Neither state or trait anxiety alter the response to distracting emotionally neutral sounds.

Attentional control theory suggests that heightened anxiety, whether due to trait or state factors, causes an increased vulnerability to distraction even when the distracters are emotionally neutral. Recent passive oddball studies appear to support this theory in relation to the distraction caused by emotionally neutral sounds. However such studies have manipulated emotional state via the content of task stimuli, thus potentially confounding changes in emotion with differences in task demands. To identify the effect of anxiety on the distraction caused by emotionally neutral sounds, 50 participants completed a passive oddball task requiring emotionally neutral sounds to be ignored. Crucially, state anxiety was manipulated independent of the task stimuli (via unrelated audiovisual stimuli) thus removing confounds relating to task demands. Neither state or trait anxiety was found to influence the susceptibility to distraction by emotionally neutral sounds. These findings contribute to the ongoing debate concerning the impact of emotion on attention.

The effect of psychological stress and expectation on auditory perception: A signal detection analysis.

Both psychological stress and predictive signals relating to expected sensory input are believed to influence perception, an influence which, when disrupted, may contribute to the generation of auditory hallucinations. The effect of stress and semantic expectation on auditory perception was therefore examined in healthy participants using an auditory signal detection task requiring the detection of speech from within white noise. Trait anxiety was found to predict the extent to which stress influenced response bias, resulting in more anxious participants adopting a more liberal criterion, and therefore experiencing more false positives, when under stress. While semantic expectation was found to increase sensitivity, its presence also generated a shift in response bias towards reporting a signal, suggesting that the erroneous perception of speech became more likely. These findings provide a potential cognitive mechanism that may explain the impact of stress on hallucination-proneness, by suggesting that stress has the tendency to alter response bias in highly anxious individuals. These results also provide support for the idea that top-down processes such as those relating to semantic expectation may contribute to the generation of auditory hallucinations.

Appraisals and responses to experimental symptom analogues in clinical and nonclinical individuals with psychotic experiences.

OBJECTIVE: Cognitive models of psychosis suggest that anomalous experiences alone do not always lead to clinical psychosis, with appraisals and responses to experiences being central to understanding the transition to "need for care". METHODS: The appraisals and response styles of Clinical (C; n = 28) and Nonclinical (NC; n = 34) individuals with psychotic experiences were compared following experimental analogues of thought interference (Cards Task) and auditory hallucinations (Virtual Acoustic Space Paradigm). RESULTS: The groups were matched in terms of their psychotic experiences. As predicted, the C group scored higher than the NC group on maladaptive appraisals following both tasks, rated the experience as more personally significant, and was more likely to incorporate the experimental setup into their ongoing experiences. The C group also appraised the Cards Task as more salient, distressing, and threatening; this group scored higher on maladaptive-and lower on adaptive-response styles, than the NC group on both tasks. CONCLUSIONS: The findings are consistent with cognitive models of psychosis, with maladaptive appraisals and response styles characterizing the C group only. Clinical applications of both tasks are suggested to facilitate the identification and modification of maladaptive appraisals.

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.

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.

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.