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Mike D Hunter

Publications and source records attributed to Mike D Hunter.

4 recordsLinked to original sources
PubMed2005

Expanding the response space in chronic schizophrenia: the relevance of left prefrontal cortex.

OBJECTIVE: This study probed the ability of people with chronic schizophrenia to control their behavior in time by requiring them to deliberately vary responses within the temporal domain (i.e., to avoid regular inter-response intervals). METHODS: Thirteen schizophrenia patients performed single finger movements (at moments of their own choosing) in an event-related functional magnetic resonance imaging paradigm. Their performance was computed using the coefficient of variation of inter-response interval duration. RESULTS: Task performance was positively correlated with activation of left lateral prefrontal cortex. Post hoc analyses revealed an inverse correlation between activation in this region and severity of attentional impairment. CONCLUSION: These findings implicate left lateral prefrontal cortex in the modulation of the temporal response space in schizophrenia and imply greater attentional (executive) impairment among those who fail to modulate their behavior in time.

Adult↗
PubMed2005

Modafinil modulates anterior cingulate function in chronic schizophrenia.

BACKGROUND: Schizophrenia is associated with widespread cognitive deficits that have an impact on social function. Modafinil promotes wakefulness and is reported to enhance cognition. AIMS: To study the acute effects of modafinil administration upon brain activity and cognitive performance in people with chronic schizophrenia. METHOD: In a randomised double-blind placebo-controlled crossover design, 19 patients received either modafinil (100 mg) or placebo prior to undertaking a working memory task with functional magnetic resonance imaging. RESULTS: Seventeen patients completed the study and another underwent acute relapse 4 days post-drug. Modafinil administration was associated with significantly greater activation in the anterior cingulate cortex during the working memory task. The anterior cingulate cortex signal correlated with cognitive performance, although only a subset of patients exhibited 'enhancement'. CONCLUSIONS: Modafinil modulates anterior cingulate cortex function in chronic schizophrenia but its beneficial cognitive effects may be restricted to a subset of patients requiring further characterisation.

Adolescent↗
PubMed2004

A cognitive neurobiological account of deception: evidence from functional neuroimaging.

An organism may use misinformation, knowingly (through deception) or unknowingly (as in the case of camouflage), to gain advantage in a competitive environment. From an evolutionary perspective, greater tactical deception occurs among primates closer to humans, with larger neocortices. In humans, the onset of deceptive behaviours in childhood exhibits a developmental trajectory, which may be regarded as 'normal' in the majority and deficient among a minority with certain neurodevelopmental disorders (e.g. autism). In the human adult, deception and lying exhibit features consistent with their use of 'higher' or 'executive' brain systems. Accurate detection of deception in humans may be of particular importance in forensic practice, while an understanding of its cognitive neurobiology may have implications for models of 'theory of mind' and social cognition, and societal notions of responsibility, guilt and mitigation. In recent years, functional neuroimaging techniques (especially functional magnetic resonance imaging) have been used to study deception. Though few in number, and using very different experimental protocols, studies published in the peer-reviewed literature exhibit certain consistencies. Attempted deception is associated with activation of executive brain regions (particularly prefrontal and anterior cingulate cortices), while truthful responding has not been shown to be associated with any areas of increased activation (relative to deception). Hence, truthful responding may comprise a relative 'baseline' in human cognition and communication. The subject who lies may necessarily engage 'higher' brain centres, consistent with a purpose or intention (to deceive). While the principle of executive control during deception remains plausible, its precise anatomy awaits elucidation.

Brain↗