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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.

Behavioural and functional anatomical responses exhibited by humans support the hypothesis that deception involves the prefrontal executive. Functional neuroimaging studies have demonstrated that ventrolateral prefrontal cortex (among other areas) is activated during lying, compared with telling the truth. However, despite some consistencies discernible across studies, problems remain concerning experimental validity, e.g., the expediencies of experimenter-sanctioned cued-deception (i.e., subjects being told when to lie); such ‘lies’ may not have comprised adequate proxies for ‘real-life’ deception. In this experiment, we attempted to address such confounding issues by designing an fMRI paradigm in which subjects chose when to lie (thereby minimising cue-dependency), using spoken words, concerning intimate material, which they regarded as ‘embarrassing’; and where further control conditions required them to ‘comply’ with their examiners or to ‘defy’ them (by withholding pre-specified responses). The main effect of lying revealed significant activation of ventrolateral prefrontal cortices. These results replicate and extend our previous findings to those circumstances under which subjects are allowed to choose when to deceive.

The perception and judgement of social hierarchies forms an integral part of social cognition. Hierarchical judgements can be either self-referential or allocentric (pertaining to two or more external agents). In psychiatric conditions such as dissocial personality disorder and schizophrenia, the impact of hierarchies may be problematic. We sought to elucidate the brain regions involved in judging allocentric social hierarchies. Twenty-two healthy male subjects underwent three fMRI scans. During scanning, subjects answered questions concerning visually-presented target pairs of human individual's relative superiority within a specific social hierarchy or their perceived degree of social alliance (i.e., whether they were “friends or enemies”). Subjects also made judgements relating to target pairs’ age, gender and fame to control for confounding factors and performed a baseline numerical task. Response times increased in line with hypothesized ascending executive load. Both social hierarchy and social alliance judgements activated left ventrolateral prefrontal cortex (VLPFC), left dorsal inferior frontal gyrus (IFG) and bilateral fusiform gyri. In addition, social alliance judgements activated right dorsal IFG and medial prefrontal cortex. When compared directly with social alliance, social hierarchy judgements activated left orbitofrontal cortex. Detecting the presence of social hierarchies and judging other's relative standing within them implicates the cognitive executive, in particular the VLPFC. Our finding informs accounts of ‘normal’ social cognition but our method also provides a means of probing the dissocial brain in personality disorder and schizophrenia where executive function may be dysfunctional. ► Social hierarchy / alliance activates left VLPFC, IFG & bilateral fusiform gyrus. ► Social hierarchy judgements uniquely activate left orbitofrontal cortex. ► Increasing response times mirror ascending executive load.

SummaryThe clinical distinction between hysterical symptoms and those that are feigned awaits objective validation. We used functional neuroimaging to examine the neural correlates of these two disorders.

Schizophrenia is associated with widespread cognitive deficits that have an impact on social function. Modafinil promotes wakefulness and is reported to enhance cognition. To study the acute effects of modafinil administration upon brain activity and cognitive performance in people with chronic schizophrenia. 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. 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'. 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.

A responsible person, a moral agent, takes account of their future behaviour and its likely impact upon others. Such an agent may choose to influence their future by exogenous means. If so, might pharmacology help them to do this? Is it doing so already? I argue that it is.

Thought insertion is commonly regarded as diagnostic of schizophrenia. Little is known of its aetiology or pathophysiology. To examine the definition and application of thought insertion in psychiatric and allied literatures. A semi-structured literature review and conceptual analysis. When 'narrowly' defined, thought insertion is reliably identified but not specific to schizophrenia. There is a range of related phenomena ('alienated', 'influenced', 'made' and 'passivity' thinking), less consistently defined but also not specific to schizophrenia. Whether thought insertion is solely an abnormal belief (or may also be an experience) is open to question. Nevertheless, the symptom has been used to explain schizophrenia, predict dangerousness and advance theories of 'normal' agency. Most applications have been subject to critique. Despite its widespread occurrence and diagnostic application, thought insertion is an ill-understood and under researched symptom of psychosis. Its pathophysiology remains obscure.

In the executive model of deception, the telling of a lie necessitates the inhibition of a veridical prepotent response (the truth), and such inhibition incurs a temporal penalty, manifest as a longer response time. If memory processes are engaged in generating such truths, then memory function should affect truthful and deceptive response times. To investigate this we examined the relationship between performance on a semantic knowledge deception task and a test of verbal memory in 40 college students. We found that verbal memory performance differentially affects the temporal parameters of truth and deception.

Using the Zimbardo Time Perspective Inventory (ZTPI; P. G. Zimbardo & J. N. Boyd, 1999), the authors found that homeless people, in comparison with a control group, had a significantly more negative outlook concerning their past and present as evinced by high Past-Negative and Present-Fatalistic scores and low Past-Positive scores on the ZTPI. However, the homeless individuals were almost indistinguishable from control participants on measures of Present-Hedonism and Future thinking. The homeless individuals had significantly higher levels of depression, with 31 out of 50 (62%) reaching criteria for probable depression. However, this finding was unrelated to their atypical time perspective. There was no significant relation between substance misuse and time perspective. Despite their current difficulties, including depression and drug abuse, the homeless individuals maintained a propensity toward future thinking characterized by striving to achieve their goals.