NCERT Solutions Class 11 Psychology Chapter 5 Sensory, Attentional and Perceptual Processes
NCERT Solutions Class 11 Psychology Chapter 5 Sensory, Attentional and Perceptual Processes : National Council of Educational Research and Training (NCERT) Class 11 Psychology Chapter 5 Solutions – Sensory, Attentional and Perceptual Processes .
Board |
NCERT |
Class |
11 |
Subject |
Psychology |
Chapter |
5 |
Chapter Name |
Sensory, Attentional and Perceptual Processes |
Topic |
Exercise Solutions |
Review Questions
1.) Explain the functional limitations of sense organs.
The following are the sense organs’ functional restrictions:
- The capacity of the senses to receive and understand sensory data is affected by the functional limitations of sense organs.
- These limitations are determined by the physical makeup and capacity of the sense organs. For instance, the human eye is sensitive to a certain range of light wavelengths.
- The functional limitations of the senses may be influenced by factors such as age, health, and environment.
- As we age, our senses may become less perceptive and less able to appropriately interpret sensory data.
- Infections or accidents may reduce sensory function in several medical conditions.
- Since some conditions, such as intense light or loud noises, can momentarily impair sensory function, the environment may also be a factor.
2.) What is meant by light and dark adaptation? How do they take place?
Light and dark adaptation is the ability of the eye to adjust to varying levels of light. The process by which the eye adjusts to intense light and allows people to see clearly in well-lit environments is known as light adaptation.
Dark adaptation, on the other hand, happens when the eye adjusts to low light levels, allowing people to see in low light or complete darkness. Both light and dark adaptation entail changes in the retina, the light-sensitive layer of tissue at the rear of the eye.
During light adaptation, the pupil (the hole in the centre of the eye through which light enters) contracts to reduce the amount of light entering the eye. The photoreceptor cells in the retina also grow less sensitive at the same time, allowing them to withstand more light without becoming overstimulated.
Dark adaptation has the opposite effect. The retina’s photoreceptor cells grow more sensitive when the pupil dilates (enlarges) to allow more light to enter the eye. This improves our ability to see well in low light or at night.
Both adaptation to light and adaptation to darkness are gradual processes that may take several minutes to complete. By adjusting the pupil and photoreceptor cell sensitivity in response to changes in light intensity, the nervous system controls the adaptation process.
3.) What is colour vision and what are the dimensions of colour?
The ability to recognise and distinguish between different colours is known as colour vision. It is a challenging procedure that involves the nervous system, eyes, and brain.
The many characteristics or attributes that are utilised to identify and distinguish colours are referred to as colour dimensions. Hue, saturation, and brightness are the three most common colour dimensions.
The term “hue” refers to an object’s primary colour, such as red, blue, or yellow. Saturation describes the power or purity of a colour, with fully saturated colours seeming rich and vibrant and less saturated colours being washed out or pale. Brightness is a term used to describe a color’s overall lightness or blackness.
Warmth and coolness, which correspond to a color’s relative placement on the colour spectrum (red and yellow are warm colours, while blue and green are cool colours), and complementing colours, which are hues that are opposite one another on the colour wheel, are further properties of colour (such as blue and orange, or red and green).
4.) How does auditory sensation take place?
The process through which sound is perceived, or auditory sensation, is intricate and includes the neurological system, the brain, and the ears. In order to reach the eardrum, a sound wave must first pass through the external auditory canal (the outer ear). This causes the eardrum to vibrate. The auditory ossicles, a group of tiny bones in the middle ear, then convey the eardrum’s vibration to the cochlea, a fluid-filled organ in the inner ear. The basilar membrane, a specialised component of the cochlea coated with hair cells, is present. The basilar membrane’s vibrations are picked up by these hair cells, which then translate them into nerve impulses. The auditory nerve subsequently transmits the nerve impulses to the brain, where the auditory nerve interprets and processes them to create the perception of sound.
The brain can distinguish between various sounds according to their frequency (pitch), strength (loudness), and other qualities including timbre (the quality of a sound), and spatial placement (the direction from which the sound is coming). Overall, the synchronisation of several distinct components of the ear and the brain is required for auditory sensation, which is a complicated process.
