John John - Academia.edu (original) (raw)

Papers by John John

Indian journal of psychiatry, 2002

The aim of this study was to evaluate the correlation between psychopathological dimensions in re... more The aim of this study was to evaluate the correlation between psychopathological dimensions in recent-onset neuroleptic-naive schizophrenic patients and EEG alpha coherence in the resting state. 37 neuroleptic-naive recent-onset schizophrenic patients were assessed on the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms, and psychopathological dimension scores on reality distortion, psychomotor poverty and disorganization were calculated. EEG alpha coherence was computed across 14 intra-hemispheric and 8 interhemispheric electrode pairs in the resting eyes closed and eyes open conditions. The relationship between the psychopathological dimension scores and coherence values was assessed using Pearson's product moment correlation with Bonferroni correction for levels of significance. Significant associations between higher psychomotor poverty scores and lower inter-hemispheric coherence values were found across the central and par...

The Journal of neuropsychiatry and clinical neurosciences, 2009

Electroencephalogram spectral power was estimated at 30 scalp locations in 28 neuroleptic-naive, ... more Electroencephalogram spectral power was estimated at 30 scalp locations in 28 neuroleptic-naive, recent-onset schizophrenia (NRS) patients and 25 healthy comparison subjects in the resting eyes closed condition. Weighted relative power values in the various bandwidths were initially compared between NRS subjects and comparison subjects and subsequently between the positive symptom subgroup, negative symptom subgroup, and comparison subjects, to look for characteristic spectral power profiles of the homogeneous symptom subgroups. Significant differences were noted especially in alpha2, delta, and theta bands between NRS patients and healthy comparison subjects, while the positive symptom and negative symptom subgroups showed characteristic spectral power profiles in alpha1, alpha2, delta, and theta bands.

BMC psychiatry, Apr 18, 2018

There is emerging evidence that there are shared genetic, environmental and developmental risk fa... more There is emerging evidence that there are shared genetic, environmental and developmental risk factors in psychiatry, that cut across traditional diagnostic boundaries. With this background, the Discovery biology of neuropsychiatric syndromes (DBNS) proposes to recruit patients from five different syndromes (schizophrenia, bipolar disorder, obsessive compulsive disorder, Alzheimer's dementia and substance use disorders), identify those with multiple affected relatives, and invite these families to participate in this study. The families will be assessed: 1) To compare neuro-endophenotype measures between patients, first degree relatives (FDR) and healthy controls., 2) To identify cellular phenotypes which differentiate the groups., 3) To examine the longitudinal course of neuro-endophenotype measures., 4) To identify measures which correlate with outcome, and 5) To create a unified digital database and biorepository. The identification of the index participants will occur at wel...

Macromolecules, 2003

The structure of hydroxypropylcellulose (HPC) was modified by covalently attaching either vinyl g... more The structure of hydroxypropylcellulose (HPC) was modified by covalently attaching either vinyl groups linked by degradable esters or methacrylate groups. The vinyl groups allowed for chemical linking of the HPC chains into nanoparticles through a free radical polymerization process ...

Psychoneuroendocrinology, 2001

Patients with Obsessive–Compulsive Disorder (OCD) have been shown to demonstrate blunted cortisol... more Patients with Obsessive–Compulsive Disorder (OCD) have been shown to demonstrate blunted cortisol and prolactin responses along with an exacerbation of obsessive–compulsive symptoms in response to oral administration of the pharmacological probe, meta– ...

Journal of the American …, 1999

The preparation of discrete erbium-doped silicon nanoparticles prepared by the co-pyrolysis of di... more The preparation of discrete erbium-doped silicon nanoparticles prepared by the co-pyrolysis of disilane and the volatile complex Er(tmhd) 3 (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionato ) is described. The nanoparticles were characterized by transmission electron ...

Journal of the American …, 2001

Since the development of simple solution-phase methods for the synthesis and stabilization of gol... more Since the development of simple solution-phase methods for the synthesis and stabilization of gold nanoparticles, 1 research in this field has undergone a rapid expansion. Applications of gold nanoparticles now include biological markers, 2 DNA sensors, 3 molecular ...

