Sensation & Perception PDF

SENSATION PERCEPTION Sensation vs. Perception SENSATION PERCEPTION The activation of the The sorting out, sense organs by a interpretation, source of physical analysis, and energy. integration of stimuli The process of bringing by...

SENSATION PERCEPTION Sensation vs. Perception SENSATION PERCEPTION The activation of the The sorting out, sense organs by a interpretation, source of physical analysis, and energy. integration of stimuli The process of bringing by the sense organs information from the and brain. environment into the body and to the brain.  Sensation is a physical response, while perception is a psychological response.  THE SENSORY SYSTEM: EXTERNAL SENSATION VISUAL SENSE | AUDITORY SENSE | OLFACTORY & GUSTATORY SENSES | CUTANEOUS SENSE External Sensation Process of knowing material, concrete stimuli through the external senses Cutaneous Sensation Olfaction Gustation Audition Vision External Sensation Four elements: Brain Stimulus Receptor Transmissor Center  STIMULUS Any aspect of the world LIGHT that influence our behavior SOUND The physical element of an external sensation OBJECTS May vary in intensity and type SCENT Activates the sense organs FLAVOR STIMULUS: Psychophysics Study of relationship between the physical aspects of stimuli and our psychological experience of them. PSYCHOPHYSICS Absolute Difference Thresholds Thresholds STIMULUS: Absolute and Difference Thresholds 1. Absolute Threshold the smallest intensity of a stimulus that must be present for it to be detected The lower the absolute threshold = the greater the sensitivity. STIMULUS: Absolute and Difference Thresholds OUR SENSE OF TOUCH IS SO SENSITIVE THAT WE CAN FEEL A BEE’S WING FALLING ON OUR CHEEK WHEN IT’S DROPPED FROM A DISTANCE OF 1 CM  STIMULUS: Approximate Absolute Thresholds for Humans Vision Hearing Candle flame seen at 30 miles Tick of a watch under quiet on a clear, dark night conditions at 20 feet Taste Smell Touch 1 teaspoon of sugar 1 drop of perfume Wing of a fly or bee falling in 20 gallons of water diffused into the entire on a person’s cheek from volume of a large a distance of 1cm apartment STIMULUS: Absolute and Difference Thresholds Difference Threshold (just noticeable difference/JND) the smallest level of added (or reduced) stimulation required to sense that a change in stimulation has occurred The smallest difference between two stimuli that people can perceive 50 percent of the time STIMULUS: Absolute and Difference Thresholds Noise Background stimulation that interferes with the perception of other stimuli RECEPTOR The stimulus is received by the Receptors specialized cells in the sense organ capable of detecting the stimulus. Any structure in the body that is excitable to a stimuli RECEPTOR: Kinds Exteroceptors Found on the external surface of the body Proprioceptors Located in muscles, joints, and tendons Interoceptors or Visceroceptors Found in the visceral organs TRANSMISSOR Bundles of nerve fibers that convey sensory messages or impulses from one neuron to the next Fiber tracts Ascending nerve fibers BRAIN CENTER Sensory areas located in the different lobes of the brain VISUAL SENSE  VISION Seeing Most valued of all external senses Starts with light VISUAL STIMULUS VISUAL STIMULUS Light physical energy that stimulates the eye a form of electromagnetic radiation waves VISUAL BRAIN CENTER VISUAL PHENOMENA COLOR VISION COLOR BLINDNESS AFTERIMAGE COLOR VISION Normal Color Vision Can distinguish no less than 7 million different colors Color-Blind Limited ability to perceive color Color Blindness TRICHROMATS people with normal color vision DICHROMATS deficient in the blue-yellow system, the red-green system, or both. (Approximately 7% of the male population and 1% of the female population are dichromats.) MONOCHROMATS sensitive only to the black-white system, totally color-blind. ISHIHARA TEST Test to identify color-blindness Trichromatic Theory of Color Vision three kinds of cones exist in the retina one most responsive to blue-violet one to green one to yellow-red The Young-Helmholtz trichromatic theory proposed three different receptors, one for blue, one for green, one for red. The ratio of activity in the three types of cones yields our experience of a particular hue, or color. Review: VISUAL SENSE ABNORMALITIES IN VISION  Damage to Primary Visual Cortex ⚫ Scotomas ⚫ Areas of blindness in contralateral visual field due to damage to primary visual cortex ⚫ Detected by perimetry test ⚫ Completion ⚫ Patients may be unaware of scotoma – missing details supplied by “completion” Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 6.26 The completion of a migraine- induced scotoma as described by Karl Lashley (1941). Copyright © 2011 Pearson Education, Inc. All rights reserved.  