Bottom-up and top-down processing are psycholinguistic processes used in speech recognition. Bottom-up processing relies solely on the acoustic signal, while top-down processing uses contextual information from the communication situation or sentence to aid understanding. An experiment found that participants understood words better when presented in sentences compared to in isolation, demonstrating the importance of top-down processing through context. Bottom-up processing decodes precise acoustic information, while top-down processing allows selection from possibilities by using context to clarify ambiguous acoustic signals.

1. By :
Zahra Aamir Kamil
Bottom-up & top-down information

2.  They are psycholinguistic processes.
 Based only on the acoustic signal.
(Top-down)
 Aided by contextual information, either in the
communication situation or within the sentence
being processed.
(Bottom-up)

3. decode the acoustic signal and retrieve the uttered words
from your lexicon.

4. “Fluffy’s bowl is empty!
Fluffy, bowl, buy.
This information that is not part of the
acoustic signal contextual information that
helps you understand what your roommate
said absent a clear acoustic signal.

5. People with (Broca’s aphasia) are good at understanding
conversational speech but poor at understanding sentences.
for which they have to do a detailed analysis

6. Pollack and Pickett asked participants to listen
to single words excised from the sentences
they had been produced in.
Participants did not do very well
understanding the words presented in
isolation, but when the same words were
presented inside their corresponding
sentences, participants understood the words
without difficulty.

7. a. Here’s the fishing gear and the….
b. Check the time and the …
c. Paint the fence and the …
bait, date, gate

8. Bottom-up Top-down
 clear and unambiguous
segmental information.
 The signal is decoded
precisely as it is
presented.
 specifies a word or
phrase.
 Indefinite or ambiguous
information.
 It is processed by using
whatever contextual
information might be
available.
 allow the hearer to select
among a range of
possibilities

9. Thank you