Schizophrenia …, 2008

☆ Note: These summaries are written by each rapporteur to the best of their knowledge and interpr... more ☆ Note: These summaries are written by each rapporteur to the best of their knowledge and interpreted by them based on what they heard at the congress. In cases where individual researchers were quoted, rapporteurs were instructed to obtain permission for and to confirm accuracy of the statements. However, neither the investigators who presented data, nor the editors of the journal, are responsible for any inaccuracies of the reporting. For confirmation, please see original publications by each speaker. ☆☆ Each author contributed one or more sections and worked equally on this project.

Schizophrenia research, 2008

The study of corpus callosal morphometry is important to unravel the underlying connectivity dist... more The study of corpus callosal morphometry is important to unravel the underlying connectivity disturbance in schizophrenia. We studied the corpus callosal area in schizophrenia subjects compared to healthy subjects, while controlling for several confounders that could affect ...

Journal of Neurology, …, 2010

Manjunatha, Narayana; Vidyendaran, Rudhran; Rao, Mukund G; Kulkarni, Girish Baburao; Muralidharan... more Manjunatha, Narayana; Vidyendaran, Rudhran; Rao, Mukund G; Kulkarni, Girish Baburao; Muralidharan, Kesavan; John, John P; Amar, BR; Jain, Sanjeev.

During the determination of macromolecular structures, scientists routinely use complex graphics ... more During the determination of macromolecular structures, scientists routinely use complex graphics software to display various representations of the molecule of interest. Once the structure determination is complete, coordinates are deposited in the Protein Data Bank (PDB), from where anyone with an Internet connection may download and view them or request them on CD-ROM. However, the nature of currently available visualization software is such that casual users, whose expertise may not be in structure determination, often cannot obtain useful images of interesting molecules without the expenditure of considerable time and effort. Existing visualization software is generally very complex, requiring a high degree of familiarity to obtain the best results, or else it is too simplistic to provide users with the level of customizability needed to get the most out of the atomic coordinates. Few of the existing software packages have the capability for collaborative visualization via the Internet. These and other issues are being addressed by the Molecular Interactive Collaborative Environment (MICE) project (http://mice.sdsc.edu/). The core of the MICE project is the MICE application, an interactive molecular structure viewer with built-in collaborative capabilities. MICE not only addresses the issues of usability and flexibility but also extends the role of traditional visualization tools by allowing multiple users to view, manipulate and interact with a single representation of a macromolecular structure. MICE is written entirely in Java, using the Java3D extensions for rendering and manipulation of the three-dimensional scene, and the Common Object Request 3 Broker Architecture (CORBA) communications suite to enable collaborative manipulation of that scene.

Apolipoprotein E4 (ApoE ε4) polymorphism is a known genetic risk factor for Alzheimer&amp... more Apolipoprotein E4 (ApoE ε4) polymorphism is a known genetic risk factor for Alzheimer's disease (AD). To evaluate the role of ApoE ε4 on white matter structural integrity in AD. Subjects were 32 patients with probable AD (ApoE ε4-positive: n = 15) and 18 matched controls (ApoE ε4-positive: n = 6). All subjects were right-handed, evaluated using standard scales and genotyped at the ApoE locus. Diffusion tensor imaging was performed with a 3-tesla MRI scanner and analyzed using the tract-based spatial statistics method. AD patients had significantly lower fractional anisotropy (FA) in bilateral temporoparietal, limbic and parahippocampal regions in comparison to healthy comparison subjects. ApoE ε4 carriers among both AD and healthy comparison subjects showed lower FA in limbic and medial temporal regions. There is a modest association between ApoE ε4 carrier status and reduction in white matter tract integrity at medial temporal and limbic regions in both healthy and AD subjects.

Journal of Hydraulic …, 1999

ABSTRACT: Three-dimensional simulations of estuarine circulation in the New York Harbor complex, ... more ABSTRACT: Three-dimensional simulations of estuarine circulation in the New York Harbor complex, Long Island Sound, and the New York Bight have been conducted using the Estuarine, Coastal and Ocean Model (ECOM) within the framework of a single grid system ...

Malaysian Journal of Medical Sciences, Oct 1, 2008

A prospective cohort study was done to evaluate the role of surgery in patients with spontaneous ... more A prospective cohort study was done to evaluate the role of surgery in patients with spontaneous supratentorial intracerebral haemorrhage (SICH) and to identify predictors of outcome including the use of invasive regional cortical cerebral blood flow (rCoBF) and microdialysis. Surgery consisted of craniotomy or decompressive craniectomy. The ventriculostomy for intracranial pressure (ICP) monitoring and drainage and regional cortical cerebral blood flow (rCoBF) and microdialysis were performed in all subjects.

