Perception MCQs Quiz

The contrast threshold for square wave gratings was 1.27 times lower than the equivalent sinusoidal gratings. This means that the square wave gratings required less contrast to be perceptually indiscriminable compared to the sinusoidal gratings.

A metamer refers to sensory stimuli that may have different physical properties, such as wavelength or intensity, but are perceived as being the same. This means that even though the stimuli may differ in their physical characteristics, they are perceived as equivalent by our senses. This phenomenon highlights the role of perception in interpreting sensory information and how our brain can compensate for variations in physical stimuli to create a consistent perceptual experience.

An individual with three photopigments but with one having atypical absorption properties is called an anomalous trichromat. This means that their color vision is altered compared to individuals with normal color vision. They may have difficulty distinguishing between certain colors or perceiving certain shades. This condition is caused by a genetic variation in the photopigments, resulting in an abnormal response to certain wavelengths of light.

The greatest visibility is for sf's of 2-6, extreme high and low sf are invisible without very high contrast

This is evidence for view-based models

Horizontal cells in the retina play a crucial role in lateral inhibition, which is the process of inhibiting neighboring cells to enhance contrast and sharpen visual perception. By inhibiting the activity of nearby photoreceptor cells, horizontal cells help to create distinct boundaries between light and dark regions, improving the detection of edges and enhancing visual acuity. This mechanism allows for better discrimination of objects and enhances the overall processing of visual information in the retina. Therefore, lateral inhibition is considered the most important function of horizontal cells in retinal processing.

In psychophysical trials to determine a threshold of perception, a percentage of correct performance is necessary. The correct answer in this case is 75%. This means that in order to accurately determine the threshold, participants need to correctly perceive or discriminate stimuli at a rate of 75% or higher. This level of accuracy ensures that the results are reliable and can be used to make conclusions about the perception threshold.

proved through lesioning studies

Taste afferent fibers do not travel through the hippocampus. The hippocampus is primarily involved in memory formation and spatial navigation, rather than processing taste information. Taste afferent fibers travel from the taste buds on the tongue to the brain stem, where they synapse with other neurons before being relayed to the thalamus and then to the gustatory cortex in the parietal lobe for further processing and perception of taste.

The Pacinian corpuscle is the most well-studied mechanoreceptor. This is because it is one of the largest and most easily identifiable mechanoreceptors in the body. It is found in various tissues and organs, including the skin, joints, and internal organs. The Pacinian corpuscle is responsible for detecting deep pressure and vibration, making it an important sensory receptor. Its structure and function have been extensively studied, leading to a better understanding of how mechanoreceptors work and contribute to our sense of touch.

Nylon filament is deployed to measure absolute thresholds for passive touch on the skin. This means that the nylon filament is used to determine the minimum amount of pressure or force required for a person to perceive the sensation of touch on their skin. It is a common tool used in sensory testing to assess tactile sensitivity and perception.

Some people suffer from agnosias

Horizontal and Amacrine are the wrong way round in the above statements

Ganglion cells can be effectively subdivided based on their size, ON/OFF response, and whether they belong to the M, P, or K cell types. However, shape is not a characteristic that is used to classify ganglion cells. Therefore, the incorrect option is "Shape".

These three methods allow different ways of finding a participant's weakest stimulus that evokes a sensation

Object inversion studies see the same results if the person is an expert in that object as faces, it just happens we are all 'experts' in faces
There is a correlation of FFA activity for different objects and how much of an expert you are in that object
We are better with faces we are familiar with, faces of our own race.

Contralateral fibers input into layers 1, 4, and 6 of the LGN.

The answer is "It is possible to isolate a specific evoking stimulus for pain in everyone." This is not a reason to distinguish pain as a distinct sensory experience because pain can be subjective and vary from person to person. While there may be common stimuli that can evoke pain in many individuals, the specific experience and perception of pain can differ greatly. Therefore, the ability to isolate a specific evoking stimulus for pain in everyone is not a valid reason to distinguish pain as a distinct sensory experience.

