Perception and Memory Higher Human Biology
SOMATIC MIX UP Put the statements in the correct order to show the pathway of nerves involved in a somatic response MOTOR NERVE SENSORY NERVE CNS EFFECTOR STIMULUS What type of movement does the somatic nervous system carry out? What are the main effectors of the somatic nervous system? STIMULUS SENSORY NERVE CNS MOTOR NERVE EFFECTOR Voluntary movements Skeletal Muscles
Read about Billy s day. Pick out the actions of the autonomic nervous system and state if they are parasympathetic or sympathetic responses. Billy yawned and stretched and tried to come alive, his cardiac output was low. He inhaled a huge deep breath causing the walls of his bronchioles to relax and his lungs to fill with air. Billy made his way into the kitchen where he prepared himself a big plate of scrambled eggs. Whilst eating his eggs the smooth muscle of Billy s intestinal tract was contracting furiously and the glandular secretions of his intestines were spraying everywhere. Following his hearty meal Billy positioned himself in his favourite arm chair and had a snooze. His cardiac output was very low and his bronchiole walls were contracting as little air entered his lungs. On awaking Billy put on his favourite exercise dvd and enjoyed an hour of Salsacise!. Billy s cardiac output was the highest it had been all day!. Quite exhausted he returned to chair for a second nap.
PARA =RED SYMP = BLUE Read about Billy s day. Pick out the actions of the autonomic nervous system and state if they are parasympathetic or sympathetic responses. Billy yawned and stretched and tried to come alive, his cardiac output was low. He inhaled a huge deep breath causing the walls of his bronchioles to relax and his lungs to fill with air. Billy made his way into the kitchen where he prepared himself a big plate of scrambled eggs. Whilst eating his eggs the smooth muscle of Billy s intestinal tract was contracting furiously and the glandular secretions of his intestines were spraying everywhere. Following his hearty meal Billy positioned himself in his favourite arm chair and had a snooze. His cardiac output was very low and his bronchiole walls were contracting as little air entered his lungs. On awaking Billy put on his favourite exercise dvd and enjoyed an hour of Salsacise!. Billy s cardiac output was the highest it had been all day!. Quite exhausted he returned to chair for a second nap.
Learning Intentions Give a definition of perception Explain how perception is used in segregation of objects Explain perception of distance Explain how perception is involved in recognition
Perception Perception is the process by which the brain analyses and makes sense of incoming sensory information.
Perception There are 3 areas of perception: Segregating objects from each other and from their background Perception of distance (to judge how far or near objects are from you) Recognition of different objects.
Segregation of Objects One way to segregate objects is by organising them into figure and ground. This involves looking at aspects of an objects shape. In drawing, a line that encloses an area whose shape is recognised appears to stand out from the background. In this shape, the black triangle appears to stand out from the white ground
Figure-Ground Perception Any field of view that contains contrasting components is perceived as figural. One or more parts of it become separated as figures stand out from the rest of the field (that forms the ground)
Reversible Figure Ground Images Although some shapes tend to become figural, by fixing your attention on different areas, the figure and ground can switch. What do you see in the pictures opposite?
Coherent Patterns The brain tends to organise visual stimulus that it receives into a coherent pattern, rather than many different parts. Even simple patterns like dots fall into ordered relationships.
Grouping of Visual Stimuli There are a number of ways that the visual system organises stimuli into patterns: Proximity Similarity Closure Orientation Proximity Closure Write a few bullet points for each using page 226/7 in the textbook! http://www.csus.edu/indiv/l/luenemannu/pdf /Perception%20quiz.pdf
Use of Visual Clues When looking at images and judging distance, you make use of visual clues like: Relative size Superimposition Height in field By appearing to decrease in size, the sleepers in the railways line indicate their increasing distance from the eye
Relative size the further away an object is situated 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. Height in field next slide
Relative Height in Horizontal Field Among a group of objects whose bases are below the horizon, those with their bases in a relatively higher position appear to be further away.
Texture gradient a change in the relative size and density of objects is perceived when they are viewed from different distances. Linear perspective parallel lines such as a railway line and a road appear to converge distance. (figure 18.14 18.15)
Each eye looks at an object from a slightly position relative to the other eye. Binocular disparity There is therefore a slight difference between the images of an object formed by the two eyes. The closer the viewer is to the object, the greater the difference between the two images.
