Lecture Week 1 Flashcards
1
Q
Define Sensation
A
- 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
2
Q
Define Perception
A
- Perception is what we do with the stimulation of sensation
- How we interpret sensation and give meaning to input
3
Q
Define Transduction
A
- 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.
4
Q
The 7 Steps of the Perceptual Process
A
- Environmental Process
- Stimulus is transformed into electrical energy
- Receptor processes
- Neural Processing
- Perception
- Recognition
- Action
5
Q
Sensation is. . .
A
The stimulus being transformed into electrical energy and going to the brain
6
Q
Perception is . . .
A
- Occurs in the higher levels of the brain
- Recognising objects
- Decide to take an action
7
Q
Sensation and Perception precedes . . .
A
Everything we do in psychology.
8
Q
How are sensation and perception received
A
- 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.
9
Q
Psychophysics
A
- 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
10
Q
Qualia
A
- a quality or property as perceived or experienced by a person
11
Q
Absolute Threshold
A
- The minumum amount of stimulus necesary to perceive a sensation.
- needs to be perceived 50% of the time
12
Q
Method of Constant Stimuli
A
- 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
13
Q
Method of Limits
A
- 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
14
Q
Method of Adjustment
A
- 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
15
Q
Measuring Perception
Participant Detects a change in stimulus
A
- 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
16
Q
Just Noticeable Difference (JND)
A
- The smallest detectable difference between two different stimuli
17
Q
Weber’s Law
A
- 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
18
Q
Fechner’s Law
A
- 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
19
Q
Steven’s Power Law
A
- 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.
20
Q
Cross-Modality Matching
A
- 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
21
Q
Signal Detection Theory
A
- 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
22
Q
Criterion
A
- A standard of judgement or criticism
- An established rule or principle for testing anything
23
Q
(d) prime value
A
- 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.
24
Q
Odourant
A
- 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
25
Odour
Once an odourant is transduced into a sensation of smell by the nose it is now called an odour
26
Olfactory System
* Detects molecules in the air and allows for sense of smell
* Converts an odourant into an odour
27
Olfactory Cleft
* Narrow space at the back of the nose
* About 2 ¾ inches above the nostril
* Contains the Olfactory epithelium
28
Olfactory Epithelium
* 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
29
Olfactory Bulbs
* 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
30
Turbinates
* 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
31
Glomerulus
* 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
32
Primary Olfactory Cortex
* 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
33
Tip of the Nose Phenomena
* Linguistic Processing is highley disconnected from Olfactory experience
* We do not have language to appropriatley describe smells
34
Smells and Memory
* Smell is durble and stable over the long term
* This is not so for other senses
* Smell is a more emotionally intense memory inducement
35
Pheromones
* 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
36
Androstadienone
* 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
37
Chemosignals
* Chemicals released by humans
* Detectable by the olfactory system
* Have an effect on mood, behaviour, hormonals status and possibly sexual arousal of other humans
