scholarly journals Effects of predictive and incentive value manipulation on sign- and goal-tracking behavior

2019 ◽  
Author(s):  
Cristina E. Maria-Rios ◽  
Christopher J. Fitzpatrick ◽  
Jonathan D. Morrow
Keyword(s):  
Predictive Value ◽  
Instrumental Learning ◽  
Simultaneous Presentation ◽  
Neutral Stimulus ◽  
Sign Tracking ◽  
Incentive Value ◽  
Negative Contingency ◽  
Before And After ◽  
Goal Tracking ◽  
Tracking Response

AbstractWhen a neutral stimulus is repeatedly paired with an appetitive reward, two different types of conditioned approach responses may develop: a sign-tracking response directed toward the neutral cue, or a goal-tracking response directed toward the location of impending reward delivery. Sign-tracking responses have been postulated to result from attribution of incentive value to conditioned cues, while goal-tracking reflects the assignment of only predictive value to the cue. We therefore hypothesized that sign-tracking would be more sensitive to manipulations of incentive value, while goal-tracking would be more responsive to changes in the predictive value of the cue. We tested sign- and goal-tracking before and after devaluation of a food reward using lithium chloride, and tested whether either response could be learned under negative contingency conditions that precluded any serendipitous reinforcement of the behavior that might support instrumental learning. We also tested the effects on sign- and goal-tracking of blocking the predictive value of a cue using simultaneous presentation of a pre-conditioned cue. We found that sign-tracking was sensitive to outcome devaluation, while goal-tracking was not. We also confirmed that both responses are Pavlovian because they can be learned under negative contingency conditions. Goal-tracking was completely blocked by a pre-conditioned cue, while sign-tracking was only partially reduced. These results indicate that sign- and goal-tracking follow different rules of reinforcement learning and suggest a need to revise current models of associative learning to account for these differences.

Behavioural and Neural Mechanisms of Sign-tracking and Goal-tracking in Animals

2013 ◽  
Vol 21 (1) ◽  
pp. 68-76
Author(s):  
Fengjin CHANG ◽  
Ruisi CUI ◽  
Xinwang LI
Keyword(s):  
Neural Mechanisms ◽  
Sign Tracking ◽  
Goal Tracking

Manipulation of Predictive and Incentive Value Have Divergent Effects on Sign- and Goal-Tracking Behavior

2021 ◽  
Vol 89 (9) ◽  
pp. S292-S293
Author(s):  
Cristina Maria-Rios ◽  
Christopher Fitzpatrick ◽  
Jonathan D. Morrow
Keyword(s):  
Incentive Value ◽  
Goal Tracking ◽  
Tracking Behavior

Effects of Depressed Mood Induction on Reasoning Performance

1988 ◽  
Vol 66 (3) ◽  
pp. 855-860 ◽  
Author(s):  
Russell A. Radenhausen ◽  
James M. Anker
Keyword(s):  
Depressed Mood ◽  
Mood Induction ◽  
Neutral Stimulus ◽  
Induction Procedure ◽  
Before And After ◽  
Perceptual Performance ◽  
Performance Results ◽  
The Relationship ◽  
Perceptual Measure ◽  
Mood Induction Procedure

The relationship between depressed mood, reasoning and perceptual performance was examined with 57 undergraduate volunteers. To intensify its effect, Velten's 1968 mood induction procedure was modified by having subjects hear a prerecording of each mood statement prior to saying it themselves. Also, midway through the experiment subjects completed an abbreviated mood induction to ensure continuation of the appropriate mood. Ratings of subjects' mood on a 13-point Likert scale before and after mood induction indicated the mood induction was effective. Subjects completed the reasoning measure of 48 syllogisms, and the perceptual measure involving identification of positive, negative, or neutral stimulus words presented tachistoscopically. “Depressed” individuals showed poorer reasoning performance of marginal significance than “elated” subjects. Mood induction did not appear to affect perceptual performance. Results are discussed in terms of the research on reasoning deficits in depression.

scholarly journals Diagnostic Test Accuracy of Diabetic Retinopathy Screening by Physician Graders Using a Hand-held Non-Mydriatic Retinal Camera at a Tertiary Level Medical Clinic

