Problematic social media use is associated with depression and similar to behavioral addictions: Physiological and behavioral evidence.

While many studies have examined the relationship between problematic social media use (PSMU) and mental health disorders, little is known about reward responsiveness mechanisms that might be driving this relationship and the neurophysiological characteristics of PSMU. We surveyed 96 undergraduate students at a private liberal arts college in upstate NY. PSMU was assessed using the Social Media Disorder Scale. Fourteen Individuals endorsing in five or more and three or less categories on the Social Media Disorder Scale were offered and underwent resting state QEEG. Mental health was assessed with the Center for Epidemiological Studies Depression Scale Short Form, Social Interaction Anxiety Scale, Penn State Worry Questionnaire, the 10-item Perceived Stress Scale, and a locally developed measure of Substance Use Disorder. Reward and motivational systems were studied using the Brief Sensation Seeking Scale, Behavioral Inhibition/Behavioral Activation Scale, and Temporal Experience of Pleasure Scale. SMDS scores were associated with poorer mental health on all measures except substance use. SMDS scores were positively associated with the behavioral inhibition scale, and the anticipatory pleasure scale. QEEG results revealed a negative association of high PSMU and right central and frontal lobeta, right central beta, and a positive association with frontal alpha asymmetry. The study replicates findings that PSMU is associated with mental health issues. Further the pattern of reward response is different compared with other addictive behaviors. QEEG results are consistent with previous work in substance use and depression.

Bi-directional Refractive Compensation for With-the-Rule and Against-the-Rule Astigmatism in Young Adults.

Purpose: The purpose of this study was to investigate the short-term effect of imposing astigmatism on the refractive states of young adults. Methods: Nineteen visually healthy low-astigmatic young adults (age = 20.94 ± 0.37 years; spherical-equivalent errors [M] = -1.47 ± 0.23 diopters [D]; cylindrical errors = -0.32 ± 0.05 D) were recruited. They were asked to wear a trial frame with treated and control lenses while watching a video for an hour. In three separate visits, the treated eye was exposed to one of three defocused conditions in random sequence: (1) with-the-rule (WTR) astigmatism = +3.00 DC × 180 degrees; (2) against-the-rule (ATR) astigmatism = +3.00 DC × 90 degrees; and (3) spherical defocus (SPH) = +3.00 DS. The control eye was fully corrected optically. Before and after watching the video, non-cycloplegic autorefraction was performed over the trial lenses. Refractive errors were decomposed into M, J0, and J45 astigmatism. Interocular differences in refractions (treated eye - control eye) were analyzed. Results: After participants watched the video with monocular astigmatic defocus for an hour, the magnitude of the J0 astigmatism was significantly reduced by 0.25 ± 0.10 D in both WTR (from +1.53 ± 0.07 D to +1.28 ± 0.09 D) and 0.39 ± 0.15 D in ATR conditions (from -1.33 ± 0.06 D to -0.94 ± 0.18 D), suggesting an active compensation. In contrast, changes in J0 astigmatism were not significant in the SPH condition. No compensatory changes in J45 astigmatism or M were found under any conditions. Conclusions: Watching a video for an hour with astigmatic defocus induced bidirectional, compensatory changes in astigmatic components, suggesting that refractive components of young adults are moldable to compensate for orientation-specific astigmatic blur over a short period.

Lack of serological evidence of Middle East respiratory syndrome coronavirus infection in virus exposed camel abattoir workers in Nigeria, 2016.

BackgroundMiddle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic threat of global public health concern and dromedary camels are the source of zoonotic infection. Although MERS-CoV is enzootic in dromedaries in Africa as well as the Middle East, zoonotic disease has not been reported in Africa. Methods: In an abattoir in Kano, Nigeria, we tested nasal swabs from camels and investigated 261 humans with repeated occupational exposure to camels, many of whom also reported drinking fresh camel milk (n = 138) or urine (n = 94) or using camel urine for medicinal purposes (n = 96). Results: Weekly MERS-CoV RNA detection in January-February 2016 ranged from 0-8.4% of camels sampled. None of the abattoir workers with exposure to camels had evidence of neutralising antibody to MERS-CoV. Conclusion: There is a need for more studies to investigate whether or not zoonotic transmission of MERS-CoV does take place in Africa.

Selective hippocampal lesions impair acquisition of appetitive trace conditioning with long intertrial and long trace intervals.

