Risk-promoting effects of reward-paired cues in human sign- and goal-trackers

Animal research suggests trait-like individual variation in the degree of incentive salience attribution to reward-predictive cues, defined phenotypically as sign-tracking (high) and goal-tracking (low incentive salience attribution). While these phenotypes have been linked to addiction features in rodents, their translational validity is less clear. Here, we examined whether sign- and goal-tracking in healthy human volunteers modulates the effects of reward-paired cues on decision making. Sign-tracking was measured in a Pavlovian conditioning paradigm as the amount of eye gaze fixation on the reward-predictive cue versus the location of impending reward delivery. In Study 1 (Cherkasova et al., 2018), participants were randomly assigned to perform a binary choice task in which rewards were either accompanied (cued, n = 63) or unaccompanied (uncued, n = 68) by money images and casino jingles. In Study 2, participants (n = 58) performed cued and uncued versions of the task in a within-subjects design. Across both studies, cues promoted riskier choice. Sign-tracking was not associated with risky choice in either study. Goal-tracking rather than sign-tracking was significantly associated with greater risk-promoting effects of cues in Study 1 but not in Study 2, although the direction of findings was consistent across both studies. These findings are at odds with the notion of sign-trackers being preferentially susceptible to the influence of reward cues on behavior and point to the role of mechanisms besides incentive salience in mediating such influences.

Erratum to: Anti-topoisomerase 1 Antibody Level Changes after B Cell Depletion Therapy in Systemic Sclerosis

An Erratum to this paper has been published: https://doi.org/10.1134/S1607672923050022

Erratum to: Different Clinical Relevance of Anti-Citrullinated Protein Antibodies in RA Patients

An Erratum to this paper has been published: https://doi.org/10.1134/S1607672923050034

Erratum to: Antibodies to Domain I β2-Glycoprotein 1 in Patients with Antiphospholipid Syndrome and Systemic Lupus Erythematosus

An Erratum to this paper has been published: https://doi.org/10.1134/S160767292305006X

Erratum to: Global Antiphospholipid Syndrome Score (GAPSS) in Patients with Systemic Lupus Erythematosus

An Erratum to this paper has been published: https://doi.org/10.1134/S1607672923050046

Noninvasive Neuromodulation in Parkinson's Disease: Insights from Animal Models

The mainstay treatments for Parkinson's Disease (PD) have been limited to pharmacotherapy and deep brain stimulation. While these interventions are helpful, a new wave of research is investigating noninvasive neuromodulation methods as potential treatments. Some promising avenues have included transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), electroconvulsive therapy (ECT), and focused ultrasound (FUS). While these methods are being tested in PD patients, investigations in animal models of PD have sought to elucidate their therapeutic mechanisms. In this rapid review, we assess the available animal literature on these noninvasive techniques and discuss the possible mechanisms mediating their therapeutic effects based on these findings.

Anti-topoisomerase 1 Antibody Level Changes after B Cell Depletion Therapy in Systemic Sclerosis

The aim of our study was to assess the relationship between the changes of antinuclear autoantibodies (ANAs) and autoantibodies to topoisomerase 1 (anti-Topo 1) in systemic sclerosis (SSs) patients on rituximab (RTX) therapy. The prospective study included 88 patients (73 women) with a mean age of 47 (17-71) years. The mean disease duration was 5.9 ± 4.8 years. The mean follow-up period was more than 2 years (27 (12-42) months). We documented a statistically significant change in skin score, the disease activity index, improvement of pulmonary function and reduction of mean dose of prednisolone after RTX treatment. There was a significant decrease in the number of patients with high levels of ANA and overall decrease of the ANA and anti-Topo 1 levels. A moderate positive statistically significant correlation was found between ANA and anti-Topo 1 (r = 0.403). In the group of patients positive for anti-Topo 1 there were a more pronounced depletion of B lymphocytes, significantly higher increase in forced vital capacity and diffusion capacity, decrease in the disease activity index, compared with patients negative for anti-Topo 1. We observed the decline in the level of ANA and anti-Topo 1 in SSc patients after RTX therapy, and it was correlated by an improvement of the main outcome parameters of the disease. Therefore, anti-Topo 1 positivity could be considered as a predictor of a better response to RTX treatment, especially in SSc patients with hyperproduction of anti-Topo 1.

Antibodies to Domain I β2-Glycoprotein 1 in Patients with Antiphospholipid Syndrome and Systemic Lupus Erythematosus

The role of antiphospholipid antibodies (aPL), which are not included in the Sydney diagnostic criteria, in antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE) is poorly understood. The aim of this study was to determine the clinical significance of IgG antibodies for domain 1 of β2-glycoprotein 1 (β2-GP1), IgG anti-β2-GP1DI, in patients with APS with and without SLE. The study included 187 patients with APS with or without SLE, 49 patients formed the comparison group, and 100 apparently healthy individuals formed the control group. IgG/IgM antibodies to cardiolipin (aCL) and IgG/IgM anti-β2-GP1 were determined by enzyme immunoassay (ELISA) in patients with or without APS, and IgG anti-β2-GP1DI was determined by chemiluminescence assay (CLA) in all patients and controls. IgG anti-β2-GP1DI was detected in 37 (71%) of 52 patients with primary APS (PAPS), in 6 (50%) of 12 patients with probable APS, in 42 (71%) of 59 patients with SLE + APS, in 17 (26%) of 64 patients with SLE, in 1 (2%) of the comparison group, and in none of the control group. IgG anti-β2-GP1DI was significantly associated with PAPS and SLE + APS compared with the patients with SLE (p = 0.0002 and 0.0001, respectively). The association of IgG anti-β2-GP1DI with clinical manifestations of APS (thrombosis (p = 0.001) and obstetric pathology (p = 0.04)) was detected. There was a significant association of IgG anti-β2-GP1DI with arterial thrombosis (p = 0.002) and with late gestational obstetric pathology (p = 0.01). High specificity of IgG anti-β2-GP1DI depending on the diagnosis and clinical manifestations of APS despite low sensitivity was noted: specificity was 84% for thrombosis, 94% for obstetric pathology, and 89% for APS. Isolated IgG anti-β2-GP1DI positivity was reported in 2% of 50 aPL-negative patients and was not associated with APS manifestations. The frequency of IgG anti-β2-GP1DI detection was higher in the patients with APS compared to the patients with SLE, comparison group, and control (p < 0.05). Positive IgG anti-β2-GP1DI values were significantly associated with thrombotic complications and with obstetric pathology (p = 0.002 and p = 0.01, respectively). Specificity of IgG anti-β2-GP1DI for APS and its clinical manifestations (thrombosis and obstetric pathology) was higher than sensitivity (89, 94, and 84%, respectively).

Global Antiphospholipid Syndrome Score (GAPSS) in Patients with Systemic Lupus Erythematosus

The Global Antiphospholipid Syndrome Score (GAPSS) is a tool proposed to quantify the risk of clinical manifestations associated with antiphospholipid antibodies (aPL) and certain cardiovascular risk factors. To validate GAPSS in a cohort of patients with systemic lupus erythematosus in Russia. 115 patients with SLE were included in the study, including 51 (44%) patients with systemic lupus erythematosus (SLE) with antiphospholipid syndrome (APS), 14 (12%) SLE patients with aPL, and 50 (44%) patients with SLE. There was a history of thrombosis in 58 (50%) out of 115 patients; of them, 14 (24%) had arterial thrombosis, 29 (50%) had venous thrombosis, and 15 (26%) had combined thrombosis. Pregnancy against the background of the disease occurred in 43 women included in the study. Of them, 29 (67%) had obstetric pathology. Patients with thrombosis and obstetric pathology had a GAPSS score of 7.17 ± 5.64 versus 4.48 ± 4.55 without these manifestations (p = 0.0003). There was a significant association between GAPSS levels and thrombosis: patients with thrombosis had a GAPSS of 7.31 ± 5.70, those without thrombosis-4.00 ± 4.81 (p = 0.001). GAPPS values were higher in arterial thrombosis compared to venous thrombosis (10.40 ± 25.30 versus 5.82 ± 5.28, p = 0.01). GAPSS levels  ≥ 6 and  ≥10 were analyzed to select GAPSS values at which a high risk of recurrent thrombosis and/or obstetric pathology could be indicated. All GAPSS levels had a significant association with clinical manifestations of APS. The quality of GAPSS by ROC analysis showed an area under the curve (AUC) for GAPSS of 0.697. GAPSS can be used to assess the risk of recurrence or development of thrombosis and/or obstetric pathology in patients with SLE in the Russian Federation. The GAPSS ≥6 values should be used to stratify patients with SLE into high risk group for recurrence of vascular complications. Further prospective follow-up is needed to confirm the value of GAPSS.

