Differences In Visual Ability Research Articles

Strain comparisons in inhibitory discrimination learning and novel object recognition procedures

Strain differences in visual abilities and exploratory tendencies can confound rats’ performance in cognitive tests of learning and memory. In the present study we compared the performance of albino Wistar and pigmented Lister Hooded rats in appetitive conditioning and recognition memory procedures, specifically within-subjects inhibitory learning (A+ /AX-) and novel object recognition (NOR) variants. The inhibition task included an excitatory training stage and summation and retardation tests. Difference scores were used to help control for individual variation in baseline nosepoke responding. NOR was tested after a 10 min delay, following 24hr delay and using a recency variant. Discrimination ratios were used to control for individual variation in exploratory activity. In the inhibitory learning procedure, Lister Hooded showed more magazine activity prior to stimulus presentations than Wistar rats but this was a transient effect restricted to day 1 of excitatory training. There was no strain difference in associative learning at the excitatory training stage. The Wistars went on to show some performance advantage at the inhibitory discrimination stage and marginally stronger retardation test performance. In the NOR tasks, there was no significant effect of strain on cognitive performance, but the Wistars showed some advantage in the 10 min delay variant, whereas in the 24hr delay and relative recency NOR variants, the Lister Hooded rats showed some advantage. Overall the results of the present study confirm the suitability of Wistar rats for use in associative learning and basic NOR procedures.

Individual differences in object recognition.

There is substantial evidence for individual differences in personality and cognitive abilities, but we lack clear intuitions about individual differences in visual abilities. Previous work on this topic has typically compared performance with only 2 categories, each measured with only 1 task. This approach is insufficient for demonstration of domain-general effects. Most previous work has used familiar object categories, for which experience may vary between participants and categories, thereby reducing correlations that would stem from a common factor. In Study 1, we adopted a latent variable approach to test for the first time whether there is a domain-general object recognition ability, o. We assessed whether shared variance between latent factors representing performance for each of 5 novel object categories could be accounted for by a single higher-order factor. On average, 89% of the variance of lower-order factors denoting performance on novel object categories could be accounted for by a higher-order factor, providing strong evidence for o. Moreover, o also accounted for a moderate proportion of variance in tests of familiar object recognition. In Study 2, we assessed whether the strong association across categories in object recognition is due to third-variable influences. We find that o has weak to moderate associations with a host of cognitive, perceptual, and personality constructs and that a clear majority of the variance in and covariance between performance on different categories is independent of fluid intelligence. This work provides the first demonstration of a reliable, specific, and domain-general object recognition ability, and suggest a rich framework for future work in this area. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The structure of inter-individual differences in visual ability: Evidence from the general population and synaesthesia

This study considers how inter-individual differences in visual ability are structured. Visual ability could be a single entity (along the lines of general intelligence, or ‘g’), or could be structured according to major anatomical or physiological pathways (dorsal v. ventral streams; magno- v. parvo-cellular systems); or may be a finer-grained mosaic of abilities. To test this, we employed seven visual psychophysical tests (generating 16 measures) on a large (100+) sample of neurotypical participants. A Varimax-rotated PCA (Principal Component Analysis) revealed a two-factor solution that broadly corresponds to a high and low spatial frequency division (consistent with a magno/parvo distinction). Over and above this, two measures (temporal order judgments; gain in contrast sensitivity) correlated with most others, and loaded on both factors, suggesting that they tap broad visual processing demands. These analyses open up further possibilities for exploring the genetic and neuroscientific foundations of differences in visual ability. The tests were also run on a group of individuals with different types of visually-based synaesthesia, given that previous research have suggested they possess a distinct profile of visual abilities. Synaesthesia was linked to enhanced processing of colour and shape/curvature information (amongst others), that may relate to differences in V4 in this group. In conclusion, individual differences in vision are both striking and meaningful, despite our difficulty to imagine seeing the world any differently.

