A5043072264- Visual perception and processing mechanisms
- Neural dynamics and brain function
- Color Science and Applications
- Face Recognition and Perception
- Color perception and design
- Neurobiology and Insect Physiology Research
- Neural and Behavioral Psychology Studies
- Primate Behavior and Ecology
- Psychology of Moral and Emotional Judgment
- Retinal Development and Disorders
- Tactile and Sensory Interactions
- Functional Brain Connectivity Studies
- Multisensory perception and integration
- Evolutionary Psychology and Human Behavior
- EEG and Brain-Computer Interfaces
- Hemispheric Asymmetry in Neuroscience
- Categorization, perception, and language
- Optical measurement and interference techniques
- Advanced Neuroimaging Techniques and Applications
- Visual Attention and Saliency Detection
- Advancements in Materials Engineering
- Psychological Testing and Assessment
- Intelligent Tutoring Systems and Adaptive Learning
- Aesthetic Perception and Analysis
- Impact of Light on Environment and Health
University of Nottingham
2011-2023
New York University
2002-2010
Babraham Institute
2000-2002
The vast majority of studies into visual processing are conducted using computer display technology. current paper describes a new free suite software tools designed to make this task easier, the latest advances in hardware and software. PsychoPy is platform-independent experimental control system written Python interpreted language entirely libraries. scripts be extremely easy read write, while retaining complete power for user customize stimuli environment. Tools provided within package...
PsychoPy is an application for the creation of experiments in behavioral science (psychology, neuroscience, linguistics, etc.) with precise spatial control and timing stimuli. It now provides a choice interface; users can write scripts Python if they choose, while those who prefer to construct graphically use new Builder interface. Here we describe features that have been added over last 10 years its development. The most notable addition has interface, allowing create studies minimal or no...
PsychoPy is a software library written in Python, using OpenGL to generate very precise visual stimuli on standard personal computers. It designed allow the construction of as wide variety neuroscience experiments possible, with least effort. By writing scripts Python syntax users can an enormous and auditory interact range external hardware (enabling its use fMRI, EEG, MEG etc.). The structure simple intuitive. As result, new be quickly, trying understand previously script easy, even...
Many researchers in the behavioral sciences depend on research software that presents stimuli, and records response times, with sub-millisecond precision. There are a large number of packages which to conduct these experiments measure times performance participants. Very little information is available, however, what timing they achieve practice. Here we report wide-ranging study looking at precision accuracy visual auditory stimulus measured Black Box Toolkit. We compared range popular...
Many researchers in the behavioral sciences depend on research software that presents stimuli, and records response times, with sub-millisecond precision. There are a large number of packages which to conduct these behavioural experiments measure times performance participants. Very little information is available, however, what timing they achieve practice. Here we report wide-ranging study looking at precision accuracy visual auditory stimulus measured Black Box Toolkit. We compared range...
Stimulation of the suppressive surround a cortical neuron affects responsivity and tuning classical receptive field (CRF) on several stimulus dimensions. In V1 V2 macaques prepared for acute electrophysiological experiments, we explored chromatic sensitivity its influence CRF. We studied fields single neurons with patches drifting grating optimal spatial frequency orientation variable size, modulated along achromatic or isoluminant color directions. The responses most declined as patch was...
Most cortical visual neurons do not respond linearly with contrast. Generally, they show saturated responses to stimuli of high contrast, a feature often characterized by divisive normalization function. This nonlinearity is generally thought be useful in focusing the dynamic response range neuron on particular region contrast space, optimizing gain. Some only saturate but also supersaturate; at decreases rather than plateaus. Under gain control theory, these cells would seem reflect...
Abstract Practice in most sensory tasks substantially improves perceptual performance. A hallmark of this 'perceptual learning' is its specificity for the basic attributes trained stimulus and task. Recent studies have challenged learned improvements, although transfer between different has yet to be demonstrated. Here, we measure degree three distinct tasks. Participants on an orientation discrimination, a curvature or 'global form' task, all using stimuli comprised multiple oriented...