Different Clinical Relevance of Anti-Citrullinated Protein Antibodies in RA Patients

The objective of the study was to find a potential relationship between ACPAs and disease activity, bone destruction, and ACPA responses to various therapeutic regimens. The study included 232 patients with rheumatoid arthritis (RA); 90 patients had early RA, and 142 patients had an advanced stage of the disease. 77 (85.6%) patients with early RA were highly positive for anti-CCP, and 29 (70.7%) patients were highly positive for anti-MCV. A positive correlation was found between anti-MCV and DAS28 (r = 0.4; p = 0.04). As for advanced RA, 78 (80.4%) patients were high-positive for anti-CCP, and 70 (79.5%) were high-positive for anti-MCV. There was a positive correlation between anti-MCV concentration and SDAI (r = 0.4; p = 0.02), as well as CDAI (r = 0.4; p = 0.02). No significant correlations were found between the anti-CCP levels and activity indices, anti-CCP and acute-phase parameters in both early and advanced RA groups. Higher total Sharp scores (96.5 (65.0-122.0)) were found in pts highl-positive for anti-MCV (n = 79), compared to low-positive/negative (n = 27) patients (57.0 (31.0-88.0); p < 0.05). Anti-MCV levels dropped significantly in pts on rituximab and tocilizumab therapy at weeks 12 and 24 after initiation of treatment, while high anti-CCP concentration persisted throughout the treatment. Anti-MCV levels correlated with inflammatory activity and development of bone destruction and decreased in pts on treatment. Anti-CCP was less responsive and showed minor changes during treatment; therefore, its thorough monitoring was not feasible.

Antibodies to the phosphatidylserine/prothrombin complex in the diagnosis of antiphospholipid syndrome

Aim. To determine the significance of antibodies to the phosphatidylserine/prothrombin complex (aPS/PT) in patients with systemic lupus erythematosus (SLE) antiphospholipid syndrome (APS). Materials and methods. A total of 190 patients were included in the study: 123 (64.7%) with reliable SLE and 55 (29%) with PAPS. The control group included 100 relatively healthy subjects of comparable age. All patients were tested for classical aPL as well as IgG/IgM-anti-PS/PT by enzyme immunoassay. Results. Based on the average values of IgG/IgM aPS/PT of the control group, the levels of positivity were allocated mean (M) + 3 or 5 standard deviations (SD): M+3SD and M+5SD. IgG aPS/PT levels above 73.6 U/ml (M+5SD) were more accurate diagnostic, for IgM aPS/PT above 18.0 U/ml. IgG-aPS/PT were detected in 84 (44%) of 190 patients. Levels above diagnostic levels were detected in 68 (65%) of 104 patients with APS (55 with PAPS and 59 with SLE+APS). Thrombosis was significantly more common in patients with IgG aPS/PT compared with patients negative for IgG aPS/PT. Arterial but not venous thrombosis was associated with IgG aPS/PT positivity. Conclusion. The frequency of detection of IgG aPS/PT in the examined patients was 44%, IgM aPS/PT 29% and their combination 19% of 190 patients. Half of the patients with probable APS had positive IgG aPS/PT and third IgM aPS/PT. Median IgG aPS/PT were significantly higher in patients with APS compared to patients without APS and the control group. Thrombosis was associated with IgG aPS/PT. Arterial thrombosis was significantly more frequently reported in patients with IgG aPS/PT. The sensitivity of IgG aPS/PT for reliable APS at levels greater than 73.6 units/ml was 59%, specificity 92%, for IgM aPS/PT 35% and 91%, respectively.

Review: Adult Outcome as Seen Through Controlled Prospective Follow-up Studies of Children With Attention-Deficit/Hyperactivity Disorder Followed Into Adulthood

OBJECTIVE

To describe adult outcome of people with attention-deficit/hyperactivity disorder (ADHD) diagnosed in childhood and its several key predictors via a review of 7 North American controlled prospective follow-up studies: Montreal, New York, Milwaukee, Pittsburgh, Massachusetts General Hospital (MGH), Berkeley, and 7-site Multimodal Treatment Study of Children With ADHD (MTA).

METHOD

All studies were prospective and followed children with a diagnosis of ADHD and an age- and gender-matched control group at regular intervals from childhood (6-12 years of age) through adolescence into adulthood (20-40 years of age), evaluating symptom and syndrome persistence, functional outcomes, and predictors of these outcomes.

RESULTS

The rates of ADHD syndrome persistence ranged from 5.7% to 77%, likely owing to varying diagnostic criteria and the source of information (self-report vs informant report) across the studies. However, all studies observed high rates of symptomatic persistence ranging from 60% to 86%. The 7 studies were largely consistent in finding that relative to control groups, research participants with childhood-diagnosed ADHD had significant impairments in the areas of educational functioning, occupational functioning, mental health, and physical health as well as higher rates of substance misuse, antisocial behavior, and unsafe driving. The most consistently observed predictors of functional outcomes included ADHD persistence and comorbidity, especially with disruptive behavior disorders.

CONCLUSION

Childhood ADHD has high rates of symptomatic persistence, which is associated with negative functional outcomes. Characteristics that predict these negative outcomes, such as comorbid disruptive behavior disorders, may be important targets for intervention.

Cortical morphology predicts placebo response in multiple sclerosis

Despite significant insights into the neural mechanisms of acute placebo responses, less is known about longer-term placebo responses, such as those seen in clinical trials, or their interactions with brain disease. We examined brain correlates of placebo responses in a randomized trial of a then controversial and now disproved endovascular treatment for multiple sclerosis. Patients received either balloon or sham extracranial venoplasty and were followed for 48 weeks. Venoplasty had no therapeutic effect, but a subset of both venoplasty- and sham-treated patients reported a transient improvement in health-related quality of life, suggesting a placebo response. Placebo responders did not differ from non-responders in total MRI T2 lesion load, count or location, nor were there differences in normalized brain volume, regional grey or white matter volume or cortical thickness (CT). However, responders had higher lesion activity. Graph theoretical analysis of CT covariance showed that non-responders had a more small-world-like CT architecture. In non-responders, lesion load was inversely associated with CT in somatosensory, motor and association areas, precuneus, and insula, primarily in the right hemisphere. In responders, lesion load was unrelated to CT. The neuropathological process in MS may produce in some a cortical configuration less capable of generating sustained placebo responses.

Study of antiphospholipid antibodies by enzyme immunoassay and chemiluminescent methods in patients with antiphospholipid syndrome and systemic lupus erythematosus (preliminary data)

Antiphospholipid antibodies (aPL) are a family of different autoantibodies that lead to recurrent vascular thrombosis of any localization and caliber, and/or obstetric pathology - fetal loss. Serological markers of antiphospholipid syndrome (APS) include only three types of aPL - lupus anticoagulant (VA), antibodies to cardiolipin (aCL) classes IgG and IgM, antibodies to β2-glycoprotein1 (aβ2GP1) classes IgG and IgM. Medium and high levels of aCL and aß2HP1 (IgG and / or IgM) were selected as serological markers of APS in the 2006 classification criteria. However, the threshold of values used from low to moderately high levels has not been standardized. aPL standardization issues are still unresolved, resulting in heterogeneous results of the ongoing studies. The aim of the study was to assess the comparability IgG/IgM-aCL and IgG/IgM-ab2GP1 by enzyme-linked immunosorbent assay and chemiluminescent analysis in patients with APS with and without (systemic lupus erythematosus) SLE. The study included 70 patients (49 women and 21 men) with APS, of which 21 (30%) were with primary APS (pAPS) and 49 (70%) with APS in combination with SLE. All study participants underwent determination of IgG/IgM-aCL and IgG/IgM-aβ2GP1 by enzyme-linked immunosorbent. A study was performed by the chemiluminescent analysis: IgG/IgM-aCL - in 70 patients; IgG/IgM-aβ2GP1 - in 69 patients. Results. According to preliminary data, the determination of IgG-aCL and IgG-aβ2GP1 by the chemiluminescent analysis is informative in assessing positivity according to the manufacturer, compared with the enzyme-linked immunosorbent (p < 0.05). However, when taking into account the levels of antibody positivity determined by enzyme-linked immunosorbent, the level of positive values according to chemiluminescent analysis was much higher than the performance of the manufacturer.

