortex corresponds to specific particular points in the body • Damage to the somatosensory cortex would often result in numbness of the corresponding body part.

44. Localization of Functions (cont..) • The Montor + Somatosenory Cortex

45. Localization of Functions (cont..) • The Occipital Lobe (located in the very back of the skull)above the cerebellum. • Much of the area if responsible for processing visual information. • The visual cortex of the occipital lobe is composed of layers of tissue that contain long axonal fibers. An action potential is stimulated in specialized cells of the visual cortex when our eyes see specific types of visual stimuli. • Damage to the visual cortex could result in blindness. Additionally, in some cases of the visual cortex damaging, blindness may occur even though the eyes are functioning properly.

46. Localization of Functions (cont..) • Temporal Lobe is in front of the occipital lobe (behind our ears in side our skull). • Major function: the processing of auditory information (aka hearing). The temporal lobe areas devoted to hearing is called the auditory cortex. • The left temporal lobe of most people contains Wernicke’s area (responsible for the comprehension of speech). • Damage to Wernicke’s area results in have difficulty or cant understand the meaning of spoken words. They can hear them they just can’t understand what they mean.

47. Localization of Functions (cont..) • Temporal Lobe is in front of the occipital lobe (behind our ears in side our skull). • The inner surfaces of the temporal lobe is important to the processing of memory. This area has direct connection to the hippocampus. • Also believe to play a role in integration of diverse sensory information.

48. Communication between the nervous and endocrine systems occur through the hypothalamus and its connection with the pituitary gland(“master” gland that is responsible for regulating hormones release in other endocrine glands).

50. Endocrine System and our Hormones and Behavior • The endocrine system is a chemical system of communication that relies on the action of specialized organs called endocrine glands. • When stimulated, the endocrine glands will release hormones into the blood stream. The body possess special receptor sites to “accept” the hormones. • When the hormone binds to the site: the create a specific change in the functioning of an organ. In the heart it can be a change of pace (depending on the hormone). • Stimulation created by the hormones last longer than the that created by action potientals at the synapse.