Whereas hippocampal lesions clearly impair performance on aversive trace conditioning tasks, recent evidence suggests that such lesions do not affect performance on appetitive trace conditioning tasks with trace intervals from 2 seconds up to 20 seconds. The current study first demonstrated that intact rats can learn trace conditioning tasks with longer trace intervals (8 s) when the average intertrial interval (intertrial interval [ITI]) was lengthened from 150-s to 300-s. In two subsequent experiments with longer ITIs (420-s and 825-s), hippocampal-lesioned rats performed similarly to intact controls in an appetitive trace conditioning task with 20-s trace interval but were impaired in an appetitive trace conditioning task with a 60-s trace interval. These results suggest that the training ITI and the trace interval are important variables to consider in appetitive trace conditioning, and the hippocampus may play an important role in appetitive trace conditioning when the ITI and trace intervals are both sufficiently long.

Hippocampal lesions impair retention of discriminative responding based on energy state cues.

The present research investigated the hypothesis that the hippocampus is involved with the control of appetitive behavior by interoceptive "hunger" and "satiety" signals. Rats were trained to solve a food deprivation intensity discrimination problem in which stimuli produced by 0-hr and 24-hr food deprivation served as discriminative cues for the delivery of sucrose pellets. For Group 0+, sucrose pellets were delivered at the conclusion of each 4-min session that took place under 0-hr food deprivation, whereas no pellets were delivered during sessions that took place when the rats had been food deprived for 24 hr. Group 24+ received the reverse discriminative contingency (i.e., they received sucrose pellets under 24-hr but not under 0-hr food deprivation). When asymptotic discrimination performance was achieved (indexed by greater incidence of food magazine approach behavior on reinforced compared with nonreinforced sessions), half of the rats in each group received hippocampal lesions, and the remaining rats in each group were designated as sham- or nonlesioned controls. Following recovery from surgery, food deprivation discrimination performance was compared for lesioned and control rats in both Groups 0+ and 24+. Discriminative responding was impaired for rats with hippocampal lesions relative to their controls. This impairment was based largely on elevated responding to nonreinforced food deprivation cues. In addition, hippocampal damage was associated with increased body weight under conditions of ad libitum feeding. The results suggest that the inhibition of appetitive behavior by energy state signals may depend, in part, on the hippocampus.

Contributions of the hippocampus and medial prefrontal cortex to energy and body weight regulation.

The effects of selective ibotenate lesions of the complete hippocampus (CHip), the hippocampal ventral pole (VP), or the medial prefrontal cortex (mPFC) in male rats were assessed on several measures related to energy regulation (i.e., body weight gain, food intake, body adiposity, metabolic activity, general behavioral activity, conditioned appetitive responding). The testing conditions were designed to minimize the nonspecific debilitating effects of these surgeries on intake and body weight. Rats with CHip and VP lesions exhibited significantly greater weight gain and food intake compared with controls. Furthermore, CHip-lesioned rats, but not rats with VP lesions, showed elevated metabolic activity, general activity in the dark phase of the light-dark cycle, and greater conditioned appetitive behavior, compared with control rats without these brain lesions. In contrast, rats with mPFC lesions were not different from controls on any of these measures. These results indicate that hippocampal damage interferes with energy and body weight regulation, perhaps by disrupting higher-order learning and memory processes that contribute to the control of appetitive and consummatory behavior.

Effects of fluoxetine on hippocampal-dependent and hippocampal-independent learning tasks.

It is generally assumed that fluoxetine does not produce cognitive impairments, based on observations that fluoxetine-treated animals do not show impairment in learning the spatial water-maze task. As fluoxetine has different effects on different brain regions and as learning is not a unitary phenomenon, it may be the case that fluoxetine has different effects on different types of learning and memory paradigms. In this study, 15 male Sprague-Dawley rats were given chronic injections of either fluoxetine or saline and received training in two hippocampal-independent tasks in addition to a spatial water-maze task. The two hippocampal-independent tasks were a short-delay appetitive Pavlovian-conditioning task and an object-recognition task. The results showed that the fluoxetine-injected rats did not show any impairment relative to the saline controls in either the acquisition or the retention phases of the water-maze task, but were significantly impaired in both of the hippocampal-independent tasks. Fluoxetine-injected rats spent significantly less time exploring the novel object in the object-recognition task and took longer to learn the association between the conditional stimulus and the appetitive unconditional stimulus in the appetitive Pavlovian-conditioning task.