A Monte Carlo approach for improving transient dopamine release detection sensitivity

Current methods using a single PET scan to detect voxel-level transient dopamine release-using F-test (significance) and cluster size thresholding-have limited detection sensitivity for clusters of release small in size and/or having low release levels. Specifically, simulations show that voxels with release near the peripheries of such clusters are often rejected-becoming false negatives and ultimately distorting the F-distribution of rejected voxels. We suggest a Monte Carlo method that incorporates these two observations into a cost function, allowing erroneously rejected voxels to be accepted under specified criteria. In simulations, the proposed method improves detection sensitivity by up to 50% while preserving the cluster size threshold, or up to 180% when optimizing for sensitivity. A further parametric-based voxelwise thresholding is then suggested to better estimate the release dynamics in detected clusters. We apply the Monte Carlo method to a pilot scan from a human gambling study, where additional parametrically unique clusters are detected as compared to the current best methods-results consistent with our simulations.

Gambling disorder is associated with reduced sensitivity to expected value during risky choice

BACKGROUND AND AIMS

Individuals with gambling disorder display increased levels of risk-taking, but it is not known if it is associated with an altered subjective valuation of gains and/or losses, perception of their probabilities, or integration of these sources of information into expected value.

METHODS

Participants with gambling disorder (n = 48) were compared with a healthy comparison group (n = 35) on a two-choice lottery task that involved either gains-only or losses-only gambles. On each trial, two lotteries were displayed, showing the associated probability and magnitude of the possible outcome for each. On each trial, participants chose one of the two lotteries, and the outcome was revealed.

RESULTS

Choice behaviour was highly sensitive to the expected value of the two gambles in both the gain and loss domains. This sensitivity to expected value was attenuated in the group with gambling disorder. The group with gambling disorder used both probability and magnitude information less, and this impairment was greater for probability information. By contrast, they used prior feedback (win vs loss) to inform their next choice, despite the independence of each trial. Within the gambling disorder group, problem gambling severity and trait gambling-related cognitions independently predicted reduced sensitivity to expected value. The majority of observed effects were consistent across both gain and loss domains.

DISCUSSION AND CONCLUSIONS

Our results provide a thorough characterization of decision processes in gain and loss domains in gambling disorder, and place these problems in the context of theoretical constructs from behavioural economics.

Zoned in or zoned out? Investigating immersion in slot machine gambling using mobile eye-tracking

BACKGROUND AND AIMS

Immersion during slot machine gambling has been linked to disordered gambling. Current conceptualizations of immersion (namely dissociation, flow and the machine zone) make contrasting predictions as to whether gamblers are captivated by the game per se ('zoned in') or motivated by the escape that immersion provides ('zoned out'). We examined whether selected eye-movement metrics can distinguish between these predictions.

DESIGN AND SETTING

Pre-registered, correlational analysis in a laboratory setting. Participants gambled on a genuine slot machine for 20 minutes while wearing eye-tracking glasses.

PARTICIPANTS

Fifty-three adult slot machine gamblers who were not high-risk problem gamblers.

MEASUREMENTS

We examined self-reported immersion during the gambling session and eye movements at different areas of the slot machine screen (the reels, the credit window, etc.). We further explored these variables' relationships with saccade count and amplitude.

FINDINGS

The ratio of dwell time on the game's credit window relative to the game's reels was positively associated with immersion (t₍₅₁₎  = 1.68, P = 0.049 one-tailed, R²  = 0.05). Follow-up analyses described event-related changes in these patterns following different spin outcomes.

CONCLUSIONS

Immersion while gambling on a slot machine appears to be associated with active scanning of the game and a focus on the game's credit window. These results are more consistent with a 'zoned in' account of immersion aligned with flow theory than a 'zoned out' account based on escape.

Efficacy of Cognitive Behavioral Therapy With and Without Medication for Adults With ADHD: A Randomized Clinical Trial

Objective: Recent trials have demonstrated efficacy of cognitive behavioral therapy (CBT) in medicated adults with ADHD. Efficacy of CBT in unmedicated versus medicated adults remains mostly unknown. We evaluated the effects of group CBT alone versus combined with medication on ADHD symptoms and functional outcomes in adult patients. Method: Eighty-eight adults with ADHD received 12 manualized group CBT sessions, accompanied by individual coaching, either without (n = 46) or with (n = 42) medication. Treatment effects were evaluated following treatment and 3-month and 6-month follow-up using un-blinded self-report and observer ratings. Results: CBT + medication resulted in greater improvements than CBT alone in ADHD symptoms, organizational skills, and self-esteem. Group differences diminished over follow-up, as the CBT alone group continued improving, while the combined group maintained the gains. Conclusion: CBT + medication outperformed CBT alone for ADHD symptoms, organizational skills, and self-esteem, although its superiority tended to decrease over follow-up.

Dopamine replacement remediates risk aversion in Parkinson's disease in a value-independent manner

INTRODUCTION

Clinical evidence suggests that Parkinson's Disease (PD) patients are risk averse. Dopaminergic therapy has been reported to increase risk tolerance, but the underlying mechanisms are unclear. Some studies have suggested an amplification of subjective reward value, consistent with the role of dopamine in reward value coding. Others have reported value-independent risk enhancement. We evaluated the value-dependence of the effects of PD and its therapy on risk using tasks designed to sensitively measure risk over a wide range of expected values.

METHOD

36 patients with idiopathic PD receiving levodopa monotherapy and 36 healthy matched controls performed two behavioural economic tasks aimed at quantifying 1) risk tolerance/aversion in the gain frame and 2) valuation of potential gains relative to losses. PD patients performed the tasks on and off their usual dose of levodopa in randomized order; controls performed the same tasks twice.

RESULTS

Relative to the controls, unmedicated PD patients showed significant value-independent risk aversion in the gain frame, which was normalized by levodopa. PD patients did not differ from controls in their valuation of gains relative to losses. However, across both tasks and regardless of medication, choices of the patients were more determined by expected values of the prospects than those of controls.

CONCLUSION

Dopamine deficiency in PD was associated with risk aversion, and levodopa promoted riskier choice in a value-independent manner. PD patients also showed an increased sensitivity to expected value, which was independent of levodopa and does not appear to result directly from dopamine deficiency.

[The role of laboratory biomarkers in monitoring of rituximab biosimilar therapy (Acellbia, "BIOCAD") in patients with rheumatoid arthritis]

AIM

to evaluate the role of laboratory biomarkers in monitoring effectiveness of rituximab (RTM) biosimilar therapy in a total dose of 1200 mg.

MATERIALS AND METHODS

20 patients (pts) with rheumatoid arthritis (RA) (18 woman, mean age 61.5(54-66.5) years, mean disease duration 39.5(20-84) months, mean DAS28 5.6(4.9-6.8)) received two intravenous RTM biosimilar infusions (600 mg №2) in combination with DMARDs and glucocorticoids. Laboratory biomarkers were assessed at baseline and weeks 12 and 24 after the first infusion of RTX.

RESULTS

RTM biosimilar induced decreases in DAS28, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) at week 12 and 24, p.

