- Brain Scans? Science? Or, ... Science Fiction?

[Guest guest]

http://psychrights.org/Articles/GEMDBrainScanCuriousConsensus.pdf

A Curious Consensus: " Brain Scans Prove Disease " ?

By Grace E. , MD

July 10, 2005

Introduction

Recently, a series of physicians have appeared on national news programs,

reassuring the

public that psychiatric disorders have been confirmed as " real " diseases of

the brain.

Perhaps the context of these announcements -a heated exchange between two

Hollywood celebrities who have clashed over the medicalization and treatment

of

postpartum depression -has prevented the media from noticing serious

inaccuracies in

the recorded testimony of their selected discussants:

" When you don't have enough neurotransmitters firing, making the

connections,

your brain doesn't act like it should. And you can see what a normal

brain should

look like. That is an objective measure. " 1, Dr. Sanjay Gupta,

neurosurgeon / CNN Sr. medical correspondent

" .we can see differences between brain images of someone who is

depressed and someone who is not depressed. And if we give

medications,

the brain of the depressed person goes back to looking like a person

not

depressed. " 2, Dr. Nada Stotland, psychiatrist / Secretary, American

Psychiatric Association

As none of the featured authorities has clarified the essential distinction

between

anatomic and functional studies of the human brain, a corrective analysis is

necessary and

overdue.

The Difference Between Anatomic and Physiological Studies of the Brain

Anatomic studies depend upon technologies such as computed tomography (CT)

and

magnetic resonance imaging (MRI) to capture static images of the brain.

Because these

techniques have been well replicated and validated, they are routinely used

by physicians

to identify somatic abnormalities, such as tumors, abscesses, or vascular

malformations.

Despite attempts to the contrary, however, more than fifty years of research

have failed to

confirm radiographic evidence linking any psychiatric condition to a

structural defect

within the brain.3-5

Functional studies, on the other hand, depend upon technologies such as

functional MRI

(fMRI) and positron emission tomography (PET). These methodologies employ

strong

magnetic fields or radioactive isotopes, respectively, for the purpose of

evaluating brain

processes when a person is at rest or engaged in specific activity. Intra-

and interindividual

investigations of this kind seek to identify the underlying substrates of

the

nervous system which are presumed to be uniquely involved in certain mental

and

psychological phenomena (e.g., during the processes of remembering,

learning,

perceiving, emoting, intending).

Referring to the images on a functional brain scan in the course of a recent

news

broadcast, Dr. Sanjay Gupta repeatedly avowed that the new technologies

display a visual

record of brain activity:

" An ADHD brain is on the left side there. You can see, it's mainly

on the right

side of the brain that things are activating. They should be

activating all over and

on the left side as well. You see a non-ADHD brain, again, it's

differentthan the

ADHD brain. These are measurements that people take. This is the

science that

people have been talking about and this is what a lot of treatment

is predicated on

[sic]. " 6

However well intended, Dr. Gupta's remarks were nevertheless misleading.

First, there

was no mention of the fact that fMRI, PET, and other functional imaging

modalities

(such as magnetic resonance spectroscopy and single photon emission computed

tomography) are incapable of measuring brain activity. Rather, what these

technologies

actually reflect are transient changes in blood flow. Second, there was no

reference to

the numerous confounds which undermine the validity of most (if not all)

comparison

studies, as researchers commonly fail to control for the influence of age,

gender, body

size (weight and height), drugs (licit or illicit), medical conditions,

physical activity,

education, and diet. Third, there was no acknowledgement of the fact that

the use of

these technologies remains controversial. Due to theoretical and practical

limitations,

their application is restricted to research settings at this time. Why this

is true is the

untold story which the news media and its chosen experts have ignored.

