Does PAC disconnection cause dreams/hallucinations to be silent?
GreenXenon
If the primary auditory cortex is completely disconnected from the
rest of the brain, will dreams be silent? Also, will it be impossible
for the individual to experience any auditory hallucinations even in
scenario that would otherwise cause them -- such as use of LSD,
ketamine or other hallucinogens?
I guess the answer is yes. I could be wrong though.
I'm thinking dreams/hallucinations would be something like watching TV/
movies, with the "mute" button on.
Do I guess correctly?
Thanks
BOfL
A good question.
Do you actually have auditory dreams?
I sense music in such states, rather like imagning a piece playing
while awake.
I would suggest we are experiencing different vibratory rates
(parallel realities) when we dream, and have a problem when we make
try to make comparisons from either side of the experience.
BOfL
James Warren
It would be worse than that! You would no longer know what sound was or have
any memory of sound and you wouldn't miss it.
--
jw.
Science is a candle in the dark. - Carl Sagan.
Curt Welch
Does the "primary auditory cortex" include all the speech and language
centers of the brain? If not, then the person would have some ability to
generate and use language which made reference to sound and in doing so,
they would have an clear understanding of what they had loss even if they
had no memory of what sound itself was _like_. They would be able to miss
not having it when someone said "didn't you hear me knocking on the door?"
and they were able to understand they had loss a sensory power.
If disconnecting the "primary auditory cortex" also removes most language
ability then it's possible they would become so unaware that they wouldn't
be able to understand what they were missing.
--
Curt Welch http://CurtWelch.Com/
cu...@kcwc.com http://NewsReader.Com/
James Warren
It's an interesting observation. I've read of cases involving total loss of
visual cortex but not auditory cortex, so I assumed it work be similar. It
would be strange: language still intact but no knowledge of sound. Could one
read for example. Does silent reading involve the auditory cortex? i think it
does. It would indeed be a curious situation.
ZerkonXXXX
> Do I guess correctly?
Is the auditory cortex responsible for sound memory?
If the auditory cortex is responsible for the processing sounds that are
being heard, how does this effect the thoughts of sound not being heard.
John Hasenkam
halluncinations.
"GreenXenon" <gluce...@gmail.com> wrote in message
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John Hasenkam
Here's the latest
Cogn Neuropsychiatry. 2008 Mar;13(2):166-79. Links
Left hemisphere lateralisation of auditory hallucinations in schizophrenia:
a dichotic listening study.
Hugdahl K, L�berg EM, J�rgensen HA, Lundervold A, Lund A, Green MF, Rund B.
Department of Biological and Medical Psychology, University of Bergen,
Bergen, Norway. hug...@psybp.uib.no
INTRODUCTION: We propose that auditory hallucinations are internally
generated speech misrepresentations that are lateralised to the left
temporal lobe. If hallucinations are misrepresentations involving the speech
perception area of the left temporal lobe, then hallucinating patients
should have problems identifying a simultaneously presented external speech
sound, especially when the sound is lateralised to the left hemisphere.
Lateralisation of speech perception can be experimentally studied with the
dichotic listening task with consonant-vowel syllables. We predicted a
negative relation between frequency of auditory hallucinations and
performance on the dichotic listening task. METHOD: We studied 87
right-handed patients with schizophrenia. Hallucination scores were taken
from the BPRS symptom scale. Right and left ear scores in the dichotic
listening task were recorded. A right ear advantage is expected in healthy
individuals, indicating left temporal lobe processing superiority. The
patients were compared with 36 right-handed healthy reference subjects.
RESULTS: A gradual decrease in the ability to process and report the right
ear stimulus with increasing frequency of hallucinations was seen in the
schizophrenia patients. No such relationship was found for processing and
reporting of the left ear stimulus. There were no significant correlations
with negative symptoms. Thus, the results were not the consequence of
illness severity. There was however a significant correlation with unusual
thought content symptom, pointing to a relationship also between delusions
and auditory hallucinations. CONCLUSION: The results support that auditory
hallucinations may be internally generated speech misrepresentations,
originating in the left temporal lobe.
PMID: 18302028 [PubMed - indexed for MEDLINE
"John Hasenkam" <jo...@goawayplease.com> wrote in message
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GreenXenon
> On Thu, 02 Jul 2009 08:13:40 -0700, GreenXenon wrote:
> > Do I guess correctly?
>
> Is the auditory cortex responsible for sound memory?