Win-Concurrent Sensory Cues Can Promote Riskier Choice

Reward-related stimuli can potently influence behavior; for example, exposure to drug-paired cues can trigger drug use and relapse in people with addictions. Psychological mechanisms that generate such outcomes likely include cue-induced cravings and attentional biases. Recent animal data suggest another candidate mechanism: reward-paired cues can enhance risky decision making, yet whether this translates to humans is unknown. Here, we examined whether sensory reward-paired cues alter decision making under uncertainty and risk, as measured respectively by the Iowa Gambling Task and a two-choice lottery task. In the cued versions of both tasks, gain feedback was augmented with reward-concurrent audiovisual stimuli. Healthy human volunteers (53 males, 78 females) performed each task once, one with and the other without cues (cued Iowa Gambling Task/uncued Vancouver Gambling Task: n = 63; uncued Iowa Gambling Task/cued Vancouver Gambling Task: n = 68), with concurrent eye-tracking. Reward-paired cues did not affect choice on the Iowa Gambling Task. On the two-choice lottery task, the cued group displayed riskier choice and reduced sensitivity to probability information. The cued condition was associated with reduced eye fixations on probability information shown on the screen and greater pupil dilation related to decision and reward anticipation. This pupil effect was unrelated to the risk-promoting effects of cues: the degree of pupil dilation for risky versus risk-averse choices did not differ as a function of cues. Together, our data show that sensory reward cues can promote riskier decisions and have additional and distinct effects on arousal.SIGNIFICANCE STATEMENT Animal data suggest that reward-paired cues can promote maladaptive reward-seeking by biasing cost-benefit decision making. Whether this finding translates to humans is unknown. We examined the effects of salient reward-paired audiovisual cues on decision making under risk and uncertainty in human volunteers. Cues had risk-promoting effects on a risky choice task and independently increased task-related arousal as measured by pupil dilation. By demonstrating risk-promoting effects of cues in human participants, our data identify a mechanism whereby cue reactivity could translate into maladaptive behavioral outcomes in people with addictions.

Habitual exercisers versus sedentary subjects with Parkinson's Disease: Multimodal PET and fMRI study

BACKGROUND

The benefits of exercise in PD have been linked to enhanced dopamine (DA) transmission in the striatum.

OBJECTIVE

To examine differences in DA release, reward signaling, and clinical features between habitual exercisers and sedentary subjects with PD.

METHODS

Eight habitual exercisers and 9 sedentary subjects completed [¹¹ C]raclopride PET scans before and after stationary cycling to determine exercise-induced release of endogenous DA in the dorsal striatum. Additionally, functional MRI assessed ventral striatum activation during reward anticipation. All participants completed motor (UPDRS III; finger tapping; and timed-up-and-go) and nonmotor (Beck Depression Inventory; Starkstein Apathy Scale) assessments.

RESULTS

[¹¹ C]Raclopride analysis before and after stationary cycling demonstrated greater DA release in the caudate nuclei of habitual exercisers compared to sedentary subjects (P < 0.05). Habitual exercisers revealed greater activation of ventral striatum during the functional MRI reward task (P < 0.05) and lower apathy (P < 0.05) and bradykinesia (P < 0.05) scores versus sedentary subjects.

CONCLUSIONS

Habitual exercise is associated with preservation of motor and nonmotor function, possibly mediated by increased DA release. This study formulates a foundation for prospective, randomized controlled studies. © 2018 International Parkinson and Movement Disorder Society.

Differential Associations between Cortical Thickness and Striatal Dopamine in Treatment-Naïve Adults with ADHD vs. Healthy Controls

Alterations in catecholamine signaling and cortical morphology have both been implicated in the pathophysiology of attention deficit/hyperactivity disorder (ADHD). However, possible links between the two remain unstudied. Here, we report exploratory analyses of cortical thickness and its relation to striatal dopamine transmission in treatment-naïve adults with ADHD and matched healthy controls. All participants had one magnetic resonance imaging (MRI) and two [¹¹C]raclopride positron emission tomography scans. Associations between frontal cortical thickness and the magnitude of d-amphetamine-induced [¹¹C]raclopride binding changes were observed that were divergent in the two groups. In the healthy controls, a thicker cortex was associated with less dopamine release; in the ADHD participants the converse was seen. The same divergence was seen for baseline D2/3 receptor availability. In healthy volunteers, lower D2/3 receptor availability was associated with a thicker cortex, while in the ADHD group lower baseline D2/3 receptor availability was associated with a thinner cortex. Individual differences in cortical thickness in these regions correlated with ADHD symptom severity. Together, these findings add to the evidence of associations between dopamine transmission and cortical morphology, and suggest that these relationships are altered in treatment-naïve adults with ADHD.

Information Processing during Face Recognition: The Effects of Familiarity, Inversion, and Morphing on Scanning Fixations

Where we make ocular fixations when viewing an object likely reflects interactions between ‘external’ object properties and internal ‘top - down’ factors, as our perceptual system tests hypotheses and attempts to make decisions about our environment. These scanning fixation patterns can tell us how and where the visual system gathers information critical to specific tasks. We determined the effects of the internal factors of expertise, experience, and ambiguity on scanning during a face-recognition task, in eight subjects. To assess the effects of expertise, we compared upright with inverted faces, since it is hypothesized that inverted faces do not access an orientation-dependent face-expert processor. To assess the effects of experience, we compared famous with novel faces, as famous faces would have stronger internal representations than anonymous ones. Ambiguity in matching seen and remembered faces was manipulated with morphed faces. We measured three classes of variables: (i) total scanning time and fixations; (ii) the spatial distribution of scanning; and (iii) the sequence of scanning, using first-order Markov matrices for local scan structure and string editing for global scan structure. We found that, with inverted faces, subjects redistributed fixations to the mouth and lower face, and their local and global scan structure became more random. With novel or morphed faces, they scanned the eyes and upper face more. Local scan structure was not affected by familiarity, but global scan structure was least random (most stereotyped) for novel upright faces. We conclude that expertise (upright faces) leads to less lower-face scanning and more predictable global patterns of information gathering. Experience (famous faces) leads to less upper-face scanning and more idiosyncratic global scan structures, suggesting a superseding influence of facial memories. With morphed faces, subjects return to the upper face to resolve ambiguity, implying a greater importance of this region in face recognition.

[The clinical informativeness of detection of antibodies to citrullinated proteins under rheumatoid arthritis]

The main diagnostic laboratory markers of rheumatoid arthritis are IgM rheumatoid factor and antibodies to citrullinated proteins. The IgM rheumatoid factor is a sensitive but insufficiently specific marker of rheumatoid arthritis. The antibodies to citrullinated proteins have a higher specificity for diagnostic of rheumatoid arthritis. The antibodies to cyclic citrullinated peptide and modified citrullinated vimentin are the main representatives of family of antibodies to citrullinated proteins applying in clinical diagnostic practice. The study was carried out to deternine the role of antibodies to citrullinated proteins and modified citrullinated vimentin in diagnostic, evaluation of activity and severity of destructive alterations under rheumatoid arthritis. The samplings of 993 patients with reliable diagnosis of rheumatoid arthritis. 179 patients with other rheumatoid diseases and 30 healthy donors were examined. The measurement of serum concentration of IgM rheumatoid factor and C-reactive protein was implemented by immune nephelometric analysis and antibodies to citrullinated proteins were analyzed by enzymoimmunoassay The erythrocyte sedimentation rate was established using the Westergreen technique. It was established that antibodies to modified citrullinated vimentin had the highest diagnostic specificity (83%), antibodies to cyclic citrullinated peptide had the highest diagnostic specificity (87%). The diagnostic specificity of joint detection of IgM rheumatoid factor, antibodies to citrullinated proteins and antibodies to modified citrullinated vimentin made up to 87%. In patients negative to rheumatoid factor the rate ofdetection of antibodies to citrullinated proteins made up to 34% and antibodies to modified citrullinated vimentin made up to 48%. The diagnostic effectiveness of detection of antibodies to citrullinitted proteins (ratio of likelihood of positive and negative results of test was correspondingly 5.5 and 0.3; area under ROC curve 0.8) and antibodies to modified citrullinated vimentin (ratio of likelihood of positive and negative results of test was correspondingly 4.4 and 0.2; area under ROC curve 0.9) surpassed the same in analysis of IgM rheumatoid factor (ratio of likelihood of positive results--3.2, ratio of likelihood of negative results--0.4, area under ROC curve--0.8). The weak positive correlation relationship was established between concentration of antibodies to cyclic citrillinatedpeptide/antibodies to modified citrullinated vimentin in blood serum and indicators of clinical laboratory activity of rheumatoid arthritis (ESR, CRP DAS 28, (r-0.2. p < 0.05). The high positive levels of antibodies to modified citrullinated vimentin associated with expressed destructive affection of joints (p < 0.02). The antibodies to cyclic citrullinated peptide are the most highly specific and clinically informative laboratory diagnostic marker of rheumatoid arthritis. The detection of antibodies to modified citrullinated vimentin is an important additional serological test to diagnose rheumatoid arthritis in IgM rheumatoid factor-negative and/or antibodies to cyclic citrullinated peptide-negative patients and to forecast severe destructive affection of joints under the given disease. The joint study of IgM rheumatoid factor, antibodies to cyclic citrullinated peptide and antibodies to modified citrullinated vimentin under rheumatoid arthritis has higher diagnostic sensitivity as compared with isolated antibodies to citrullinated proteins.