5.) Define attention. Explain its properties.
Attention is a cognitive process that involves choosing to focus on a certain aspect of the surrounding environment or the task at hand. Because it is a limited resource, we can only concentrate on a certain amount of information at once.
It’s important to comprehend the attention’s many essential characteristics. Here are a few instances:
Selectivity: Because attention is selective, we can only focus on a specific amount of information at any given time. This helps us to focus on what is most important by removing irrelevant or unneeded information.
Divisibility: When our attention is split, we may pay attention to several different things at once, such as several different tasks or inputs. However, dividing our focus might lead to subpar performance in each individual task.
Sustainability: We have the capacity to sustain our attention on a certain activity or stimulus for a considerable period of time. On the other hand, staying focused for a long time could make you tired or bored.
Flexibility: Because attention is adaptable, we may shift it from one task or stimulus to another as needed. This makes it possible for us to adapt to changing demands or priorities.
6.) State the determinants of selective attention. How does selective attention differ from sustained attention?
Selective attention is influenced by a number of things. They often have something to do with the traits of stimuli and the traits of people.
The characteristics of stimuli are connected to external circumstances. The size, intensity, and velocity of stimuli seem to be significant factors of attention, other things being equal. We are readily distracted by things that are big, bright, and moving. Novel and fairly complicated stimuli are also quickly brought into our focus. According to studies, images of people are more likely to be looked at than those of inanimate items. Similar to spoken narrations, rhythmic aural stimuli are more easily attended to. It is amazing how quickly sudden, strong stimuli may grab our attention.
Internal variables are factors that the person has. They may be classified into two primary groups: cognitive variables and motivational factors. Our biological or social requirements are related to motivational factors. Even a slight food smell might be detected by us when we are hungry. A student who is taking an exam will probably pay closer attention to the teacher’s instructions than other pupils. The term “cognitive factors” refers to elements like interest, attitude, and preparation. People are eager to attend things or activities that seem engaging. Similar to this, when we have a positive attitude towards something, we tend to pay close attention to it. A mental state of preparation to behave a specific way and the ability to react to some stimuli while ignoring others are produced by the preparatory set.
7.) What is the main proposition of Gestalt psychologists with respect to perception of the visual field?
The core hypothesis of gestalt psychology is that the mind organises sensory information into meaningful wholes rather than focusing on individual components in isolation. This hypothesis is particularly relevant to the study of visual field perception. This organisational paradigm is referred to as Gestalt. Gestalt psychologists claim that using ideas like similarity, closeness, continuity, and closure, the mind actively organises sensory data into coherent patterns and structures.
Our brain, for instance, organises dots into meaningful patterns when we see a group of them on a page, like a face or a geometric design. This enables us to comprehend the gestalt, or general structure, of the visual field and make sense of the sensory information.
Gestalt psychologists proposed that this organising principle is fundamental to perception and is essential to how we comprehend our surroundings. They also emphasised the value of context and the entirety of the situation in perception as opposed to focusing only on the individual components.
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8.) How does perception of space take place?
Space is the visible surface or field in which objects can be positioned, moved, or exist.
Our living environment is three-dimensionally organised. We are able to distinguish between the distances between the numerous items in this space in addition to the spatial characteristics of those objects (such size, shape, and orientation). Although though the pictures of the things that are put onto our retina are two dimensional and flat (left, right, up, down), we nonetheless perceive the space to have three dimensions. We can convert our two-dimensional retinal vision into a three-dimensional perception, which is how it happens.
9.) What are the monocular cues of depth perception? Explain the role of binocular cues in the perception of depth?
The impression of depth Monocular cues are visual cues that may be used to determine an object’s position and distance in the environment using only one eye.
These signals allow for depth perception with only one eye open and do not need binocular vision (the use of both eyes).
Typical monocular depth perception signals include the following:
The linear perspective cue relies on the illusion of parallel lines coming together at the vanishing point, which is a far-off location. You can gauge the distance between objects in the surroundings by looking at how much the lines converge.
Size: This cue is based on the idea that objects appear smaller the further they are from the observer.By contrasting their sizes, we may determine the distances between objects in the environment.
