Psychology: Sense and Perception
What is flavor?
A combination of taste with smell. Flavor includes: odor, temperature, texture and taste. It allows us to distinguish between flavors with the same taste. Taste is simply the five tastes hitting our taste buds. Ex: vanilla ice cream vs. chocolate ice cream, lemon juice vs. vinegar
How do we taste?
Chemical sensation. When we chew, saliva helps break down molecules. Molecules run down trenches in our tongue and stimulate our taste buds (aka taste receptors). The taste buds then transduce the tastes into nerve impulses which get sent off to the brain. Taste buds get regenerated every 10 days and can be damaged by smoking, extreme temperatures, alcohol and extreme spiciness/sourness.
Optical illusions, color constancy, and inattentional blindness
Color constancy - when your brain, from experience, recognizes that changes in light may change how colors are registered by your eyes so it builds on your experience to continue to perceive a color a certain way even if the lighting has changed. For example: the strawberry picture from class where we know strawberries should be red so our brain says yup they're red even if technically they are not. -Optical illusions (irradiation) - our brains tend to perceive light objects against dark objects as larger, appearing to "bend" the horizontal lines. -Also we perceive the size of objects as relative to the objects around them - even though both yellow lines are the same size, the higher one looks longer because its surrounding lines are smaller/further away. Inattentional blindness/selective attention - your brain only has the capacity to focus on so much. If you've set your mind to focusing on one thing, your brain will selectively drown out the rest. -Peripheral vision - to save itself some work the brain takes a lot of shortcuts while processing visual information out of your eye's central focus (periphery). It is guesisng what's happening in the periphery. If it appears quite similar to your central focus your brain will assume it's all the same and alter your periphery to appear so. What we see in our periphery is all an illusion.
What is the difference between sense and perception? What is the process from sense to perception?
Difference: Sense= the physiological basis of perception - a faculty by which the body perceives an external stimulus (sight, smell, hearing, taste, touch) Perception= the way sensory information is organized, interpreted and consciously experiences The process from sense to perception= sensation (process by which input about the physical world obtained by our sensory receptors gets processed by the brain in perception where it is selected, organized and interpreted.
What is echolocation and what does it reveal about the brain?
Echolocation is our ability to use sound waves to locate an object in space Echolocation reveals that the brain can adapt to new/other processes when we have a sense missing, for example sight in blind people, and find a way to do that function in an untraditional way - abstractly, blind people can "see" through audition/echolocation.
How do the eyes work? When and how is vision impaired?
Light waves are transmitted across the cornea, the transparent covering over eye that focuses light waves. The waves enter the eye through the pupil which dilates and expands to control how much light enters the eye. Light passes through the pupil and crosses the lens which further helps focus light and directs it to a retina which contains densely packed photoreceptors cells called cones which work best in bright light. In darker light, rods pick up the slack of receiving light waves (but lack spatial and color abilities that the cones provide). The cones and rods convert light waves into electrical signals for the brain. Those electrical signals travel down each eye's optic nerve to reach the occipital lobe for processing. There are 2 kinds of vision impairment: Low vision - any kind of vision impairment that allows for some light perception and cannot be corrected by corrective lenses: blind spots in field of vision, loss of peripheral vision, night blindness, blurred vision, hazy vision. Can be caused by: deterioration of the retina, damage to the optic nerve and cataracts (cloudy areas in the eye's lens) Complete blindness - total lack of light perception. Can be caused by: severe trauma or injury, complete retinal detachment, severe internal eye infection, damage to the optic nerve
The relationship between smell & memory
Nerve impulses generated by touch, vision, gustation and audition go first to the thalamus (a relay center). However, olfactory information goes straight to the olfactory bulb (smell processing part of the brain). Olfactory bulb directly connected to the Amygdala and hippocampus, which help handle memory and emotion. Scientists believe this is because smell is our oldest sense, evolutionarily, it is best suited to protect us from danger. It can be used for shopping - the brain associate's chocolate for example with a certain store and has good memories of chocolate, obviously, so more inclined to feel comfortable, browse for longer, ultimately higher chance of buying shoes. Or sometimes you smell something and it reminds you of something else ex: artificial cotton candy flavored food smell - reminds me of childhood and ice pops and camp.
How does audition help us locate objects in space?
Our ears help us perceive distance and location. Having 2 ears - binaural hearing - allows us to locate the horizontal origin of a sound. Sound coming from the right or left reaches one ear before the other -> the brain determines the direction of a sound by calculating the sight difference in time that it takes the sound waves to reach the two ears. Because the positions of our ears were better at locating the horizontal source of a sound than the vertical source. So, hearing helps us "see" in a way... so can blind people see? Technically no but abstractly, disability is a construct so by using audition to locate objects they can in another way. Echolocation - using sound waves to locate an object in space (sound bounces off object and returning echo activates the visual processing area in the brain (visual cortex) of an experienced echolocator.)