A brain network response to sham surgery

Evaluation of potential therapies for neurological disease has been challenging due to beneficial responses in patients receiving the sham/placebo treatment. Placebo effects are especially prominent in Parkinson's disease (PD), which has become a useful model for studying the neurobiology of placebo responses. In this issue of the JCI, Ko and colleagues identify a neural circuit associated with the placebo response in a PD patient cohort. The observed placebo effect-associated pattern involved metabolic activity increases that corresponded with long-term motor improvements after sham surgery. Presurgery activity in this network was inversely related to sham response, suggesting that this network has potential for identifying sham responders and thus reducing placebo-related variance in surgical trials.

Reduced dopamine response to amphetamine in subjects at ultra-high risk for addiction

BACKGROUND

Not everyone who tries addictive drugs develops a substance use disorder. One of the best predictors of risk is a family history (FH) of substance use problems. In part, this might reflect perturbed mesolimbic dopamine responses.

METHODS

We measured amphetamine-induced changes in [(11)C]raclopride binding in 1) high-risk young adults with a multigenerational FH of substance use disorders (n = 16); 2) stimulant drug-naïve healthy control subjects with no known risk factors for addiction (n = 17); and 3) subjects matched to the high-risk group on personal drug use but without a FH of substance use problems (n = 15).

RESULTS

Compared with either control group, the high-risk young adults with a multigenerational FH of substance use disorders exhibited smaller [(11)C]raclopride responses, particularly within the right ventral striatum. Past drug use predicted the dopamine response also, but including it as a covariate increased the group differences.

CONCLUSIONS

Together, the results suggest that young people at familial high risk for substance use disorders have decreased dopamine responses to an amphetamine challenge, an effect that predates the onset of addiction.

[The immunologic predictors of effect of anti-B-cell therapy under rheumatoid arthritis]

The article deals with results of study targeted to reveal laboratory biomarkers which can be useful in prognosis of effectiveness of rituximab therapy under rheumatoid arthritis. The sampling consisted of 34 patients with rheumatoid arthritis (31 women, average age 49 years, 42-64 years, mean duration of disease 66, 36-132 months). All patients were examined and received two infusions of rituximab intravenously with interval in 2 weeks against the background of standard therapy. The serum concentration of C-reactive protein, IgM rheumatoid factor IgG, IgM, IgA were measured using immune nephelometric method. The level of cyclic citrullinated peptide antibodies, modified citrullinated vimentin antibodies and IgA rheumatoid factor was measured using method of immune enzyme analysis. The panel of 27 cytokines was measured using multiplex technology xMAP. Before rituximab therapy indices DAS28 (6,12; 5. 52-6, 81), SDA1 (34.3; 23, 8-45, 9) and CDAI (31.3; 21, 8-38.5) corresponded to high activity of rheumatoid arthritis. Up to 24th week of therapy good response on criteria EULAR was registered in 15 patients, moderate response in 18 patients and was absent in 1 patient. The remission on DAS achieved more rarely in patients with initially negative/ low positive values of IgM rheumatoid factor, basal level of IgM less than 2.4 g/l and duration of disease more than 40 months. In the group of patients who attained remission on CDAI up to 24th week of therapy higher basal level of IL-IRA, IL-2, IL-8, IL-15, Eotaxin, GM-CSF, IFN-gamma, MIP-1alpha and TNF-alpha was registered In patients who attained remission on DAS 28 higher level of IL-1beta. IL-2, IL-6, G-CSF, IFN-gamma, MIP-1alpha and TNF-alpha was registered in comparison with patients with disease in active mode. The detection of basal level of IgM rheumatoid factor, IgM and also certain cytokines (IL-1beta, IL-IRA, IL-2, IL-8, IL-15, GM-CSF, IFN-gamma, MIP-1alpha, Eotaxin, TNF-alpha) can be useful in prognosis of effectiveness of rituximab therapy under rheumatoid arthritis.

[Relationship of the clinical efficiency of tocilizumab therapy to the serum level of matrix metalloproteinase-3 in patients with rheumatoid arthritis]

AIM

To evaluate the impact of tocilizumab (TCZ) therapy on the level of matrix metalloproteinase-3 (MMP-3) 4, 24, and 48 weeks after treatment initiation in relation to the clinical efficiency of TCZ therapy by the Disease Activity Score (DAS28), the Clinical Disease Activity Index (CDAI), and the Simplified Disease Activity Index (SDAI).

SUBJECTS AND METHODS

Forty-two rheumatoid arthritis (RA) patients who had received 6 intravenous infusions of TCZ 8 mg/kg at a 4-week interval during permanent therapy with disease-modifying anti-rheumatic drugs (DMARD) and glucocorticosteroids (GCS) were examined. Then TCZ was discontinued and the patients continued to receive the previous therapy with DMARD and GCS. The European League Against Rheumatism (EULAR) classification criteria, as well as SDAI and CDAI were used to evaluate the efficiency of TCZ therapy. The serum concentration of MMP-3 was measured by enzyme immunoassay using the test systems (Invitrogen, USA).

RESULTS

After 24 weeks of TCZ therapy (at 48 weeks following trial initiation), DAS28 was 4.69 (3.86; 5.44); the SDAI of 17.8 (10.7; 29.5) and the CDAI of 17.1 (7.2; 26.2) corresponded to moderate disease activity. At 48 weeks, DAS28 remission (< 2.6 scores) remained in 5 (11.90%) patients; SDAI (< or = 3.3 scores) and CDAI (< or = 2.8 scores) remissions did in 3 (7.1%) and 4 (9.5%) patients, respectively. There was a significant reduction in MMP-3 concentrations at 4, 24, and 48 weeks of the therapy, which was 61, 73, and 49.40% of the baseline level. ROC analysis indicated that the normalization of MMP-3 levels in RA patients at 24 weeks of TCZ therapy (a cut-off < or =16.5 ng/ml) was associated with the maintenance of remission/low disease activity from SDAI and CDAI 24 weeks after the drug use (the area under the receiver operating curve was 0.762; 95% confidence interval: 0.548-0.976).

CONCLUSION

Analysis of the results of 48-week TCZ therapy suggests its ability to reduce the levels of markers of bone and cartilage destruction in patients with RA. Serum MMP-3 determination at 24 weeks of therapy may be useful in predicting the maintenance of remission/low activity from SDAI and CDAI after discontinuation of the drug.