Clinically Meaningful Rehabilitation Outcomes of Low Vision Patients Served by Outpatient Clinical Centers

To facilitate comparative clinical outcome research in low vision rehabilitation, we must use patient-centered measurements that reflect clinically meaningful changes in visual ability. To quantify the effects of currently provided low vision rehabilitation (LVR) on patients who present for outpatient LVR services in the United States. Prospective, observational study of new patients seeking outpatient LVR services. From April 2008 through May 2011, 779 patients from 28 clinical centers in the United States were enrolled in the Low Vision Rehabilitation Outcomes Study. The Activity Inventory, a visual function questionnaire, was administered to measure overall visual ability and visual ability in 4 functional domains (reading, mobility, visual motor function, and visual information processing) at baseline and 6 to 9 months after usual LVR care. The Geriatric Depression Scale, Telephone Interview for Cognitive Status, and Medical Outcomes Study 36-Item Short-Form Health Survey physical functioning questionnaires were also administered to measure patients' psychological, cognitive, and physical health states, respectively, and clinical findings of patients were provided by study centers. Mean changes in the study population and minimum clinically important differences in the individual in overall visual ability and in visual ability in 4 functional domains as measured by the Activity Inventory. Baseline and post-rehabilitation measures were obtained for 468 patients. Minimum clinically important differences (95% CIs) were observed in nearly half (47% [95% CI, 44%-50%]) of patients in overall visual ability. The prevalence rates of patients with minimum clinically important differences in visual ability in functional domains were reading (44% [95% CI, 42%-48%]), visual motor function (38% [95% CI, 36%-42%]), visual information processing (33% [95% CI, 31%-37%]), and mobility (27% [95% CI, 25%-31%]). The largest average effect size (Cohen d = 0.87) for the population was observed in overall visual ability. Age (P = .006) was an independent predictor of changes in overall visual ability, and logMAR visual acuity (P = .002) was predictive of changes in visual information processing. Forty-four to fifty percent of patients presenting for outpatient LVR show clinically meaningful differences in overall visual ability after LVR, and the average effect sizes in overall visual ability are large, close to 1 SD.

Hearing differences of gregarious and solitary locusts (Schistocerca gregaria), an example of epigenetic effects

Hearing differences of gregarious and solitary locusts (Schistocerca gregaria), an example of epigenetic effects

Togetherness and Diversity in Pre-school Play e Togetherness f et la Diversité dans le jeu des Enfants d'âge Préscolaire Sentimiento de Unio´n y Diversidad en el Juego Preescolar

Togetherness is seen as a function of shared activity, not just proximity in physical space. In the case of make-believe play, this activity is assumed to take place in three interrelated contexts: the physical, social and symbolical. Togetherness implies that each player has access to these contexts in order to participate in the process of co-construction and collective symbolisation characteristic of play. Through the study of blind and sighted pre-school children in play interaction the differences in the way players have access to physical space, experience social interaction and create meaningful symbols are demonstrated. Transcribed episodes of play negotiations illustrate how differences in visual ability may impede togetherness. As a conclusion it is posited that to understand such impediments differences in apprehension of the situation as opposed to disabilities defined as individual characteristics should be highlighted and made the focus of educational practice and intervention. e Togetherness f est considérée comme une fonction de l'activité partagée, et non seulement de la proximité dans l'espace physique. Dans le cas du jeu de e faire-semblant f , cette activité est supposée avoir lieu dans trois contextes interdépendants: physique, social et symbolique. e Togetherness f implique que chaque participant a accès à ces contextes, afin de participer au processus de co-construction et de symbolisation collective qui caractérise le jeu. Par l'étude d'enfants non-voyants et voyants d'âge préscolaire dans une interaction de jeu, on démontre les différences dans la manière dont les participants ont accès à l'espace physique, ont l'expérience de l'interaction sociale, et créent des symboles significatifs. Des épisodes transcrits de négociations de jeu illustrent comment les différences d'aptitude visuelle peuvent faire obstacle à e togetherness f . En conclusion, on pose que, pour comprendre ces obstacles, les différences d'appréhension de la situation plutôt que les handicaps définis comme caractéristiques individuelles devraient être soulignées et rendues centres de convergence de la pratique éducative et de l'intervention. El sentimiento de unión se ve como función de una actividad compartida, no sólo como proximidad en el espacio fisico. En el caso de hacer-creer-jugar, se supone que esta actividad tiene lugar en tres contextos interrelacionados: el físico, el social y el simbólico. Unión implica que cada jugador tiene acceso a estos contextos, a fin de participar en el proceso de co-construcción y simbolización colectiva, característico del juego. A través del estudio de niños preescolares ciegos y videntes, se demuestran las diferencias en la manera que los niños tienen acceso al espacio físico, experimentan la interacción social y crean símbolos con signifícado. Episodios grabados de negociaciones de juego ilustran cómo las diferencias en habilidad visual pueden dificultar la unión. Como conclusión se plantea que, para entender dichos impedimentos, deberían ponerse en relieve las diferencias en apreciación de la situación en oposición a discapacidades definidas como características individuales y convertilas en el centro de la práctica educativa e intervención.

