1. Brain and Nervous System

2. Divisions of the nervous system. Structures and functions of the central nervous system (CNS) to include the somatic nervous system (SNS). Structures and functions of the peripheral nervous system (PNS) to include the autonomic nervous system (ANS). The antagonistic action of the sympathetic and parasympathetic systems on heart rate, breathing rate and digestive processes Sensory and motor neurons of the somatic nervous system (SNS) control the voluntary movement of skeletal muscles. Homeostatic control through sensory neurons and motor neurons conducting involuntary impulses to smooth muscle, cardiac muscle and glands. Sympathetic ‘fight or flight’ and parasympathetic ‘rest and digest’ responses on heart rate, breathing rate, peristalsis and intestinal secretions. Structural division of the nervous system Nervous system brain spinal cord Central nervous system peripheral nervous system

3. Functional division of the nervous system Peripheral nervous system Somatic nervous system (mostly voluntary but also involved in involuntary reflex actions)) Autonomic nervous system (involuntary) Sympathetic nervous system (prepares body for action) Parasympathetic nervous system (calms body down, returns it to normal)

4. Effects of autonomic nervous system Part of body affectedEffect of sympathetic nerves Effect of parasympathetic nerves Heart muscle Blood distribution Digestive system Sweat glands Adrenal glands Increased rate of contraction - increased heartbeat Decreased rate of contraction - decreased heartbeat Increased flow to muscles, decrease flow to digestive system. Vasodilation of skin blood vessels Decreased flow to muscles, increase flow to digestive system. Vasoconstriction of skin blood vessels Decreased rate of peristalsis Increased rate of peristalsis Increased sweatingNo parasympathetic nerve connection - no effect Increased adrenaline secretionNo parasympathetic nerve connection - no effect The sympathetic and parasympathetic nervous systems are antagonistic – this means they have opposite effects, e.g.

5. Sensory and motor neurons A neuron is a nerve cell. Sensory neurons carry nerve impulses from receptors (e.g. those that detect heat in the skin or those that detect light in the retina of the eye) to the central nervous system. A motor neuron carries impulses from the central nervous system to effectors (muscles or glands) that bring about a response

6. Parts of the brain (i) The functions of the medulla and cerebellum in the central core. The central core contains the medulla that regulates the basic life processes of breathing, heart rate, arousal and sleep and the cerebellum which is responsible for controlling balance, posture and movement cerebrum cerebellum medulla The central core contains the medulla that regulates the basic life processes of breathing, heart rate, arousal and sleep and the cerebellum which is responsible for controlling balance, posture and movement. The functions of the medulla and cerebellum in the central core of the brain

7. Parts of the brain (ii) The functions of the limbic system Functions include processing information for memories and influencing emotional and motivational states. The limbic system The limbic system consists of several areas in the brain. The limbic system functions are: Processing information needed to form long term memories Regulating emotional states, e.g. anxiety, fear Influencing biological motivation, e.g. hunger, thirst, sex drive The limbic system also contains the hypothalamus. The hypothalamus is found above the pituitary gland. It releases trigger hormones that trigger the release of pituitary hormones, e.g. growth hormone, TSH and gonadotrophic hormones. The hypothalamus also contains thermoreceptors that detect the blood temperature and osmoreceptors that detect the blood water concentration hypothalamus Pituitary gland hypothalamus

8. Parts of the brain (iii) The functions of the cerebral cortex in receiving sensory information, coordinating voluntary movement and makes decisions in the light of experience Cerebral cortex is the centre of conscious thought; it also recalls memories and alters behaviour in the light of experience Information from one side of the body is processed in the opposite side of the cerebrum, transfer of information occurs through the corpus callosum The left cerebral hemisphere deals with information from the right visual field and controls the right side of the body and vice versa. The cerebral cortex The cerebral cortex is the outer layer of the cerebrum. The cerebrum is in two halves called cerebral hemispheres. The left hemisphere receives information from the right visual field and controls the right side of the body and the right hemisphere receives information from the left visual field and controls the left side. The two hemispheres are connected by a bundle of nerve fibres called the corpus callosum that allow transfer of information from one hemisphere to the other. Cerebral cortex is the centre of conscious thought; it also recalls memories and alters decision making behaviour in the light of experience. The cerebral cortex also receives sensory information and coordinates voluntary movement.

9. (iv) Localisation of functions to include sensory areas, motor areas and the association areas concerning language, personality, imagination and intelligence. Some association areas deal with thought processes., Localisation of function Different areas of the cerebrum have different functions, for example there are: Sensory areas - these receive nerve impulses from receptors (sense organs) carried by sensory neurons. Motor areas - these send nerve impulses through motor neurons to effectors like muscles. Association areas - co-ordinate information from different parts of the cerebral cortex, function in language, personality, intelligence and imagination.