[Which patients with ovarian cancer shows the combination of trabectedin with pegylated liposomal doxorubicin]

Given the high rate of recurrence of ovarian cancer, the search for new therapeutic strategies are topical issue. According to various studies the effectiveness of drug treatment relapse depends on the platinum-free interval, increasing in proportion to its duration. If therapy is platinum-resistant recurrent ovarian cancer is a standard approach, the treatment of platinum-sensitive recurrent algorithm is not fully defined. Comparison of platinum and non-platinum combinations revealed the advantage of combined platinum- treatment for patients with platinum-free interval of more than 6 months without an increase in life expectancy. Non-platinum combination of trabected in with pegylated liposomal doxorubicin has shown comparable efficacy with an advantage in overall survival in patients with platinum-free interval of 6-12 months. A platinum-free interval prolongation by the use of non-platinum mode increases the efficiency of subsequent platinum-based therapy, increasing the life expectancy of patients. Currently under study molecular markers and prognostic factors allowing to define a group of patients who have the greatest benefit from the use trabectedin with pegylated liposomal doxorubicin as second-line chemotherapy.

[The comparative evaluation of the diagnostic value of methods of detection of antibodies to citrullinized proteins under rheumatoid arthritis]

The hyper production of large specter of autoantibodies, primarily rheumatoid factors and antibodies to citrullinized proteins, is a characteristic sign of rheumatoid arthritis. The detection of these antibodies plays an important role in diagnosing the disease, especially on its early stages. The study compared the diagnostic accuracy of different methods of detection of antibodies to citrullinized proteins under rheumatoid arthritis. The examined sample included 144 patients aged 33-58 years with reliable diagnosis of rheumatoid arthritis. The patients with systemic lupus erythematous, osteoarthritis, psoriatic arthritis, OVERLAP syndrome, ankylosing spondylitis and conditionally healthy donors consisted the comparative group. To detect antibodies to citrullinized proteins the methods of enzyme immunoassay, electrochemiluminescence, immunochromatography were applied. The study demonstrated that all the methods of detection of antibodies to citrullinized proteins have adequate diagnostic value to be implemented both in a routine clinical diagnostic practice and on the stage of screening of patients.

[Rituximab therapy for systemic manifestations and MALT lymphomas of the parotid gland in Sjögren's disease: preliminary data]

AIM

To evaluate the efficacy of rituximab (RT) in cryoglobulinemic vasculitis (CGV) and MALT lymphomas of the parotid gland (PG) in patients with Sjögren's disease (SD).

SUBJECTS AND METHODS

RT therapy was performed in 13 patients with SD and CGV and in 17 with SD and PC MALT lymphoma. Eleven patients with SD received RT monotherapy and 19 with this disease had combined therapy with RT and cyclophosphan (CP). RT was used intravenously dropwise at a dose of 500 mg weekly or once every two weeks in combination with intravenous dropwise CP 1000 mg the next day with 4-6 per course. For the diagnosis of MALT lymphomas, all the patients with SD underwent incisional PG biopsy under local anesthesia at the Research Institute of Rheumatology, Russian Academy of Medical Sciences. PG biopsy specimens were histologically and immunohistochemically studied at the Russian Cancer Research Center, Russian Academy of Medical Sciences. In 11 cases, B-cell clonality was identified from immunoglobulin (Ig) heavy chain genes rearrangements, by using polymerase chain reaction at the Hematology Research Center, Ministry of Health and Social Development of the Russian Federation.

RESULTS

Cutaneous manifestations of vasculitis disappeared in 75% of cases after monotherapy with RT and in 100% of cases after combination therapy with RT and CP. At 6-month follow-up, a complete response to therapy remained in 25% of the patients after a course of monotherapy and in 83% after combined therapy. Serum monoclonal Ig cryoglobulins and their urinary light chains ceased to be detectable in 75% of the patients in both groups at 3 months. At 6 months, a recurrence of mixed monoclonal cryoglobulinemia was seen in 50 and 43% of cases after monotherapy and combined therapy, respectively. The clinical and laboratory response of cryoglobunemic glomerulonephritis to combined therapy with RT and CP was complete in 60% of cases at 6-month follow-up. After RT monotherapy, the patients with SD and PG MALT lymphoma achieved a complete clinical response in 88%, of whom histological and immunohistochemical reexaminations of PG biopsy specimens revealed no signs of MALT lymphoma in 71% of cases. B-cell clonality remained in the PG biopsy specimens following RT monotherapy. After the combination of RT and CP, a complete clinical response to therapy was observed in 100% of the patients, a complete histological response and a complete molecular one were seen in 83 and 60%, respectively.

CONCLUSION

RT showed its efficacy in treating SD patients with CGV and PG MALT lymphomas.

Neuroimaging in attention-deficit hyperactivity disorder: beyond the frontostriatal circuitry

OBJECTIVES

To review the findings of structural and functional neuroimaging studies in attention-deficit hyperactivity disorder (ADHD), with a focus on abnormalities reported in brain regions that lie outside the frontostriatal circuitry, which is currently believed to play a central role in the pathophysiology of ADHD.

METHODS

Relevant publications were found primarily by searching the MEDLINE and PubMed databases using the keywords ADHD and the abbreviations of magnetic resonance imaging (MRI), functional MRI, positron emission tomography, and single photon emission computed tomography. The reference lists of the articles found through the databases were then reviewed for the purpose of finding additional articles.

RESULTS

There is now substantial evidence of structural and functional alterations in regions outside the frontostriatal circuitry in ADHD, most notably in the cerebellum and the parietal lobes.

CONCLUSIONS

Although there is compelling evidence suggesting that frontostriatal dysfunction may be central to the pathophysiology of ADHD, the neuroimaging findings point to distributed neural substrates rather than a single one. More research is needed to elucidate the nature of contributions of nonfrontostriatal regions to the pathophysiology of ADHD.

[Diagnostic value of antibodies to modified citrullinized vimentin in early rheumatoid arthritis]

A hundred and two patients (18 males, 84 females; mean age, 50.3 +/- 12.3 years) diagnosed as having early rheumatoid arthritis (RA) were examined. A control group consisted of 189 patients with various rheumatic diseases and 30 healthy donors. The serum concentrations of antibodies to modified citrullinized vimentin (MCVA) and to cyclic citrullinized peptide2 (CCTP2A) were measured by enzyme immunoassay (EIA); rheumatoid factor (RF) IgM was determined by nephelometric immunoassay. In early RA, the level of MCVA (median, 49.6 U/ml; interquartile range, 0.9-249.3) was significantly higher than in the control group 1.65 U/ml; 0.3-19.7). There was a direct significant correlation between the levels of MCVA and CCTP2A (p = 0.9), as well as RF IgM (p = 0.6). The diagnostic efficiency of MCVA (area under the curve, 0.705; 95% confidence interval, 0.607-0.803) was higher than that of CCTP, (0.590; 0.467-0.714), but lower than that of RF IgM (0.813; 0.736-0.889). MCVA was comparable with CCTP, and RF IgM in sensitivity; however, it ranked below them in specificity (71%). Choice of the optimum upper normal range (30 U/ml) permits up to an 88% increase in MCVA specificity and the concurrent consideration of results of testing MCVA, CCTP2A, and RF IgM is attended by up to a 78% increase in sensitivity. EIA of MCVA is a sensitive and specific serological test for the diagnosis of early RA.

[Subclinical and clinical manifestations of atherosclerosis in antiphospholipid syndrome]

AIM

To evaluate intima-media complex (IMC) thickness in patients with antiphospholipid syndrome in terms of clinical-laboratory manifestations and thrombosis risk factors.

MATERIAL AND METHODS

The trial included 206 patients (57 males and 149 females, age 16-59, mean age 35.9 years). Of them, 58 (28%) patients had primary antiphospholipid syndrome (PAPS) alone, 148 had documented concomitant systemic lupus erythematosus (SLE). Seventy two (48.6%) SLE patients had antiphospholipid syndrome (APS), 29 (19.6%)--anticardiolipin antibodies (aCL) level above 40 IU in two and more measurements without clinical symptoms of APS. In addition to standard tests, APL (lupus anticoagulant), aCL and antibodies to beta-2 glycoprotein, blood lipids were measured. Thrombosis and atherothrombosis risk factors were evaluated. Ultrasound dopplerography estimated thickness of IMC in the carotid and femoral arteries. The control group consisted of 89 donors free of autoimmune diseases.

