Chemical senses and Multisensory Integration Flashcards
What are the 2 main chemosenses in humans?
Taste and Smell
Gustation is a scientific word for…?
Taste
Olfaction is a scientific word for…?
Smell
What is a more scientific word for smell?
Olfaction
What is a more scientific word for taste?
Gustation
What do chemosenses do?
Detect chemicals
How can taste and smell have a survival value?
They prevent ingestion of toxins and avoid danger
What are the social effects of smell?
Pheromones
(Pheromones are substances which are secreted to the outside by an individual and received by a second individual of the same species; they induce activity in other individuals)
What are the 5 core tastes?
1) Sweet
2) Sour
3) Salty
4) Bitter
5) Umami
What is umami taste?
Savoury
Each taste bud cell contains…….. that respond to each of the 4 tastes
Taste receptors
How many taste buds do humans have?
9000-10000
Different areas of the tongue more responsive to the core tastes
True or False?
False. This is an old view.
What causes sweet tastes? List 2 things
1) Sugars (fructose, glucose, saccharose…)
2) Artificial sweeteners (aspartame, saccharin…)
What causes sour tastes? List 1 thing
All acids (acetic acid, citric acid, ascorbic acid, phosphoric acid, lactic acid…)
What causes bitter tastes? List 4 examples
No unique chemical class:
1) Quinine
2) Caffeine
3) Peptide
4) Phenols
What causes salty tastes? List 1 thing
Salts like table salt (NaCl) or NH4Cl, KCl
What causes umami tastes? List 3 examples
1) Mono sodium glutamate
2) Inosine 5’- monophosphate
3) Guanosine 5’-monophosphate
Saccharin causes what taste?
a. Salty
b. Bitter
c. Sweet
d. Umami
e. Sour
c. Sweet
Quinine causes what taste?
a. Salty
b. Bitter
c. Sweet
d. Umami
e. Sour
b. Bitter
Guanosine 5’-monophosphate causes what taste?
a. Salty
b. Bitter
c. Sweet
d. Umami
e. Sour
d. Umami
Aspartame causes what taste?
a. Salty
b. Bitter
c. Sweet
d. Umami
e. Sour
c. Sweet
Peptide causes what taste?
a. Salty
b. Bitter
c. Sweet
d. Umami
e. Sour
b. Bitter
Ascorbic acid causes what taste?
a. Salty
b. Bitter
c. Sweet
d. Umami
e. Sour
e. Sour
Phenols causes what taste?
a. Salty
b. Bitter
c. Sweet
d. Umami
e. Sour
b. Bitter
What is the difference in tongue between super tasters and normal tasters? List 3 points
- Supertasters have more papillae on their tongues
- Meaning they have a more sensitive tongue
- They also have more taste buds
What % population qualifies as supertasters?
25%
What do large amounts of papillae on the tongue help supertasters do?
Detect ‘tasteless’ substance PROP (6-n- propylthiouracil)
Some researchers suggest the existence of a sixth taste. What taste is it?
Starch taste
Why is detecting starch tastes important?
It may be important for detection as a slow-release form of energy
Olfaction (smell) can discriminate up to ………. types of molecules?
10,000
What is smell limited by?
Limited by our memory for what they indicate
Is there a satisfactory classification of odours?
No
What are the 2 routes of smell?
1) Orthonasal
2) Retronasal
What is the orthonasal route of smelling?
We smell chemicals by inhaling/breathing in through our nose and into the olfactory membrane
What is the retronasal route of smelling?
We smell chemicals during chewing and swallowing. The smell comes from the back of our mouth and into the olfactory membrane
Which route of smell is this?
We smell chemicals by inhaling/breathing in through our nose and into the olfactory membrane
Orthonasal (via inhalation)
Which route of smell is this?
We smell chemicals during chewing and swallowing. The smell comes from the back of our mouth and into the olfactory membrane
Retronasal (during chewing and swallowing)
How many different types of olfactory receptors do humans have?
350
What can olfactory receptors do?
They are able to discriminate large number of different smells
They are able to discriminate a large number of different smells
These are known as…?
Olfactory receptors
How do olfactory receptors work?