10. Perception

11. Perception. Process by which the brain analyses and makes sense out of incoming sensory information. The three areas of perception are: (i) Segregation of objects. Perceptual organisation into figure and ground. Perceptual organisation of stimuli into coherent patterns. Visual cues such as relative size, superimposition and relative height in field. Perception allows us to segregate objects from one another and their background, recognise what they are and to judge their distance from us. Binocular disparity in judging distance. Perceptual constancy as objects become nearer and the viewing angle changes. The importance of shape rather than detail in the recognition of objects. Matching perceived shapes to shape descriptions stored in memory and the role of inference in recognition. The influence of perceptual set where past experience, context or expectation influences the way a stimulus is perceived Perception Awareness of the external environment Based on information detected by receptors and analysed and interpreted by the brain Visual perception Enables a person to Segregate objects from each other and their background Judge their distance from the viewer Recognise different objects

12. Segregation of objects Perceptual organisation into figure and ground First stage in developing visual perception is to determine an object’s shape The perception of an object as distinct from it’s background is called the figure-ground phenomenon. e.g. Black triangle on white background – Figure (black triangle) appears slightly in front of the white background though they are on the same two dimensional surface. Any field of view that has contrasting parts is seen as figural – one or more parts are perceived as ‘figures’, the rest as ‘ground’ Figure Ground There are 2 words in each of these boxes but only one is perceived because the other has the same colour as the background and so does not contrast with it Figure Ground When the back ground is changed and both words contrast, they can both be seen Segregation of objects. Perceptual organisation into figure and ground.

13. What is seen depends on what is perceived as figure and what is perceived as ground, e.g. vase or faces? Perceptual organisations into coherent patterns The brain organises visual stimuli it receives into coherent patterns rather than many different parts, e.g. Relationship is perceived as 3 paired lines on the left and a single line on the right Modifying the lines alters the relationship perceived – pairs now on the right with unpaired on the left. Perceptual organisation of stimuli into coherent patterns. Perceptual organisation into figure and ground.

14. Effect of proximity The brain groups visual stimuli that are close together as part of the same object, e.g. Perceived as separate objects Perceived as the same object Groups of dots perceived as distinct images Perceptual organisation of stimuli into coherent patterns.

15. Perception of distance Visual cues The distance of an object from the eye is indicated by one or more visual cues in the scene being viewed. Relative size The further an object from the eye, the smaller it is perceived to be Superimposition When one object partially blocks the view of another, the blocked object is perceived to be further away. circle perceived as closer square perceived as closer e.g. mountains are further away than the trees Visual cues such as relative size, superimposition and relative height in field.

16. Relative height In objects whose bases are below the horizon, those with bases in a relatively higher position appear to be further away. Linear perspective Parallel lines such as a road or railway appear to converge in the distance Visual cues such as relative size, superimposition and relative height in field.

17. Texture gradient A change in the relative size and density of objects is perceived when viewed from different distances – smaller and less textured objects are seen as more distant More distant mountains lighter in colour Mountains lighter in colour than trees Furthest cobbles smaller and less textured than closer ones

18. Binocular disparity Each eye looks at an object from a slightly different position A slight difference occurs between the images of the same object formed by each of the two eyes The closer the object to the viewer, the greater the difference between the two images The two images are merged into one in the brain producing a binocular image This indicates the depth and distance of the object more effectively than either single eye monocular image Perceptual constancy A person’s visual perception of their surroundings stays stable despite the image in their retinas changing as they move their eyes or move their body around If retinal images were taken at face value, objects would appear to increase or decrease in size as they moved towards or away from us or to change shape when viewed from different angles Binocular disparity in judging distance.

19. Size constancy The perception that an object stays the same size regardless of the size of the image on the retina is called size constancy. Shape constancy The perception that an object stays the same shape regardless of the angle it is viewed from is called shape constancy. Shape constancy is thought to depend on past experience and stored knowledge. As an object moves away from you, its size on the retina becomes smaller and as it moves towards you its size on the retina becomes larger Size constancy is thought to depend in part on past experience and stored knowledge and in part on the cue of relative size, i.e. as you move towards an object, the size of its image on the retina increases but so does the size of all neighbouring objects. Object viewed as same shape despite viewing angle changing Perceptual constancy as objects become nearer and the viewing angle changes

20. Recognition Importance of shape The ability to perceive an object’s physical properties such as shape, colour and texture is called object recognition. Shape is considered to be the most important of these features in recognition e.g. these objects can be recognised by their shape alone It would not be possible to recognise the fruits based on their colour only, but it is using only their shape It is by shape that objects are characterised and distinguished during early learning The most important feature of an objects shape is its general outline. The importance of shape rather than detail in the recognition of objects.

21. Matching perceived shapes to shape descriptions stored in memory and the role of inference in recognition. Matching perceived shapes When a shape is seen, a subconscious effort is made to match the shape with a visual description stored in the brain. If the shape is familiar, it is quickly matched If unfamiliar, it may not be matched or may be recognised as in some way similar to one or more visual descriptions stored in the brain. The brain infers that it is related to one or more stored images and may perhaps recognise the shape as a familiar object seen from an unusual angle What is the object? CRAYONS

22. The influence of perceptual set where past experience, context or expectation influences the way a stimulus is perceived Perceptual set Perceptual set is the tendency to perc4eive certain aspects of available sensory information while ignoring others. Perceptual set is affected by: Expectation Context Past experience Expectation and context Central figure read as the letter B because it is seen in the context of other letters so that the viewer expects it to be a letter Central figure read as the number 13 because it is seen in the context of other numbers so that the viewer expects it to be a number.

23. Past experience When a group were shown pictures of people, some bald and wearing glasses, like those above, they mainly identified the figure opposite as a bald man wearing glasses. When a different group were shown pictures of small mammals, including rodents, like those below, they identified the figure as a rat or mouse In each case, perceptual set brought about by previous experience had influenced which sensory data were perceived and which ignored. The influence of perceptual set where past experience, context or expectation influences the way a stimulus is perceived