Damage to Primary Visual Cortex Continued ⚫ Blindsight ⚫ Response to visual stimuli outside conscious awareness of “seeing” ⚫ Possible explanations of blindsight ⚫ Islands of functional cells within scotoma ⚫ Direct connections between subcortical structures and secondary visual cortex, not available to conscious awareness Copyright © 2011 Pearson Education, Inc. All rights reserved.  Functional Areas of Secondary and Association Visual Cortex ⚫ Neurons in each area respond to different visual cues, such as color, movement, or shape ⚫ Lesions of each area results in specific deficits ⚫ Anatomically distinct (about 12 functionally distinct areas identified so far) ⚫ Retinotopically organized Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 6.27 Some of the visual areas that have been identified in the human brain. Copyright © 2011 Pearson Education, Inc. All rights reserved.  Prosopagnosia ⚫ Inability to distinguish among faces ⚫ Most prosopagnosic’s recognition deficits are not limited to faces ⚫ Prosopagnosics may be able to recognize faces in the absence of conscious awareness ⚫ Prosopagnosics have different skin conductance responses to familiar faces compared to unfamiliar faces, even though they reported not recognizing any of the faces Copyright © 2011 Pearson Education, Inc. All rights reserved. Prosopagnosia ⚫ Prosopagnosia is associated with damage to the ventral stream between the occipital and temporal lobes Copyright © 2011 Pearson Education, Inc. All rights reserved.  Akinetopsia ⚫ Deficiency in the ability to see movement progress in a normal smooth fashion ⚫ Can be induced by a high dose of certain antidepressants ⚫ Associated with damage to the middle temporal (MT) area of the cortex Copyright © 2011 Pearson Education, Inc. All rights reserved. FIGURE 6.30 The location of MT: Damage to this middle temporal area of the human brain is associated with akinetopsia. Copyright © 2011 Pearson Education, Inc. All rights reserved. Biological/Physiological Psychology ❑Agenda February 15, 2022: ❑Non Visual Sensation ❑Auditory ❑Cutaneous ❑Olfactory ❑Gustatory AUDITORY SENSE  sound AUDITORY STIMULUS VIBRATIONS  SOUND The air around is made up of so many particles, and these particles are what carries sounds. Like marbles – if you put a few marbles together so that they’re touching, then roll another marble so that it crashes into them, the group of marbles will move. When we strum the guitar, we cause the string to vibrate really fast. The vibration of the string shakes up the particles in the air around it and makes them vibrate and so on. L  AUDITORY STIMULUS Sound movement of air molecules brought about by vibration (sound waves)  AUDITORY STIMULUS Sound movement of air molecules brought about by vibration (sound waves) AUDITORY RECEPTOR AUDITORY Sense Organ: EAR RECEPTOR Sensitive to sound waves within 20- 20,000Hz Composed of: 1. Outer Ear 2. Middle Ear 3. Inner Ear Auditory System Natural sounds are complex patterns of vibrations A Fournier analysis breaks natural sounds down into sine waves There is a complex relationship between natural sounds and perceived frequency Parts of the ear Ossicles Semicircular The structures canals Malleus Incus Stapes Tympanic (hammer) (anvil) (stirrup) Auditory vestibular membrane (eardrum) nerves (to brain) that transmit Cochlea sound waves from the auditory External auditory canal canal to the cochlea. Oval Round Vestibular Auditory window window sacs tube Parts of the ear Ossicles Semicircular Malleus Incus Stapes canals The inner ear Tympanic