When Snitches Corroborate: Effects of Post-identification Feedback from a Potentially Compromised Source

Feedback provided to eyewitnesses can influence memory as to how confident their previous line-up selections were. Witnesses given confirming feedback remember being more confident than witnesses who are told their selection was incorrect regardless of their accuracy. This can have a powerful impact on judges and juries. In this article, we examine the effect of feedback from a ‘snitch’ (a jailhouse informant). This manipulation often occurs in real cases, despite that fact that snitches could have something to gain from providing information to police. Our participants witnessed a staged crime and then identified the perpetrator from a target-absent line-up. Two days later, participants were provided with feedback and were probed for confidence. Results show that confirming feedback from a snitch has the same effect as a confession made by the actual suspect, and disconfirming feedback reduces confidence. Implications and relation to the extant literature on eyewitness confidence are discussed.     

D1 dopamine agonist effects assessed in vivo with [14C]-2-deoxyglucose autoradiography

In rats with unilateral 6-hydroxydopamine (6-OHDA) lesions of the substantia nigra, the 2-deoxyglucose (2-DG) autoradiographic method of measuring regional cerebral glucose utilization (RCGU) was used to assess the effects of three systemically administered dopamine agonists: bromocriptine, pergolide and (+)-4-propyl-9-hydroxynaphoxazine (PHNO). Pergolide increased RCGU in the substantia nigra pars reticulata (SNr) ipsilateral to the lesion in a dose-dependent manner (0.04 mg/kg, up 52%; 0.4 mg/kg, up 111%), resulting in asymmetric glucose utilization on the dopamine-denervated and intact sides of the brain. Pretreatment with a selective D1 antagonist (SCH 23390, 0.5 mg/kg) blocked completely the RCGU increase elicited by pergolide (0.4 mg/kg) whereas pretreatment with a selective D2 antagonist (eticlopride, 1.0 mg/kg) only mildly attenuated this increase. The effect of drug treatments on RCGU in the entopeduncular nucleus (EP) paralleled that in the SNr. These results demonstrate that the RCGU increase in the EP and SNr after pergolide administration is dependent primarily on D1 receptor stimulation. Administration of bromocriptine and PHNO minimally altered RCGU in the ipsilateral EP and SNr and did not result in significant left/right RCGU asymmetry. Considered in the context of prior studies of selective D1 and D2 agonists, the results suggest that, in this model, the magnitude of the RCGU increase in the EP and SNr elicited by a dopamine agonist, above the modest effects produced by selective D2 stimulation, represents a measure of D1 agonist effect in vivo. The results support a nonselective D1/D2 stimulatory effect of pergolide (0.04-0.4 mg/kg) and a selective D2 action of both bromocriptine and PHNO.     

The effect of Parkinson's disease on interference control during action selection

Basal ganglia structures comprise a portion of the neural circuitry that is hypothesized to coordinate the selection and suppression of competing responses. Parkinson's disease (PD) may produce a dysfunction in these structures that alters this capacity, making it difficult for patients with PD to suppress interference arising from the automatic activation of salient or overlearned responses. Empirical observations thus far have confirmed this assumption in some studies, but not in others, due presumably to considerable inter-individual variability among PD patients. In an attempt to help resolve this controversy, we measured the performance of 50 PD patients and 25 healthy controls on an arrow version of the Eriksen flanker task in which participants were required to select a response based on the direction of a target arrow that was flanked by arrows pointing in the same (congruent) or opposite (incongruent) direction. Consistent with previous findings, reaction time (RT) increased with incongruent flankers compared to congruent or neutral flankers, and this cost of incongruence was greater among PD patients. Two novel findings are reported. First, distributional analyses, guided by dual-process models of conflict effects and the activation-suppression hypothesis, revealed that PD patients are less efficient at suppressing the activation of conflicting responses, even when matched to healthy controls on RT in a neutral condition. Second, this reduced efficiency was apparent in half of the PD patients, whereas the remaining patients were as efficient as healthy controls. These findings suggest that although poor suppression of conflicting responses is an important feature of PD, it is not evident in all medicated patients.     

The effect of speed-accuracy strategy on response interference control in Parkinson's disease

Studies that used conflict paradigms such as the Eriksen Flanker task show that many individuals with Parkinson's disease (PD) have pronounced difficulty resolving the conflict that arises from the simultaneous activation of mutually exclusive responses. This finding fits well with contemporary views that postulate a key role for the basal ganglia in action selection. The present experiment aims to specify the cognitive processes that underlie action selection deficits among PD patients in the context of variations in speed-accuracy strategy. PD patients (n = 28) and healthy controls (n = 17) performed an arrow version of the flanker task under task instructions that either emphasized speed or accuracy of responses. Reaction time (RT) and accuracy rates decreased with speed compared to accuracy instructions, although to a lesser extent for the PD group. Differences in flanker interference effects among PD and healthy controls depended on speed-accuracy strategy. Compared to the healthy controls, PD patients showed larger flanker interference effects under speed stress. RT distribution analyses suggested that PD patients have greater difficulty suppressing incorrect response activation when pressing for speed. These initial findings point to an important interaction between strategic and computational aspects of interference control in accounting for cognitive impairments of PD. The results are also compatible with recent brain imaging studies that demonstrate basal ganglia activity to co-vary with speed-accuracy adjustments.     