1) Odorants bind to the olfactory receptors
2) Olfactory receptor cells are activated and send electrical signals
3) The signals are relayed in glomeruli
4) The signals are transmitted to higher regions of the brain
True or False?
Olfactory receptors of different types project electrical signals to the same glomerulus
False
Olfactory receptors of similar types project electrical signals to the same glomerulus
How many olfactory stimuli/molecules can humans discriminate?
1 trillion
What are the 3 types of top-down effects on smell?
1) Attention
2) Effect of labelling
3) Effect of learning
How can attention affect smell?
Sniffing something pleasant can catch your automatic attention and make you more likely to do something
e.g. When you want to sell a house, you can bake bread to induce a “bakery” and “homely” smell to attract potential buyers
People would be more likely to buy because of the smell (it smells like home, cosy, comforting)
How can the effect of labelling affect smell?
An odour can smell bad if it is labelled as something bad rather than something not as bad
e.g. The same odour smells worse when labelled as body odour rather than cheese
How can the effect of learning affect smell?
When you have smelt something multiple times, you are able to recognise if it is good or bad
e.g. Expert wine tasters identifying wine odours
When you have smelt something multiple times, you are able to recognise if it is good or bad
e.g. Expert wine tasters identifying wine odours
This is known as…?
Effect of learning on smell
An odour can smell bad if it is labelled as something bad rather than something not as bad
e.g. The same odour smells worse when labelled as body odour rather than cheese
This is known as…?
Effect of labelling on smell
Sniffing something pleasant can catch your automatic attention and make you more likely to do something
e.g. When you want to sell a house, you can bake bread to induce a “bakery” and “homely” smell to attract potential buyers
People would be more likely to buy because of the smell (it smells like home, cosy, comforting)
This is known as…?
Effect of attention on smell
True or False?
Context is important in influencing whether you’ll like a smell or not
True
What is the Proust effect?
When vivid memories are brought back by particular smells
When vivid memories are brought back by particular smells
This is known as…?
Proust effect
What is one explanation for the Proust effect?
There is a close linkage between smell and the limbic system in the brain (emotion)
True or False?
Eating is not multisensory
False
Eating is multisensory
What are the 2 influences of flavour?
Smell and Taste
Other than smell and taste, what other factors influence eating? List 4 other factors
- Texture
- Pain
- Sound
- Vision
Our tongues are well represented in the somatosensory cortex. What does this suggest?
Our tongues are very sensitive
Many foods (e.g. mushrooms) are widely disliked because of their…?
a. Flavour
b. Texture
c. Sound
b. Texture
Many foods are widely disliked because of their texture. Give an example
Mushrooms
Chilli acts on …… receptors in the tongue
Pain
How can tongue pain from eating chilli be suppressed?
Eating sweet and sour liquids
Eating sweet and sour liquids is best for suppressing what type of sensation?
Pain from eating chilli
Are bitter foods good for suppressing tongue pain from eating chilli?
No
Are salty foods good for suppressing tongue pain from eating chilli?
Yes but only intermediately
Foods taste crunchier and fresher when the sound is …… or the …….. increased
a. Amplified or the Low frequencies
b. Reduced or the Low frequencies
c. Amplified or the High frequencies
d. Reduced or the High frequencies
c. Amplified or the High frequencies
Foods were rated as……. sweet and salty in the presence of background noise
a. More
b. Less
b. Less
Tastiness ratings……. for art-inspired dishes
a. Increased
b. Decreased
a. Increased
In an experiment investigating the influence of food visuals on taste, participants rated which meal as more appetising than the rest?
a. Painting A201 by Kandinsky
b. Kandinsky-inspired artistic presentation of food
c. Regular presentation of food
d. Neat and ‘broken down’ presentation of food
b. Kandinsky-inspired artistic presentation of food
Multisensory stimulus generates several independent energies, which are simultaneously detectable by ….?
Different types of sensory receptors
Which cortex in the brain is involved with vision?
Visual cortex (at the back of the brain)
Which cortex in the brain is involved with sound?
Primary auditory cortex
Which cortex in the brain is involved with touch?
Primary somatosensory cortex
Which cortex in the brain is involved with smell?
Olfactory Cortex (part of the cerebral cortex)
Which cortex in the brain is involved with taste?