membrane (hammer) (anvil) (stirrup) Auditory vestibular nerves contains the (eardrum) (to brain) cochlea, COCHLEA a snail-shaped tube about 1.4 inches in External auditory length canal is filled with fluid and vibrates in Oval Round Vestibular window window sacs Auditory tube response to sound. Parts of the ear: Inside the Cochlea Tectorial Vestibular membrane membrane Scala media (cochlear duct) In the cochlea, hair Scala vestibuli Organ of Corti cells in the organ of corti. Its composed of two membranes Basilar membrane – auditory receptors, hair cells, are Hair cells mounted here Tectorial membrane – rests on the hair cells Basilar membrane Scala tympani Stimulation of hair Auditory nerve cells triggers action potentials in the auditory nerve  Ossicles Semicircular canals Malleus Incus Stapes Tympanic (hammer) (anvil) (stirrup) Auditory vestibular membrane nerves (eardrum) (to brain) Cochlea External auditory canal Oval Round Vestibular Auditory window window sacs tube Sound waves This sets in enter the motion the The cochlea’s auditory canal bones of the Vibration of the internal of the ear and middle ear, the oval window membrane, the then cause the ossicles, which sets in motion organ of Corti, tympanic trigger the fluid of the is the auditory membrane (the vibrations of cochlea receptor organ eardrum) to the oval vibrate window  AUDITORY TRANSMISSOR AUDITORY TRANSMISSOR Tectorial Vestibular membrane Scala media membrane (cochlear duct) Scala Organ of Corti vestibuli Hair Cochlear coding: cells Scala tympani Auditory nerve AUDITORY TRANSMISSOR Tectorial In the cochlea, sound waves membrane Scala media Vestibular (cochlear duct) are translated into fluid membrane Scala waves that stimulate hair Organ of Corti cells in the organ of corti. vestibuli Hair Different frequencies cells produce maximal stimulation of hair cells at different points along the basilar membrane Scala tympani Auditory nerve The resulting impulses reach the brain via the auditory nerve. BRAIN CENTER Auditory Pathway FIGURE 7.6 Some of the pathways of the auditory system that lead from one ear to the cortex. AUDITORY BRAIN CENTER Auditory Cortex Auditory cortex is located in the temporal lobe Core region: includes primary cortex Belt surrounds the core region A band of secondary cortex Secondary cortex outside the belt referred to as parabelt areas About ten seperate areas of secondary auditory cortex in primates AUDITORY PHENOMENA PITCH LOUDNESS TONE QUALITY / TIMBE AUDITORY PHENOMENA PHYSICAL ELEMENT PSYCHICAL ELEMENT (SOUND WAVES) (SOUND) FREQUENCY PITCH INTENSITY LOUDNESS COMPLEXITY TONAL QUALITY OR TIMBRE FREQUENCY / PITCH INTENSITY / LOUDNESS COMPLEXITY / TIMBRE OR TONE QUALITY Warning: Not for those with Hearing Sensitivity Review: AUDITORY SENSE CUTANEOUS SENSE CUTANEOUS STIMULUS Cutaneous Sense: Somatosensation Touch Pain Pressure KINAESTHESIA Temperature - awareness of position & movement CUTANEOUS RECEPTORS SOMATOSENSORY RECEPTORS Somatosensation Receptor Touch Merkel’s Disk Pressure Pacinian Corpuscles Pain Free Nerve Endings Cold Krause’s Corpuscles Warm Ruffini’s Endings Kinaesthesia Proprioceptors  Touch, pressure, temperatur e, and pain receptor cells in the skin are distributed unevenly throughout Skin senses the body.  What are the most sensitive body parts?  Fingers & thumb, lips, nose, cheeks, & big toe are the most sensitive. BRAIN CENTER Two Major Somatosensory Pathways Dorsal-column medial- lemniscus system Mainly touch and proprioception Proprioception, otherwise known as kinesthesia, is your body's ability to sense movement, action, and location Anterolateral system Mainly pain and temperature Two Major Somatosensory Pathways FIGURE 7.12 The dorsal- FIGURE 7.13 The anterolateral column medial-lemniscus system. system. SOMATO SENSORY BRAIN CENTER SOMATOSENSORY PHENOMENA Phantom Limbs Gender & Susceptibility to Pain The lower the threshold = the more sensitive a body part is. Skin senses Some people are more susceptible to pain than others. Women typically experience painful stimuli more intensely than men. In addition, certain genes are linked to the experience of pain, so that we may inherit our sensitivity