Nutritional Considerations After Gastrectomy and Esophagectomy for Malignancy

This article reviews various methods of assessing and managing post-gastrectomy or esophagectomy patients from a nutritional standpoint, by examining recent research focusing on assessment models, components of enteral feeding, timing of feeding, safety of enteral nutrition (EN) vs total parenteral nutrition (TPN), appetite stimulants, alternative treatments, and long-term care. Pre-, peri-, and post-operative nutrition represent a major prognostic indicator in patients undergoing a gastrectomy or esophagectomy for malignant cancer. An accurate initial nutrition assessment to determine risk, followed by close monitoring pre-operatively and early enteral feeding post-operatively, has been shown to have the most beneficial effects. The optimal delivery route for nutrition involves the use of EN with immune enhancing nutrients while avoiding TPN. In practice, TPN is reserved for patients with post-operative complications that delay enteral feeding for an extended time. While megace is commonly used as an appetite stimulant, the hormone ghrelin is another novel, safe, and efficacious treatment to improve appetite, increase by mouth (PO) intake, and minimize loss of weight and lean body mass. Although use of ghrelin is not yet common practice, as more studies are published, we predict that this will become a more common treatment. While complementary and alternative therapies are commonly employed in this patient population, more research needs to be done before incorporation into our mainstay of treatment. Long term, these patients continue to be at nutritional risk and therefore should be followed to optimize weight maintenance and prevent micronutrient deficiencies.     

Systemic sclerosis and malignancy: a review of the literature

Malignancy is associated with systemic sclerosis in between 3.6 and 10.7% of patients diagnosed with systemic sclerosis. The diagnosis of systemic sclerosis may occur before, concurrent with, or after the diagnosis of malignancy. All published reports of malignancy with systemic sclerosis are reviewed. Lung cancer is the most frequent type of cancer seen in patients with systemic sclerosis, followed by breast cancer. Risk factors for the development of malignancy in patients with systemic sclerosis are female gender, increased age, and diffuse systemic sclerosis. Autoantibodies such as anticentromere and antitopoisomerase I are inconsistent in their risk for developing malignancy. Vigilance is recommended in this group of patients based on their increased risk of developing cancer.     

Validity, sensitivity and specificity of the mentation, behavior and mood subscale of the UPDRS

OBJECTIVE: The unified Parkinson's disease rating scale (UPDRS) is the most widely used tool to rate the severity and the stage of Parkinson's disease (PD). However, the mentation, behavior and mood (MBM) subscale of the UPDRS has received little investigation regarding its validity and sensitivity. Three items of this subscale were compared to criterion tests to examine validity, sensitivity and specificity. METHODS: Ninety-seven patients with idiopathic PD were assessed on the UPDRS. Scores on three items of the MBM subscale, intellectual impairment, thought disorder and depression, were compared to criterion tests, the telephone interview for cognition status (TICS), psychiatric assessment for psychosis and the geriatric depression scale (GDS). Non-parametric tests of association were performed to examine concurrent validity of the MBM items. The sensitivities, specificities and optimal cutoff scores for each MBM item were estimated by receiver operating characteristic (ROC) curve analysis. RESULTS: The MBM items demonstrated low to moderate correlation with the criterion tests, and the sensitivity and specificity were not strong. Even using a score of 1.0 on the items of the MBM demonstrated a sensitivity/specificity of only 0.19/0.48 for intellectual impairment, 0.60/0.72 for thought disorder and 0.61/0.87 for depression. Using a more appropriate cutoff of 2.0 revealed sensitivities of 0.01, 0.38 and 0.13 respectively. DISCUSSION: The MBM subscale items of intellectual impairment, thought disorder and depression are not appropriate for screening or diagnostic purposes. Tools such as the TICS and the GDS should be considered instead.     

The effects ofl-DOPA on regional cerebral glucose utilization in rats with unilateral lesions of the substantia nigra

Using [¹⁴C]2-deoxyglucose autoradiography, we have studied the effects of systemically administeredl-DOPA (10, 25 and 50 mg/kg s.c.) on regional cerebral glucose utilization (RCGU) in rats with unilateral substantia nigra lesions. In comparison with lesioned rats treated with saline, the lesioned-DOPA treated rats demonstrated contralateral turning and RCGU changes in both ipsilateral and contralateral brain regions.l-DOPA treatment markedly increased RCGU in the ipsilateral entopeduncular nucleus (EP) and substantia nigra pars reticulata (SNr), cell groups that receive direct striatal input and function as major outflow pathways of corpus striatal activity. In contrast,l-DOPA did not alter RCGU in the globus pallidus (GP), supporting the thesis that dopamine (DA) has different effects on striatal outflow to the GP compared with outflow to both the EP and SNr. Moderate RCGU increases were observed in the ipsilateral subthalamic nucleus (STN), lateral midbrain reticular formation (LMRF), and deep layers of the superior colliculus (DLSC), all regions which receive direct projections from the GP, EP or SNr.l-DOPA decreased RCGU in the ipsilateral lateral habenular nucleus (LHN) and increased RCGU in the contralateral LHN, changes that we suggest are mediated via altered neuronal activity in the striatum and EP. The results suggest that systemically administeredl-DOPA, after conversion to DA in the brain, interacts with supersensitive DA receptors in the DA-depleted striatum to selectively activate efferent pathways. Furthermore, the data suggest that the LMRF and DLSC are functionally activated duringl-DOPA induced turning and support the hypothesis that nigroreticular and nigrocollicular projections are of physiologic significance in the expression of striatal activity.