Primary gustatory cortex (part of the cerebral cortex)
True or False
Single neurone can only respond to one modality
False
Single neurone may respond to more than one modality
The orbitofrontal cortex is involved with what types of sensory? List 2
1) Taste
2) Smell
True or False?
A cell which responds to touches to the index finger may also respond to visual stimuli close to the index finger
True
The posterior parietal cortex is involved with what types of sensory? List 3
1) Touch
2) Vision
3) Audition
1) Touch
2) Vision
3) Audition
These types of sensory modalities are involved with…?
a. Posterior parietal cortex
b. Orbitofrontal cortex
a. Posterior parietal cortex
1) Taste
2) Smell
These types of sensory modalities are involved with…?
a. Posterior parietal cortex
b. Orbitofrontal cortex
b. Orbitofrontal cortex
What are the 3 main characteristics of multisensory integration?
1) Can allow detection of weak stimulus in another modality
2) Can make sense of an ambiguous stimulus in another modality
3) Can alter the quality of a stimulus in another modality
What can allow the detection of weak stimuli in another modality?
Multisensory integration
What can make sense of an ambiguous stimulus in another modality?
Multisensory integration
What can alter the quality of a stimulus in another modality?
Multisensory integration
What is multisensory integration?
Multisensory integration is the way our brains combine information from different senses such as sight, sound, touch, smell, and taste to create a unified perception of the world around us.
e.g. Ventriloquism Effect
How does ventriloquism relate to multisensory integration?
- Ventriloquism is an example of multisensory integration because it involves the integration of auditory and visual information
- When we see a ventriloquist’s dummy “talking,” our eyes tell us that the sound is coming from the dummy’s mouth, rather than the ventriloquist’s
- This illusion is created because our brain is integrating the auditory and visual information, and interpreting them as coming from the same source
Visual information can influence …… in space we perceive a sound source
a. When
b. How
c. Where
d. Why
c. Where
What allows us to follow what is happening in TV/ cinema?
Visual capture of sound
What is the McGurk effect?
When you watch someone’s lips moving to make the sound ‘ga-ga’ but the audio over it plays the sound ‘ba-ba’
Participants perceive it as ‘da-da’
True or False?
Visual information does not affect the sound that you hear
False
Visual information affects the sound that you hear
When you watch someone’s lips moving to make the sound ‘ga-ga’ but the audio over it plays the sound ‘ba-ba’
Participants perceive it as ‘da-da’
This is known as…?
The McGurk effect
When we see a dummy “talking,” our eyes tell us that the sound is coming from the dummy’s mouth, rather than the puppeteer’s
This illusion is created because our brain is integrating the auditory and visual information, and interpreting them as coming from the same source
This is known as…?
The ventriloquist effect
The way our brains combine information from different senses such as sight, sound, touch, smell, and taste to create a unified perception of the world around us.
This is known as…?
Multisensory integration
What is the rubber hand illusion?
When Ps place their hand away from their vision (behind a divider) and only look at the rubber hand in front of them
The experimenter touches and tickets both the Ps hand and the rubber hand simultaneously and the Ps believe that the rubber hand is their own hand
When the experimenter smashes the hammer on the rubber hand, the Ps flinch and move their real hand away, suggesting that they really did think the rubber hand was theirs.
An ant lands on your hand but you can’t really feel it due to how small it is. But as soon as you lay eyes on the ant, you can suddenly feel it moving on your hand
This is an example of…?
Multisensory integration
It can allow the detection of weak stimuli in another modality
When Ps place their hand away from their vision (behind a divider) and only look at the rubber hand in front of them
The experimenter touches and tickets both the Ps hand and the rubber hand simultaneously and the Ps believe that the rubber hand is their own hand
When the experimenter smashes the hammer on the rubber hand, the Ps flinch and move their real hand away, suggesting that they really did think the rubber hand was theirs.
This is known as…?
The rubber hand illusion
One’s own hand may feel as if it is in the location of a rubber hand
This is known as…?
The rubber hand illusion
What is Kinaesthesia?
The illusion of speed
The illusion of speed is known as…?
