Multi-sensory integration and synaesthesia Flashcards
What is meant by the ventriloquism effect?
Audiovisual integration
Relies on synchrony of both audio and visual input –> perceive sound as coming from that area even when it isn’t
What is the McGurk effect?
Audio-visual integration
When a face produces one sound and another sound is played, the sound you hear is different to both
Inputs are temporally synchronous but incongruent and in the end what we see overrides what we hear
What do the ventriloquism and McGurk effects relate to?
Development - we learn to integrate as we are increasingly exposed to the necessity for it
Developmental disorders such as autism and dyslexia show problems with coherence and reduction in these effects
How has sound been shown to modify texture?
Pringles experiments - freshness and crispness enhanced when higher frequency tones played, especially when these frequencies are played at higher amplification
What did Ramachandran and Hubbard find in relation to how sound influences visual and spatial information?
“Rounder” sounds such as B associated with rounder shapes and “sharper” sounds associated with pointy shapes universally
Angular gyrus damage and autism reduce this effect
Which 3 studies illustrates how colour influences taste perception?
Morrot et al - white wine coloured red described as having similar aroma to red wine
Parr et al - Professional wine tasters only succumb to this illusion when the glass is transparent (social drinkers fooled regardless)
Zampini et al - Coloured water led to different taste perceptions and expectations influenced by previous experiences (supertasters not affected) - cultural differences found
What does multi-sensory integration rely on?
Spatial and temporal coincidence
Semantic congruency
Probabilistic information - use reasoning to predict the things most likely to be happening at the same time, pattern-based
What is the “Unity Effect”?
Matching between different sensory modalities in a percept - features bound together as one coherent experience
What is synaesthesia?
An atypical perception of an additional sense (only affects 1 in 2000) - a feature (INDUCER) automatically evokes a synaesthetic percept (CONCURRENT EXPERIENCE)
What are the 6 different types of synaesthetes?
Grapheme-colour Phoneme colour Day-colour Music-colour Auditory-gustatory Mirror touch
What did Bannissy et al suggest?
Synaesthesia is modality-specific
They ran colour hue discrimination and gratings tests, comparing grapheme-colour and visuo-tactile synaesthetes and found that the grapheme-colour only showed enhanced colour perception relative to controls, and visuotactile only showed enhanced visual perception to gratings compared to controls
What do grapheme-colour synaesthetes do?
Display more vivid mental imagery e.g. more vivid colour, while spatial imagery is no different to normal
More likely to engage in artistic hobbies
What is a biological characteristic of synaesthetes from childhood?
Increased white matter connectivity
Increased activation in inferior parietal cortex and fusiform gyrus
Increased activation also found in frontal lobes
Illustrates that they are not “impaired”, just atypical
What did Ward et al suggest regarding creativity in synaesthetes?
Tested convergent and divergent thinking and synaesthetes outperformed controls on convergent but not divergent
Suggests ability to make stronger associations but no better in terms of originality
What is the speeded classification paradigm?
Used to probe for interactions between different dimensions or modalities –> rapid identification of a stimulus in one modality, while an irrelevant stimulus in another modality is ignored
If the two modalities are automatically registered, it may be difficult to attend selectively to one of the pair and variation in the irrelevant modality may affect latencies to the relevant one.
Any overall increase in latencies induced by variation on the irrelevant dimension is known as Garner interference