As far as I know, the primary auditory cortex is only responsible for
direct sound perception. Not memories, speech, associations, or
language. Just the direct perception of audio.
So I'm guessing the answer to my question in the 1st post of this
thread is *yes*, dreams would be silent and the patient would be
totally unable to experience any auditory hallucinations/perceptions
of any kind. I could be wrong though and that's why I'm asking about
it.
GreenXenon
> GreenXenon wrote:
I doubt it. From what I've read, the PAC is only involved in direct
perception of audio, not with anything else.
GreenXenon
> Recent studies have found activation of the auditory cortex during auditory
> halluncinations.
Are there any conditions in the primary auditory cortex that would
cause paroxysmal total deafness -- with "CRT tinnitus"* -- from the
left ear [even in dreams] without affecting audio perception in the
right ear?
*"CRT tinnitus" is a barely audible but still noticeable tinnitus
which resembles the near-ultrasonic high-frequency pure-sine-wave tone
emitted by most CRT monitors.
James Warren
I will say yes. The brain uses the auditory cortex for hearing, auditory
memory and auditory imagination just like it uses the visual cortex for
all thing visual. If you imagine a cube in space then the representation of
that and whatever you're looking at, are superimposed. I bet its the same
for audition. The brain uses the same tissue for several related functions.
John Stafford
> GreenXenon wrote:
>> On Jul 3, 3:53 am, ZerkonXXXX <Z...@erkonx.net> wrote:
>>
>>
>>> On Thu, 02 Jul 2009 08:13:40 -0700, GreenXenon wrote:
>>
>>
>>>> Do I guess correctly?
>>
>>
>>> Is the auditory cortex responsible for sound memory?
>>
>>
>> As far as I know, the primary auditory cortex is only responsible for
>> direct sound perception. Not memories, speech, associations, or
>> language. Just the direct perception of audio.
Part of the auditory cortex is heavily involved in speech processing.
There are parts of the primary auditory cortex that have a regular
physical pattern in order to efficiently process signals from the cochlea.
A higher level part of the auditory cortex appears to specialize in
language processing, such as differentiating syllables, spaces between
words, and astoundingly, placing them in proper temporal order so it can
be said that it relates to associations and language.
>> So I'm guessing the answer to my question in the 1st post of this
>> thread is *yes*, dreams would be silent and the patient would be
>> totally unable to experience any auditory hallucinations/perceptions
>> of any kind. I could be wrong though and that's why I'm asking about
>> it.
>
> I will say yes. The brain uses the auditory cortex for hearing, auditory
> memory and auditory imagination just like it uses the visual cortex for
> all thing visual. If you imagine a cube in space then the representation of
> that and whatever you're looking at, are superimposed. I bet its the same
> for audition. The brain uses the same tissue for several related functions.
>
Yes, in a way. The general auditory cortex is active when one plays
music in is head (so to speak), or recalls certain sounds.
GreenXenon
> GreenXenon wrote:
>
> >>> Do I guess correctly?
If only the primary auditory cortex is disconnected but the 2ndary and
tertiary auditory cortices are left intact, then auditory memory and
imagination will continue but the direct perception of audio
[including in dreams and hallucinations] would be lost. Right?
GreenXenon
> James Warren wrote:
> > GreenXenon wrote:
> >> On Jul 3, 3:53 am, ZerkonXXXX <Z...@erkonx.net> wrote:
>
> >>> On Thu, 02 Jul 2009 08:13:40 -0700, GreenXenon wrote:
>
> >>>> Do I guess correctly?
>
> >>> Is the auditory cortex responsible for sound memory?
>
> >> As far as I know, the primary auditory cortex is only responsible for
> >> direct sound perception. Not memories, speech, associations, or
> >> language. Just the direct perception of audio.
>
> Part of the auditory cortex is heavily involved in speech processing.
>
> There are parts of the primary auditory cortex that have a regular
> physical pattern in order to efficiently process signals from the cochlea.
>
> A higher level part of the auditory cortex appears to specialize in
> language processing, such as differentiating syllables, spaces between
> words, and astoundingly, placing them in proper temporal order so it can
> be said that it relates to associations and language.
What parts of the brain would have to be disconnected in order for
direct audio perception [including in dreams and hallucinations] to be
completely lost *without* impairing or affecting speech, language,
sound-memory, auditory imagination, and auditory associations? In this
condition, the environment [in physical reality as well as in dreams/
hallucinations] will seem completely silent but the patient can still
remember music, think about sounds, and if talented, even sing
fluently.