2019 ◽  
Author(s):  
Mapa Mudiyanselage Prabhath Nishantha Piyasena ◽  
Jennifer L.Y. Yip ◽  
David MacLeod ◽  
Min Kim ◽  
Venkata S. Murthy Gudlavalleti
Keyword(s):  
Diabetic Retinopathy ◽  
Diagnostic Test ◽  
Predictive Value ◽  
Digital Camera ◽  
Diagnostic Test Accuracy ◽  
Test Accuracy ◽  
Medical Clinic ◽  
Middle Income ◽  
Diabetic Retinopathy Screening ◽  
Before And After

Abstract Background The evidence on diagnostic test accuracy (DTA) of diabetic retinopathy (DR) screening utilising photographic studies by non-ophthalmologist personnel in low and middle-income country (LMIC) settings is scarce. We aimed to assess DTA of DR screening using a nonmydriatic hand-held digital camera by trained general physicians in a non-ophthalmic setting. Methods This study is a validation of a screening intervention. We selected 700 people with diabetes (PwDM) > 18 years of age, not previously screened or treated for DR, presenting at a tertiary medical clinic in Sri Lanka. Two-field retinal imaging was used to capture fundus images before and after pupil dilatation, using a hand-held non-mydriatic (Visuscout 100®-Germany) digital retinal camera. The images were captured and graded by two trained, masked independent physician graders. The DTA of different levels of DR was assessed comparing physician’s grading with a retinologist’s clinical examination by mydriatic bio-microscopy, according to a locally adopted guideline. Results Seven hundred eligible PwDM were screened by physician graders. The mean age of participants was 60.8 years (SD ±10.08) and mean duration of DM was 9.9 years (SD ±8.09). Ungradable image proportion in non-mydriatic imaging was 43.4% (either eye-31.3%, both eyes 12.1%). This decreased to 12.8% (either eye-11.6%, both eyes-1.2%) following pupil dilatation. In comparison to detection of any level of DR, a referable level DR (moderate non-proliferative DR and levels above) showed a higher level of DTA. The sensitivity of the defined referable DR was 88.7% (95% CI 81.7-93.8%) for grader 1 (positive predictive value [PPV] 59.1%) and 92.5% (95% CI 86.4-96.5%) for grader 2 (PPV 68%), using mydriatic imaging, after including ungradable images as screen positives. The specificity was 94.9% (95% CI 93.6-96.0%) for grader 1 (negative predictive value [NPV] 99%) and 96.4% (95% CI 95.3-97.3%) for grader 2 (NPV 99.4%). Conclusions The Physicians grading of images from a digital hand-held non-mydriatic camera at a medical clinic, with dilatation of pupil of those who have ungradable images, provides a valid modality to identify referable level of DR. This could be a feasible alternative modality to the existing opportunistic screening to improve the access and coverage.

scholarly journals Computed tomography indicators of cerebral microperfusion improve long term after carotid stenting in symptomatic patients

2019 ◽  
Author(s):  
Pawel J Winklewski ◽  
Mariusz Kaszubowski ◽  
Grzegorz Halena ◽  
Agnieszka Sabisz ◽  
Kamil Chwojnicki ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Carotid Artery ◽  
Predictive Value ◽  
Carotid Artery Stenting ◽  
Ct Perfusion ◽  
Carotid Stenting ◽  
Cerebral Microcirculation ◽  
Symptomatic Carotid ◽  
Symptomatic Carotid Stenosis ◽  
Before And After

Objectives: We tested the hypothesis that computed tomography (CT) perfusion markers of cerebral microcirculation would improve 36 months after internal carotid artery stenting for symptomatic carotid stenosis while results obtained 6–8 weeks after the stenting procedure would yield a predictive value. Methods: We recruited consecutive eligible patients with >70% symptomatic carotid stenosis with a complete circle of Willis and normal vertebral arteries to the observational cohort study. We detected changes in the cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP) and permeability surface area-product (PS) before and after carotid stenting. We have also compared the absolute differences in the ipsilateral and contralateral CT perfusion markers before and after stenting. The search for regression models of “36 months after stenting” results was based on a stepwise analysis with bidirectional elimination method. Results: A total of 34 patients completed the 36 months follow-up (15 females, mean age of 69.68±S.D. 7.61 years). At 36 months after stenting, the absolute values for CT perfusion markers had improved: CBF (ipsilateral: +7.76%, contralateral: +0.95%); CBV (ipsilateral: +5.13%, contralateral: +3.00%); MTT (ipsilateral: –12.90%; contralateral: –5.63%); TTP (ipsilateral: –2.10%, contralateral: –4.73%) and PS (ipsilateral: –35.21%, contralateral: –35.45%). MTT assessed 6–8 weeks after stenting predicted the MTT value 36 months after stenting (ipsilateral: R2=0.867, contralateral R2=0.688). Conclusions: We have demonstrated improvements in CT perfusion markers of cerebral microcirculation health that persist for at least 3 years after carotid artery stenting in symptomatic patients. MTT assessed 6–8 weeks after stenting yields a predictive value.

