L6 - Multisensory integration 2 5/11

Question 1

Explain challenges in multisensory integration using a train

Answer 1

Sitting in the train and see the train outside the window starts moving - you think the train you are sat in is moving but it isn’t - we still feel movement but visually movement would look the same.
Multisensory problems are you getting different inputs from your senses - first a visual input by seeing the train moving - then input from body and stimulus saying there is no movement. In the train case - conflict is resolved by trusting the visual input then later revising that opinion and realising it was incorrect.

Question 2

What is the McGurk effect?

Answer 2

Participants watch a video of a person saying a syllable like ‘ga’ but the audio plays a different syllable (like ba). Instead of hearing ba or ga many people perceive a third syllable such as da – a combination of visual and auditory inputs. This shows our perception of speech sounds can be influenced by what we see, not just by what we hear.

Question 3

Why do we get contradictory inputs? (in general)

Answer 3

There is lots of sensory uncertainty and generally the information we get from our senses we can fully trust

Question 4

What are the three reasons that sensory uncertainty occurs?

Answer 4

Perceptual limits, neural noise, cognitive resource limits

Question 5

Explain perceptual limits and sensory uncertainty

Answer 5

We can’t perceive some stimuli because they are outside the perceptual limit - eg visual resolution determined by spacing of photoreceptors in the fovea

Question 6

Explain neural noise and sensory uncertainty

Answer 6

Sensory information travelling is unaffected by neural noise before it can be processed - some information gets lost - leads to uncertainty if there is more we have to process

Question 7

Explain cognitive resource limits and sensory uncertainty

Answer 7

E.g attention - there is only so much brain power we can dedicate to processing data