110 research outputs found
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Cortical activation elicited by unrecognized stimuli
BACKGROUND: It is unclear whether a stimulus that cannot be recognized consciously, could elicit a well-processed cognitive response. METHODS: We used functional imaging to examine the pattern of cortical activation elicited by unrecognized stimuli during memory processing. Subjects were given a recognition task using recognizable and non-recognizable subliminal stimuli. RESULTS: Unrecognized stimuli activated the cortical areas that are associated with retrieval attempt (left prefrontal), and novelty detection (left hippocampus). This indicates that the stimuli that were not consciously recognized, activated neural network associated with aspects of explicit memory processing. CONCLUSION: Results suggest that conscious recognition of stimuli is not necessary for activation of cognitive processing
Theory of mind and schizophrenia☆
A number of cognitive and behavioral variables influence the performance in tasks of theory of mind (ToM). Since two of the most important variables, memory and explicit expression, are impaired in schizophrenic patients, the ToM appears inconsistent in these patients. An ideal instrument of ToM should therefore account for deficient memory and impaired ability of these patients to explicitly express intentions. If such an instrument is developed, it should provide information that can be used not only to understand the pathophysiology but also to monitor patients
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Auditory Priming within and across Modalities: Evidence from Positron Emission Tomography
Previous neuroimaging studies of perceptual priming have reported priming-related decreases in the extrastriate cortex. However, because these experiments have used visual stimuli, it is unclear whether the observed decreases are associated specifically with some aspect of visual perceptual processing or with more general aspects of priming. We studied within-and cross-modality priming using an auditory word stem completion paradigm. Positron emission tomography (PET) images were obtained during stem completion and a fixation task. Within-modality auditory priming was associated with blood flow decreases in the extrastriate cortex (bilateral), medial/ right anterior prefrontal cortex, right angular gyrus, and precuneus. In cross-modality priming, the study list was presented visually, and subjects completed auditory word stems. Cross-modality priming was associated with trends for blood flow decreases in the left angular gyrus and increases in the medial/right anterior prefrontal cortex. Results thus indicate that reduced activity in the extrastriate cortex accompanies within-modality priming in both visual and auditory modalities.Psycholog
Evidence of Dopaminergic Processing of Executive Inhibition
Inhibition of unwanted response is an important function of the executive system. Since the inhibitory system is impaired in patients with dysregulated dopamine system, we examined dopamine neurotransmission in the human brain during processing of a task of executive inhibition. The experiment used a recently developed dynamic molecular imaging technique to detect and map dopamine released during performance of a modified Eriksen's flanker task. In this study, young healthy volunteers received an intravenous injection of a dopamine receptor ligand (11C-raclopride) after they were positioned in the PET camera. After the injection, volunteers performed the flanker task under Congruent and Incongruent conditions in a single scan session. They were required to inhibit competing options to select an appropriate response in the Incongruent but not in the Congruent condition. The PET data were dynamically acquired during the experiment and analyzed using two variants of the simplified reference region model. The analysis included estimation of a number of receptor kinetic parameters before and after initiation of the Incongruent condition. We found increase in the rate of ligand displacement (from receptor sites) and decrease in the ligand binding potential in the Incongruent condition, suggesting dopamine release during task performance. These changes were observed in small areas of the putamen and caudate bilaterally but were most significant on the dorsal aspect of the body of left caudate. The results provide evidence of dopaminergic processing of executive inhibition and demonstrate that neurochemical changes associated with cognitive processing can be detected and mapped in a single scan session using dynamic molecular imaging
Pilot clinical observations between food and drug seeking derived from fifty cases attending an eating disorder clinic
Background The reward deficiency syndrome hypothesis posits that genes are responsible for reward dependence and related behaviors. There is evidence that both bulimia and anorexia nervosa, especially in women, have been linked to a lifetime history of substance use disorder (SUD). There are difficulties in accepting food as an addiction similar to drugs; however, increasingly neuroimaging studies favor such an assertion. Case presentations We are reporting the evidence of comorbidity of eating disorders with SUD found within these case presentations. We show 50 case reports derived from two independent treatment centers in Florida that suggest the commonality between food and drug addictions. In an attempt to provide data from this cohort, many participants did not adequately respond to our questionnaire. Discussion We propose that dopamine agonist therapy may be of common benefit. Failure in the past may reside in too powerful D2 agonist activity leading to D2 receptor downregulation, while the new methodology may cause a reduction of “dopamine resistance” by inducing “dopamine homeostasis.” While this is not a definitive study, it does provide some additional clinical evidence that these two addictions are not mutually exclusive. Conclusion Certainly, it is our position that there is an overlap between food- and drug-seeking behavior. We propose that the studies focused on an effort to produce natural activation of dopaminergic reward circuitry as a type of common therapy may certainly be reasonable. Additional research is warranted
Neurogenetic and epigenetic aspects of cannabinoids
