Elizabeth Zachariah

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To elucidate the neural correlates of cognitive effects of nicotine, we examined behavioral performance and blood oxygenation level-dependent regional brain activity, using functional magnetic resonance imaging, during a parametric "n-back" task in healthy nonsmoking males after the administration of nicotine (12 microg/kg body weight) or saline. Nicotine,(More)
BACKGROUND South Asians who have settled overseas and those in urban India have an increased risk of ischaemic heart disease (IHD). Reasons for this increased risk are unclear. Most studies have been based on migrants to western nations, so their findings may not apply to most south Asians, who live in their own countries. Therefore, we assessed the(More)
Schizophrenia patients display an excessive rate of smoking compared to the general population. Nicotine increases acoustic prepulse inhibition (PPI) in animals as well as healthy humans, suggesting that smoking may provide a way of restoring deficient sensorimotor gating in schizophrenia. No previous study has examined the neural mechanisms of the effect(More)
We investigated whether prepulse inhibition of the startle response is reduced in siblings of schizophrenia patients compared to age- and sex-matched healthy controls. Nineteen unaffected biological siblings and 19 controls were assessed on prepulse inhibition by monaural and binaural acoustic prepulse stimuli, with the startle stimuli always presented(More)
Violent behaviour has a strong association with antisocial personality disorder (APD) and schizophrenia. Although developments in the understanding of socio-environmental factors associated with violence should not be ignored, advances in prevention and treatment of violent behaviour would benefit by improved understanding of its neurobiological and(More)
The critical flicker fusion threshold (CFFT) is thought to index alertness and cortical arousal. Sedative drugs reduce CFFT while psychostimulants increase it. Procyclidine is an anticholinergic that is used to control the extrapyramidal side-effects of antipsychotics in schizophrenia. This study examined the effects of clinically relevant doses of oral(More)
OBJECTIVE The objective of this study was to investigate neuropsychological impairment as a genetically mediated risk indicator for schizophrenia while accounting for prevalence of schizotypy signs/symptoms in siblings. METHOD Cognitive functioning in 25 individuals with schizophrenia, 25 unaffected siblings and 25 unrelated healthy controls, was assessed(More)
Rationale: Prepulse inhibition (PPI) of the startle response refers to an attenuation in response to a strong stimulus (pulse) if this is preceded shortly by a weak non-startling stimulus (prepulse). Patients with schizophrenia have repeatedly been found to show reduced PPI when compared to healthy people. Anticholinergic drugs are often used to control(More)
Smooth pursuit eye movement (SPEM) and antisaccade deficits are observed in the schizophrenia spectrum and have been used to study the pathophysiology as well as the genetic basis of this condition. The neurotransmitter acetylcholine has been implicated in a number of cognitive processes thought to underlie SPEM and antisaccade performance. This study(More)
OBJECTIVE The excitement cluster (excitement, hostility, uncooperativeness and impulsivity) may contribute to the risk of violent behaviour, treatment non-adherence, likelihood of discharge and substance use in psychosis. Evidence suggests involvement of frontal executive mechanisms that may show sex differences in their association with symptom severity.(More)