Top-down

• Top-down effects

  • phoneme perception not passive bottom-up process
  • top-down = influence of higher-level cognitive processes - expectations, knowledge, context, on lower-level sensory processing.
  • phoneme perception = expectations or context sound occurs = influence how perceive sound
• Top-down effects - Ganong effect 


  • shows categorical boundaries between phonemes can be modulated by context = impacting how perceive speech sounds
  • when hear nonsense words - chance perception into proper words to fit context (Ganong 1980)
• Top-down effects - Phoneme restoration effect (Warren 1970)


  • participants' perception of ambiguous vowel sound influenced by context provided
  • = perceptual system fills in gaps into what you expect - what makes sense

  effects stronger =

  • words (compared to non-words)
  • later in words
  • strongly biasing contexts
• Top-down effects - McGurk effect (McGurk & MacDonald 1967)


  • visual speech perception influences auditory perception of speech sounds
  • multimodal speech perception
  • ps saw 1 phoneme & heard another - reported hearing fusion
• Active speech perception 


  • speech perception involves auditory information (bottom-up processing)& cognitive processes (top-down processing) = active process
  • combination = efficient & accurate speech perception - overcome imperfect speech input
• Word recognition - top down effects

  • influence of higher-level cognitive processes & expectations
  • Ganong effect or phonemic restoration phenomenon, listeners perceive phonemes differently depending on context