Visual demands of modern primary classrooms and the impact of refractive anomalies on academic performance

This research investigated the visual demands in modern primary school classrooms and also the impact of common refractive anomalies on a child's ability to perform academic-related tasks. The results showed that relatively high levels of visual acuity, contrast demand and sustained accommodative-convergence are required to perform optimally in the modern classroom environment. It was also demonstrated that relatively low magnitudes of uncorrected refractive error may have a detrimental impact on children's ability to perform academic-related activities at school, with sustained near work further exacerbating this effect. These findings have important implications for both eye care practitioners and education authorities.

Visual demands in modern Australian primary school classrooms

BACKGROUND The visual demands of modern classrooms are poorly understood yet are relevant in determining the levels of visual function required to perform optimally within this environment. METHODS Thirty-three Year 5 and 6 classrooms from eight south-east Queensland schools were included. Classroom activities undertaken during a full school day (9 am to 3 pm) were observed and a range of measurements recorded, including classroom environment (physical dimensions, illumination levels), text size and contrast of learning materials, habitual working distances (distance and estimated for near) and time spent performing various classroom tasks. These measures were used to calculate demand-related minimum criteria for distance and near visual acuity, contrast and sustained use of accommodation and vergence. RESULTS The visual acuity demands for distance and near were 0.33 ± 0.13 and 0.72 ± 0.09 logMAR, respectively (using habitual viewing distances and smallest target sizes) or 0.33 ± 0.09 logMAR assuming a 2.5 times acuity reserve for sustained near tasks. The mean contrast levels of learning materials at distance and near were greater than 70 per cent. Near tasks (47 per cent) dominated the academic tasks performed in the classroom followed by distance (29 per cent), distance to near (15 per cent) and computer-based (nine per cent). On average, children engaged in continuous near fixation for 23 ± 5 minutes at a time and during distance-near tasks performed fixation changes 10 ± 1 times per minute. The mean estimated habitual near working distance was 23 ± 1 cm (4.38 ± 0.24 D accommodative demand) and the vergence demand was 0.86 ± 0.07Δ at distance and 21.94 ± 1.09Δ at near assuming an average pupillary distance of 56 mm. CONCLUSIONS Relatively high levels of visual acuity, contrast demand and sustained accommodative-convergence responses are required to meet the requirements of modern classroom environments. These findings provide an evidence base to inform prescribing guidelines and develop paediatric vision screening protocols and referral criteria.

Evaluation of the Cartographic Communication Performance of a Route Guidance and Navigation System

This study evaluates the influence of different cartographic representations of in-car navigation systems on visual demand, subjective preference, and navigational error. It takes into account the type and complexity of the representation, maneuvering complexity, road layout, and driver gender. A group of 28 drivers (14 male and 14 female) participated in this experiment which was performed in a low-cost driving simulator. The tests were performed on a limited number of instances for each type of representation, and their purpose was to carry out a preliminary assessment and provide future avenues for further studies. Data collected for the visual demand study were analyzed using non-parametric statistical analyses. Results confirmed previous research that showed that different levels of design complexity significantly influence visual demand. Non-grid-like road networks, for example, influence significantly visual demand and navigational error. An analysis of simple maneuvers on a grid-like road network showed that static and blinking arrows did not present significant differences. From the set of representations analyzed to assess visual demand, both arrows were equally efficient. From a gender perspective, women seem to took at the display more than men, but this factor was not significant. With respect to subjective preferences, drivers prefer representations with mimetic landmarks when they perform straight-ahead tasks. For maneuvering tasks, landmarks in a perspective model created higher visual demands.

Morphology, characterization, and distribution of retinal photoreceptors in the Australian lungfish Neoceratodus forsteri (Krefft, 1870)