The Limitations of Functional Imaging Technologies 7-11

the theory of neurovascular coupling

The clinical utility of functional neuroimaging depends upon the premise

that changes in

regional blood flow correspond directly to neural activity. This theory of

neurovascular

coupling suggests that cellular activity (primarily within neurons) creates

changes in the

consumption of oxygen and sugar. These cellular processes are believed to

recruit a

regenerative surge in blood flow. Interestingly, refutations of this theory

have been

provided by animal research documenting shifts in regional blood flow in the

absence of

oxidative metabolism or glycolysis. Similarly, the presence of cerebral

hypoxia and/or

hypoglycemia in survivors of stroke or traumatic brain injury has not been

reliably

associated with surges in blood flow. As perplexing as these contradictions

may seem,

one can easily imagine the existence of an alternative scenario, in which

the homeostatic

mechanisms of the brain might shift blood into areas of underactivity in an

effort to

revive cells which are sluggish or dormant. Until neurophysiologists

understand the

cause and timing of changes in cerebral blood flow, the implications of

functional

imaging technologies will remain ambiguous.

the time lag associated with blood flow

Electrical brain events happen in a span of hundreds of milliseconds. In

contrast, the

movement of fresh blood into an active tissue is delayed by 1 to 3 seconds.

This time lag

limits the temporal resolution of functional imaging technologies, because

the

scanner and the brain are never in temporal synchrony (in the language of

still

photography: the brain activity is like a flash of lightning for which the

scanner lacks

an appropriate shutter speed). This results in the unfortunate reality that

functional

imaging technologies may be able to provide information about certain

locations

associated with mental phenomena, but not about the onset or duration of the

inciting

events.

the localization of neuronal activity

Since vascular and electrical processes cannot be co-determined inside the

brains of

humans, researchers have experimented upon a variety of non-human species.

A significant body of work has revealed the fact that sections of the

neocortex can

experience changes in blood flow and metabolism without firing an action

potential of

their own (no spiking). These findings have tremendous scientific import,

for they

suggest that the intensities which appear on functional brain scans might

not reflect the

electrical activity of the underlying regions. Rather, the bright spots

might reflect the

activity of remote (invisible) cell populations whose action potentials have

propagated a

certain distance but not moved on (inhibitory post-synaptic potentials >

excitatory

post-synaptic potentials).

the statistical averaging of images

Because the contrast resolution of the functional neuroimaging technologies

is so poor

(the " activated vs. baseline " differences which they capture are

extraordinarily small -

on the order of a mere 2-5%), multiple scans must be obtained for the

purpose of

achieving statistical significance (i.e., to rule out the possibility that

the observed changes

have occurred simply by chance). Consequently, when reports about " between

group "

differences are based upon functional technologies, it means that the brain

scans of

several individuals have been integrated by computer software in order to

produce a

composite or average result.

When physicians like Dr. Gupta display the picture of an ADHD brain, they

are not

referring to any specific child or adult. Rather, they refer to an image

which reflects a

subset of the population whose brain features have been averaged together.

The final

graphic may or may not resemble any real person. High rates of intra- and

interindividual

variability reduce the sensitivity and specificity of these procedures, so

that

they cannot be used dependably in the clinical setting.

the subtraction method of analysis (paired image subtraction)

The subtraction method of analysis infers neural activity by subtracting

baseline from

activated scans, or by subtracting the images of controls from

" abnormals. " For example,

if an experimental task activates zones 1, 2, and 3 in a healthy subject,

and zones 1, 2, 3,

and 4 in the brain of a patient, zone 4 would be interpreted as the

substrate responsible for

aberrant behavior. The problem with this approach lies in the assumption

that the

difference between two tasks (active vs. resting) or two conditions (healthy

vs. ill) can be

divided into separable and mutually exclusive cortical or subcortical

components, and

that changes in regional blood flow will correspond neatly to these

specialized units of

the brain.

the premature assumptions of safety

Functional neuroimaging technologies pose dangers which remain largely

unexplored.

The magnetic fields used in MRI have been found to disrupt the blood brain

barrier in

several animal studies. If similar perturbations occur in humans, it is

possible that even

transient changes arising from the exposure to these increasingly powerful

devices (up to

7 Tesla) might permit toxins and other plasma components to enter the brain

parenchyma,

where they could initiate inflammatory or autoimmune responses. Furthermore,

the long

term health effects of ionizing radiation (i.e., the gamma rays produced by

the

annihilation photons of PET) are equally unclear. It is important to

appreciate the fact

that the potential mutagenicity of radioisotopes is greater when a given

dose is

administered over minutes to hours (as occurs in psychiatric research

protocols) as

compared to gradual exposures over months to years. No dose of ionizing

radiation is

hazard free,12-13 and the potential risks (of cancers, birth defects, heart

disease) are

cumulative, not fleeting.