This paper presents Keypad, an auditing file system for theftprone devices, such as laptops and U... more This paper presents Keypad, an auditing file system for theftprone devices, such as laptops and USB sticks. Keypad provides two important properties. First, Keypad supports finegrained file auditing: a user can obtain explicit evidence that no files have been accessed after a device's loss. Second, a user can disable future file access after a device's loss, even in the absence of device network connectivity. Keypad achieves these properties by weaving together encryption and remote key storage. By encrypting files locally but storing encryption keys remotely, Keypad requires the involvement of an audit server with every protected file access. By alerting the audit server to refuse to return a particular file's key, the user can prevent new accesses after theft. We describe the Keypad architecture, a prototype implementation on Linux, and our evaluation of Keypad's performance and auditing fidelity. Our results show that Keypad overcomes the challenges posed by slow networks or disconnection, providing clients with usable forensics and control for their (increasingly) missing mobile devices.

In this paper we present Botlab, a platform that continually monitors and analyzes the behavior o... more In this paper we present Botlab, a platform that continually monitors and analyzes the behavior of spamoriented botnets. Botlab gathers multiple real-time streams of information about botnets taken from distinct perspectives. By combining and analyzing these streams, Botlab can produce accurate, timely, and comprehensive data about spam botnet behavior. Our prototype system integrates information about spam arriving at the University of Washington, outgoing spam generated by captive botnet nodes, and information gleaned from DNS about URLs found within these spam messages. We describe the design and implementation of Botlab, including the challenges we had to overcome, such as preventing captive nodes from causing harm or thwarting virtual machine detection. Next, we present the results of a detailed measurement study of the behavior of the most active spam botnets. We find that six botnets are responsible for 79% of spam messages arriving at the UW campus. Finally, we present defensive tools that take advantage of the Botlab platform to improve spam filtering and protect users from harmful web sites advertised within botnet-generated spam.

Journal of Controlled …, 2004

Monodisperse nanoparticles of poly-N-isopropylacrylamide-co-allylamine (PNIPAM-co-allylamine) and... more Monodisperse nanoparticles of poly-N-isopropylacrylamide-co-allylamine (PNIPAM-co-allylamine) and PNIPAM-co-acrylic acid (PNIPAM-co-AA) were synthesized. The close-packed PNIPAM-co-allylamine and PNIPAM-co-AA nanoparticles were converted ...

Social Indicators Research, 2011

This study aimed to explore subjective well-being (SWB) in an urban Indian sample. Adults (n = 10... more This study aimed to explore subjective well-being (SWB) in an urban Indian sample. Adults (n = 1099) belonging to two wards in the city of Bangalore in South India, responded to a study-specific questionnaire. This paper is based on data generated as part of an ongoing larger study looking at correlates of SWB. Almost equal number of men and women responded to the study and their age ranged from 20 to 81 years (mean age 37 years). Majority of them were married, Hindus, from middle socio-economic status, had studied above pre-university level and more than half were earning. The mean scores on positive affect (40.9), negative affect (27.6) and life satisfaction (24) suggested above average levels of SWB. Higher age, being married, having higher education, higher income and working in a full time job seemed to improve life satisfaction and decrease negative affect. Religion was also significantly associated with negative affect. Step-wise regression analysis suggested that only educat...

Schizophrenia research, 2009

Brodmann's area (BA) 10, which occupies the frontal pole (FP) of the human brain, has been p... more Brodmann's area (BA) 10, which occupies the frontal pole (FP) of the human brain, has been proven to play a central role in the executive control of cognitive operations. Previous in vivo morphometric studies of the FP have been limited by the lack of an accepted boundary of its posterior limit. We studied the FP gray matter volume in 23 healthy subjects who were age-, sex-, and education-matched to 23 neuroleptic-naïve recent-onset schizophrenia subjects in the age span 20-40 years, using a cytoarchitectonically and functionally valid landmark-based definition of its posterior boundary that we proposed recently (John, J.P., Yashavantha, B.S., Gado, M., Veena, R., Jain, S., Ravishankar, S., Csernansky, J.G., 2007. A proposal for MRI-based parcellation of the frontal pole. Brain Struct. Funct. 212, 245-253. 2007). Additionally, we examined the relationship between FP volume and age in both healthy and schizophrenia subjects to examine evidence for a possible differential relatio...