The Australian lungfish Neoceratodus forsteri (Dipnoi) is an ancient fish that has a unique phylogenetic relationship among the basal Sarcopterygii. Here we examine the ultrastructure, histochemistry, and distribution of the retinal photoreceptors using a combination of light and electron microscopy in order to determine the characteristics of the photoreceptor layer in this living fossil. Similar proportions of rods (53%) and cones (47%) reveal that N. forsteri optimizes both scotopic and photopic sensitivity according to its visual demands. Scotopic sensitivity is optimized by a tapetum lucidum and extremely large rods (18.62 +/- 2.68 mu m ellipsoid diameter). Photopic sensitivity is optimized with a theoretical spatial resolving power of 3.28 +/- 0.66 cycles degree(-1), which is based on the spacing of at least three different cone types: a red cone containing a red oil droplet, a yellow cone containing a yellow ellipsoidal pigment, and a colorless cone containing multiple clear oil droplets. Topographic analysis reveals a heterogeneous distribution of all photoreceptor types, with peak cone densities predominantly found in temporal retina (6,020 rods MM 2, 4,670 red cones mm(-2), 900 yellow cones mm(-2), and 320 colorless cones mm(-2)), but ontogenetic changes in distribution are revealed. Spatial resolving power and the diameter of all photoreceptor types (except yellow cones) increases linearly with growth. The presence of at least three morphological types of cones provides the potential for color vision, which could play a role in the clearer waters of its freshwater environment.

Refracting the pseudophakic patient

Pseudophakic patients are frequently encountered in optometric practice, often the result of cataract extraction but also presbyopia correction. Given advances in technology and surgery, the demand for intraocular lenses for correcting a variety of refractive requirements has increased owing to an ageing population. Based on the patient’s needs, either fixed focus, toric, accommodating or multifocal intraocular lenses (IOLs) may be implanted. During optometric examination, attention should be drawn to a history of IOLs and the potential complications they may cause in order to manage them effectively, particularly where sight is threatened. Although objective and subjective refraction does not differ greatly between phakic and pseudophakic patients, care should be taken to set the patient up correctly and the reflex during retinoscopy observed for posterior sub-capsular opacification. Additional tests such as reading speed, and glare and contrast sensitivity are necessary to determine the outcome of IOL surgery and detect potential problems associated with multifocal and accommodating IOLs. Based upon the results of these tests, refraction, and type of IOL, contact lens or spectacle correction may be required to meet the visual demands of the patient.

Editorial

Full text: There are phrases in daily use today which were not so common a decade or so back, such as ‘ageing population’ or ‘climate changes’ or ‘emerging markets’ or even ‘social networking’. How do these things affect our lives is certainly interesting but for us as eye care practitioners how these changes affect our clinical work may be also relevant and sometimes more interesting. A recent advertisement for recruitment to the Royal Marine Corps of the British Army ended with a comment ‘find us on Facebook!’ The BCLA, IACLE and other organisations as well as many manufacturers have their own Facebook groups. In 2011 Chandni Thakkar was awarded the BCLA summer studentship and her project was based around increasing the contact lens business of a small independent optometric practice where contact lens sales were minimal. The practice typically recruited one new wearer per month. Chandni was able to increase the number of new patient fits with various strategies (her work was presented as poster at the 2012 BCLA conference in Birmingham). One of her strategies was to start a Facebook group and 655 joined the special group she started in just over a month. Interestingly she found that the largest single factor in convincing patients to trial contact lenses was recommendation by the eye care practitioner at the end of the examination, but nonetheless it is interesting that so many people used the social networking site to find out more information regarding contact lenses in her study. Moreover, we already see the use, by some practitioners, of smart phone ‘apps’ or electronic diaries or text messages when coordinating patient check-ups. Climate change has affected the way we think and act; we now leave out special recycle bins and we hope that the items that are recyclable are actually recycled and do not just join our other refuse somewhere down the track! How environmentally friendly are contact lenses? This was discussed by various speakers at this year's BCLA conference in Birmingham. Daily disposable lenses surely produce more contact lens waste but do not involve solutions in plastic bottles like monthly lenses. It is certainly something that manufacturers are taking seriously and of course there are environmental benefits but the cynic in each of us sees the marketing potential too. The way the ageing population is certainly something that will impact all healthcare providers. In the case of eye care with people living longer they will need refractive corrections for longer. Furthermore, since presbyopes are not resigning themselves to only gentle hobbies like knitting and gardening, but instead want to continue playing tennis or skiing or whatever, their visual demands are becoming more complex. This is certainly an area that contact lens manufacturers are focussing on (pun not intended!). Again the BCLA conference in Birmingham saw the launch of various new products by different companies to help us deal with our presbyopic contact lens wearers. It is great to have such choice and now with fitting methods becoming easier too we have no excuse not to try them out with our clients. Finally to emerging markets – well there was not a specific session at the BCLA conference in May discussing this but this most certainly would have been discussed by professional services managers and marketing directors of most of the contact lens companies. ‘How will we conquer China?’ ‘How can we increase our market share in Russia?’ Or ‘How should we spend our marketing budget in India?’ These topics as well as others would certainly have cropped up in backroom discussions. Certainly groups like IACLE (International Association of CL Educators) have increasing numbers of members and activities in developing markets to ensure that educators educate, to that practitioners can practice successfully and in turn patients can become successful contact lenses wearers. Companies also wish to increase their market share in these developing markets and from the point of view of CLAE we are certainly seeing more papers being submitted from these parts of the world. The traditional centres of knowledge are being challenged, I suppose as they have been throughout history, and this can only be a good thing for the pursuit of science. The BCLA conference in Birmingham welcomed more international visitors than ever, and from more countries, and long may that continue. Similarly, CLAE looks forward to a wider audience in years to come and a wider network of authors too.

