Sensory Symptoms and Processing of Nonverbal Auditory and Visual Stimuli in Children with Autism Spectrum Disorder.

Atypical sensory responses are common in autism spectrum disorder (ASD). While evidence suggests impaired auditory-visual integration for verbal information, findings for nonverbal stimuli are inconsistent. We tested for sensory symptoms in children with ASD (using the Adolescent/Adult Sensory Profile) and examined unisensory and bisensory processing with a nonverbal auditory-visual paradigm, for which neurotypical adults show bisensory facilitation. ASD participants reported more atypical sensory symptoms overall, most prominently in the auditory modality. On the experimental task, reduced response times for bisensory compared to unisensory trials were seen in both ASD and control groups, but neither group showed significant race model violation (evidence of intermodal integration). Findings do not support impaired bisensory processing for simple nonverbal stimuli in high-functioning children with ASD.

Can simultaneously acquired electrodermal activity improve accuracy of fMRI detection of deception?

Observation of changes in autonomic arousal was one of the first methodologies used to detect deception. Electrodermal activity (EDA) is a peripheral measure of autonomic arousal and one of the primary channels used in polygraph exams. In an attempt to develop a more central measure to identify lies, the use of functional magnetic resonance imaging (fMRI) to detect deception is being investigated. We wondered if adding EDA to our fMRI analysis would improve our diagnostic ability. For our approach, however, adding EDA did not improve the accuracy in a laboratory-based deception task. In testing for brain regions that replicated as correlates of EDA, we did find significant associations in right orbitofrontal and bilateral anterior cingulate regions. Further work is required to test whether EDA improves accuracy in other testing formats or with higher levels of jeopardy.

Functional MRI detection of deception after committing a mock sabotage crime.

Using Blood Oxygen Level Dependent (BOLD) functional MRI (fMRI) to detect deception is feasible in simple laboratory paradigms. A mock sabotage scenario was used to test whether this technology would also be effective in a scenario closer to a real-world situation. Healthy, nonmedicated adults were recruited from the community, screened, and randomized to either a Mock-crime group or a No-crime group. The Mock-crime group damaged and stole compact discs (CDs), which contained incriminating video footage, while the No-crime group did not perform a task. The Mock-crime group also picked up an envelope from a researcher, while the No-crime group did not perform this task. Both groups were instructed to report that they picked up an envelope, but did not sabotage any video evidence. Participants later went to the imaging center and were scanned while being asked questions regarding the mock crime. Participants also performed a simple laboratory based fMRI deception testing (Ring-Watch testing). The Ring-Watch testing consisted of "stealing" either a watch or a ring. The participants were instructed to report that they stole neither object. We correctly identified deception during the Ring-Watch testing in 25 of 36 participants (Validated Group). In this Validated Group for whom a determination was made, computer-based scoring correctly identified nine of nine Mock-crime participants (100% sensitivity) and five of 15 No-crime participants (33% specificity). BOLD fMRI presently can be used to detect deception concerning past events with high sensitivity, but low specificity.

A single 20 mg dose of the full D1 dopamine agonist dihydrexidine (DAR-0100) increases prefrontal perfusion in schizophrenia.

Dopamine D1 receptors play an important role in memory and cognition in non-human primates. Dopamine D1 agonists have been shown to reverse performance deficits in both aged non-human primates and in primates with lesions to dopamine systems. This study explored whether a single dose of the first full D1 agonist dihydrexidine (DAR-0100) would cause changes in brain activity (perfusion) in dopamine-rich brain regions. We used a new gadolinium-contrast magnetic resonance perfusion scanning technique to measure brain activity. A within-subject cross-over double-blind randomized design was used in 20 adults with SCID-diagnosed schizophrenia. Each morning at 0800 h, they were scanned on a 3.0 T MRI scanner for perfusion. They then received either 20 mg of dihydrexidine, or placebo, subcutaneously over 15 min. Over the next 45 min, they had intermittent MRI scans. Two days later, they had a repeat of the Day 1 schedule, but received the opposite treatment from that given on the first day. Within-day, as well as between-day, comparisons were made to test for perfusion effects of dihydrexidine. Analysis revealed that dihydrexidine induced a significant increase in both prefrontal and non-prefrontal perfusion compared to placebo. The greatest increases occurred approximately 20 min after dihydrexidine infusion, consistent with the short pharmacokinetic half-life of dihydrexidine. These data are consistent with the hypothesis formulated from studies of non-human primates that dihydrexidine and other D1 agonists may be able to modulate prefrontal dopaminergic function.

A single 20 mg dose of dihydrexidine (DAR-0100), a full dopamine D1 agonist, is safe and tolerated in patients with schizophrenia.

The potential of dopamine D(1) receptor agonists to have beneficial effects on cognitive function has been suggested by a body of preclinical evidence. We now report the use of dihydrexidine (DAR-0100), the first full D(1) agonist, in a pilot study assessing single low dose safety and tolerability in patients with schizophrenia. A within-subject cross-over design was used in 20 adults (18-65 years) with SCID-IV diagnosed schizophrenia. Subjects were outpatients with a moderate level of residual negative symptoms, and were on stable dosing of non-D(1)-blocking antipsychotic drugs. Following screening, subjects were hospitalized for 48 h, and at 0800 h each morning scanned on a 3 T MRI scanner for resting brain perfusion, followed by a Blood Oxygen Level Dependent (BOLD) fMRI scan during an N-Back working memory task. They then received 20 mg subcutaneously (SC) of dihydrexidine or placebo over 15 min, followed by 45 min of intermittent MRI scans of perfusion and BOLD activity during the working memory task. Blood was drawn for serum drug levels and subjects were evaluated for clinical and cognitive changes. The procedure was repeated using the opposite challenge 2 days later. Dihydrexidine was well tolerated with no serious adverse events although three subjects had mild dizziness and five subjects experienced nausea. There was no significant effect of drug on clinical interview ratings or delayed (afternoon) neuropsychological performance. No medication interactions were seen. Thus, a single subcutaneous dose of dihydrexidine is tolerated and safe in patients with schizophrenia and does not produce delayed clinical or neuropsychological improvements.

Detecting deception using functional magnetic resonance imaging.

BACKGROUND: The ability to accurately detect deception is presently very limited. Detecting deception might be more accurately achieved by measuring the brain correlates of lying in an individual. In addition, a method to investigate the neurocircuitry of deception might provide a unique opportunity to test the neurocircuitry of persons in whom deception is a prominent component (i.e., conduct disorder, antisocial personality disorder, etc.). METHODS: In this study, we used functional magnetic resonance imaging (fMRI) to show that specific regions were reproducibly activated when subjects deceived. Subjects participated in a mock crime stealing either a ring or a watch. While undergoing an fMRI, the subjects denied taking either object, thus telling the truth with some responses, and lying with others. A Model-Building Group (MBG, n = 30) was used to develop the analysis methods, and the methods were subsequently applied to an independent Model-Testing Group (MTG, n = 31). RESULTS: We were able to correctly differentiate truthful from deceptive responses, correctly identifying the object stolen, for 93% of the subjects in the MBG and 90% of the subjects in the MTG. CONCLUSIONS: This is the first study to use fMRI to detect deception at the individual level. Further work is required to determine how well this technology will work in different settings and populations.