Biomedical subjects

Jin Fan

Publications and source records attributed to Jin Fan.

At least 19 recordsLinked to original sources

PubMed2007

Does the emotional go/no-go task really measure behavioral inhibition? Convergence with measures on a non-emotional analog.

This study tested the convergence of behavioral inhibition measures across emotional and non-emotional versions of the same go/no-go task in 85 college students. The two tasks differed only in the stimuli used for trial cues (i.e., circles versus facial expressions). Moderate correlations (r=.51-.56) between commission errors across the emotional and non-emotional tasks support the construct validity of behavioral inhibition. Further, parametric manipulation of preceding context had comparable effects on performance on the two tasks. Responses were slower and more variable, commission errors were more numerous, and perceptual sensitivity was lower on the emotional than the non-emotional task. A bias for happy faces on the emotional task resulted in faster responses and more commission errors for happy than sad faces despite marginally greater sensitivity for the latter. These results suggest that the basic neuropsychological constructs of the original go/no-go task were preserved in the emotional adaptation.

Adolescent↗

PubMed2006

Neural basis of cultural influence on self-representation.

Culture affects the psychological structure of self and results in two distinct types of self-representation (Western independent self and East Asian interdependent self). However, the neural basis of culture-self interaction remains unknown. We used fMRI to measured brain activity from Western and Chinese subjects who judged personal trait adjectives regarding self, mother or a public person. We found that the medial prefrontal cortex (MPFC) and anterior cingulate cortex (ACC) showed stronger activation in self- than other-judgment conditions for both Chinese and Western subjects. However, relative to other-judgments, mother-judgments activated MPFC in Chinese but not in Western subjects. Our findings suggest that Chinese individuals use MPFC to represent both the self and the mother whereas Westerners use MPFC to represent exclusively the self, providing neuroimaging evidence that culture shapes the functional anatomy of self-representation.

Adult↗

PubMed2006

Neuroimaging and genetic associations of attentional and hypnotic processes.

In the aftermath of the human genome project, genotyping is fast becoming an affordable and technologically viable complement to phenotyping. Whereas attempts to characterize hypnotic responsiveness have been largely phenomenological, data emanating from exploratory genetic data may offer supplementary insights into the genetic bases of hypnotizability. We outline our genetic and neuroimaging findings and discuss potential implications to top-down control systems. These results may explain individual differences in hypnotizability and propose new ideas for studying the influence of suggestion on neural systems.

Attention↗

PubMed2006

In search of the Chinese self: an fMRI study.

Cultural influences on the concept of self is a very important topic for social cognitive neuroscientific exploration, as yet, little if anything is known about this topic at the neural level. The present study investigates this problem by looking at the Chinese culture's influence on the concept of self, in which the self includes mother. In Western cultures, self-referential processing leads to a memory performance advantage over other forms of semantic processing including mother-referential, other-referential and general semantic processing, and an advantage that is potentially localizable to the medial prefrontal cortex (MPFC). In Chinese culture, however, the behavioral study showed that mother-referential processing was comparable with self-referential processing in both memory performance and autonoetic awareness. The present study attempts to address whether similar neural correlates (e.g. MPFC) are acting to facilitate both types of referencing. Participants judged trait adjectives under three reference conditions of self, other and semantic processing in Experiment I, and a mother-reference condition replaced the other-reference condition in Experiment II. The results showed that when compared to other, self-referential processing yielded activations of MPFC and cingulate areas. However, when compared to mother, the activation of MPFC disappeared in self-referential processing, which suggests that mother and self may have a common brain region in the MPFC and that the Chinese idea of self includes mother.

Awareness↗

PubMed2006

Evaluation of a structural polymorphism in the ankyrin repeat and kinase domain containing 1 (ANKK1) gene and the activation of executive attention networks.

The specificity of genetic effects on brain activation is a central issue in understanding how molecular actions at the synapse relate to anatomic patterns of brain activity. In an effort to understand the basis for the specificity of gene-associated brain activity, we explore a well-studied genetic polymorphism, TaqIA, which lies downstream of the DRD2 gene in the protein-encoding region of a neighboring gene, ANKK1, which is not expressed in the brain. We utilize the attention network test and find that carriers of the A1 allele show gene-associated functional activation in an anatomically specific, dopamine-rich region of the brain comprising the anterior cingulate gyrus, a finding partially consistent with prior data from functional imaging genetics. A review of the patterns of expression for ANKK1 and DRD2 and the extent of linkage disequilibrium between the two genes sheds light on additional criteria for the selection of candidate genes in imaging-genetic studies.