Indian journal of psychiatry, 2002

The aim of this study was to evaluate the correlation between psychopathological dimensions in re... more The aim of this study was to evaluate the correlation between psychopathological dimensions in recent-onset neuroleptic-naive schizophrenic patients and EEG alpha coherence in the resting state. 37 neuroleptic-naive recent-onset schizophrenic patients were assessed on the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms, and psychopathological dimension scores on reality distortion, psychomotor poverty and disorganization were calculated. EEG alpha coherence was computed across 14 intra-hemispheric and 8 interhemispheric electrode pairs in the resting eyes closed and eyes open conditions. The relationship between the psychopathological dimension scores and coherence values was assessed using Pearson's product moment correlation with Bonferroni correction for levels of significance. Significant associations between higher psychomotor poverty scores and lower inter-hemispheric coherence values were found across the central and par...

The Journal of neuropsychiatry and clinical neurosciences, 2009

Electroencephalogram spectral power was estimated at 30 scalp locations in 28 neuroleptic-naive, ... more Electroencephalogram spectral power was estimated at 30 scalp locations in 28 neuroleptic-naive, recent-onset schizophrenia (NRS) patients and 25 healthy comparison subjects in the resting eyes closed condition. Weighted relative power values in the various bandwidths were initially compared between NRS subjects and comparison subjects and subsequently between the positive symptom subgroup, negative symptom subgroup, and comparison subjects, to look for characteristic spectral power profiles of the homogeneous symptom subgroups. Significant differences were noted especially in alpha2, delta, and theta bands between NRS patients and healthy comparison subjects, while the positive symptom and negative symptom subgroups showed characteristic spectral power profiles in alpha1, alpha2, delta, and theta bands.

BMC psychiatry, Apr 18, 2018

There is emerging evidence that there are shared genetic, environmental and developmental risk fa... more There is emerging evidence that there are shared genetic, environmental and developmental risk factors in psychiatry, that cut across traditional diagnostic boundaries. With this background, the Discovery biology of neuropsychiatric syndromes (DBNS) proposes to recruit patients from five different syndromes (schizophrenia, bipolar disorder, obsessive compulsive disorder, Alzheimer's dementia and substance use disorders), identify those with multiple affected relatives, and invite these families to participate in this study. The families will be assessed: 1) To compare neuro-endophenotype measures between patients, first degree relatives (FDR) and healthy controls., 2) To identify cellular phenotypes which differentiate the groups., 3) To examine the longitudinal course of neuro-endophenotype measures., 4) To identify measures which correlate with outcome, and 5) To create a unified digital database and biorepository. The identification of the index participants will occur at wel...

Macromolecules, 2003

The structure of hydroxypropylcellulose (HPC) was modified by covalently attaching either vinyl g... more The structure of hydroxypropylcellulose (HPC) was modified by covalently attaching either vinyl groups linked by degradable esters or methacrylate groups. The vinyl groups allowed for chemical linking of the HPC chains into nanoparticles through a free radical polymerization process ...

Psychoneuroendocrinology, 2001

Patients with Obsessive–Compulsive Disorder (OCD) have been shown to demonstrate blunted cortisol... more Patients with Obsessive–Compulsive Disorder (OCD) have been shown to demonstrate blunted cortisol and prolactin responses along with an exacerbation of obsessive–compulsive symptoms in response to oral administration of the pharmacological probe, meta– ...

Journal of the American …, 1999

The preparation of discrete erbium-doped silicon nanoparticles prepared by the co-pyrolysis of di... more The preparation of discrete erbium-doped silicon nanoparticles prepared by the co-pyrolysis of disilane and the volatile complex Er(tmhd) 3 (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionato ) is described. The nanoparticles were characterized by transmission electron ...

Journal of the American …, 2001

Since the development of simple solution-phase methods for the synthesis and stabilization of gol... more Since the development of simple solution-phase methods for the synthesis and stabilization of gold nanoparticles, 1 research in this field has undergone a rapid expansion. Applications of gold nanoparticles now include biological markers, 2 DNA sensors, 3 molecular ...