to pain. Phantom Limb Phenomenon OLFACTORY SENSE SENSE OF SMELL OLFACTORY STIMULUS OLFACTORY STIMULUS Chemical Substance in Gaseous state: Scent  OLFACTORY RECEPTOR and TRANSMISSOR OLFACTORY RECEPTORS More than a thousand receptor cells, known as olfactory cells, are spread across the olfactory epithelium (nasal cavity) Olfactory cells are specialized to react to particular odors OLFACTORY TRANSMISSOR OLFACTORY BULB & TRACT - The Bulb located near the front of the brain where the olfactory axons ends - The Tract is a bundle of nerves starting at the bulb going to the brain  OLFACTORY TRANSMISSION 3) Responses sent to brain, 1) Molecules enter the nasal 2) Pass over olfactory cells where they are combined passage (receptor neurons) for recognition  OLFACTORY BRAIN CENTER OLFACTORY BRAIN CENTER Your nose protects you Smell plays a key role in taste. The sense of smell is not only for 4 primary tastes: bitter, sour, sweet and pleasure; it is necessary for safety. salty. Smell to detect smoke, spoiled food and People feel that food is tasteless when some toxic gases. their ability to smell is decreased. People who lost their sense of smell need to have alarms for these gases and they have to be careful with what they eat. Smell may be important in identification. Many people can identify those close to them by their smell, whether that’s through their characteristic lotion or perfume or body odor. Your nose shapes the sound of your voice What we hear when people speak and sing is in large part related to the resonating structures of the throat and nose. The nasal voice we hear in someone with a cold and allergies is due to the loss of this nasal resonation since the air cannot pass through the nose. OLFACTORY PHENOMENA GUSTATORY SENSE GUSTATORY STIMULUS GUSTATORY STIMULUS Chemical substances in the liquid form Flavor GUSTATORY RECEPTOR GUSTATORY RECEPTORS The receptor cells for taste are located in roughly ten thousand taste buds, distributed across the tongue, parts of the mouth, & throat The taste buds wear out and are replaced every 10 days or so.  GUSTATORY TRANSMISSORS GUSTATORY TRANSMISSORS Nerves: 1. Facial Nerve 2. Glossopharynge al Nerve GUSTATORY BRAIN CENTER GUSTATORY BRAIN CENTER OLFACTORY & GUSTATORY PHENOMENA Coffee contains nitrogen, which helps neutralize odors in the air quickly and safely. When you punch your nose, the upper part of your nose isn't clear to receive the chemicals that trigger the olfactory receptors, hence no flavor. Loss of an external sense Loss of Medical Term Vision (Blindness) Anopsia Audition (Deafness) Anacousia Olfaction Anosmia Gustation Ageusia Ability to feel pain Analgesia Ability to identify an Asteriognosia object through touch PERCEPTION  it made me wonder if people even notice me. It literally made me feel I am under the table. I can see my cats small, though I don’t think that is really The world seems bigger, even though and appliances in the house. I can hear how a toddler would think because all are the same. Everything felt big, and my father cooking for our dinner, - most of the time, they don’t care with high. – Alexandra Mabulac Micaela Adao how things happen as long as they have something that entertain them - Marypatricia R. Fernandez I remember something that reinds me The toddler’s point of view is way too of my childhood just like how I use to imaginative and happy, where they can wait for my favorite cartoon to air on I feel small and vulnerable -Hannah do whatever they think they want to the television and how I used to play all do. -Cyndie day without thinking of any problem or responsibilities. – Alkyshane But the child, as curious as they come, Toddlers have an amazing capacity to As I was doing this my mom actually they will try to hold and touch pay attention to every aspect in their ask me what I was doing under the everything they see, sometimes they environment. It's a superpower of table and just observing everything I even lick it without any hesitation. theirs! Adults automatically filter out see, I just told her I'm doing this in That’s how carefree they are, but for irrelevant information, such as a order to see things on