Investigating the utility of clinical assessments to predict success with presbyopic contact lens correction

PURPOSE: To determine the utility of a range of clinical and non-clinical indicators to aid the initial selection of the optimum presbyopic contact lens. In addition, to assess whether lens preference was influenced by the visual performance compared to the other designs trialled (intra-subject) or compared to participants who preferred other designs (inter-subject). METHODS: A double-masked randomised crossover trial of Air Optix Aqua multifocal, PureVision 2 for Presbyopia, Acuvue OASYS for Presbyopia, Biofinity multifocal and monovision was conducted on 35 presbyopes (54.3±6.2years). Participant lifestyle, personality, pupil characteristics and aberrometry were assessed prior to lens fitting. After 4 weeks of wear, high and low contrast visual acuity (VA) under photopic and mesopic conditions, reading speed, Near Activity Visual Questionnaire (NAVQ) rating, subjective quality-of-vision scoring, defocus curves, stereopsis, halometry, aberrometry and ocular physiology were quantified. RESULTS: After trialling all the lenses, preference was mixed (n=12 Biofinity, n=10 monovision, n=7 Purevision, n=4 Air Optix Aqua, n=2 Oasys). Lens preference was not dependent on personality (F=1.182, p=0.323) or the hours spent working at near (p=0.535) or intermediate (p=0.759) distances. No intersubject or strong intrasubject relationships emerged between lens preference and reading speed, NAVQ rating, halo size, aberrometry or ocular physiology (p>0.05). CONCLUSIONS: Participant lifestyle and personality, ocular optics, contact lens visual performance and ocular physiology provided poor indicators of the preferred lens type after 4 weeks of wear. This is confounded by the wide range of task visual demands of presbyopes and the limited optical differences between current multifocal contact lens designs.

Making sense of an everyday science text : linguistic, visual and spatial design

In this article, we take a close look at the literacy demands of one task from the ‘Marvellous Micro-organisms Stage 3 Life and Living’ Primary Connections unit (Australian Academy of Science, 2005). One lesson from the unit, ‘Exploring Bread’, (pp 4-8) asks students to ‘use bread labels to locate ingredient information and synthesise understanding of bread ingredients’. We draw upon a framework offered by the New London Group (2000), that of linguistic, visual and spatial design, to consider in more detail three bread wrappers and from there the complex literacies that students need to interrelate to undertake the required task. Our findings are that although bread wrappers are an example of an everyday science text, their linguistic, visual and spatial designs and their interrelationship are not trivial. We conclude by reinforcing the need for teachers of science to also consider how the complex design elements of everyday science texts and their interrelated literacies are made visible through instructional practice.

The effect of prolonged reading on visual functions and reading performance in students with low vision