Schizophrenia …, 2008

☆ Note: These summaries are written by each rapporteur to the best of their knowledge and interpr... more ☆ Note: These summaries are written by each rapporteur to the best of their knowledge and interpreted by them based on what they heard at the congress. In cases where individual researchers were quoted, rapporteurs were instructed to obtain permission for and to confirm accuracy of the statements. However, neither the investigators who presented data, nor the editors of the journal, are responsible for any inaccuracies of the reporting. For confirmation, please see original publications by each speaker. ☆☆ Each author contributed one or more sections and worked equally on this project.

Schizophrenia research, 2008

The study of corpus callosal morphometry is important to unravel the underlying connectivity dist... more The study of corpus callosal morphometry is important to unravel the underlying connectivity disturbance in schizophrenia. We studied the corpus callosal area in schizophrenia subjects compared to healthy subjects, while controlling for several confounders that could affect ...

Journal of Neurology, …, 2010

Manjunatha, Narayana; Vidyendaran, Rudhran; Rao, Mukund G; Kulkarni, Girish Baburao; Muralidharan... more Manjunatha, Narayana; Vidyendaran, Rudhran; Rao, Mukund G; Kulkarni, Girish Baburao; Muralidharan, Kesavan; John, John P; Amar, BR; Jain, Sanjeev.

During the determination of macromolecular structures, scientists routinely use complex graphics ... more During the determination of macromolecular structures, scientists routinely use complex graphics software to display various representations of the molecule of interest. Once the structure determination is complete, coordinates are deposited in the Protein Data Bank (PDB), from where anyone with an Internet connection may download and view them or request them on CD-ROM. However, the nature of currently available visualization software is such that casual users, whose expertise may not be in structure determination, often cannot obtain useful images of interesting molecules without the expenditure of considerable time and effort. Existing visualization software is generally very complex, requiring a high degree of familiarity to obtain the best results, or else it is too simplistic to provide users with the level of customizability needed to get the most out of the atomic coordinates. Few of the existing software packages have the capability for collaborative visualization via the Internet. These and other issues are being addressed by the Molecular Interactive Collaborative Environment (MICE) project (http://mice.sdsc.edu/). The core of the MICE project is the MICE application, an interactive molecular structure viewer with built-in collaborative capabilities. MICE not only addresses the issues of usability and flexibility but also extends the role of traditional visualization tools by allowing multiple users to view, manipulate and interact with a single representation of a macromolecular structure. MICE is written entirely in Java, using the Java3D extensions for rendering and manipulation of the three-dimensional scene, and the Common Object Request 3 Broker Architecture (CORBA) communications suite to enable collaborative manipulation of that scene.

Apolipoprotein E4 (ApoE ε4) polymorphism is a known genetic risk factor for Alzheimer&amp... more Apolipoprotein E4 (ApoE ε4) polymorphism is a known genetic risk factor for Alzheimer's disease (AD). To evaluate the role of ApoE ε4 on white matter structural integrity in AD. Subjects were 32 patients with probable AD (ApoE ε4-positive: n = 15) and 18 matched controls (ApoE ε4-positive: n = 6). All subjects were right-handed, evaluated using standard scales and genotyped at the ApoE locus. Diffusion tensor imaging was performed with a 3-tesla MRI scanner and analyzed using the tract-based spatial statistics method. AD patients had significantly lower fractional anisotropy (FA) in bilateral temporoparietal, limbic and parahippocampal regions in comparison to healthy comparison subjects. ApoE ε4 carriers among both AD and healthy comparison subjects showed lower FA in limbic and medial temporal regions. There is a modest association between ApoE ε4 carrier status and reduction in white matter tract integrity at medial temporal and limbic regions in both healthy and AD subjects.

Journal of Hydraulic …, 1999

ABSTRACT: Three-dimensional simulations of estuarine circulation in the New York Harbor complex, ... more ABSTRACT: Three-dimensional simulations of estuarine circulation in the New York Harbor complex, Long Island Sound, and the New York Bight have been conducted using the Estuarine, Coastal and Ocean Model (ECOM) within the framework of a single grid system ...

Malaysian Journal of Medical Sciences, Oct 1, 2008

A prospective cohort study was done to evaluate the role of surgery in patients with spontaneous ... more A prospective cohort study was done to evaluate the role of surgery in patients with spontaneous supratentorial intracerebral haemorrhage (SICH) and to identify predictors of outcome including the use of invasive regional cortical cerebral blood flow (rCoBF) and microdialysis. Surgery consisted of craniotomy or decompressive craniectomy. The ventriculostomy for intracranial pressure (ICP) monitoring and drainage and regional cortical cerebral blood flow (rCoBF) and microdialysis were performed in all subjects.