Conclusion

It is notable that the official website of the American Psychiatric

Association features a

position paper (January 2005) regarding the use of functional imaging

technologies in

children and teens:

" Imaging research cannot yet be used to diagnose psychiatric illness

and may not be useful in clinical practice for a number of years.

Specifically, no published investigation in the field has determined

that any

structural or functional abnormality is specific to a single

psychiatric disorder.

Additionally, imaging studies examine groups of patients and groups

of healthy

controls; therefore, findings may not apply to all individuals with

a given

disorder. Even when significant differences are identified between

groups, there

is a substantial overlap among individuals in both groups.

" We conclude that, at the present time, the available evidence does

not support

the use of brain imaging for clinical diagnosis or treatment of

psychiatric

disorders. " 14

Contrary to the reports which have been emphasized by the major news

outlets, there is

no evidence to justify the claim that psychiatric disorders arise from

anatomic or

physiological abnormalities in the brain. Based upon a variety of

theoretical and practical

limitations, the functional imaging technologies cannot identify the origin

of mental

phenomena. Philosophical observers might suggest a host of reasons

(epistemological

and ontological) why they never will.

The media have the power to shape popular and professional perceptions by

disseminating the facts of science, or by perpetuating science fictions.

Responsible

journalism accepts the challenge of embracing the former, while avoiding the

latter.

===============================================================

Notes

1 " Scientologist Explains Tom Cruise's Recent Anti-Psychiatry comments, "

360 Degrees. CNN, New York. 30 JUN 2005. Transcript.

2 Ibid.

3 Darin D. Dougherty, L. Rauch, and Jerrold F. Rosenbaum, Ed.,

Essentials of

Neuroimaging for Clinical Practice, (Washington, DC: American Psychiatric

Publishing,

Inc., 2004), pp. 13-14, 49-51.

4 U.S. Department of Health and Human Services, Mental Health: A Report of

the

Surgeon General, (Rockville, MD: U.S. Department of Health and Human

Services,

1999), p. 15.

5 E. Hales, Stuart C. Yudofsky, and A. Talbott, Ed., The

American

Psychiatric Press Textbook of Psychiatry, 3rd Edition, (Washington, DC:

American

Psychiatric Press, Inc., 1999), pp. 300-304.

6 " Scientologist Explains Tom Cruise's Recent Anti-Psychiatry comments, "

360 Degrees. CNN, New York. 30 JUN 2005. Transcript.

7 Cheryl J. Aine, " A Conceptual Overview and Critique of Functional

Neuroimaging

Techniques in Humans: I. MRI/fMRI and PET, " Critical Reviews in Neurobiology

9 (1995), pp. 229-209.

8 J. Heeger and Ress, " What Does fMRI Telll Us About Neuronal

Activity? " Nature Reviews 3 (2002): 142-151.

9 A. Poldrack, " Imaging Brain Plasticity: Conceptual and

Methodological Issues

- A Theoretical Review, " NeuroImage 12 (2000): 1-13.

10 Dara S. Manoach, Elkan F. Halpern, Todd S. Kramer, Yuchiao Chang,

C.

Goff, et. al., " Test-Retest Reliability of a Functional MRIWorking Memory

Paradigm in

Normal and Schizophrenic Subjects, " American Journal of Psychiatry 158

(2001):

955-958.

11 G.D. Honey, P.C. Fletcher, and E.T. Bullmore, " Functional brain mapping

of

psychopathology, " Journal of Neurology, Neurosurgery, and Psychiatry 72

(2002):

432-439.

12 W. Gofman, Preventing Breast Cancer: The Story of a Major, Proven,

Preventable Cause of This Disease, 2nd Ed., (San Francisco: C.N.R. Book

Division,

1996).

13 W. Gofman, Radiation from Medical Procedures in the Pathogenesis of

Cancer

and Ischemic Heart Disease: Dose-Response Studies with Physicians per

100,000

Population, (San Francisco: C.N.R. Book Division, 1999).

14 Loris Talbott Flaherty, Arroyo, Irene Chatoor, Roxanne Dryden

,

B. Ferguson, et. al., " Brain Imaging and Child and Adolescent

Psychiatry With

Special Emphasis on SPECT, " (January 2005), retrieved on 09 JUL 05 at:

www.psych.org/psych_pract/clin_issues/ populations/children/SPECT.pdf.