This study is the first to investigate the effect of prolonged reading on reading performance and visual functions in students with low vision. The study focuses on one of the most common modes of achieving adequate magnification for reading by students with low vision, their close reading distance (proximal or relative distance magnification). Close reading distances impose high demands on near visual functions, such as accommodation and convergence. Previous research on accommodation in children with low vision shows that their accommodative responses are reduced compared to normal vision. In addition, there is an increased lag of accommodation for higher stimulus levels as may occur at close reading distance. Reduced accommodative responses in low vision and higher lag of accommodation at close reading distances together could impact on reading performance of students with low vision especially during prolonged reading tasks. The presence of convergence anomalies could further affect reading performance. Therefore, the aims of the present study were 1) To investigate the effect of prolonged reading on reading performance in students with low vision 2) To investigate the effect of prolonged reading on visual functions in students with low vision. This study was conducted as cross-sectional research on 42 students with low vision and a comparison group of 20 students with normal vision, aged 7 to 20 years. The students with low vision had vision impairments arising from a range of causes and represented a typical group of students with low vision, with no significant developmental delays, attending school in Brisbane, Australia. All participants underwent a battery of clinical tests before and after a prolonged reading task. An initial reading-specific history and pre-task measurements that included Bailey-Lovie distance and near visual acuities, Pelli-Robson contrast sensitivity, ocular deviations, sensory fusion, ocular motility, near point of accommodation (pull-away method), accuracy of accommodation (Monocular Estimation Method (MEM)) retinoscopy and Near Point of Convergence (NPC) (push-up method) were recorded for all participants. Reading performance measures were Maximum Oral Reading Rates (MORR), Near Text Visual Acuity (NTVA) and acuity reserves using Bailey-Lovie text charts. Symptoms of visual fatigue were assessed using the Convergence Insufficiency Symptom Survey (CISS) for all participants. Pre-task measurements of reading performance and accuracy of accommodation and NPC were compared with post-task measurements, to test for any effects of prolonged reading. The prolonged reading task involved reading a storybook silently for at least 30 minutes. The task was controlled for print size, contrast, difficulty level and content of the reading material. Silent Reading Rate (SRR) was recorded every 2 minutes during prolonged reading. Symptom scores and visual fatigue scores were also obtained for all participants. A visual fatigue analogue scale (VAS) was used to assess visual fatigue during the task, once at the beginning, once at the middle and once at the end of the task. In addition to the subjective assessments of visual fatigue, tonic accommodation was monitored using a photorefractor (PlusoptiX CR03™) every 6 minutes during the task, as an objective assessment of visual fatigue. Reading measures were done at the habitual reading distance of students with low vision and at 25 cms for students with normal vision. The initial history showed that the students with low vision read for significantly shorter periods at home compared to the students with normal vision. The working distances of participants with low vision ranged from 3-25 cms and half of them were not using any optical devices for magnification. Nearly half of the participants with low vision were able to resolve 8-point print (1M) at 25 cms. Half of the participants in the low vision group had ocular deviations and suppression at near. Reading rates were significantly reduced in students with low vision compared to those of students with normal vision. In addition, there were a significantly larger number of participants in the low vision group who could not sustain the 30-minute task compared to the normal vision group. However, there were no significant changes in reading rates during or following prolonged reading in either the low vision or normal vision groups. Individual changes in reading rates were independent of their baseline reading rates, indicating that the changes in reading rates during prolonged reading cannot be predicted from a typical clinical assessment of reading using brief reading tasks. Contrary to previous reports the silent reading rates of the students with low vision were significantly lower than their oral reading rates, although oral and silent reading was assessed using different methods. Although the visual acuity, contrast sensitivity, near point of convergence and accuracy of accommodation were significantly poorer for the low vision group compared to those of the normal vision group, there were no significant changes in any of these visual functions following prolonged reading in either group. Interestingly, a few students with low vision (n =10) were found to be reading at a distance closer than their near point of accommodation. This suggests a decreased sensitivity to blur. Further evaluation revealed that the equivalent intrinsic refractive errors (an estimate of the spherical dioptirc defocus which would be expected to yield a patient’s visual acuity in normal subjects) were significantly larger for the low vision group compared to those of the normal vision group. As expected, accommodative responses were significantly reduced for the low vision group compared to the expected norms, which is consistent with their close reading distances, reduced visual acuity and contrast sensitivity. For those in the low vision group who had an accommodative error exceeding their equivalent intrinsic refractive errors, a significant decrease in MORR was found following prolonged reading. The silent reading rates however were not significantly affected by accommodative errors in the present study. Suppression also had a significant impact on the changes in reading rates during prolonged reading. The participants who did not have suppression at near showed significant decreases in silent reading rates during and following prolonged reading. This impact of binocular vision at near on prolonged reading was possibly due to the high demands on convergence. The significant predictors of MORR in the low vision group were age, NTVA, reading interest and reading comprehension, accounting for 61.7% of the variances in MORR. SRR was not significantly influenced by any factors, except for the duration of the reading task sustained; participants with higher reading rates were able to sustain a longer reading duration. In students with normal vision, age was the only predictor of MORR. Participants with low vision also reported significantly greater visual fatigue compared to the normal vision group. Measures of tonic accommodation however were little influenced by visual fatigue in the present study. Visual fatigue analogue scores were found to be significantly associated with reading rates in students with low vision and normal vision. However, the patterns of association between visual fatigue and reading rates were different for SRR and MORR. The participants with low vision with higher symptom scores had lower SRRs and participants with higher visual fatigue had lower MORRs. As hypothesized, visual functions such as accuracy of accommodation and convergence did have an impact on prolonged reading in students with low vision, for students whose accommodative errors were greater than their equivalent intrinsic refractive errors, and for those who did not suppress one eye. Those students with low vision who have accommodative errors higher than their equivalent intrinsic refractive errors might significantly benefit from reading glasses. Similarly, considering prisms or occlusion for those without suppression might reduce the convergence demands in these students while using their close reading distances. The impact of these prescriptions on reading rates, reading interest and visual fatigue is an area of promising future research. Most importantly, it is evident from the present study that a combination of factors such as accommodative errors, near point of convergence and suppression should be considered when prescribing reading devices for students with low vision. Considering these factors would also assist rehabilitation specialists in identifying those students who are likely to experience difficulty in prolonged reading, which is otherwise not reflected during typical clinical reading assessments.