RESULTS

Mean values of IMC thickness did not differ between the groups. Atherosclerotic plaques (ASP) were detected in 25 (12%) of 206 patients: in 5 (9%) from PAPS group, 10 (14%) from SLE+APS, in 4 (14%) and 6 (13%) from SLE groups aPL+ and aPL-, respectively. Mean age of patients with ASP was 46 +/- 6.9 years (32-55 years). ASP occurrence was associated with older age: ASP were detected in 10 (38%) of 26 patients aged over 51 years (24 plaques), in 10 (20%) of 50 patients aged 41-50 years (18 plaques) and in 5 (10%) of 50 patients aged 41-50 years (18 plaques) and in 5 (10%) of 50 patients aged 31-40 years (9 plaques, p = 0.001). IMC thickness and plaques were associated with prior arterial and venous thromboses and occurred significantly more frequently in patients with myocardial infarction and transient ischemic attacks (p < 0.001). Thrombosis and atherothrombosis risk factors were associated with changed IMC thickness. The level of aPL and their type had no effect on IMC thickness and ASP incidence in the groups studied.

CONCLUSION

Increased IMC thickness was associated with age irrespective of APS presence. In SLE, ASP appeared at younger age than in PAPS patients. Atherothrombosis risk factors affect IMC thickness irrespective of the level and type of aPL.

Investigations of face expertise in the social developmental disorders

BACKGROUND

Patients with social developmental disorders (SDD), also known as autism spectrum disorders, may have impaired recognition of facial identity or facial expressions.

OBJECTIVE

Our goal was to determine whether SDDs were characterized by loss of a perceptual mechanism responsible for face expertise, as current theories suggest that such a loss should be selective for upright faces, disproportionately affect the perception of facial configuration, and possibly be more severe in the eye region.

METHOD

We tested a group of 24 adult patients with SDD with an oddity paradigm that required them to detect changes in facial configuration or feature color, in either the eyes or the mouth, in both upright and inverted faces.

RESULTS

One group of subjects with SDD with normal famous face recognition had only a mild reduction in accuracy and a normal pattern of inversion effects. A second group of subjects with SDD with impaired famous face recognition had a severe reduction of accuracy. This deficit was not limited to upright faces. It affected the perception of feature configuration and feature color to a similar degree and both eye and mouth changes were discriminated poorly in upright faces.

CONCLUSION

The impaired face recognition that is present in a subset of patients with social developmental disorders is accompanied by impaired face perception, and this impairment is not exclusive to upright faces, facial configuration, or the eye region. The reduced face processing skills in these subjects may be more consistent with recent computational models of face expertise than with classic dual-route hypotheses.

Scan patterns during the processing of facial identity in prosopagnosia

The scan patterns of ocular fixations made by prosopagnosic patients while they attempt to identify faces may provide insights into how they process the information in faces. Contrasts between their scanning of upright versus inverted faces may index the presence of a hypothesized orientation-dependent expert mechanism for processing faces, while contrasts between their scanning of familiar versus novel faces may index the influence of residual facial memories on their search for meaningful facial information. We recorded the eye movements of two prosopagnosics while they viewed faces. One patient, with acquired prosopagnosia from a right occipitotemporal lesion, showed degraded orientation effects but still with a normal distribution of fixations to more salient facial features. However, the dynamics of his global scan patterns were more chaotic for novel faces, suggesting degradation of an internal facial schema, and consistent with other evidence of impaired face configuration perception in this patient. His global scan patterns for famous faces differed from novel faces, suggesting the influence of residual facial memories, as indexed previously by his relatively good imagery for famous faces. The other patient, with a developmental prosopagnosia, showed anomalous orientation effects, abnormal distribution of fixations to less salient regions, and chaotic global scan patterns, in keeping with a more severe loss of face-expert mechanisms. The effects of fame on her scanning were weaker than those in the first subject and non-existent in her global scan patterns. We conclude that scan patterns in prosopagnosia can both reflect the loss of orientation-dependent expert mechanisms and index the covert influence of residual facial memories. In these two subjects the scanning data were consistent with other results from tests of configuration perception, imagery, and covert recognition.

Impaired spatial coding within objects but not between objects in prosopagnosia

BACKGROUND

Patients with prosopagnosia from occipitotemporal lesions have impaired perception of the configuration of facial features. This may be an example of impaired "within-object" spatial coding, which others propose to be distinct from "between-object" spatial coding.

OBJECTIVE

To determine whether the prosopagnosic deficit in perceiving spatial configuration was specific to within-face and not between-face spatial coding and whether the deficit was face-selective or extended to objects other than faces.

METHODS

Six prosopagnosic patients were tested using an oddity paradigm in which they detected which of three simultaneously seen stimuli was an altered target. In the "within-face" task, the target face had altered interocular distance or mouth position. In the "between-face" task, the target face was located farther away from the other two. In the "within-object" task, the stimulus was a two-dot pattern, and the target pattern had altered interdot distance.

RESULTS

Spatial judgments were impaired within faces for all six patients and within the two-dot pattern for five of six patients. However, all six had normal between-face spatial perception.

CONCLUSIONS

Impaired perception of spatial relations in prosopagnosia is selective to the spatial structure within individual objects and spares the perception of spatial location of objects. It is not specific to faces. It reveals a process involved in analyzing object structure, consistent with the patients' deficits in recognizing facial identity, and illustrates a different type of "visuospatial" defect.

What is perseverated in schizophrenia? Evidence of abnormal response plasticity in the saccadic system

Although perseveration is sometimes attributed to defective set switching, the authors have recently shown that set-switching is normal in schizophrenia. In this article, the authors tested for persistent states of the saccadic response system, rather than set perseveration. Schizophrenic and healthy subjects performed antisaccades and prosaccades. The authors analyzed for 3 carry-over effects. First, whereas the latency of the current saccade correlated with that of the prior saccade in both groups, the correlations under mixed-task conditions declined in healthy but not in schizophrenic subjects. Second, antisaccades in penultimate trials delayed upcoming saccades in schizophrenic but not in healthy subjects. Third, schizophrenic subjects were more likely to erroneously perseverate the direction of a prior antisaccade but not a prior prosaccade. The authors concluded that, in schizophrenia, the effects of correct antisaccades are persistent not weak. Saccades in schizophrenia are characterized by perseveration of antisaccade-induced changes in the saccadic response system rather than failures to switch task set.

Perceptual functions in prosopagnosia

Some patients with prosopagnosia may have an apperceptive basis to their recognition defect. Perceptual abnormalities have been reported in single cases or small series, but the causal link of such deficits to prosopagnosia is unclear. Our goal was to identify candidate perceptual processes that might contribute to prosopagnosia, by subjecting several prosopagnosic patients to a battery of functions that may be necessary for accurate facial perception. We tested seven prosopagnosic patients. Three had unilateral right occipitotemporal lesions, two had bilateral posterior occipitotemporal lesions, and one had right anterior-to-occipital temporal damage along with a small left temporal lesion. These lesions all included the fusiform face area, in contrast to one patient with bilateral anterior temporal lesions. Most patients had impaired performance on face-matching tests and difficulty with subcategory judgments for non-face objects. The most consistent deficits in patients with lesions involving the fusiform face area were impaired perception of spatial relations in dot patterns and reduced contrast sensitivity in the 4 to 8 cycles deg(-1) range. Patients with bilateral lesions were impaired in saturation discrimination. Luminance discrimination was normal in all but two patients, and spatial resolution was uniformly spared. Curvature and line-orientation discrimination were impaired in only one patient, who also had the most difficulty with more basic-level object recognition. We conclude that deficits in luminance, spatial resolution, curvature, line orientation, and contrast at low spatial frequencies are unlikely to contribute to apperceptive prosopagnosia. More relevant may be contrast sensitivity at higher spatial frequencies and the analysis of object spatial structure. Deficits in these functions may impair perception of subtle variations in object shape, and may be one mechanism by which the recognition defect in prosopagnosia can extend to other classes of object subcategorization.

The covert priming effect of faces in prosopagnosia

BACKGROUND

There are many methods of testing covert face recognition in prosopagnosia, but it is not clear whether different types of covert recognition share a common mechanism.