Salty comes from organic salts such as NaCl

The average human has 10,000 tastebuds. Tastebuds are small sensory organs on the tongue that allow us to taste different flavors. They are responsible for detecting sweet, sour, salty, bitter, and umami (savory) tastes. The number of tastebuds can vary from person to person, but on average, it is estimated that humans have around 10,000 tastebuds.

Moving from a column to a hypercolumn in the visual cortex adds a complete range of orientations to the structure. This means that within a hypercolumn, there are neurons that are specialized in detecting different orientations of visual stimuli, such as vertical, horizontal, or diagonal lines. By combining the information from multiple hypercolumns, the visual cortex is able to process and perceive a wide range of orientations in the visual field.

Bit of a bitch question if this comes up

The correct answer is "They are most likely encoded by cross fibre theory." This means that both smell and taste are likely encoded by the cross-fiber theory, which suggests that different combinations of neurons firing in response to different stimuli create the perception of different smells and tastes. This theory suggests that there is not a one-to-one relationship between a specific chemical and a specific sensation, but rather a complex interaction of neural signals.

Humans are generally very good as this

The best estimate to the number of filters we have in the human CSF is 6. This suggests that there are six filters present in the human CSF.

3D primitive volumes organised hierarchically

Structural description is considered the most computationally elegant model of object recognition because it focuses on representing objects in terms of their underlying structure and relationships between different parts. This approach allows for efficient and concise representation of objects, making it easier to recognize and classify them. Unlike other models such as view dependent, template matching, and feature-detector, which may require more computational resources or rely on specific viewpoints or templates, structural description provides a more general and flexible framework for object recognition.

The evidence that the fusi-form face area (FFA) is involved in facial recognition does not come from the fact that FFA only responds to faces. This statement suggests that FFA's response is specific to faces, indicating its role in facial recognition. Other options such as FFA stimulation in monkeys, FFA stimulation causing face morphing, and FFA recordings being coordinated with when faces are shown, provide additional evidence of FFA's involvement in facial recognition.

The correct answer is the Part-whole effect for objects. The experiment used Greebles to test this phenomenon, which refers to the tendency to recognize parts of an object more easily when they are presented in the context of the whole object. This effect suggests that our perception and recognition of objects are influenced by the relationship between the parts and the whole.

Through the lateral inhibition of horizontal cells, peripheral ganglion cells inhibit each other only allowing certain ones to fire and an image to be created

Individual differences in retinal topography refer to variations in the arrangement or distribution of the L and M cones in the retina. L cones are responsible for perceiving long-wavelength light (red), while M cones detect medium-wavelength light (green). These cones play a crucial role in color vision and are distributed differently in each person's retina, leading to variations in color perception and sensitivity to different wavelengths of light.

Pain afferent fibers have large receptive fields. This means that they can detect and respond to pain signals over a wide area of the body. This is important because pain signals need to be detected and transmitted accurately to the brain in order for us to perceive and respond to pain appropriately. Having large receptive fields allows pain afferent fibers to capture a broader range of painful stimuli and ensure that important pain signals are not missed.

This process is called ADAPTION

The correct answer is "Provides information about objects in the world that are in direct contact with us." This is because the sensation of touch is unique in that it allows us to perceive and gather information about objects that are in direct physical contact with our body. This is different from other sensory modalities such as vision or hearing, which rely on different mechanisms to gather information about the external world.

The Pacinian corpuscle is the largest mechanoreceptor in the body. Mechanoreceptors are sensory receptors that respond to mechanical stimuli such as pressure or vibration. The Pacinian corpuscle is found in the skin and other tissues and is responsible for detecting deep pressure and high-frequency vibrations. It has a large, onion-like structure that allows it to detect these stimuli effectively. Therefore, it is considered the largest mechanoreceptor in the body.