This paper presents Keypad, an auditing file system for theftprone devices, such as laptops and U... more This paper presents Keypad, an auditing file system for theftprone devices, such as laptops and USB sticks. Keypad provides two important properties. First, Keypad supports finegrained file auditing: a user can obtain explicit evidence that no files have been accessed after a device's loss. Second, a user can disable future file access after a device's loss, even in the absence of device network connectivity. Keypad achieves these properties by weaving together encryption and remote key storage. By encrypting files locally but storing encryption keys remotely, Keypad requires the involvement of an audit server with every protected file access. By alerting the audit server to refuse to return a particular file's key, the user can prevent new accesses after theft. We describe the Keypad architecture, a prototype implementation on Linux, and our evaluation of Keypad's performance and auditing fidelity. Our results show that Keypad overcomes the challenges posed by slow networks or disconnection, providing clients with usable forensics and control for their (increasingly) missing mobile devices.

In this paper we present Botlab, a platform that continually monitors and analyzes the behavior o... more In this paper we present Botlab, a platform that continually monitors and analyzes the behavior of spamoriented botnets. Botlab gathers multiple real-time streams of information about botnets taken from distinct perspectives. By combining and analyzing these streams, Botlab can produce accurate, timely, and comprehensive data about spam botnet behavior. Our prototype system integrates information about spam arriving at the University of Washington, outgoing spam generated by captive botnet nodes, and information gleaned from DNS about URLs found within these spam messages. We describe the design and implementation of Botlab, including the challenges we had to overcome, such as preventing captive nodes from causing harm or thwarting virtual machine detection. Next, we present the results of a detailed measurement study of the behavior of the most active spam botnets. We find that six botnets are responsible for 79% of spam messages arriving at the UW campus. Finally, we present defensive tools that take advantage of the Botlab platform to improve spam filtering and protect users from harmful web sites advertised within botnet-generated spam.

Journal of Controlled …, 2004

Monodisperse nanoparticles of poly-N-isopropylacrylamide-co-allylamine (PNIPAM-co-allylamine) and... more Monodisperse nanoparticles of poly-N-isopropylacrylamide-co-allylamine (PNIPAM-co-allylamine) and PNIPAM-co-acrylic acid (PNIPAM-co-AA) were synthesized. The close-packed PNIPAM-co-allylamine and PNIPAM-co-AA nanoparticles were converted ...

Social Indicators Research, 2011

This study aimed to explore subjective well-being (SWB) in an urban Indian sample. Adults (n = 10... more This study aimed to explore subjective well-being (SWB) in an urban Indian sample. Adults (n = 1099) belonging to two wards in the city of Bangalore in South India, responded to a study-specific questionnaire. This paper is based on data generated as part of an ongoing larger study looking at correlates of SWB. Almost equal number of men and women responded to the study and their age ranged from 20 to 81 years (mean age 37 years). Majority of them were married, Hindus, from middle socio-economic status, had studied above pre-university level and more than half were earning. The mean scores on positive affect (40.9), negative affect (27.6) and life satisfaction (24) suggested above average levels of SWB. Higher age, being married, having higher education, higher income and working in a full time job seemed to improve life satisfaction and decrease negative affect. Religion was also significantly associated with negative affect. Step-wise regression analysis suggested that only educat...

Schizophrenia research, 2009

Brodmann's area (BA) 10, which occupies the frontal pole (FP) of the human brain, has been p... more Brodmann's area (BA) 10, which occupies the frontal pole (FP) of the human brain, has been proven to play a central role in the executive control of cognitive operations. Previous in vivo morphometric studies of the FP have been limited by the lack of an accepted boundary of its posterior limit. We studied the FP gray matter volume in 23 healthy subjects who were age-, sex-, and education-matched to 23 neuroleptic-naïve recent-onset schizophrenia subjects in the age span 20-40 years, using a cytoarchitectonically and functionally valid landmark-based definition of its posterior boundary that we proposed recently (John, J.P., Yashavantha, B.S., Gado, M., Veena, R., Jain, S., Ravishankar, S., Csernansky, J.G., 2007. A proposal for MRI-based parcellation of the frontal pole. Brain Struct. Funct. 212, 245-253. 2007). Additionally, we examined the relationship between FP volume and age in both healthy and schizophrenia subjects to examine evidence for a possible differential relatio...