The frontal lobes are necessary for 'theory of mind'.
(1/23)
Patients with limited focal frontal and nonfrontal lesions were tested for visual perspective taking and detecting deception. Frontal lobe lesions impaired the ability to infer mental states in others, with dissociation of performance within the frontal lobes. Lesions throughout the frontal lobe, with some suggestion of a more important role for the right frontal lobe, were associated with impaired visual perspective taking. Medial frontal lesions, particularly right ventral, impaired detection of deception. The former may require cognitive processes of the lateral and superior medial frontal regions, the latter affective connections of the ventral medial frontal with amygdala and other limbic regions. (+info)
Dissociable roles of prefrontal and anterior cingulate cortices in deception.
(2/23)
Recent neuroimaging studies have shown the importance of the prefrontal and anterior cingulate cortices in deception. However, little is known about the role of each of these regions during deception. Using positron emission tomography (PET), we measured brain activation while participants told truths or lies about two types of real-world events: experienced and unexperienced. The imaging data revealed that activity of the dorsolateral, ventrolateral and medial prefrontal cortices was commonly associated with both types of deception (pretending to know and pretending not to know), whereas activity of the anterior cingulate cortex (ACC) was only associated with pretending not to know. Regional cerebral blood flow (rCBF) increase in the ACC was positively correlated with that in the dorsolateral prefrontal cortex only during pretending not to know. These results suggest that the lateral and medial prefrontal cortices have general roles in deception, whereas the ACC contributes specifically to pretending not to know. (+info)
Imaging or imagining? A neuroethics challenge informed by genetics.
(3/23)
From a twenty-first century partnership between bioethics and neuroscience, the modern field of neuroethics is emerging, and technologies enabling functional neuroimaging with unprecedented sensitivity have brought new ethical, social and legal issues to the forefront. Some issues, akin to those surrounding modern genetics, raise critical questions regarding prediction of disease, privacy and identity. However, with new and still-evolving insights into our neurobiology and previously unquantifiable features of profoundly personal behaviors such as social attitude, value and moral agency, the difficulty of carefully and properly interpreting the relationship between brain findings and our own self-concept is unprecedented. Therefore, while the ethics of genetics provides a legitimate starting point--even a backbone--for tackling ethical issues in neuroimaging, they do not suffice. Drawing on recent neuroimaging findings and their plausible real-world applications, we argue that interpretation of neuroimaging data is a key epistemological and ethical challenge. This challenge is two-fold. First, at the scientific level, the sheer complexity of neuroscience research poses challenges for integration of knowledge and meaningful interpretation of data. Second, at the social and cultural level, we find that interpretations of imaging studies are bound by cultural and anthropological frameworks. In particular, the introduction of concepts of self and personhood in neuroimaging illustrates the interaction of interpretation levels and is a major reason why ethical reflection on genetics will only partially help settle neuroethical issues. Indeed, ethical interpretation of such findings will necessitate not only traditional bioethical input but also a wider perspective on the construction of scientific knowledge. (+info)
Accuracy and utility of post-conviction polygraph testing of sex offenders.
(4/23)
BACKGROUND: Polygraphy is used increasingly in the treatment and supervision of sex offenders, but little research has addressed its accuracy in this setting, or linked accuracy with utility. AIMS: To investigate the utility and accuracy of polygraphy in post-conviction testing of community-based sex offenders. METHOD: A self-report measure examined the experiences of offenders with polygraphy. RESULTS: Based on self-report, the polygraph's accuracy was approximately 85%. False negatives and false positives were not associated with demographic characteristics, personality variables or IQ. The majority of offenders found the polygraph to be helpful in both treatment and supervision. Nine percent of offenders claimed to have made false disclosures; these individuals had higher scores on ratings of neuroticism and lower scores on ratings of conscientiousness. CONCLUSIONS: These results support the view that the polygraph is both accurate and useful in the treatment and supervision of sex offenders. (+info)
Localisation of increased prefrontal white matter in pathological liars.
(5/23)
We examined white matter volumes in four prefrontal subregions using structural magnetic resonance imaging in 10 pathological liars, 14 antisocial controls, and 20 normal controls. Liars showed a relatively widespread increase in white matter (23-36%) in orbitofrontal, middle and inferior, but not superior, frontal gyri compared with antisocial and normal controls. This white matter increase may predispose some individuals to pathological lying. (+info)
Lie-specific involvement of dorsolateral prefrontal cortex in deception.
(6/23)
Lies are intentional distortions of event knowledge. No experimental data are available on manipulating lying processes. To address this issue, we stimulated the dorsolateral prefrontal cortex (DLPFC) using transcranial direct current stimulation (tDCS). Fifteen healthy volunteers were tested before and after tDCS (anodal, cathodal, and sham). Two types of truthful (truthful selected: TS; truthful unselected: TU) and deceptive (lie selected: LS; lie unselected: LU) responses were evaluated using a computer-controlled task. Reaction times (RTs) and accuracy were collected and used as dependent variables. In the baseline task, the RT was significantly longer for lie responses than for true responses ([mean +/- standard error] 1153.4 +/- 42.0 ms vs. 1039.6 +/- 36.6 ms; F(1,14) = 27.25, P = 0.00013). At baseline, RT for selected pictures was significantly shorter than RT for unselected pictures (1051.26 +/- 39.0 ms vs. 1141.76 +/- 41.1 ms; F(1,14) = 34.85, P = 0.00004). Whereas after cathodal and sham stimulation, lie responses remained unchanged (cathodal 5.26 +/- 2.7%; sham 5.66 +/- 3.6%), after anodal tDCS, RTs significantly increased but did so only for LS responses (16.86 +/- 5.0%; P = 0.002). These findings show that manipulation of brain function with DLPFC tDCS specifically influences experimental deception and that distinctive neural mechanisms underlie different types of lies. (+info)
Children's knowledge of deceptive gaze cues and its relation to their actual lying behavior.
(7/23)