Kinaesthesia
Explain how Kinaesthesia works in a driving experiment
1) Initially Ps drive at 70 mph
2) 10 mins later, after driving at a steady 70 mph, Ps feel like they are going at 50 mph
How does Kinaesthesia occur?
The nervous system turns down the ‘gain’ on steady-state inputs
Simply = When there is a constant input, such as a continuous sound or light source, the nervous system can reduce the amplification of those signals to prevent sensory overload
When there is a constant input, such as a continuous sound or light source, the nervous system can reduce the amplification of those signals to prevent sensory overload
This is related to…?
Kinaesthesia (illusion of speed)
Why does the nervous system turn down the gain on steady-state inputs?
To filter out irrelevant or background stimuli, and allow us to better detect and respond to changes or novel stimuli in our environment
e.g. When you enter a room with a humming air conditioner, your brain initially registers the sound, but after a while, you may not notice it anymore.
This is because your nervous system has turned down the gain on that constant sound input, allowing you to focus on other sensory inputs that may require more attention
How do town planners increase drivers’ awareness of speed?
- Follow a multisensory approach
- Painted lines/small bumps to increase awareness of speed via vision/audition
What is Synaesthesia?
When the stimulation of one sensory or cognitive pathway leads to automatic and involuntary experiences in another pathway
e.g. A person with grapheme-colour synaesthesia may associate specific colours with certain letters or numbers
How common is Synaesthesia?
Approximately 1 in 200 people
When the stimulation of one sensory or cognitive pathway leads to automatic and involuntary experiences in another pathway
e.g. A person may associate specific colours with certain letters or numbers, some can taste shapes etc.
This is known as…?
Synaesthesia
Seeing coloured letters and tasting shapes are examples of…?
Synaesthesia
What is mirror-touch synaesthesia?
When a person feels the same physical sensations that they observe in others
e.g. If one sees someone else being tapped on the shoulder, they may feel a sensation of being tapped on their own shoulder
When a person feels the same physical sensations that they observe in others
e.g. If one sees someone else being tapped on the shoulder, they may feel a sensation of being tapped on their own shoulder
This is known as…?
Mirror-touch synaesthesia
What are crossmodal correspondences?
When we make assumptions about how certain things act/behave based on similarities in sensory features, such as the pitch of a sound and the brightness of a colour
e.g. People are more likely to associate prunes with slow movements relative to fast because prunes are small and wrinkly, similar to old people. Hence we assume they move slowly, even though prunes cannot realistically move by itself
People tend to associate high-pitched sounds with bright or light colours, and low-pitched sounds with dark or dull colours
This is an example of…?
Crossmodal correspondences
People are more likely to associate prunes with slow movements relative to fast because prunes are small and wrinkly, similar to old people. Hence we assume they move slowly, even though prunes cannot realistically move by itself
This is an example of…?
Crossmodal correspondences
What are the crossmodal correspondences of high-pitch sounds? List 4 assumptions
High-pitch sounds are related to:
1) Lighter stimulus
2) Smaller objects
3) More angular shapes
4) Brighter visual stimulus
High-pitch sounds are often paired with…?
a. Lighter stimulus
b. Heavier stimulus
a. Lighter stimulus
High-pitch sounds are often paired with…?
a. More angular shapes
b. More circular/rounded shapes
a. More angular shapes
High-pitch sounds are often paired with…?
a. Bigger objects
b. Smaller objects
b. Smaller objects
High-pitch sounds are often paired with…?
a. Darker visual stimulus
b. Brighter visual stimulus
b. Brighter visual stimulus
When we make assumptions about how certain things act/behave based on similarities in sensory features, such as the pitch of a sound and the brightness of a colour
This is known as…?
Crossmodal correspondences
Who has better memory?
a. People with Synaesthesia
b. People without Synaesthesia
a. People with Synaesthesia
Can Synaesthesia be trained?
Yes
Describe the results of a study by Bar et al. investigating training people to develop Synaesthesia
1) Following a 9-week training regime, participants pass tests for genuine synaesthesia
2) Participants described vivid experiences
‘‘I see the colours like on a monitor in my head and it’s very automatic’’
3) Also led to increases in IQ
True or False?
Synaesthesia leads to a decrease in IQ
False
Synaesthesia leads to an increase in IQ