Chromatic induction refers to the phenomenon where the perceived color of an object is influenced by the surrounding colors. It occurs due to the interaction between the different wavelengths of light that reach the eye. In this process, the color of an object is not perceived in isolation but is influenced by the colors surrounding it. Therefore, chromatic induction can cause a change in the perceived color of an object.

The Multiple Filters Model

Parvocellular ganglion cells have chromatically opponent receptive fields. These cells are responsible for color vision and are sensitive to the differences in wavelengths of light. They receive input from cones in the retina that are responsible for color vision. The opponent receptive fields mean that these cells respond differently to different combinations of colors, such as red-green or blue-yellow. Magnocellular and koniocellular ganglion cells, on the other hand, are responsible for detecting motion and do not have chromatically opponent receptive fields.

if we assume the MTF follows a strict set of rules then we predict exactly how the visual system will respond to all images made up of sinusoidal gratings

This is the point we require maximum contrast because our sensitivity is so low

Graham and Nachmias (1971) conducted a study and found that the quality of gratings, specifically the phase, did not affect detection. This means that variations in the phase of the gratings did not have a significant impact on the ability to detect them. The study suggests that other factors, such as contrast, spatial frequency, and orientation, may have a greater influence on the detection of gratings.

A ganglionic OFF response refers to a situation where there is a significant decrease in the firing rate of neurons when the light is on, and then a sudden burst of firing when the light is switched off. This pattern of activity suggests that the neurons are more active in the absence of light and are inhibited by the presence of light.

The separate ON and OFF systems of ganglial processing are necessary to detect incremental and decremental changes in light. This means that the visual system can detect both increases and decreases in light intensity, allowing for a more comprehensive perception of the environment. Without these separate systems, the visual system would only be able to detect overall changes in light, rather than the specific changes in intensity that occur.

Peri-Stimulus-Time-Histogram - firing rate of a cell against time a stimulus is presented in its receptive field

this is what Snellen's test is

A sinusoidal grating refers to a pattern where the luminance (brightness) of the image varies across space. It consists of a series of alternating light and dark bars that repeat in a sinusoidal manner. The variation in luminance occurs in the spatial dimension, meaning that the brightness changes as you move across the pattern. This type of grating is commonly used in vision research to study visual perception and sensitivity to spatial frequencies.

The orbito-frontal cortex is responsible for processing sensory information related to taste and is involved in the subjective experience of pleasure or pleasantness. It receives afferent connections from taste receptors in the mouth and relays this information to other areas of the brain involved in decision-making and emotional processing. Therefore, the degree of pleasantness a sensory stimulus, particularly taste, provides is likely mediated by afferent connections to the orbito-frontal cortex.

The temporal lobe of the brain is critical for object recognition. This lobe is responsible for processing visual information and is involved in recognizing and identifying objects and faces. It plays a crucial role in visual perception and memory, allowing us to recognize and remember objects that we have encountered before. The frontal lobe is primarily responsible for executive functions such as decision-making and problem-solving. The occipital lobe is responsible for processing visual stimuli, while the parietal lobe is involved in sensory perception and spatial awareness.

Square-wave gratings are unique in that the contrast necessary to see it if it was a sinusoidal grating is smaller than the lowest spatial frequency sinosodial grating making it up, hence if the human system performs fourier analysis it will be able to see square wave gratings at a lower contrast

Marr's 3 levels of analysis to follow a computational approach to object recognition include computational, algorithmic, and implementation levels. The functional level is not included in Marr's approach. The functional level refers to the understanding of the purpose and goals of object recognition, while the other three levels focus on the technical aspects of achieving object recognition.

This technique has to record extracellularly, it is reductionist because measuring single cells tells us little about the combined activity of many neurones

It is a measure of the contrast we need to see specific spatial frequencies, a contrast detection threshold for sinusoidal gratings

The receptive fields of ganglion cells explains low sf grating insensitivity

Merkel discs are slow adapting fibers with a small receptive field size that respond to pressure sensations. These mechanoreceptors are located in the skin and are responsible for detecting fine details and textures. They play a crucial role in our ability to perceive pressure and touch sensations.

