Purpose: This study will identify that patients with chronic neck pain have an altered autonomic functioning compared to a control group, and that manipulation might directly influence the autonomic nervous system as measured by using a fully automated pupillometry system. Subjects: 100 chronic pain patients and 50 control subjects participated in this study to achieve a power of 0.80, effect size of 0.5, and a type I error rate of 0.05 for two-tailed hypothesis testing. Method: A quasi-experimental design was be used. The ANOVA and Chi square test were used to establish homogeneity of baseline characteristics. The Mann-Whitney U test was performed to compare the pre-intervention pupil diameter amongst the groups. The Friedman's test was used to determine the pupil diameter change during the three measurements. The Wilcoxen Signed-ranks test was used to analyze the difference in pupil size between the pre- and post-intervention measures and to determine if there was a difference in pupil diameter between the two groups undergoing the thoracic manipulation. The Kruskal-Wallis test was used to compare the pupil diameter change to the presence of joint sounds. And the Fisher's Exact test was used to determine the relationship between the number of pops and the VAS change score > 13mm. Results: This study demonstrated that the chronic pain group had a statistically significant smaller pupil diameter than the healthy control group (P=0.022). Manipulation resulted in a relative increase in pupil diameter following the manipulation, however this was not statistical significant. There was a statistical significant decrease in pupil diameter in the placebo group (pConclusions: It appears that a T3-T4 manipulation results in a relative non-specific increase in sympathetic activity. Recommendations: Manipulation may be used by physical therapists to affect the autonomic nervous system. Visual pupil assessment may become part of the evaluation process to identify patients that might present with autonomic dysfunction and to determine the effect of treatment modalities.

Kan återkallning från långtidsminnet vara belönande i sig, oberoende av hur användbar informationen är? Intern motivation och metakognitiva bedömningar har tidigare undersökts i förhållande till igenkänning och återkallning. Studien ämnade att undersöka ifall korrekt återkallning av information instuderad närmare i tid kan leda till högre skattningar av konfidens och belåtenhet. Tidigare forskning kompletterades genom att undersöka effekten av kognitiv ansträngning på belåtenhet och konfidens. Eventuella relationer mellan återkallning och pupilldilatation undersöktes. Elva personer (M = 29 år) studerade 100 ord på swahili fördelade på fem tillfällen över en vecka. Därefter skulle samtliga ord återkallas i ett test med samtidig registrering av pupillstorlek. Resultaten indikerade att högre konfidens och lägre ansträngning kunde predicera högre belåtenhet vid korrekt återkallning. Genomsnittlig prestation var en bättre prediktor för belåtenhet än tid sedan instudering. Högre prestation predicerade högre belåtenhet vid korrekt återkallning. Resultaten indikerade en uppskattning för säkra minnen samt enkel och korrekt återkallning av dessa. Detta föreslås bero på ett samspel mellan instrumentella och belönande funktioner vid återkallning. Inga signifikanta relationer observerades mellan pupilldilatation och belåtenhet, konfidens eller ansträngning. Pupillförändring uppvisade svaga samband med samtliga men dessa hade inget prediktivt värde. / Can recollection from long-term memory in itself be rewarding, regardless of its usefulness? Internal motivation and metacognitive judgements have previously been explored in relation to recognition and recollection of memories. This study aimed to explore whether recollection of information studied closer in time can lead to higher ratings of confidence and satisfaction. Previous research was complemented by further investigating the effects of cognitive effort on satisfaction and confidence. Relationships between pupil dilation and recollection were also explored. Eleven people (M = 29 years) studied 100 words in swahili distributed over five sessions during one week. Recollection of the words was tested following the last study session. Pupil size was registered during the test. The results showed that higher confidence and lower cognitive effort could predict higher satisfaction at correct recollection. Average performance was a better predictor of satisfaction than time since a word was studied. Higher performance could predict higher satisfaction at correct recollection. The results indicated an appreciation of confidence in memories as well as easy and correct recollection. This may suggest an interplay between instrumental and rewarding functions during recollection. No significant relations were found between pupil dilation and satisfaction, confidence or cognitive effort. Pupil changes resulted in weak correlations with the aforementioned but were not predicted by any of them.

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The aim of the present study was to characterize participants’ abilities to answer binary yes/no questions by mentally manipulating imagery to produce imagined changes in luminance, which would in turn cause reflexive perturbations in pupil diameter. First, a paired association was established with participants, linking “yes” responses with imagining a “sunny sky” and “no” responses with imagining a “dark room”. Participants (N=20) then answered 16 yes/no questions using this response method, in place of providing verbal or gestural (e.g., head nod) answers. Pupil diameters were recorded for a period of 8000 ms following each stimulus question while participants maintained the mental image that corresponded with their answer. We hypothesized that on average, “no” responses would yield a pupil dilation and increased diameter relative to baseline, while “yes” responses would instead result in constrictions and smaller pupil diameters compared to baseline. A 2-factor repeated measures analysis of variance (ANOVA), where time was one factor and response type (i.e., yes or no) was the other, revealed a statistically significant interaction of time and response type, a significant main effect of time, and a trend toward significance for response type in aggregated group data. Item level discrimination consisted of comparing the mean pupil diameter in response to a single item for a single participant (e.g., “yes” response on one trial) to the mean pupil diameter of all contrasting responses for that same participant (e.g., all “no” response trials). This method achieved a 64.5% discrimination accuracy. This investigation affirmed the plausibility of leveraging pupillometry and luminance-based mental imagery in favor of an alternative communication system for individuals who are locked-in, as well as its potential as a screening tool. However, further investigation is warranted prior to its implementation. / Communication Sciences

It has been demonstrated that retinal photoreception among mammals extends beyond rods and cones to include a small number of intrinsically photosensitive retinal ganglion cells (pRGCs), which are capable of responding to light due to expression of the melanopsin (OPN4) photopigment. OPN4 may have therapeutic potential if ectopically expressed in the degenerate retina in cases where photoreceptors are lost, but the other molecules involved in this light induced transduction cascade are less well characterized. Therefore I sought to probe further the mechanism of OPN4 mediated light sensitivity by siRNA mediated knock down of specific molecules in two mice models in which complete loss of rods and cones renders them almost exclusively dependent on the OPN4 pathway for light sensitivity. I generated siRNA probes against the long transcript variant of murine Opn4 mRNA and first tested these probes on the murine Neuro2A (N2a) cell line, before assessing effects in C3H/HeN rd and rodless/coneless rd/rd cl mice. siRNA was injected intravitreally into one eye and pupillometry was assessed, combined with molecular analyses at various timepoints. Reverse transcription polymerase chain reaction (RT-PCR) analysis in N2a cells confirmed Opn4 knockdown and immunolabelling techniques identified >85% silencing with siRNA. Pupil responses in the rd and rd/rd cl mice were inhibited by the siRNA injections in vivo which confirmed the functional effect of Opn4 silencing detected by molecular analysis. I therefore present a novel reproducible in vivo model in which siRNA induced silencing of the melanopsin pathway can be assessed by pupillometry and compared to levels of mRNA and protein at specific timepoints. Probes against other putative candidate genes, such as TRPC3, may unravel the molecular interactions of this pathway. This may help in future to induce light sensitivity in other retinal neurons in patients who are completely blind from photoreceptor loss.