OBJECTIVE

To determine whether direct forced-choice techniques and indirect face-priming methods yielded similar behavioral estimates of covert ability in a series of prosopagnosic patients.

METHODS

The authors tested seven control subjects and seven prosopagnosic patients. Six patients had an apperceptive prosopagnosia: one with childhood onset, three with bilateral lesions, and two with unilateral occipitotemporal lesions. The last had an associative prosopagnosia from bilateral anterior temporal lesions. The direct tests of covert function involved sorting faces by occupation or the forced choosing of which of two faces was famous with a name cue. The indirect test assessed name classification by occupation after priming with a facial stimulus.

RESULTS

In normal subjects, the chief priming effect was facilitation by the true face. In the six patients with apperceptive prosopagnosia, direct covert measures were correlated with the face-priming effect, with better covert ability in patients with unilateral posterior lesions. In the patient with associative prosopagnosia, there was a dissociation between excellent direct covert function and absent face priming.

CONCLUSIONS

Direct and indirect covert functions likely share similar mechanisms in patients with apperceptive prosopagnosia and may reflect residual activity in anterior and left hemispheric components of the normal face-processing network. However, face priming may be ineffectual in patients with severely degraded facial memories from anterior temporal damage. This may indicate a difference between residual patterns of face-related activity in associative and apperceptive prosopagnosia.

The relationship of saccadic peak velocity to latency: evidence for a new prosaccadic abnormality in schizophrenia

Antisaccades have not only longer latencies but also lower peak velocities than prosaccades. It is not known whether these latency and velocity differences are related. Studies of non-human primates suggest that prosaccade peak velocity declines as latency from target appearance increases. We examined whether a similar relationship between peak velocity and latency existed in human saccades, whether it accounted for the difference in peak velocity between antisaccades and prosaccades, and whether it was affected by schizophrenia, a condition that affects antisaccade performance. Sixteen control and 21 schizophrenia subjects performed prosaccade and antisaccade trials in the same test session. In both groups antisaccades had lower peak velocities than prosaccades. Latency did not influence the peak velocities of antisaccades in either subject group. At short latencies, the peak velocities of prosaccades were also similar in the two groups. However, while prosaccade peak velocities declined minimally with increasing latency in control subjects, those in the schizophrenia group declined significantly until they reached a value similar to antisaccade peak velocities. We conclude that, in normal subjects, the effect of latency on prosaccade peak velocity is minimal and cannot account for the lower velocity of antisaccades. In schizophrenia, we hypothesize that the latency-related decline in prosaccade peak velocity may reflect either an increased rate of decay of the effect of the transient visual signal at the saccadic goal, or a failure of the continuing presence of the target to sustain neural activity in the saccadic system.

Are patients with social developmental disorders prosopagnosic? Perceptual heterogeneity in the Asperger and socio-emotional processing disorders

It has been hypothesized that social developmental disorders (SDD) like autism, Asperger's disorder and the social-emotional processing disorder may be associated with prosopagnosic-like deficits in face recognition. We studied the ability to recognize famous faces in 24 adults with a variety of SDD diagnoses. We also measured their ability to discriminate changes in internal facial configuration, a perceptual function that is important in face recognition, and their imagery for famous faces, an index of their facial memory stores. We contrasted their performance with both healthy subjects and prosopagnosic patients. We also performed a cluster analysis of the SDD patients. One group of eight SDD subjects performed normally on all tests of face perception and recognition. The other 16 subjects were impaired in recognition, though most were better than prosopagnosic patients. One impaired SDD subgroup had poor perception of facial structure but relatively preserved imagery, resembling prosopagnosic patients with medial occipitotemporal lesions. Another subgroup had better perception than imagery, resembling one prosopagnosic with bilateral anterior temporal lesions. Overall, SDD subgroup membership by face recognition did not correlate with a particular SDD diagnosis or subjective ratings of social impairment. We conclude that the social disturbance in SDD does not invariably lead to impaired face recognition. Abnormal face recognition in some SDD subjects is related to impaired perception of facial structure in a manner suggestive of occipitotemporal dysfunction. Heterogeneity in the perceptual processing of faces may imply pathogenetic heterogeneity, with important implications for genetic and rehabilitative studies of SDD.

Developmental prosopagnosia: a study of three patients

We studied perception in three patients with prosopagnosia of childhood onset. All had trouble with other 'within-category' judgments. All were deficient on face matching tests and severely impaired on tests of perception of the spatial relations of facial features and abstract designs, indicating a deficit in the encoding of coordinate relationships, similar to adult-onset prosopagnosia with lesions of the fusiform face area. Two had difficulty perceiving feature colour, which correlated with reduced luminance sensitivity. In contrast to adult-onset patients, saturation discrimination was spared in two and spatial resolution impaired in two. Curvature discrimination was relatively spared. Contrast sensitivity showed variable reductions at different spatial frequencies. We conclude that developmental prosopagnosia is similar to the adult-onset form in encoding deficits for the spatial arrangement of facial elements. Deficits in luminance perception and spatial resolution are more associated with defective encoding for basic object-level recognition, as shown on tests of object and spatial perception.

Antisaccades and task-switching: interactions in controlled processing

Smaller latency costs for switching from dominant (habitual) to non-dominant (unusual) tasks compared to the reverse direction have been noted in some studies of task-switching. This asymmetry has been cited as evidence of inhibitory effects from the prior trial. We examined accuracy and latency costs of task-switching between prosaccades and antisaccades, where task-switching is limited to stimulus-response re-mapping and occurs between tasks highly asymmetric in dominance. Eighteen subjects executed prosaccades and antisaccades in single-task and mixed-task blocks. In mixed-task blocks, antisaccade and prosaccade trials were ordered randomly, resulting in 'repeated' trials that were preceded by the same type of trial (i.e. antisaccade-antisaccade), and 'switched' trials that were preceded by the opposite type of trial. Comparisons of the single-task blocks and repeated trials of the mixed-task blocks indexed the mixed-list costs, which were small for prosaccades and insignificant for antisaccades. Comparison of the repeated and switched trials from the mixed-task blocks indexed the residual task-switch cost. Accuracy costs of task-switching and antisaccades were equivalent. The accuracy of trials incorporating both switching and antisaccades in a single response (i.e. switched antisaccade) equalled the product of the accuracies of doing each operation alone, supporting independence of these two functions. In contrast, the latency cost of antisaccade performance was 3 times greater than that of task-switching. Task-switching from prosaccades to antisaccades resulted in a paradoxical decrease in antisaccade latency. This decrease correlated with other indices of vigilance, with the paradoxical effect minimized in more attentive observers. The latency data suggest that either an antisaccade on the prior trial perturbs saccadic responses more than a task-switch, or concurrent task-switching specifically facilitates antisaccades. In either case, the paradoxical benefit of task-switching for antisaccades challenges current models of task-switching.

Schizophrenic subjects show deficient inhibition but intact task switching on saccadic tasks

BACKGROUND

Schizophrenic patients have executive function deficits, presumably on the basis of prefrontal cortex dysfunction. Although they consistently show impaired inhibition, the evidence of a task switching deficit is less consistent and is often based on performance of neuropsychological tests that require several cognitive processes (e.g., the Wisconsin Card Sort Test [WCST]). We investigated inhibition and task switching using saccadic tasks to determine whether schizophrenic patients have selective impairments of these executive functions.

METHODS

Sixteen normal and 21 schizophrenic subjects performed blocks of randomly mixed prosaccade and antisaccade trials. This gave rise to four trial types: prosaccades and antisaccades that were either repeated or switched. Response accuracy and latency were measured. Schizophrenic subjects also performed the WCST.

RESULTS

Schizophrenic subjects showed abnormal antisaccade and WCST performance. In contrast, task switching was normal and unrelated to either antisaccade or WCST performance.

CONCLUSIONS

The finding of intact task switching performance that is unrelated to other measures of executive function demonstrates selective rather than general impairments of executive functions in schizophrenia. The findings also suggest that abnormal WCST performance is unlikely to be a consequence of deficient task switching. We hypothesize that inhibition and task switching are mediated by distinct neural networks, only one of which is dysfunctional in schizophrenia.