According to the gate control theory of pain, activity in fast touch fibers partially closes the gate to reduce pain. This means that when these fibers are activated, they can block or inhibit the transmission of pain signals to the brain, resulting in a reduction of pain perception. Therefore, rubbing the skin, which stimulates these fast touch fibers, can alleviate pain by partially closing the gate and reducing the transmission of pain signals.

regions that are size and position invariant and then match the resulting input to the closest stored view that memory has

The correct answer is 1. The visual cortex has 6 layers, but layer 1 is where the vast majority is dedicated to central vision.

The effect of familiarity supports the expertise hypothesis rather than the domain specific hypothesis of face recognition because it suggests that familiarity with faces improves recognition. This implies that expertise in recognizing faces is developed through exposure and experience, rather than being a result of a specific cognitive process dedicated to face recognition.

I hope this is not a Q

In the LGN (lateral geniculate nucleus), input into layer 5 will be from ipsilateral P cells. The LGN is a structure in the thalamus that receives visual information from the retina and relays it to the visual cortex. Layer 5 of the LGN receives input from the ipsilateral (same side) P cells, which are responsible for processing color and fine detail information. The other options, such as ipsilateral M cells and contralateral M or P cells, do not accurately describe the input into layer 5 of the LGN.

The back side = SOUR (also the soft palate)
front sides= SALTY

The final one is stability (under minor object changes)

The duplex theory of retinal processing states that there are two separate systems in the retina that allow the eyes to function in both light and dark conditions. One of these systems is the rod-driven scotopic system, which is responsible for vision in low light conditions. The other system is the cone-driven photopic system, which is responsible for color vision and operates in bright light conditions. Therefore, the correct answer is "Colour vision" as it is a part of the duplex theory of retinal processing.

They are also BINOCULAR (respond to L and R receptive field) and MOTION sensitive (direction selective)

The Meissner corpuscle is a rapidly adapting mechanoreceptor with a small receptor size that responds to fluttering vibrations. It is located in the skin and is particularly sensitive to light touch and low-frequency vibrations. The Pacinian corpuscle, Ruffini ending, and Merkel discs are also mechanoreceptors, but they have different characteristics and functions.

The fact that some IT neurons are selective for medial axis configurations supports a view-dependent model of object recognition. This suggests that the recognition of objects is dependent on specific configurations and orientations, rather than being viewpoint invariant.

Cells individually responded to different orientations, hence brain has to build up an image through this pattern like firing

View dependent models for object recognition have the most empirical support. This is because these models take into account the viewpoint or perspective from which an object is being observed. They recognize objects based on specific views or angles, allowing for more accurate and robust recognition in real-world scenarios. Empirical evidence and research studies have shown that view dependent models outperform other approaches, such as structural description, feature-detector, and template matching, in terms of recognition accuracy and generalization to different viewpoints.

It does not allow handwriting distinctions

The distribution shift model explains the Blakemore and Sutton Aftereffect on adaptation to sinusoidal gratings. This model suggests that the aftereffect occurs because the adapting stimulus causes a shift in the distribution of neural responses, leading to a change in perception. This shift is believed to be due to changes in the sensitivity of neurons that respond to different spatial frequencies.

The olfactory bulb is responsible for processing sensory information related to smell. Afferent nerves carry this information from the olfactory bulb to various destinations in the brain. The olfactory cortex, thalamus, and limbic system are all known destinations for the afferent nerves from the olfactory bulb. However, the brain stem is not a destination for these nerves. The brain stem is primarily involved in controlling basic functions such as breathing, heart rate, and consciousness, rather than processing sensory information.

The study conducted by Young et al in 1987 found that when faces were inverted, there was a significant improvement in recognizing misaligned faces. This means that participants were better able to identify misaligned faces when they were inverted compared to when they were upright.