Lecture Week 1

Question 1

Define Sensation

Answer 1

• Being able to detect a sensation through your receptors
• Transduce that into electrical energy
• Then process that in the brain
• Becomes a personal experience such as a memory or observation

Question 2

Define Perception

Answer 2

• Perception is what we do with the stimulation of sensation
• How we interpret sensation and give meaning to input

Question 3

Define Transduction

Answer 3

• Sensation occurs via transduction
• Converts one energy to another
• Pressure converts to electical energy
• This causes action potentials in the axons
• We percieve the sensation then the brain can recognise the sensation
• Finally the brain takes an action based upon the recognition.

Question 4

The 7 Steps of the Perceptual Process

Answer 4

1. Environmental Process
2. Stimulus is transformed into electrical energy
3. Receptor processes
4. Neural Processing
5. Perception
6. Recognition
7. Action

Question 5

Sensation is. . .

Answer 5

The stimulus being transformed into electrical energy and going to the brain

Question 6

Perception is . . .

Answer 6

• Occurs in the higher levels of the brain
• Recognising objects
• Decide to take an action

Question 7

Sensation and Perception precedes . . .

Answer 7

Everything we do in psychology.

Question 8

How are sensation and perception received

Answer 8

• Bottom up path to processing
• Move from sensation to perception to cognition
• Some Top Down processing
  
  • Existing Knowledge can influence sensation
  • Existing knowledge affects our gaze direction
  • In hearing, cochlear is finely tuned to hear and amplify sounds that we have become conditioned to hear.
    eg: hearing your name in a crowd.

Question 9

Psychophysics

Answer 9

• The science of defining quantitative relationships between physical and psychological events
• How we measure perception objectively?
• How can we be sure that we all see the colour green in the same way

Question 10

Qualia

Answer 10

• a quality or property as perceived or experienced by a person

Question 11

Absolute Threshold

Answer 11

• The minumum amount of stimulus necesary to perceive a sensation.
• needs to be perceived 50% of the time

Question 12

Method of Constant Stimuli

Answer 12

• most commonly used to measure absolute threshold
• give participants a range of stimuli one at a time
• vary randomly between not perceivable and always perceivable

Question 13

Method of Limits

Answer 13

• Present the stimulus incrementally until the participant can detect it
• Usually presented from least perceivable tone to always perceivable tone.
• Often there is an overshoot, it will take a participant a while to hear it unlike the other methods that are used

Question 14

Method of Adjustment

Answer 14

• Simmilar to Method of Limits except participants have control of the dial
• They can adjust the sound as they hear or do not hear the stimulus tone

Question 15

Measuring Perception

Participant Detects a change in stimulus

Answer 15

• Participants given a weight to lift a number of times
• The weight is then changed without the participant noticing
• Given another weight,
• at what weight difference can the participant detect the change.
• What is the minimum weight difference that can be detected

Question 16

Just Noticeable Difference (JND)

Answer 16

• The smallest detectable difference between two different stimuli

Question 17

Weber’s Law

Answer 17

• Found the JND is a constant fraction of the comparison stimulus.
• In weight the JND is 1/40 of the comparison weight.
• JND = 1/40*Weight

Question 18

Fechner’s Law

Answer 18

• Found Weber’s Law doesn’t work for High and low intensities
• 1/40 Law doesn’t hold true at these ends of the spectum
• Fechner came up with a logarithmic rule
• Instead of a straight line relationship in Weber’s Law, the JND increases proportionally to the intensity of the stimulus

Question 19

Steven’s Power Law

Answer 19

• Fechner’s logarithmic calculation of the proportional JND doesn’t hold true for all modalities
• If we double the intensity of a light does it look twice as bright?
• Looking for a qualitative measure for a subjective experience of the magnitude of the stimulation
• The magnitude of the subjective sensation is in proportion with the stimulus magnitude offered to participant
• Participants subjective experience of changes in the magnitude of sensation differs in the modality we are talking about.

