what about the voices ?

Failing to find a normal increase in white matter integrity over time in the at-risk subjects healthy subjects showed a normal and expected increase in measures indexing white matter integrity in the temporal lobe as they age," said Karlsgodt, "but young people at high-risk for psychosis showed no such increase — that is, they fail to show the normal developmental pattern." ...The other important finding, she said, was that by looking at white matter integrity in the temporal lobe at people's first appointment, "we could predict how well they would be functioning 15 months later at work, school and home.

Functional imaging data have either shown increased or decreased activation depending on whether patients have been presented an external stimulus during scanning. Structural imaging data have shown reduction of grey matter density and volume in the same areas in the temporal lobe. We have proposed a model for the understanding of auditory hallucinations that trace the origin of auditory hallucinations to neuronal abnormality in the speech areas in the left temporal lobe, which is not suppressed by volitional cognitive control processes, due to dysfunctional fronto-parietal executive cortical networks.

the notable neurophysiological finding was a general slowing of delta-theta activity within the temporal lobe an increase in beta activity was found within the same zone during auditory hallucinations which raises the question of whether this might be an intermittent compensation mechanism of the brain also in the senseof a self-healing function.

shergill
They found that each auditory verbal hallucination lasted an average of 16 seconds with a range of 3–42 secs. They found specific areas of the brain were activated 6–9 secs before the person signalled the onset of the hallucination. These were areas that are involved in generation of inner speech (left inferior frontal, right middle temporal gyri). Different areas of the brain, which are involved in perception of auditory material or hearing, were active once the person became aware of the hallucination (bilateral temporal gyri, left insula).

the difference between word generation and auditory hallucinations

activation in the right homologue of Broca's area, bilateral insula, bilateral supramarginal gyri and right superior temporal gyrus. Broca's area and left superior temporal gyrus were not activated. Group analysis for word generation in these patients yielded activation in Broca's and Wernicke's areas and to a lesser degree their right-sided homologues, bilateral insula and anterior cingulate gyri. Lateralization of activity during AVH was not correlated with language lateralization, but rather with the degree to which the content of the hallucinations had a negative emotional valence. The main difference between cerebral activity during AVH and activity during normal inner speech appears to be the lateralization. The predominant engagement of the right inferior frontal area during AVH may be related to the typical low semantic complexity and negative emotional content.

G. H. Brans, MS, N E. M. van Haren, PhD, G. M. van Baal, PhD, W G. Staal, PhD, MD, HG. Schnack, PhD, R S. Kahn, PhD, MD and H E. Hulshoff Pol, PhD University Medical Center Utrecht, The Netherlands

The progressive decreases over time in whole brain and cerebral grey matter volume [ the cells ]
and less prominent increases in white matter [ the joining connecting lines ] observed in schizophrenia patients
but not in siblings may represent a (disease-related) non-genetic risk factor for the disease.

Our finding of progressive decrease over time is consistent with those of other longitudinal studies in schizophrenia.

The findings in siblings are consistent with the normalisation of cortical thickness
by the age of 20 in siblings of patients with childhood-onset schizophrenia.

Could it be disuse ? How otherwise to find late 'recoveries - unless another pathway is found to get round the grey matter loss ?

mica@jidgey.e7even.com

Time course of regional brain activation associated with onset of auditory/verbal hallucinations.

Hoffman, Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut : Anderson, M Varanko, JC. Gore,

Two sites exhibiting positive BOLD [ blood oxygen up levels becasue of activity in local cells ] signal correlations with hallucination time course exclusively at negative time lags [ occuring so many seconds before hallucinating ] largely replicated pre-hallucination activation sites described previously.

Positive Blood Oxygen signal correlations with hallucination time course were detected selectively at negative time intervals ( time lags ranging from –4.5 s to –1.5 s) in the left insula and a right middle temporal region, as well as in left pre-central areas .

Positive correlations also emerged in the superior temporal gyrus bilaterally at negative time lags, peaking approximately at zero time lag [ i.e. the same time as hallucinating ]
Negative blood oxygen signal correlations with hallucination time course were detected in the right ventral anterior cingulate , and left parahippocampal gyri at negative time lags.

Right middle temporal site

The right middle temporal site (Brodmann area 21) was located remarkably close to middle temporal gyrus sites of pre-hallucination activation reported by Lennox et al and Shergill et al.

Activation in the bilateral superior temporal gyrus (Brodmann area 22) emerged at negative time lags also, but peaked later and was broadly distributed over both positive and negative time lags.

Our correlation-based method for mapping BOLD signal time course will produce temporal smearing that broadens with increasing neural activation.
The temporal pattern of our data suggests therefore that the more robust bilateral activation in the superior temporal gyrus arose somewhat later – perhaps at hallucination onset – than the middle temporal gyrus activation.

Bilateral activation of the latter region has been associated with aspects of verbal comprehension during speech processing distinct from acoustic feature detection referable to the superior temporal gyrus, whereas non-dominant middle temporal gyral activation has been associated with detecting prosodic features of spoken speech.

One plausible account of our findings is that pre-hallucination activation in the middle temporal gyrus reflecting verbal content and/or prosody [ the study of poetic meters, metrics and versification - the stress and intonation patterns of an utterance ] is subsequently propagated to the superior temporal gyrus via top-down processing, which generates (hallucinated) acoustic representations.

Left anterior insula

The left anterior insula was close to a site of activation in the left inferior frontal gyrus 9 , prior to hallucination onset, identified by Shergill et al, who reported expanded activation incorporating the left insula at later times.
Left insula activation has been associated with speech articulation, imagining spoken speech of others, and focused auditory attention,
suggesting that pre-hallucination insula activation reflects inner speech
or auditory imagery generation as previously hypothesised, or enhanced auditory attention.

However, pre-hallucination insula activation might instead reflect motor movement required to signal these events.
This possibility is suggested by the fact that simple doing finger movements
is preceded by activation in the adjacent Broca's area, which has been postulated to reflect mental preparation.

Other sites

Evidence of right ventral anterior cingulate and left parahippocampal deactivation preceding hallucination onset was detected.
Co-occurring deactivations in these regions have also been linked to heightened vigilance/attention, suggesting a shift in cognitive state preceding auditory/verbal hallucinations.
Along these lines, Arieti described a `listening attitude' that predisposes people with schizophrenia to hear `voices'.

Pre-central activation emerging prior to hallucination onset in our study could reflect either inner speech generation or signalling hallucinations by finger movement.

In summary, activation detected as BOLD signal changes correlated with auditory/verbal hallucination time course at negative time lags may reveal complex brain processes triggering these experiences.

Future studies of this type would be advanced by controlling for effects of motor behaviour required to signal hallucination occurrences.

To me this means that activity goes on in the area of the brain dealing with 'hearing' hallucinatory voices before there is activity in the areas of the brain that do speech or silent speech ?

People with autism are supposed not to do 'day dreaming'. What about people with schizophrenia - anybody know ??? How will day dreaming fit in with the above.

People in schizophrenia are often in a state of doing nothing - the default state of daydreaming.
Then, when actually 'paying attention' e.g at a professional interview
when it is important to be paying attention, because of the possible consequences ...
...that seems to be when the 'voices' are not there or are disregarded.
Similarly when taken up with concentrating on doing something connected with 'outside the person ' activities.

What about the 'fantasy dreaming that goes on ? when 'dozing' on the way to sleep,
or being half to waking up ?? Help ??

mica@jidgey.e7even.com

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