Cannabis is one of the most commonly used and abused illicit drugs in the world today. The United States (US) currently has the highest annual prevalence rate of cannabis consumption in the world, 17.9% in individuals aged 12 or older, and it is on the rise. With increasing cannabis use comes the potential for an increase in abuse, and according to the Substance Abuse and Mental Health Services Administration (SAMHSA), approximately 5.1% of Americans had Cannabis Use Disorder (CUD) in 2020. Research has shown that genetics and epigenetics play a significant role in cannabis use and CUD. In fact, approximately 50-70% of liability to CUD and 40-48% of cannabis use initiation have been found to be the result of genetic factors. Cannabis usage and CUD have also been linked to an increased risk of psychiatric disorders and Reward Deficiency Syndrome (RDS) subsets like schizophrenia, depression, anxiety, and substance use disorder. Comprehension of the genetic and epigenetic aspects of cannabinoids is necessary for future research, treatment plans, and the production of pure cannabinoid compounds, which will be essential for FDA approval. In conclusion, having a better understanding of the epigenetic and genetic underpinnings of cannabis use, CUD, and the endocannabinoid system as a whole will aid in the development of effective FDA-approved treatment therapies and the advancement of personalized medicine
A review of DNA risk alleles to determine epigenetic repair of mRNA expression to prove therapeutic effectiveness in reward deficiency syndrome (RDS): Embracing Precision Behavioral Management
This is a review of research on Precision Behavioral Management of substance use disorder (SUD). America is experiencing a high prevalence of substance use disorder, primarily involving legal and illegal opioid use. A 3000% increase in treatment for substance abuse has occurred between 2000 and 2016. Unfortunately, present day treatment of opioid abuse involves providing replacement therapy with powerful opioids to, at best, induce harm reduction, not prophylaxis. These interventions do not enhance gene expression and restore the balance of the brain reward system\u27s neurotransmitters. We are proposing a generalized approach called Precision Behavioral Management . This approach includes 1) using the Genetic Addiction Risk Severity (GARS, a 10 candidate polymorphic gene panel shown to predict ASI-alcohol and drug severity) to assess early pre-disposition to substance use disorder; 2) using a validated reward deficiency syndrome (RDS) questionnaire; 3) utilization of the Comprehensive Analysis of Reported Drugs (CARD™) to assess treatment compliance and abstinence from illicit drugs during treatment, and, importantly; 4) utilization of a Pro-dopamine regulator (KB220) (via IV or oral [KB220Z] delivery systems) to optimize gene expression, restore the balance of the Brain Reward Cascade\u27s neurotransmitter systems and prevent relapse by induction of dopamine homeostasis, and; 5) utilization of targeted DNA polymorphic reward genes to direct mRNA genetic expression profiling during the treatment process. Incorporation of these events can be applied to not only the under-considered African-American RDS community, but all victims of RDS, as a demonstration of a paradigm shift that uniquely provides a novel putative standard of care based on DNA guided precision nutrition therapy to induce dopamine homeostasis and rebalance neurotransmitters in the Brain Reward Cascade. We are also developing a Reward Deficiency Syndrome Diagnostic Criteria (RDSDC) to assist in potential tertiary treatment
Pro-dopamine regulator, KB220Z, attenuates hoarding and shopping behavior in a female, diagnosed with SUD and ADHD
Background: Addictive-like behaviors (e.g., hoarding and shopping) may be the result of the cumulative effects of
dopaminergic and other neurotransmitter genetic variants as well as elevated stress levels. We, therefore, propose that dopamine homeostasis may be the preferred goal in combating such challenging and unwanted behaviors, when
simple dopaminergic activation through potent agonists may not provide any resolution. Case presentation: C.J. is a 38-year-old, single, female, living with her mother. She has a history of substance use disorder as well as attention deficit hyperactivity disorder, inattentive type. She had been stable on buprenorphine/naloxone combination and amphetamine, dextroamphetamine mixed salts for many years when unexpectedly she lost her job for oversleeping and not calling into work. KB200z (a pro-dopamine compound) was added to her regimen for complaints of low drive and motivation. After taking this nutraceutical for 4 weeks, she noticed a marked improvement in her mental status and many behaviors. She noted that her shopping and hoarding addictions had appreciably decreased. Furthermore, her lifelong history of terrifying lucid dreams was eliminated. Finally, she felt more in control; her locus of control shifted from external to more internal. Discussion: The hypothesis is that C.J.’s reported, behavioral, and psychological benefits resulted from the pro-dopamine-regulating effect of KB220Z across the brain reward system. Conclusions:
This effect, we surmise, could be the result of a new dopamine balance, across C.J.’s brain reward system. Dopamine homeostasis is an effect of KB220Z seen in both animal and human placebo-controlled fMRI experiments
Genetic addiction risk severity assessment identifies polymorphic reward genes as antecedents to reward deficiency syndrome (RDS) hypodopaminergia\u27s effect on addictive and non-addictive behaviors in a nuclear family
This case series presents the novel genetic addiction risk score (GARS), which shows a high prevalence of polymorphic risk alleles of reward genes in a nuclear family with multiple reward deficiency syndrome (RDS) behavioral issues expressing a hypodopaminergic antecedent. The family consists of a mother, father, son, and daughter. The mother experienced issues with focus, memory, anger, and amotivational syndrome. The father experienced weight issues and depression. The son experienced heavy drinking, along with some drug abuse and anxiety. The daughter experienced depression, lethargy, brain fog, focus issues, and anxiety, among others. A major clinical outcome of the results presented to the family members helped reduce personal guilt and augment potential hope for future healing. Our laboratory\u27s prior research established that carriers of four or more alleles measured by GARS
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