Binocular Disparity in Judging Distance Hold a pen about 30mm away from your face with its tip angled slightly downwards pointing towards your nose. Close each eye in turn repeatedly What happens? View with both eyes at the same time what happens? Now try pouring water from a beaker into a test tube using one eye then both and compare the volume collected in the test tube Is one eye of two better at judging distance?
Binocular Image The two images are merged by the brain into one image by fusing them together. This produces a binocular image. This image indicates depth and distance much more effectively than a monocular image.
Seeing Double! Binocular vision can fail to occur if excessive quantities of alcohol have been consumed. The person might see double
Perceptual Constancy A person s visual perception of their surroundings remains stable despite changing images landing on their retinas as they move. Even if the object becomes nearer, or viewing angle changes, visual perception remains constant.
The perception that an object remains the same size regardless of the size of the image on the retina is called size constancy. Size Constancy If you throw a ball for a dog, as it runs away from you to fetch it, its image on your retina becomes smaller. However you do not believe the dog has shrunk!
Shape Constancy The perception that an object remains the same shape despite changes in the angle at which it is viewed is called shape constancy.
Importance of Shape The ability to perceive an object s physical appearance such as shape, colour and texture is called object recognition. Of these, shape is more important than other details. The pictures represent fruit based on their outline and colour colour can t be used on its own.
Matching Perceived Shapes When a person perceives a shape, the brain attempts to match the shape with one of the visual descriptions already stored in the brain. If the shape is familiar, it will be quickly matched and the object recognised. If the shape is unfamiliar it may draw a blank. If the shape doesn t match, but is similar, the brain might conclude that it is related to a known object. E.g. That this is a citrus fruit
Perceptual set is the tendency of a person to perceive some aspects of sensory information, and ignore others. Perceptual Set Perceptual set is affected by expectation, context and past experience. It influences the way in which a stimulus is perceived. Letter or number? (Cover the letters, then cover the numbers, the context changes how you perceive the stimulus)
What do you see?
Perceptual Set- Past Experience Expectations are partly due to past experience. Test group A shown images of rats then this image see a rat. Test group B shown images of bald men with glasses then this image see a bald man with glasses.
SQA Summary Perception is the process by which the brain analyses and makes sense out of incoming sensory information. The three areas of perception involve segregation of objects, perception of distance and recognition. 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
SQA Summary 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.
Learning Intentions Give a definition of memory Explain short term memory
Memory Memory is the ability of the brain to store information, retain it and then retrieve it when required.
Memory Memory is selective, only a fraction of the sensory images formed become committed to memory. To become part of the memory, the selected sensory image first must be encoded (converted to a form that the brain can process and store). Storage is the retention of information over a period of time, it could be 30 seconds or a lifetime. Retrieval is the recovery of stored material. This involved the recall of information from the short-term or long-term memory.
Levels of Memory There are different levels of memory that information can pass through: Sensory memory (very short lived E.g. 0.5 seconds) Short-term memory (can hold about 7 items for 30 seconds) Long-term memory (Unlimited amount of information for up to a lifetime) video
Short-Term Memory Can only hold about 7 pieces of information. Information is held for about 30 seconds, during which time retrieval is very accurate. After this they are either transferred to the next level or lost by: displacement (pushed out by new information) decay video
SQA Summary Memory involves storage, retention and retrieval of information. Memories include past experiences, knowledge and thoughts. All information entering the brain passes through sensory memory and enters shortterm memory. Information is then transferred to long-term memory (LTM) or discarded.
Chunking A chunk is a meaningful unit of information made up of several smaller units, which helps to increase memory span. This is often used to remember information like phone numbers: E.g. 0141337598 0141 337 598 10 pieces of info 3 pieces of info
Rehearsal Rehearsal involves repeating to yourself over and over again (silently or out loud) a piece of information that you are trying to memorise. This process helps to extend the time for which the information is maintained in the STM.