The ecological approach to visual perception and the actor performance captured in the gaming landscape

The use of Performance Capture techniques in the creation of games that involve Motion Capture is a relatively new phenomenon. To date there is no prescribed methodology that prepares actors for the rigors of this new industry and as such there are many questions to be answered around how actors navigate these environments successfully when all available training and theoretical material is focused on performance for theatre and film. This article proposes that through a deployment of an Ecological Approach to Visual Perception we may begin to chart this territory for actors and begin to contend with the demands of performing for the motion captured gaming scenario.

Feature-based visual odometry and featureless place recognition for SLAM in 2.5D environments

In this paper we present a novel algorithm for localization during navigation that performs matching over local image sequences. Instead of calculating the single location most likely to correspond to a current visual scene, the approach finds candidate matching locations within every section (subroute) of all learned routes. Through this approach, we reduce the demands upon the image processing front-end, requiring it to only be able to correctly pick the best matching image from within a short local image sequence, rather than globally. We applied this algorithm to a challenging downhill mountain biking visual dataset where there was significant perceptual or environment change between repeated traverses of the environment, and compared performance to applying the feature-based algorithm FAB-MAP. The results demonstrate the potential for localization using visual sequences, even when there are no visual features that can be reliably detected.

Semantic context and visual feature effects in object naming : an fMRI study using arterial spin labeling

Previous behavioral studies reported a robust effect of increased naming latencies when objects to be named were blocked within semantic category, compared to items blocked between category. This semantic context effect has been attributed to various mechanisms including inhibition or excitation of lexico-semantic representations and incremental learning of associations between semantic features and names, and is hypothesized to increase demands on verbal self-monitoring during speech production. Objects within categories also share many visual structural features, introducing a potential confound when interpreting the level at which the context effect might occur. Consistent with previous findings, we report a significant increase in response latencies when naming categorically related objects within blocks, an effect associated with increased perfusion fMRI signal bilaterally in the hippocampus and in the left middle to posterior superior temporal cortex. No perfusion changes were observed in the middle section of the left middle temporal cortex, a region associated with retrieval of lexical-semantic information in previous object naming studies. Although a manipulation of visual feature similarity did not influence naming latencies, we observed perfusion increases in the perirhinal cortex for naming objects with similar visual features that interacted with the semantic context in which objects were named. These results provide support for the view that the semantic context effect in object naming occurs due to an incremental learning mechanism, and involves increased demands on verbal self-monitoring.

Enhancing the teaching and learning of mathematical visual images

The literacy demands of mathematics are very different to those in other subjects (Gough, 2007; O'Halloran, 2005; Quinnell, 2011; Rubenstein, 2007) and much has been written on the challenges that literacy in mathematics poses to learners (Abedi and Lord, 2001; Lowrie and Diezmann, 2007, 2009; Rubenstein, 2007). In particular, a diverse selection of visuals typifies the field of mathematics (Carter, Hipwell and Quinnell, 2012), placing unique literacy demands on learners. Such visuals include varied tables, graphs, diagrams and other representations, all of which are used to communicate information.