Adolescent↗

PubMed2006

[The treatment of pneumocystis Carinii pneumonia with caspofungin in elderly patients: a case report and literature review].

OBJECTIVE: To describe the treatment with caspofungin of pneumocystis Carinii pneumonia (PCP) in elderly patients. METHODS: A 93 year old male patient with chronic obstructive pulmonary disease (COPD) and in mechanical ventilation for 25 months. PCP was diagnosed and treated with trimethoprim-sulphamethoxazole compound (SMZ/TMP) and caspofungin. RESULTS: The diagnosis of PCP was confirmed by clinical features, radiographic abnormalities and sputum smear Giemsa stain PC (+) or PCR (+). SMZ/TMP was the first choice in treatment of PCP but caspofungin can be used in patients. SMZ/TMP had to be discontinued because of side effect or treatment failure. Caspofungin was effective and without any side effects in this patient. CONCLUSIONS: PCP is one of opportunistic infections in elderly patient admitted for long term mechanical ventilation. SMZ/TMP is the first choice for treatment but caspofungin may be an alternative.

Aged, 80 and over↗

PubMed2005

Selective impairment of attentional networks of orienting and executive control in schizophrenia.

BACKGROUND: Difficulty attending is a common deficit of schizophrenic patients. However, it is not known whether this is a global attentional deficit or relates to a specific attentional network. METHOD: This study used the attention network test to compare schizophrenic patients (N=77) with controls (N=53) on the efficiency of three anatomically defined attentional networks: alerting, orienting, and executive control. RESULTS: Schizophrenic patients showed a large and highly significant deficit in the executive network and a smaller but significant deficit in the orienting network as well as in overall RT and accuracy. There was no deficit in the alerting network. CONCLUSION: These results suggest some specificity in the attentional networks influenced by the disorder. The executive attention network has been shown in normal subjects to activate the anterior cingulate and lateral prefrontal areas. Previous data using neuroimaging with schizophrenic patients has shown abnormal control by the anterior cingulate. Our findings support this previous research by indicating that the major attentional deficit in schizophrenic patients is in a network that includes the anterior cingulate.

Adult↗

PubMed2005

Development of attentional networks: an fMRI study with children and adults.

Data on the development of the attentional systems remain scarce. We used structural and event-related functional magnetic resonance imaging to investigate differences in the neural mechanisms associated with alerting, reorienting, and executive control of attention between children (ages 8 to 12 years) and adults, while controlling for effects of performance and brain morphology. Behaviorally, children exhibited a numerically smaller alerting effect and significantly larger invalidity (reorienting) and interference (executive control of attention) effects. Neurally, children showed significantly reduced brain activation in a priori defined regions-of-interest in right-sided frontal-midbrain regions during alerting, in the right-sided temporo-parietal junction during reorienting of attention, and in the dorsolateral prefrontal cortex during executive control of attention. In addition, children activated significantly more brain regions outside the a priori defined regions-of-interest, such as the superior frontal gyrus during reorienting and the superior temporal gyrus during executive control of attention. Functional group differences overlapped with structural group differences in gray matter volume in particular within the frontopolar areas. The data suggest that there is a transition from functional yet immature systems supporting attentional functions in children to the more definitive adult networks and that the differences observed may reflect both developmental changes in cognitive strategies and morphology.

Adult↗

PubMed2005

Hypnotic suggestion reduces conflict in the human brain.

Many studies have suggested that conflict monitoring involves the anterior cingulate cortex (ACC). We previously showed that a specific hypnotic suggestion reduces involuntary conflict and alters information processing in highly hypnotizable individuals. Hypothesizing that such conflict reduction would be associated with decreased ACC activation, we combined neuroimaging methods to provide high temporal and spatial resolution and studied highly and less-hypnotizable participants both with and without a suggestion to interpret visual words as nonsense strings. Functional MRI data revealed that under posthypnotic suggestion, both ACC and visual areas presented reduced activity in highly hypnotizable persons compared with either no-suggestion or less-hypnotizable controls. Scalp electrode recordings in highly hypnotizable subjects also showed reductions in posterior activation under suggestion, indicating visual system alterations. Our findings illuminate how suggestion affects cognitive control by modulating activity in specific brain areas, including early visual modules, and provide a more scientific account relating the neural effects of suggestion to placebo.

Adult↗

PubMed2005

The activation of attentional networks.