Question 20

Cross-Modality Matching

Answer 20

• The ability to match the intensities of sensations that come from different sensory modalities.
• Can our different sensations be cross matched?
  
  • can we quantify; does taste have a value of sound
• Helps to explore whether or not we have the same experiences.
• Is sensation a universal or unique experience

Question 21

Signal Detection Theory

Answer 21

• There are four options possible when a stimulus is present
• Detection of a stimulus depends on the participants sensitivity to the stimulus and the participants response criterion
• Depends on
  
  • presence of a signal
  • expectation of signal.
  • Response criterion

Question 22

Criterion

Answer 22

• A standard of judgement or criticism
• An established rule or principle for testing anything

Question 23

(d) prime value

Answer 23

• Look at the proportion of hits & correct rejections vs miss & false alarms to calculate (d) prime value
• The larger the (d) prime the more certain the participant is that the signal is actually there.

Question 24

Odourant

Answer 24

• A molecule capable of being translated into the perception of smell by the nervous system
• Must be small enough, be able to fly thought the air and be water repellent

Question 25

Odour

Answer 25

Once an odourant is transduced into a sensation of smell by the nose it is now called an odour

Question 26

Olfactory System

Answer 26

• Detects molecules in the air and allows for sense of smell
• Converts an odourant into an odour

Question 27

Olfactory Cleft

Answer 27

• Narrow space at the back of the nose
• About 2 ¾ inches above the nostril
• Contains the Olfactory epithelium

Question 28

Olfactory Epithelium

Answer 28

• The seat of transduction
• Where Olfactory Sensory Neurons are located
• Odour molecules are transduced into sense of stimulation or the odour
• Contains around 5-10 Million OSNs
• OSNs regenerate every 2 months or so

Question 29

Olfactory Bulbs

Answer 29

• Receptor cells send transduce odourant into neural firing to olfactory bulbs
• Olfactory Bulbs are an extension to the brain that receive the axons from OSNs
• About the size of a blueberry
• Sit just above the olfactory epithelium

Question 30

Turbinates

Answer 30

• Ridges inside the nose that add turbulence to the air before it reaches the olfactory cleft
• Puffs air right up into the olfactory cleft so it can stick to the mucous patch of the olfactory epithelium
• Olfaction begins when the odourant travels to the olfactory cleft and then activates transduction in the OSNs

Question 31

Glomerulus

Answer 31

• Collects activation from OSNs
• Gathers and combines all that electrical information and sends it on to the brain.
• Happens in 400 ms to travel to the brain
• In terms of sensory activation this is considered slow
• Olfactory bulb sends information to the Primary Olfactory Cortex

Question 32

Primary Olfactory Cortex

Answer 32

• Receives electrical energy from olfactory bulb
• Located in the Limbic System
• Same area as the amygdala and the hippocampus
• Considered part of the basic brain structures from and evolutionary perspective
• Primary olfactory cortex projects to the Orbitofrontal Cortex both directly and via the amygdala

Question 33

Tip of the Nose Phenomena

Answer 33

• Linguistic Processing is highley disconnected from Olfactory experience
• We do not have language to appropriatley describe smells

Question 34

Smells and Memory

Answer 34

• Smell is durble and stable over the long term
• This is not so for other senses
• Smell is a more emotionally intense memory inducement

Question 35

Pheromones

Answer 35

• chemicals emitted by one member of a species to attract an opposite member of that species
• Androstadienone is an endogenous steroid that has been attributing potent pheromone activity in Humans

Question 36

Androstadienone

Answer 36

• Chemical wih potent pheromone like activity in humans
• Has been added to male scents claiming to make the wearer more sexually attractive to women
• Studies demonstrate that this does not work as it is a chemical mostly attrubited to pigs not humans

Question 37

Chemosignals

Answer 37

• Chemicals released by humans
• Detectable by the olfactory system
• Have an effect on mood, behaviour, hormonals status and possibly sexual arousal of other humans