What is pain?
Pain is an alert that something is happening to/in our body that shouldn't be happening/something is wrong. It is essential for survival because it warns us to avoid or escape danger and forces us to take recovery time for an injury in order to properly heal. It keeps us safe. Most pain comes from tissue damage. Remember the story we read in class about that girl who can't feel pain and how it is hard for her to stay safe. Nociception - the nervous systems protective response to harmful stimuli If enough sensors are activated, the brain weights importance of those signals and causes pain Amplification - chronic pain (lasts more than 3 months) Sometimes pain can outlast physical injury and the longer pain persists the more difficult it becomes to reverse
What is sensory adaptation, and why does it occur?
Sensory adaptation - by adapting to the smells in our environment after a long enough time our receptors decrease their sensitivity to the stimuli and make them less noticeable. It occurs to allow us to quickly detect new changes that could be potentially threatening - smart from an evolutionary standpoint. Once your used to the way something smells, the only way to accurately detect it is to leave and come back You can slow down the adaptation process with physical activity or anything that increases blood flow ex: perfumery/running on stairs.
Why do we like the foods that we like, and dislike the foods we dislike?
Smell vs. taste Smell develops in stomach and since its linked to certain memories we have good experiences with food - developed around contrast - if first meal after prison or thanksgiving - context of being with your fam We adapt to like food also because of dinner table familial peer pressure/redundant eating of that food- hot peppers children podcast Challenge our body with unthreatening thrill Experience of when we eat the experience first and last part of a meal - we remember that the most And sometimes the reason for disliking a food cannot be explained - we just don't like it!
What kinds of stimuli do our senses react to?
Smells, sights, touches, tastes, sounds etc. and our brain perceives them (makes sense of what those stimuli are) based on learning, memory and attention. For example: you could be at a party focusing on a convo with a friend and there's music playing in the background (stimulus) and your ears are picking up on it (sensation) but because you're not focusing you might ot perceive the specific song that is playing.
In what ways is somatosensation different from the other senses?
Somatosensation is different from the other senses because the somatosensory system has to figure out temperature, pressure, pain, intensity of all of the above, how hot/cold something is, how much pressure and where on the body you are feeling something rather than simply what does that taste like? or what is that sound? touch is all over your body, not localized like the other senses
How does somatosensation work?
Somatosensation is touch. The somatosensory system is your skin, the largest organ in the body. The skin houses several different somatic receptors each with different responsibilities (pain, temperature, vibration, pressure, location). The somatosensory cortex in the brain processes all somatic sensation that the receptors pick up on as specific regions correspond to specific parts of the body. It transforms nerve impulses to sensations of touch, temperature pressure location and pain. There is a direct correlation between the size of a designated area on the cortex and how sensitive a part of the body is. Pain receptors (nociceptors) send information to the brain which might signal other body function such as motor functions: "take your hand away from the fire!" or "stop walking on that twisted ankle!"
What is sound?
Sound is the perception of the sense of hearing. Vibrations that travel through the air (or another medium) and can be heard when they reach a person or animal's ear, which processes the vibrations. In order for a noise or vibration (sound wave) to be considered a sound it must be perceived and processed by your brain. So, if a tree falls in a forest and nobody is around does it make a sound? NO.
Why do we stop smelling something after a while?
To keep your nervous system from exhausting itself with continuous stimuli, the receptors experience temporary olfactory adaptation where our odor receptors stop sending messages to the brain about a lingering odor and instead focus on new, maybe threatening smells. By adapting to the smells in our environment, we stop using energy to detect those and focus on new changes that may be threatening - it makes sense form an evolutionary standpoint Once we are used to the way something smells, the only way to detect it is to leave and come back after a period of time. Sensory adaptation
How do we smell?
Vaporized molecules reach the nose and dissolve in the mucus at the roof of each nostril. Beneath the mucus are olfactory neurons that can detect up to 10,000 odors and help transduce the chemical molecules into nerve signals. Those olfactory neurons transmit information into the olfactory bulb in the brain.
What is color blindness?
Your cones (photo receptors that pick up on color) are designated to specific wavelengths for example, red is transmitted off of a different wavelength than blue. When a cone that is only supposed to pick up on one color picks up on another one too confused it and in the end the person ends up seeing a muddy color - a color blind person. To clarify, color blindness is a failure for certain cones in one's eyes to sense certain colors or distinguish between certain colors. It doesn't mean total color blindness/monochromacy but that is EXTREMELY rare. It can mean deuteranopia, protanopia, anomalous trichromacy or tritanopia. These subcategories differ in how one sees the world. Being color blind includes confusing red and green and having them both look yellowish or seeing the world in greenish/pinkish tones or something else. Color blind glasses filter light in a way that makes it easier for certain people with different types of colorblindness to detect the difference between colors but it is not always going to work for everyone especially in severe cases.
