L11 Chemical sensory and multisensory integration

What are the two chemical senses?

Taste (gustation) and smell (olfaction)

What are the 2 main functions of chemical senses in terms of survival?

To detect chemicals that help avoid toxins and danger.

What are the social effects of smell

pheromones

What are the five core tastes?

Sweet, Sour, Salty, Bitter, Umami.

How are tastes processed by the tongue

each taste bud cell contains taste receptors that respond to each taste

What 2 things causes the sweet taste?

Sugars and artificial sweeteners like aspartame.

What causes the sour taste?

Acids such as citric and acetic acid.

What causes the salty taste?

Salts like NaCl, NH4Cl, and KCl.

What causes the bitter taste?

No unique chemical class; examples include quinine and caffeine.

3 examples of umami taste?

MSG, inosine, and guanosine monophosphates.

Who are 'supertasters'?

Individuals with more papillae and taste buds who can detect certain substances

What new taste was suggested

The taste of starch.

What is the estimated number of smells humans can discriminate

Over 1 trillion.

What are the two routes of smelling?

Orthonasal (inhalation) and retronasal (chewing/swallowing).

How many types of olfactory receptors do humans have?

Approximately 350 (ability to discriminate large number of different smells)

3 top-down effects on smell

attention, labelling and learning

What is the 'Proust effect'?

The vivid recall of memories triggered by smells.

What brain area links smell to emotion and memory?

The limbic system.

Other than taste and olfaction, what 4 sensory components contribute to flavour?

texture, pain, sound, and vision.

How does texture influence taste perception?

Texture can cause like/dislike of certain foods.

Why does texture influence taste perception

the tongue is well represented in the somatosensory cortex

Which tastes reduce the pain of chili?

Sweet and sour liquids.

What sound makes foot taste fresher/crunchier

Amplified/high-pitched sounds

How do background noise impact taste

reduce sweetness/saltiness.

How does vision influence taste?

Presentation and colour can alter perceived flavour (e.g., dyed wine study).

What is a multisensory stimulus?

A stimulus that activates more than one type of sensory receptor.

What brain area integrates taste and smell?

The orbitofrontal cortex.

What brain area integrates touch, vision and audition

posterior parietal cortex

What 3 things does multisensory integration allow us to do?

Detect weak stimuli, resolve ambiguous stimuli, and alter quality of stimuli.

What is the ventriloquism effect?

Visual cues altering perceived location of sounds.

What is the McGurk effect?

Visual and auditory info combine to create a new perceived sound

What is the rubber hand illusion?

The feeling that a fake hand is your own due to synchronized visual and tactile input.

How can sensory input affect speed perception in driving?

The brain reduces awareness of constant speed;

What can be done to increase awareness of speed

visual/auditory cues

What is synaesthesia?

A condition where stimulation in one modality evokes a perception in another (e.g., seeing colors when hearing music).