Visual completion in an illusory figure

The visual systems of humans and animals represent physical reality in a modified way, depending on the specific demands that the species in question has for survival. The ability to perceive visual illusions is found in independently evolved visual systems, from honeybees to humans. In humans, the ability emerges early, at the age of four months. Thus the perception of illusion is likely to reflect visual processes of fundamental importance for object perception in natural vision. The experiments reported in this thesis employed various modifications of the Kanizsa triangle, a drawn configuration composed of three black disks with missing sectors on a white background. The sectors appear to form the tips of a triangle. The visual system completes the physically empty area between the disks, generally called inducers, with giving the perception of an illusory triangle. The illusory triangle consists of an illusory surface bounded by illusory contours; the triangle appears brighter than and to lie above the background. If the sectors are coloured, the colour fills the illusory area, a phenomenon known as neon colour spreading . We investigated spatial limitations on the perception of Kanizsa-type illusions and how other stimuli and viewing parameters affected these limitations. We also studied complex configurations thick, bent, mobile and chromatic inducers - to determine whether illusions combining several attributes can be perceived. The results suggest that the visual system is highly effective in completing a percept. The perception of an illusory figure is spatially scale invariant when perceived at threshold. The processing time and the number of fixations modify the percept, making the perception of the illusion more probable in various viewing conditions. Furthermore, the fact that the illusion can be perceived when only one inducer is physically present at any given moment indicates the potential of single inducers. Apparently, modelling illusory figure perception will require a combination of low-level, local processes and higher-level integrative processes. Our studies with stimuli combining several attributes relevant to object perception demonstrate that the perception of an illusory figure is flexible and is maintained also when it contains colour and volume and when shown in movement. All in all, the results confirm the assumed importance of the visual processes related with the perception of illusory figures in everyday viewing. This is indicated by the variety of inducer modifications that can be made without destroying the percept. Furthermore, the illusion can acquire additional attributes from such modifications. Due to individual differences in the perception of illusory figures, universal values for absolute performance are not always meaningful, but stable trends and general relations do exist.

Social saliency : visual psychophysics and single-neuron recordings in humans

My thesis studies how people pay attention to other people and the environment. How does the brain figure out what is important and what are the neural mechanisms underlying attention? What is special about salient social cues compared to salient non-social cues? In Chapter I, I review social cues that attract attention, with an emphasis on the neurobiology of these social cues. I also review neurological and psychiatric links: the relationship between saliency, the amygdala and autism. The first empirical chapter then begins by noting that people constantly move in the environment. In Chapter II, I study the spatial cues that attract attention during locomotion using a cued speeded discrimination task. I found that when the motion was expansive, attention was attracted towards the singular point of the optic flow (the focus of expansion, FOE) in a sustained fashion. The more ecologically valid the motion features became (e.g., temporal expansion of each object, spatial depth structure implied by distribution of the size of the objects), the stronger the attentional effects. However, compared to inanimate objects and cues, people preferentially attend to animals and faces, a process in which the amygdala is thought to play an important role. To directly compare social cues and non-social cues in the same experiment and investigate the neural structures processing social cues, in Chapter III, I employ a change detection task and test four rare patients with bilateral amygdala lesions. All four amygdala patients showed a normal pattern of reliably faster and more accurate detection of animate stimuli, suggesting that advantageous processing of social cues can be preserved even without the amygdala, a key structure of the “social brain”. People not only attend to faces, but also pay attention to others’ facial emotions and analyze faces in great detail. Humans have a dedicated system for processing faces and the amygdala has long been associated with a key role in recognizing facial emotions. In Chapter IV, I study the neural mechanisms of emotion perception and find that single neurons in the human amygdala are selective for subjective judgment of others’ emotions. Lastly, people typically pay special attention to faces and people, but people with autism spectrum disorders (ASD) might not. To further study social attention and explore possible deficits of social attention in autism, in Chapter V, I employ a visual search task and show that people with ASD have reduced attention, especially social attention, to target-congruent objects in the search array. This deficit cannot be explained by low-level visual properties of the stimuli and is independent of the amygdala, but it is dependent on task demands. Overall, through visual psychophysics with concurrent eye-tracking, my thesis found and analyzed socially salient cues and compared social vs. non-social cues and healthy vs. clinical populations. Neural mechanisms underlying social saliency were elucidated through electrophysiology and lesion studies. I finally propose further research questions based on the findings in my thesis and introduce my follow-up studies and preliminary results beyond the scope of this thesis in the very last section, Future Directions.