scholarly journals μ-Opioid modulation in the rostral solitary nucleus and reticular formation alters taste reactivity: evidence for a suppressive effect on consummatory behavior

2011 ◽  
Vol 301 (3) ◽  
pp. R690-R700 ◽  
Author(s):  
Nicole R. Kinzeler ◽  
Susan P. Travers
Keyword(s):  
Reticular Formation ◽  
Neural Control ◽  
Suppressive Effect ◽  
Neutral Stimulus ◽  
Endogenous Opioids ◽  
Facilitatory Effect ◽  
Consummatory Behavior ◽  
Taste Reactivity ◽  
Before And After ◽  
Ventral Border

The neural control of feeding involves many neuromodulators, including the endogenous opioids that bind μ-opioid receptors (MORs). Injections of the MOR agonist, Damgo, into limbic and hypothalamic forebrain sites increase intake, particularly of palatable foods. Indeed, forebrain Damgo injections increase sucrose-elicited licking but reduce aversive responding (gaping) to quinine, suggesting that MOR activation may enhance taste palatability. A μ-opioid influence on taste reactivity has not been assessed in the brain stem. However, MORs are present in the first-order taste relay, the rostral nucleus of the solitary tract (rNST), and in the immediately subjacent reticular formation (RF), a region known to be essential for consummatory responses. Thus, to evaluate the consequences of rNST/dorsal RF Damgo in this region, we implanted rats with intraoral cannulas, electromyographic electrodes, and brain cannulas aimed at the ventral border of the rNST. Licking and gaping elicited with sucrose, water, and quinine were assessed before and after intramedullary Damgo and saline infusions. Damgo slowed the rate, increased the amplitude, and decreased the size of fluid-induced lick and gape bouts. In addition, the neutral stimulus water, which typically elicits licks, began to evoke gapes. Thus, the current results demonstrate that μ-opioid activation in the rNST/dorsal RF exerts complex effects on oromotor responding that contrast with forebrain effects and are more indicative of a suppressive, rather than a facilitatory effect on ingestion.

T214. Sign-Tracking, Goal-Tracking, and Impulsivity in College-Aged Subjects

2019 ◽  
Vol 85 (10) ◽  
pp. S212
Author(s):  
Jonathan Morrow ◽  
Ali Gheidi ◽  
Lora Cope ◽  
Sanjeev Billing
Keyword(s):  
Sign Tracking ◽  
Goal Tracking ◽  
Aged Subjects

scholarly journals Clinical Performance of the Spot Vision Photo Screener before and after Induction of Cycloplegia in Children

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Konuralp Yakar
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Clinical Performance ◽  
High Specificity ◽  
Screening Criteria ◽  
Predictive Values ◽  
Before And After ◽  
Sensitivity Specificity ◽  
Vision Screener

Aim. To compare the clinical performance of the Spot Vision Screener used to detect amblyopia risk factors (ARFs) in children before and after induction of cycloplegia; the children were referred because they met the screening criteria of the American Association for Pediatric Ophthalmology and Strabismus (AAPOS). Methods. The Spot Vision Screener and a standard autorefractometer were used to examine 200 eyes of 100 children aged 3–10 years, before and after cycloplegia induction, in terms of ARFs. Sensitivity, specificity, and positive and negative predictive values for the detection of significant refractive errors were measured using the AAPOS referral criteria. It was explored that Spot Screener data were affected by cycloplegia. The extent of agreement between cycloplegic/noncycloplegic photoscreening data and cycloplegic autorefraction measurements was assessed using Wilcoxon and Spearman correlation analyses. Results. The Spot’s sensitivity was improved from 60.9% to 85.3% and specificity from 94.9% to 87.4% with cycloplegia compared to cycloplegic standard autorefractometer results. The positive predictive value of Spot was 75.7%, and the negative predictive value was 90.4% without cycloplegia. With cycloplegia, the positive predictive value of Spot was 63.6% and the negative predictive value was 95.8%. Conclusions. The Spot Screener afforded moderate sensitivity and high specificity prior to cycloplegia. The sensitivity and negative predictive value improved after induction of cycloplegia. Examiners should be aware of the effects of cycloplegia on their findings.

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