[Guest guest]

http://psychrights.org/Articles/GEMDBrainScanCuriousConsensus.pdf

A Curious Consensus: " Brain Scans Prove Disease " ?

By Grace E. , MD

July 10, 2005

Introduction

Recently, a series of physicians have appeared on national news programs,

reassuring the

public that psychiatric disorders have been confirmed as " real " diseases of

the brain.

Perhaps the context of these announcements -a heated exchange between two

Hollywood celebrities who have clashed over the medicalization and treatment

of

postpartum depression -has prevented the media from noticing serious

inaccuracies in

the recorded testimony of their selected discussants:

" When you don't have enough neurotransmitters firing, making the

connections,

your brain doesn't act like it should. And you can see what a normal

brain should

look like. That is an objective measure. " 1, Dr. Sanjay Gupta,

neurosurgeon / CNN Sr. medical correspondent

" .we can see differences between brain images of someone who is

depressed and someone who is not depressed. And if we give

medications,

the brain of the depressed person goes back to looking like a person

not

depressed. " 2, Dr. Nada Stotland, psychiatrist / Secretary, American

Psychiatric Association

As none of the featured authorities has clarified the essential distinction

between

anatomic and functional studies of the human brain, a corrective analysis is

necessary and

overdue.

The Difference Between Anatomic and Physiological Studies of the Brain

Anatomic studies depend upon technologies such as computed tomography (CT)

and

magnetic resonance imaging (MRI) to capture static images of the brain.

Because these

techniques have been well replicated and validated, they are routinely used

by physicians

to identify somatic abnormalities, such as tumors, abscesses, or vascular

malformations.

Despite attempts to the contrary, however, more than fifty years of research

have failed to

confirm radiographic evidence linking any psychiatric condition to a

structural defect

within the brain.3-5

Functional studies, on the other hand, depend upon technologies such as

functional MRI

(fMRI) and positron emission tomography (PET). These methodologies employ

strong

magnetic fields or radioactive isotopes, respectively, for the purpose of

evaluating brain

processes when a person is at rest or engaged in specific activity. Intra-

and interindividual

investigations of this kind seek to identify the underlying substrates of

the

nervous system which are presumed to be uniquely involved in certain mental

and

psychological phenomena (e.g., during the processes of remembering,

learning,

perceiving, emoting, intending).

Referring to the images on a functional brain scan in the course of a recent

news

broadcast, Dr. Sanjay Gupta repeatedly avowed that the new technologies

display a visual

record of brain activity:

" An ADHD brain is on the left side there. You can see, it's mainly

on the right

side of the brain that things are activating. They should be

activating all over and

on the left side as well. You see a non-ADHD brain, again, it's

differentthan the

ADHD brain. These are measurements that people take. This is the

science that

people have been talking about and this is what a lot of treatment

is predicated on

[sic]. " 6

However well intended, Dr. Gupta's remarks were nevertheless misleading.

First, there

was no mention of the fact that fMRI, PET, and other functional imaging

modalities

(such as magnetic resonance spectroscopy and single photon emission computed

tomography) are incapable of measuring brain activity. Rather, what these

technologies

actually reflect are transient changes in blood flow. Second, there was no

reference to

the numerous confounds which undermine the validity of most (if not all)

comparison

studies, as researchers commonly fail to control for the influence of age,

gender, body

size (weight and height), drugs (licit or illicit), medical conditions,

physical activity,

education, and diet. Third, there was no acknowledgement of the fact that

the use of

these technologies remains controversial. Due to theoretical and practical

limitations,

their application is restricted to research settings at this time. Why this

is true is the

untold story which the news media and its chosen experts have ignored.