Correlated Size Variations in Human Visual Cortex, Lateral Geniculate Nucleus, and Optic Tract

We have examined several components of the human visual system to determine how the dimensions of the optic tract, lateral geniculate nucleus (LGN), and primary visual cortex (V1) vary within the same brain. Measurements were made of the cross-sectional area of the optic tract, the volumes of the magnocellular and parvocellular layers of the LGN, and the surface area and volume of V1 in one or both cerebral hemispheres of 15 neurologically normal human brains obtained at autopsy. Consistent with previous observations, there was a two- to threefold variation in the size of each of these visual components among the individuals studied. Importantly, this variation was coordinated within the visual system of any one individual. That is, a relatively large V1 was associated with a commensurately large LGN and optic tract, whereas a relatively small V1 was associated with a commensurately smaller LGN and optic tract. This relationship among the components of the human visual system indicates that the development of its different parts is interdependent. Such coordinated variation should generate substantial differences in visual ability among humans.

Age Differences in Visual Abilities in Nighttime Driving Field Conditions

This study was conducted to provide field data on age differences in sign legibility and object detection. Two age groups of healthy drivers with normal vision were tested for nighttime visual ability. The older group had an average age of 65.6 years and the younger group averaged 22.5 years. The field study was conducted on a private road with the subjects seated in the front passenger seat. Subjects performed a Landolt ring legibility task for four types of signs; positive and negative contrast, new and worn material. Subjects also performed object detection tasks using a small object and a pedestrian target appearing in average and low reflectance. In addition, sign legibility and object detection were completed for some trials using a simulated inclement weather visor to create a worst-case scenario. The object detection task was also completed in the presence of glare from oncoming headlamps. Results showed that older driver's legibility distances were 65% those of the younger drivers. Age differences in the object detection task ranged from a 20% to a 45% reduction for older drivers across visibility conditions.

Visual Memory, Verbal Schemas, and Film Comprehension

An ambiguous silent film was viewed either by itself or with an improbable but plausible verbal synopsis presented either before or after the film. In general, the verbal synopsis significantly influenced inferences made one hour later, but there was an interaction between visualization ability and the order in which the synopsis and film were presented. Visualization ability significantly decreased biased inferences when the film was seen first, but significantly increased this bias when the synopsis preceded the film. Greater synopsis influence was also associated with greater comprehensibility of the film. Visualization ability significantly affected recognition of “hits” while presenting the synopsis after the film increased the rate of false alarms. Results suggest that individual differences in visual ability and conflict between visual and verbal information should be considered when generalizing about encoding, retrieval, and story comprehension using visual media. Implications for media influences, film study and the use of film/video in other settings are also discussed.