Serial Position Effect Write numbers 1 to 12 in your jotter. You are about to see 12 objects. Look at them, remember the order of them and then when told to do so write them down in order next to the appropriate number. go to 55mins
1. Horse 2. Books 3. Light bulb 4. Paddington bear 5. Bread 6. Tree 7. Tractor 8. Microscope 9. Snowman 10. Puppy 11. Fruit 12. Aeroplane Answers
Serial Position Effect The results of the experiment show that recall is best for the objects shown at the end (recency effect), closely followed by those shown at the start (primacy effect). Those in the middle gain a poor score. This is called the serial position effect.
Serial Position Effect The first few objects have enough time to be rehearsed and in many cases are transferred to the LTM. The last few are remembered because they are still in the STM.
Working Memory Working memory is an extension of shortterm memory. It actively processes, manipulates and controls information that is held in the STM.
SQA Summary Sensory memory lasts a few seconds and retains all of the visual or auditory input. Short-term memory (STM) includes memory span, the serial position effect, maintaining items by rehearsal and loss of items by displacement and decay. Improvement of STM by chunking.
Learning Intention Explain long term memory
Long-Term Memory It is thought to hold unlimited amounts of information. During encoding, items are organised into categories like personal facts and useful skills.
Transfer of Information
Transfer of Information If information in the STM is encoded then it can be transferred for storage in the LTM. The transfer of information from the STM to the LTM is promoted by the process of rehearsal, organisation and elaboration of meaning.
Rehearsal Rehearsal facilitates transfer from STM to LTM. Research shows that pupils who regularly stop reading and rehearse what they are trying to learn are much more successful at committing the information to memory.
Organisation Information that is organised into logical categories is more easily transferred from STM to LTM. Making use of contextual cues aids this.
Which List is Easier to Remember? List A Summer Apple Shirt Autumn banana Pear skirt winter jacket Explain why List B is organised into categories List B Apple Banana Pear Shirt Skirt Jacket Autumn Winter summer
Elaboration of meaning aids transfer as it makes the information more interesting and meaningful so is more likely to be successfully stored in the LTM. Elaboration
Encoding Is the conversion of one or more nerve impulses into a form that can be received and held by the brain and retrieved later from the short or long term memory. The quality of the memory is affected by the attention given to the task of encoding the material
Types of encoding Shallow encoding- is information encoded by repetition Elaborative encoding is information encoded by linking it to previous memories
Retrieval of Information from the LTM Retrieval is aided by contextual cues at the time of encoding A memory whose encoding in the LTM is accompanied by an unusual, emotional or dramatic event possess powerful contextual cues that enables the experience to be retrieved and recalled clearly throughout life Can you think of any examples?
SQA Summary The transfer of information from STM to LTM due to rehearsal, organisation and elaboration. Information is encoded using shallow encoding or elaborative encoding. Retrieval is aided by the use of contextual cues.
Extended Response Practise
Essay Practise
Learning Intention Explain the locations of different types of memory in the brain
Location of Memory There are several different types of memory within the LTM which are associated with different areas of the brain.
remembering that... Episodic memory is the recall of personal facts, experiences and events. Semantic memory is the recall of general knowledge and non-personal facts.
Storage of Episodic and Semantic Memories Episodic and semantic memories are stored in a region of the cerebral cortex called the temporal lobe. This is where the sensory information was received and coded
Procedural Memory
Remembering how to... Procedural memories contain the information needed to Perform motor skills (e.g. Remembering how to swim) Perform mental skills (e.g. Remembering how to read)
Procedural Memories Procedural memories are linked to the motor cortex.
Emotional Memories Emotional memories are formed as a result of positive or negative associations with certain stimuli. Emotional memories involve links between the cerebral cortex and limbic system.
Spatial Memory Spatial memory holds information that can be recalled about a person s environment and its spatial orientation. E.g. the relationship of one object to another in a room. Spatial memory is located in the limbic system in the hippocampus.
SQA Summary Episodic and semantic memories are stored in the cortex. Procedural memories (skills) are linked to the motor cortex. Emotional memories involve links between the cortex and the limbic system. Spatial memory is located in the limbic system.
Spatial Limbic system and hippocampus Emotional Cerebral cortex and Limbic system Episodic Cerebral cortex Procedural Motor cortex Semantic cerebral cortex