Week 9 Lecture 1 Flashcards
What is inner speech? How is it studied?
It is a silent speech experience in the mind.
Subjective self-reports are used to study it but there are no ways to verify these. Hard to study as no outward behaviour.
How is inner speech related to other domains?
Cognition - memory, reading, problem solving and consciousness (thinking about the self).
Working memory is affected by speaking out loud.
Reading - identifying tongue twisters by saying it in your head.
Problem solving - talk through the steps as you go along if doing something new.
Give an example of a dysfunction in inner speech
In mental disorders…
rumination - negative repetitive thinking
auditory verbal hallucination - positive symptoms for schizophrenia.
What are the three main theories of inner speech? Name, date, author
Speech with attenuated (reduced) articulation (Watson, 1913).
Internalised speech by complex transformation (Vygotsky, 1934/87)
Part of the phonological loop and store in working memory (Baddeley and Hitch, 1974).
Speech with attenuated articulation
Watson, 1913
Trying to say something but not out loud (reduced articulation).
It does not describe the subjective experience of inner speech.
It does not predict the cognitive impact of inner speech e.g. working memory
Does not explain the self-regulatory functions of inner speech
Internalised speech by complex transformation
Vygotsky 1934, 1987
Emphasises the role of self-talk in language development.
Babbling –> internalised inner speech used for self-regulating emotions (as scaffolded by parents).
Predicts that lots of inner speech takes a dialogue form.
Predicts turn taking behaviour is to regulate emotion.
Doesn’t explain what has changed to enable the ‘transformation’.
Inner speech as part of the phonological loop and store in working memory
Baddeley and Hitch (1974).
Inner speech forms part of the phonological loop in working memory.
There are other working memory models which don’t believe in separate components.
Doesn’t give any suggestions of how speech is generated internally.
Methodological considerations of studying inner speech
Intrinsically difficult to study as it is a private event that cannot be seen or heard.
Questionnaires - lack validity and reliability
Experience sampling - randomly ask participants throughout the day what are you thinking right now - gives snapshots of people’s lives to compare to other data.
Phonological judgements - a cognitive task to illicit inner speech e.g. rhyme judgements - not very naturalistic.
Instructed imagery - give people a cue and ask them to say the sentence in their voice, a friend’s voice etc. Follow instructions. Works better as sentences are more naturalistic, but still different from spontaneous inner speech.
Inner speech production
This relies on the idea of corollary discharge - the predictive signal of speech production.
Speech production regions coordinate vocal mouth movements to produce speech sounds.
Normally when speaking out loud it sends a motor signal to the motor cortex to execute these movements and sends a copy of the signal (efference copy) to the back of the brain to posterior parietal temporal junction where it is converted from an action signal (movement) to a perception signal (sound).
If you plan to move your mouth, a sound will be predicted by the brain depending on the way you plan to move (this prediction is corollary discharge).
Speech production areas engaged by rhyme judgements
Aparicio et al., 2007
2 written words are presented to the participant - do they rhyme or not?
Spellings can be different with the same sound so no visual input.
Control task e.g. motor/visual task is used.
String matching tasks do not include inner speech.
Rhyme judgements do - the temporal area (where corollary discharge is produced) is more activated during rhyme judgement tasks. Requires phonological activation, string tasks do not.
Speech production areas engaged when imagining talking to oneself
Grandchamp et al., 2019
Participants shown written words and picture of object. Asked to silently explain definition of presented word.
Brain scanned and compared to silent scan, similar areas activated as in the rhyme judgement study. Left inferior frontal, premotor and supplementary motor areas.
How can corollary discharge be observed?
The sound you hear inside your head is affected by corollary discharge.
When we speak out loud, one signal goes to the motor area and another to the auditory cortex (predicts sound which should match the sound you hear through your ears.) The sound you hear is the sound of your own voice counteracted by the voice in your head.
The sound you produce is checked against an internal prediction to check it is produced correctly.
Corollary discharge reduces the N100 response
Jack et al 2019
Participants asked to predict an external sound with inner speech
E.g. 3,2,1 baa is said in their head and baa is said out loud from a speaker - no surprise if said at the same time but if not there is a stronger N100 signal.
This proves the auditory signal (sound prediction) is being generated because it impacts the perception of an auditory signal.
What limitations are there to the corollary discharge model of inner speech?
Although the model can explain rhyme judgements and instructed imagery tasks it has a problem with explaining other kinds of inner speech. For example, it cannot explain why you can hear inner speech in other people’s voices. E.g. pretend to be a Dalek.
It is incompatible with the observation that inner speech is faster than overt speech.
Can explain deliberate inner speech (i.e. you intend to say something) but can’t explain spontaneous inner speech (hearing voices without explicit intention – when your mind wanders).
Restricts investigations to internal monologue only, which is incompatible with the dialogic variety of inner speech reported. In dialogue you have to have 2 voices to contribute to the back and forth conversation, corollary discharge only explains one voice.
Task elicited vs spontaneous inner speech
Hurlburt et al., 2016
Spontaneous inner speech - letting the mind wander is driven by activity in the auditory perception system.
Task elicited inner speech is driven by activity in the speech production system.