The Limitations of Functional Imaging Technologies 7-11

the theory of neurovascular coupling

The clinical utility of functional neuroimaging depends upon the premise

that changes in

regional blood flow correspond directly to neural activity. This theory of

neurovascular

coupling suggests that cellular activity (primarily within neurons) creates

changes in the

consumption of oxygen and sugar. These cellular processes are believed to

recruit a

regenerative surge in blood flow. Interestingly, refutations of this theory

have been

provided by animal research documenting shifts in regional blood flow in the

absence of

oxidative metabolism or glycolysis. Similarly, the presence of cerebral

hypoxia and/or

hypoglycemia in survivors of stroke or traumatic brain injury has not been

reliably

associated with surges in blood flow. As perplexing as these contradictions

may seem,

one can easily imagine the existence of an alternative scenario, in which

the homeostatic

mechanisms of the brain might shift blood into areas of underactivity in an

effort to

revive cells which are sluggish or dormant. Until neurophysiologists

understand the

cause and timing of changes in cerebral blood flow, the implications of

functional

imaging technologies will remain ambiguous.

the time lag associated with blood flow

Electrical brain events happen in a span of hundreds of milliseconds. In

contrast, the

movement of fresh blood into an active tissue is delayed by 1 to 3 seconds.

This time lag

limits the temporal resolution of functional imaging technologies, because

the

scanner and the brain are never in temporal synchrony (in the language of

still

photography: the brain activity is like a flash of lightning for which the

scanner lacks

an appropriate shutter speed). This results in the unfortunate reality that

functional

imaging technologies may be able to provide information about certain

locations

associated with mental phenomena, but not about the onset or duration of the

inciting

events.

the localization of neuronal activity

Since vascular and electrical processes cannot be co-determined inside the

brains of

humans, researchers have experimented upon a variety of non-human species.

A significant body of work has revealed the fact that sections of the

neocortex can

experience changes in blood flow and metabolism without firing an action

potential of

their own (no spiking). These findings have tremendous scientific import,

for they

suggest that the intensities which appear on functional brain scans might

not reflect the

electrical activity of the underlying regions. Rather, the bright spots

might reflect the

activity of remote (invisible) cell populations whose action potentials have

propagated a

certain distance but not moved on (inhibitory post-synaptic potentials >

excitatory

post-synaptic potentials).

the statistical averaging of images

Because the contrast resolution of the functional neuroimaging technologies

is so poor

(the " activated vs. baseline " differences which they capture are

extraordinarily small -

on the order of a mere 2-5%), multiple scans must be obtained for the

purpose of

achieving statistical significance (i.e., to rule out the possibility that

the observed changes

have occurred simply by chance). Consequently, when reports about " between

group "

differences are based upon functional technologies, it means that the brain

scans of

several individuals have been integrated by computer software in order to

produce a

composite or average result.

When physicians like Dr. Gupta display the picture of an ADHD brain, they

are not

referring to any specific child or adult. Rather, they refer to an image

which reflects a

subset of the population whose brain features have been averaged together.

The final

graphic may or may not resemble any real person. High rates of intra- and

interindividual

variability reduce the sensitivity and specificity of these procedures, so

that

they cannot be used dependably in the clinical setting.

the subtraction method of analysis (paired image subtraction)

The subtraction method of analysis infers neural activity by subtracting

baseline from

activated scans, or by subtracting the images of controls from

" abnormals. " For example,

if an experimental task activates zones 1, 2, and 3 in a healthy subject,

and zones 1, 2, 3,

and 4 in the brain of a patient, zone 4 would be interpreted as the

substrate responsible for

aberrant behavior. The problem with this approach lies in the assumption

that the

difference between two tasks (active vs. resting) or two conditions (healthy

vs. ill) can be

divided into separable and mutually exclusive cortical or subcortical

components, and

that changes in regional blood flow will correspond neatly to these

specialized units of

the brain.

the premature assumptions of safety

Functional neuroimaging technologies pose dangers which remain largely

unexplored.

The magnetic fields used in MRI have been found to disrupt the blood brain

barrier in

several animal studies. If similar perturbations occur in humans, it is

possible that even

transient changes arising from the exposure to these increasingly powerful

devices (up to

7 Tesla) might permit toxins and other plasma components to enter the brain

parenchyma,

where they could initiate inflammatory or autoimmune responses. Furthermore,

the long

term health effects of ionizing radiation (i.e., the gamma rays produced by

the

annihilation photons of PET) are equally unclear. It is important to

appreciate the fact

that the potential mutagenicity of radioisotopes is greater when a given

dose is

administered over minutes to hours (as occurs in psychiatric research

protocols) as

compared to gradual exposures over months to years. No dose of ionizing

radiation is

hazard free,12-13 and the potential risks (of cancers, birth defects, heart

disease) are

cumulative, not fleeting.