Alerting, orienting, and executive control are widely thought to be relatively independent aspects of attention that are linked to separable brain regions. However, neuroimaging studies have yet to examine evidence for the anatomical separability of these three aspects of attention in the same subjects performing the same task. The attention network test (ANT) examines the effects of cues and targets within a single reaction time task to provide a means of exploring the efficiency of the alerting, orienting, and executive control networks involved in attention. It also provides an opportunity to examine the brain activity of these three networks as they operate in a single integrated task. We used event-related functional magnetic resonance imaging (fMRI) to explore the brain areas involved in the three attention systems targeted by the ANT. The alerting contrast showed strong thalamic involvement and activation of anterior and posterior cortical sites. As expected, the orienting contrast activated parietal sites and frontal eye fields. The executive control network contrast showed activation of the anterior cingulate along with several other brain areas. With some exceptions, activation patterns of these three networks within this single task are consistent with previous fMRI studies that have been studied in separate tasks. Overall, the fMRI results suggest that the functional contrasts within this single task differentially activate three separable anatomical networks related to the components of attention.

Adolescent↗

PubMed2005

Auditory abnormalities in autism: toward functional distinctions among findings.

Recently, findings on a wide range of auditory abnormalities among individuals with autism have been reported. To date, functional distinctions among these varied findings are poorly established. Such distinctions should be of interest to clinicians and researchers alike given their potential therapeutic and experimental applications. This review suggests three general trends among these findings as a starting point for future analyses. First, studies of auditory perception of linguistic and social auditory stimuli among individuals with autism generally have found impaired perception versus normal controls. Such findings may correlate with impaired language and communication skills and social isolation observed among individuals with autism. Second, studies of auditory perception of pitch and music among individuals with autism generally have found enhanced perception versus normal controls. These findings may correlate with the restrictive and highly focused behaviors observed among individuals with autism. Third, findings on the auditory perception of non-linguistic, non-musical stimuli among autism patients resist any generalized conclusions. Ultimately, as some researchers have already suggested, the distinction between impaired global processing and enhanced local processing may prove useful in making sense of apparently discordant findings on auditory abnormalities among individuals with autism.

Auditory Perceptual Disorders↗

PubMed2005

Differential prefrontal cortex activation during inhibitory control in adolescents with and without childhood attention-deficit/hyperactivity disorder.

The authors examined inhibitory control processes in 8 adolescents diagnosed with attention-deficit/ hyperactivity disorder (ADHD) during childhood and in 8 adolescent control participants using functional MRI with the Stimulus and Response Conflict Tasks (K. W. Nassauer & J. M. Halperin, 2003). No group differences in performance were evident on measures of interference control and/or response competition created by location and direction stimuli. However, the ADHD group demonstrated significantly greater activation of the left ventrolateral prefrontal cortex during interference control as well as greater activation of the left anterior cingulate cortex, right ventrolateral prefrontal cortex, and left basal ganglia during the dual task of interference control and response competition. The magnitude of the prefrontal and basal ganglia activation was positively correlated with severity of ADHD. Response competition alone did not yield group differences in activation.

Adolescent↗

PubMed2005

Brain activation gradients in ventrolateral prefrontal cortex related to persistence of ADHD in adolescent boys.

OBJECTIVE: To explore the possible role that functional abnormalities of the prefrontal cortex and basal ganglia play in the persistence of attention-deficit/hyperactivity disorder (ADHD) in adolescents aged 15 to 19 years. METHOD: Ten male adolescents who were diagnosed with ADHD during childhood were grouped into those who continued to meet full diagnostic criteria for DSM-IV ADHD (persisters; n = 5) and those in whom symptoms had remitted sufficiently to warrant a diagnosis of ADHD in partial remission (remitters; n = 5). Persisters, remitters, and five carefully matched controls with no history of ADHD were scanned using functional magnetic resonance imaging while performing a go/no-go task. RESULTS: Parallel linear trends were found in performance on the go/no-go task and activation of ventrolateral prefrontal cortex, such that persisters made the most commission errors (33%) and showed the greatest activation, remitters made fewer commission errors (24%) and had lower activity, and activation was lowest in controls who made the fewest errors (13%). CONCLUSIONS: These preliminary results suggest that developmental changes in ADHD symptomatology are associated with functional changes in ventrolateral prefrontal cortex activity.

Adolescent↗

PubMed2005

[Clinical research of qingkailing soft capsules in treating acute upper respiratory infection].