Anecdotally, spouses are often said to resemble one another. This study investigates the effects of similarity between participants and stimuli on judgements facial attractiveness: does "like prefer like"? Using computer graphic techniques, opposite sex were generated from subjects' photographs. Experiment 1 showed a correlation attractiveness but effect can be explained by average faces. Beyond this, there was trend for individual subjects rate images with similar face shape their own as...
Functional magnetic resonance imaging (fMRI) has become a ubiquitous tool in cognitive neuroscience. The technique allows noninvasive measurements of cortical responses the human brain, but only on millimeter scale. Because typical voxel contains many thousands neurons with varied properties, establishing selectivity their directly is impossible. In recent years, two methods using fMRI aimed at studying neuronal populations 'subvoxel' scale have been heavily used. first technique,...
Research suggests that detection of low-frequency radial frequency (RF) patterns involves global shape processing and points maximum curvature (corners) contribute more than minimum (sides). However, this has only been tested with stimuli presented at the threshold discriminability from a circle. We used RF pattern adaptation to (a) examine whether supra-threshold is processed as (b) determine what critical features are for representing its shape. measured perceived amplitude shift an test...
Neurons in the early stages of visual processing are often thought as edge detectors for different orientations. Here we investigate existence specific combinations edges—detectors curvatures. Previous attempts to demonstrate such through aftereffects have ultimately been explained by adaptation local orientation rather than curvature per se. To control aftereffects, adapted one patch field two adjacent gratings presented an obtuse contour (compound patch), and another same component...
The preferred stimulus size of a V1 neuron decreases with increases in contrast. It has been supposed that contrast is the primary determinant such spatial summation cells, though extent to which it depends on other attributes as orientation and frequency remains untested. We investigated this by recording from single cells anaesthetized cats monkeys, measuring size-tuning curves for high-contrast drifting gratings optimal configuration, comparing these those obtained at lower or sub-optimal...
Previous studies have demonstrated that the perceived direction of motion a visual stimulus can be decoded from pattern functional magnetic resonance imaging (fMRI) responses in occipital cortex using multivariate analysis methods (Kamitani and Tong, 2006). One possible mechanism for this is difference sampling selective cortical columns between voxels, implying information at level smaller than voxel size might accessible with fMRI. Alternatively, driven by organization neurons into...
Sheep, like humans, show a bias in favour of the left visual field when discriminating familiar faces. This, is thought to be caused by right hemisphere dominance for processing faces involving temporal cortex. We have directly investigated inter-hemispheric differences face-processing sheep recording frequencies and response profiles single cells cortex which respond selectively While there was no evidence increased face-sensitive neurones within cortex, or their relative selectivity...
In the study of neurosciences, and complex biological systems in general, there is frequently a need to fit mathematical models with large numbers parameters highly datasets. Here we consider algorithms two different classes, gradient following (GF) methods evolutionary (EA) examine their performance fitting 9-parameter model filter-based visual neuron real data recorded from sample 107 neurons macaque primary cortex (V1). Although GF method converged very rapidly on solution, it was...
It is widely believed that the cortical mechanisms of color vision are monocular because stereopsis poor for isoluminant patterns. By measuring and comparing chromatic tuning binocular neurons in areas V1 V2 macaque, we show this not case. Not only many color-preferring cells early visual cortex well-driven binocularly, but their preferences unusually well-matched two eyes. The receptive fields these well equipped to convey information about surface color, they insensitive local spatial...
Relatively little is known about the processes, both linear and nonlinear, by which signals are combined beyond V1. By presenting two stimulus components simultaneously, flickering at different temporal frequencies (frequency tagging) while measuring steady-state visual evoked potentials, we can assess responses to individual components, including direct measurements of suppression on each other, various nonlinear their combination found intermodulation frequencies. The result a rather rich...
The dialects theory of cross-cultural communication suggests that due to culture-specific characteristics in the expression emotion, we can recognise own-culture emotional expressions more accurately than other-culture expressions. This effect is suggested occur nonconvergent social evolution takes place different geographical regions. Based on evolutionary value signals, previous research has be appraised without conscious awareness. current study tested this hypothesis. We developed,...