Conclusion

It is notable that the official website of the American Psychiatric

Association features a

position paper (January 2005) regarding the use of functional imaging

technologies in

children and teens:

" Imaging research cannot yet be used to diagnose psychiatric illness

and may not be useful in clinical practice for a number of years.

Specifically, no published investigation in the field has determined

that any

structural or functional abnormality is specific to a single

psychiatric disorder.

Additionally, imaging studies examine groups of patients and groups

of healthy

controls; therefore, findings may not apply to all individuals with

a given

disorder. Even when significant differences are identified between

groups, there

is a substantial overlap among individuals in both groups.

" We conclude that, at the present time, the available evidence does

not support

the use of brain imaging for clinical diagnosis or treatment of

psychiatric

disorders. " 14

Contrary to the reports which have been emphasized by the major news

outlets, there is

no evidence to justify the claim that psychiatric disorders arise from

anatomic or

physiological abnormalities in the brain. Based upon a variety of

theoretical and practical

limitations, the functional imaging technologies cannot identify the origin

of mental

phenomena. Philosophical observers might suggest a host of reasons

(epistemological

and ontological) why they never will.

The media have the power to shape popular and professional perceptions by

disseminating the facts of science, or by perpetuating science fictions.

Responsible

journalism accepts the challenge of embracing the former, while avoiding the

latter.

===============================================================

Notes

1 " Scientologist Explains Tom Cruise's Recent Anti-Psychiatry comments, "

360 Degrees. CNN, New York. 30 JUN 2005. Transcript.

2 Ibid.

3 Darin D. Dougherty, L. Rauch, and Jerrold F. Rosenbaum, Ed.,

Essentials of

Neuroimaging for Clinical Practice, (Washington, DC: American Psychiatric

Publishing,

Inc., 2004), pp. 13-14, 49-51.

4 U.S. Department of Health and Human Services, Mental Health: A Report of

the

Surgeon General, (Rockville, MD: U.S. Department of Health and Human

Services,

1999), p. 15.

5 E. Hales, Stuart C. Yudofsky, and A. Talbott, Ed., The

American

Psychiatric Press Textbook of Psychiatry, 3rd Edition, (Washington, DC:

American

Psychiatric Press, Inc., 1999), pp. 300-304.

6 " Scientologist Explains Tom Cruise's Recent Anti-Psychiatry comments, "

360 Degrees. CNN, New York. 30 JUN 2005. Transcript.

7 Cheryl J. Aine, " A Conceptual Overview and Critique of Functional

Neuroimaging

Techniques in Humans: I. MRI/fMRI and PET, " Critical Reviews in Neurobiology

9 (1995), pp. 229-209.

8 J. Heeger and Ress, " What Does fMRI Telll Us About Neuronal

Activity? " Nature Reviews 3 (2002): 142-151.

9 A. Poldrack, " Imaging Brain Plasticity: Conceptual and

Methodological Issues

- A Theoretical Review, " NeuroImage 12 (2000): 1-13.

10 Dara S. Manoach, Elkan F. Halpern, Todd S. Kramer, Yuchiao Chang,

C.

Goff, et. al., " Test-Retest Reliability of a Functional MRIWorking Memory

Paradigm in

Normal and Schizophrenic Subjects, " American Journal of Psychiatry 158

(2001):

955-958.

11 G.D. Honey, P.C. Fletcher, and E.T. Bullmore, " Functional brain mapping

of

psychopathology, " Journal of Neurology, Neurosurgery, and Psychiatry 72

(2002):

432-439.

12 W. Gofman, Preventing Breast Cancer: The Story of a Major, Proven,

Preventable Cause of This Disease, 2nd Ed., (San Francisco: C.N.R. Book

Division,

1996).

13 W. Gofman, Radiation from Medical Procedures in the Pathogenesis of

Cancer

and Ischemic Heart Disease: Dose-Response Studies with Physicians per

100,000

Population, (San Francisco: C.N.R. Book Division, 1999).

14 Loris Talbott Flaherty, Arroyo, Irene Chatoor, Roxanne Dryden

,

B. Ferguson, et. al., " Brain Imaging and Child and Adolescent

Psychiatry With

Special Emphasis on SPECT, " (January 2005), retrieved on 09 JUL 05 at:

www.psych.org/psych_pract/clin_issues/ populations/children/SPECT.pdf.