OBJECTIVE: To discuss the efficacy of Qingkailing soft capsules in treating acute fever, and the relationship between symptoms-effect and time effect. METHOD: Qingkailing soft capsules was taken orally, 4 times a day, 1.6 g each time. Shuanghuanglian kou fu liquid was taken as control. 129 patients with acute upper respiratory tract infection were recruited. RESULT: There were 73.34% of patients cured by Qingkailing soft capsules and 43.59% cured by Shuanghuanglian kou fu liquid. The efficacy of the former was better than that of the latter (P < 0.05). The efficacy of Qingkailing soft capsules in treating Fengrexing was better than that in Fenghanxing (P < 0.05). The efficacy of Qingkailing soft capsules in reducing rapid pulse and adding moderate pulse was more remarkable than Shuanghuanglian kou fu liquid (P < 0.05). Taking Qingkailing soft capsules seldom induced mild gastrointestinal disturbance. CONCLUSION: Qingkailing soft capsules showed good result in the treatment of acute upper respiratory tract infection with less adverse effect.

Adult↗

PubMed2004

[A preliminary study on the attentional networks of attention deficit hyperactivity disorder].

OBJECTIVE: To investigate the efficiency of the three attentional networks in attention deficit hyperactivity disorder (ADHD). METHODS: Subjects were 25 children, aged 7 to 12 years, with DSM-IV ADHD and 25 non-ADHD controls matched by age, sex and IQ. Attentional networks tests were performed in all the subjects on an IBM compatible computer. RESULTS: No differences were found between the ADHD children and the normal controls in alerting and orienting effects. However, ADHD children had a significantly larger executive control effect than their normal counterparts. The general accuracy of the ADHD children was significantly lower than that of the normal controls. CONCLUSION: ADHD children may have impairments in their executive control network of attention.

Attention↗

PubMed2004

Development of attentional networks in childhood.

Recent research in attention has involved three networks of anatomical areas that carry out the functions of orienting, alerting and executive control (including conflict monitoring). There have been extensive cognitive and neuroimaging studies of these networks in adults. We developed an integrated Attention Network Test (ANT) to measure the efficiency of the three networks with adults. We have now adapted this test to study the development of these networks during childhood. The test is a child-friendly version of the flanker task with alerting and orienting cues. We studied the development of the attentional networks in a cross-sectional experiment with four age groups ranging from 6 through 9 (Experiment 1). In a second experiment, we compared children (age 10 years) and adult performance in both child and adults versions of the ANT. Reaction time and accuracy improved at each age interval and positive values were found for the average efficiency of each of the networks. Alertness showed evidence of change up to and beyond age 10, while conflict scores appear stable after age seven and orienting scores do not change in the age range studied. A final experiment with forty 7-year-old children suggested that children like adults showed independence between the three networks under some conditions.

Adult↗

PubMed2004

Human attentional networks.

In recent years it has been possible to treat attention as an organ system with its own anatomy, circuitry and set of functions. We view attention in terms of three interrelated neural networks in the human brain. These networks carry out the specific functions of developing and maintaining the alert state, orienting to sensory input, and executive control. Damage to these networks or their chemical neuromodulators can produce specific neurological and psychiatric deficits. We have conducted behavioral, developmental, and patient studies using functional magnetic resonance imaging (fMRI), event related potentials (ERP), genetics, and computational modeling to investigate the anatomy, circuitry, pathology, and development of attentional networks. The Attentional Network Test (ANT) is developed to measure the efficiency of each of the attention networks. The ANT can also serve as an endophenotype for genetic studies on attentional networks. This paper reviews our work with the ANT in studies of normal performance and various forms of psychopathology.

Arousal↗

PubMed2004

A novel gene delivery system targeting urokinase receptor.

Recombinant proteins that combine different functions required for cell targeting and intra-cellular delivery of DNA present an attractive approach for the development of nonviral gene delivery vectors. Here, we described a novel protein termed ATF-lys10 which facilitated cell-specific gene transfer via receptor-mediated endocytosis. ATF-lys10 was composed of the amino-terminal fragment of urokinase and ten lysines at the carboxyl terminus. Bacterially expressed ATF-lys10 protein existed in soluble form, and had antigenicity of human urokinase. Purified ATF-lys10 specifically bound to uPAR-expressing cells and formed protein-DNA complexes with plasmid pGL3-control. After neutralization of excess negative charge with poly-L-lysine, these complexes served as a specific gene delivery vector for uPAR-expressing cells. Lyso-somotropic compounds, such as chloroquine, drastically increased the ATF-lys10 mediated gene delivery efficiency. Our results suggest that the recombinant protein ATF-lys10 with the properties of DNA binding and tumor cell targeting represents a promising method for gene transfer and expression in tumor cells.

Base Sequence↗