Aerial perspective: From above, distant things appear hazy or indistinct due to tiny dust and moisture particles in the air.Aerial perspective is the term for this phenomenon. For instance, the atmosphere’s dispersion of blue light causes faraway mountains to seem blue, yet when the atmosphere is clear, the same mountains appear to be closer.
Light and Shade: When an item is lit up, some areas are emphasised while others are made darker. We can determine the distance to an item by looking at its highlights and shadows.
Relative Height: The observer perceives larger items as being closer and smaller ones as being farther away. The larger of the two will look closer and the smaller will appear further away when we anticipate two items to be the same size but they are not.
Texture gradient: This cue is based on the observation that an object’s texture, such as the degree of roughness or smoothness on a surface, looks to compress or condense as one gets closer to it. To determine the separation between two objects in the environment, utilise this method.
Interposition or Overlapping :When one item covers a section of another, this is known as interposition or overlapping. The covered item seems closer, whereas the overlapping object is perceived to be further away.
In addition to these monocular cues, depth perception also rely on binocular cues, which are visual messages that demand the use of both eyes. Among the binocular cues are the following:
Retinal or Binocular Disparity: The two eyes in our head are located differently, which leads to retinal disparity. They are around 6.5 cm apart from one another on the horizontal. The picture of the identical object created on the retina of each eye is somewhat different as a result of this distance. Retinal disparity is the term used to describe the contrast between the two pictures. Because the retinal disparity is greater for near objects and smaller for far ones, the brain perceives a big retinal disparity to indicate a close item and a small retinal disparity to indicate a distant object.
Convergence: The eyes must converge (bend inward) to focus on a close object and diverge (turn outward) to focus on a distant object. This is the basis for the convergence cue. The brain makes use of this information to determine the separation between objects in the immediate environment.
Accommodation: Accommodation is the process through which the ciliary muscle helps us concentrate the picture on the retina. These muscles alter the eye’s lens’s thickness. The muscle relaxes if the item travels more than two metres. The muscle tightens as the item draws closer, and the lens gets thicker. The brain receives a signal regarding the strength of the muscle contraction, and uses that information to determine how far away something is.
10.) Why do illusions occur?
Sometimes our perceptions are not accurate. There are times when we misinterpret the sensory data. The physical stimulus and its perception are therefore out of sync. These false impressions brought on by a misunderstanding of the data gathered by our sensory organs are commonly referred to as illusions. We all feel this to some extent. They arise from a circumstance involving an external stimulus and produce the same sort of experience in every person. Illusions are often referred to as “primitive organisations” for this reason.Although any of our senses can be stimulated to produce illusions, psychologists have focused more of their research on the visual sense than on the other sense modalities. There are several perceptual illusions that are shared by all people. For instance, the train lines seem to be coming together for all of us. As they do not alter with effort or experience, these illusions are referred to as universal illusions or permanent illusions. Some illusions, known as personal illusions, appear to differ from person to person.
11.) How do socio-cultural factors influence our perceptions?
Several psychologists have investigated how perception works in various socio-cultural contexts. By comparing samples from distant African communities and western settings, they have employed Muller-Lyer and vertical-Horizontal illusion figures with various groups of individuals living in Europe, Africa, and many other places.
- It was discovered that although Western participants were more susceptible to the Muller-Lyer illusion, African respondents were more susceptible to the horizontal-vertical illusion.
- Several research have observed similar results as well. Due to their frequent exposure to verticality—long trees, for example—the African respondents who lived in deep woods tended to overestimate it.
- Europeans, who inhabited a world where right angles predominated, developed a propensity to underestimate the length of line that characterised enclosure (e.g., arrowhead).
- According to this research, various cultural contexts lead to distinct learning processes for developing perceptual habits.
- In an experiment he conducted in Africa, Hudson discovered that people who had never seen photographs had a hard time identifying objects and understanding depth signals.
- Sinha and Mishra have conducted a number of research on visual perception utilising a range of images with individuals from various cultural contexts, such as farmers in cities and hunters and gatherers living in forests.
• Their research suggests that how people interpret images is closely tied to their cultural experiences
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