Jennifer M. C. Vendemia

Reaction Time of Motor Responses in Two-Stimulus Paradigms Involving Deception and Congruity with Varying Levels of Difficulty

Deception research has focused on identifying peripheral nervous system markers while ignoring cognitive mechanisms underlying those markers. Cognitive theorists argue that the process of deception may involve such constructs as attentional capture, working memory load, or perceived incongruity with memory, while psychophysiologists argue for stimulus salience, arousal, and emotion. Three studies were conducted to assess reaction time (RT) in relation to deception, response congruity, and preparedness to deceive. Similar to a semantic verification task, participants evaluated sentences that were either true or false, and then made truthful or deceptive evaluations of the sentence’s base truth-value. Findings indicate that deceptive responses have a longer RT than truthful responses, and that this relationship remains constant across response type and preparedness to deceive. The authors use these findings in preliminary support of a comprehensive cognitive model of deception.

Evaluating Methods for Constructing Average High-Density Electrode Positions

Abstract Accurate analysis of scalp-recorded electrical activity requires the identification of electrode locations in 3D space. For example, source analysis of EEG/ERP (electroencephalogram, EEG; event-related-potentials, ERP) with realistic head models requires the identification of electrode locations on the head model derived from structural MRI recordings. Electrode systems must cover the entire scalp in sufficient density to discriminate EEG activity on the scalp and to complete accurate source analysis. The current study compares techniques for averaging electrode locations from 86 participants with the 128 channel “Geodesic Sensor Net” (GSN; EGI, Inc.), 38 participants with the 128 channel “Hydrocel Geodesic Sensor Net” (HGSN; EGI, Inc.), and 174 participants with the 81 channels in the 10–10 configurations. A point-set registration between the participants and an average MRI template resulted in an average configuration showing small standard errors, which could be transformed back accurately into the participants’ original electrode space. Average electrode locations are available for the GSN (86 participants), Hydrocel-GSN (38 participants), and 10–10 and 10–5 systems (174 participants).

Resting state signatures of domain and demand-specific working memory performance

Working memory (WM) is one of the key constructs in understanding higher-level cognition. We examined whether patterns of activity in the resting state of individual subjects are correlated with their off-line working and short-term memory capabilities. Participants completed a resting-state fMRI scan and off-line working and short-term memory (STM) tests with both verbal and visual materials. We calculated fractional amplitude of low frequency fluctuations (fALFF) from the resting state data, and also computed connectivity between seeds placed in frontal and parietal lobes. Correlating fALFF values with behavioral measures showed that the fALFF values in a widespread fronto-parietal network during rest were positively correlated with a combined memory measure. In addition, STM showed a significant correlation with fALFF within the right angular gyrus and left middle occipital gyrus, whereas WM was correlated with fALFF values within the right IPS and left dorsomedial cerebellar cortex. Furthermore, verbal and visuospatial memory capacities were associated with dissociable patterns of low-frequency fluctuations. Seed-based connectivity showed correlations with the verbal WM measure in the left hemisphere, and with the visual WM measure in the right hemisphere. These findings contribute to our understanding of how differences in spontaneous low-frequency fluctuations at rest are correlated with differences in cognitive performance.

Neuronal injury in the motor cortex after chronic stroke and lower limb motor impairment: a voxel-based lesion symptom mapping study

Many studies have examined motor impairments using voxel-based lesion symptom mapping, but few are reported regarding the corresponding relationship between cerebral cortex injury and lower limb motor impairment analyzed using this technique. This study correlated neuronal injury in the cerebral cortex of 16 patients with chronic stroke based on a voxel-based lesion symptom mapping analysis. Neuronal injury in the corona radiata, caudate nucleus and putamen of patients with chronic stroke could predict walking speed. The behavioral measure scores were consistent with motor deficits expected after damage to the cortical motor system due to stroke. These findings suggest that voxel-based lesion symptom mapping may provide a more accurate prognosis of motor recovery from chronic stroke according to neuronal injury in cerebral motor cortex.

Repressors vs. low- and high-anxious coping styles: EEG differences during a modified version of the emotional Stroop task

In this study of 49 undergraduate university women, those exhibiting a repressive coping style - characterized by defensiveness against negative emotions - were compared to women with low-anxious and high-anxious coping styles during neutral and negative versions of a computerized emotional Stroop task (EST). Using Weinberger, Schwartz, and Davidsons (1979) approach, the present study implemented the Marlowe-Crowne Social Desirability and the Spielberger Trait Anxiety scales for selection. Participants viewed neutral or negative words during the EST but responded to the color of the word. Analysis of continuous EEG recordings for the negative vs. neutral words revealed that the repressor group differed significantly from the other two groups in many aspects but that low- vs. high-anxious groups differed in fewer aspects. Based upon Eysenck and Derakshans (1997) model, repressor women appear to differ from low- and high-anxious women by utilizing an inhibitory process to avoid perceiving low-intensity threatening stimuli.

Deception Processing by Third-Party Observers: The Role of Speaker Intent

Deception studies typically focus on the deceiver (or the deceived), with lie detection of paramount concern. Consequently, little attention has been paid to the experience of third-party observers of deceptive communications. In the current study, therefore, we investigated the impact of deception priming on the subsequent information processing of outsiders, with a primary focus on the intent to deceive. Participants read pairs of stories (A and B) depicting everyday interpersonal interactions. In Story A, a phrase was rendered truthful, intentionally deceptive, or unintentionally misleading by context. In Story B, this same phrase was initially presented ambiguously, but followed by a sentence revealing it to be intentionally deceptive. Reading about an intentionally deceptive (as opposed to truthful) speaker (Experiment 1) and an unintentionally deceptive (as opposed to unintentionally misleading) speaker (Experiment 2) in Story A primed faster reading of the “deception” sentence in Story B. These results support the possibility of deception priming and suggest that observers are sensitive to intent (and not mere falsity) when exposed to misinformation scenarios.