me, I tried analyzing the things I see, fascinating shadow pattern on the the toddler’s perspective of everyday familiarize myself with the things while I pavement, but toddlers have no idea events - Erika Labian am under there -Angela Borres what's essential. – Trisha lacaran Definition: Perception Mind’s interpretation of sensation A process: raw sensory information is collected/ acquired, organized and interpreted or translated into meaningful information. Process: Perception Selection Organization where one selects the stimuli to which Interpretation he/she will attend to. where the information from the sensory organs is Giving meaning to transmitted to the the information. brain and organized so it can be understood and be given meaning. Gestalt Laws of Organization Organizing the separate parts of our perceptual field into a unified and meaningful whole. The Gestalt Laws of Organization Principles that describe how we organize pieces of information into meaningful wholes (gestalts = patterns) We do not just passively respond to our retinas. Instead, we actively try to organize and make sense of what we see. Figure- Similarity Closure Ground Proximity Continuity GESTALT LAWS OF ORGANIZATION Figure-ground organization we usually perceive objects as a figure standing out against a background The Gestalt Laws of Organization The Gestalt Laws of Organization The Gestalt Laws of Organization Is it going the left or top right? Perceptual Constancy  Physical objects are perceived as unvarying and consistent despite changes in appearance or changes in the physical environment Allows us to recognize PERCEPTUAL familiar stimuli under varying CONSTANCY conditions SHAPE CONSTANCY Allows us to recognize people and other objects from many different angles. BRIGHTNESS CONSTANCY The relative brightness of objects remains the same under different conditions of illumination (full sunlight and shade). Which one is lighter? SIZE CONSTANCY Perception that the size of objects remains relatively constant even though images on our retina change in size with variations in distance. MOON ILLUSION MOON ILLUSION DEPTH PERCEPTION the ability to view the world in three dimensions and to perceive distance translating two- dimensional information (length and width) into three-dimensional perceptions. Depth Perception Monocular Depth Cues requiring only one eye Binocular depth cues require both eyes Monocular Depth Cues PATTERNS OF LIGHT AND SHADOW Typically used by artists to create perceptions of depth in their pictures. Patterns of light and shadow can serve as monocular depth cues. Drawing Hands, by M.C. Escher Monocular Depth Cues LINEAR PERSPECTIVE The perception that parallel lines converge as they recede into the distance. Monocular Depth Cues INTERPOSITION Objects closer to us may cut off part of our view of more distant objects.  Monocular Depth Cues TEXTURE GRADIENT The texture or grain of an object appears finer as distance increases. CLARITY We can see nearby hills more clearly than ones that are far away. Monocular Depth Cues RELATIVE SIZE Looking at two objects of similar size, the one that looks smaller will be judged to be farther away. Monocular Depth Cues HEIGHT IN THE HORIZONTAL PLANE A ship 5 miles offshore appears to be in a higher plane and closer to the horizon than does one that is only 1 mile from shore.  Monocular Depth Cues MOTION PARALLAX if we are moving, nearby objects appear to move faster in the opposite direction than do far-away ones.  Binocular Depth Cues BINOCULAR DISPARITY Each eye sees a slightly different image. CONVERGENCE Produced by feedback from the muscles that turn your eyes inward to view a close object. PERCEPTUAL ILLUSIONS Perceptual Illusions: The Deceptions of Perceptions Visual illusions: physical stimuli that consistently produce errors in perception Muller-Lyer illusion The Parthenon looks perfectly straight, with right angles at every corner. b. The Parthenon looks perfectly straight, with right angles at every corner. However, if had been built with true right angles, it would have looked as it does in figure (b). b. The Parthenon looks perfectly straight, with right angles at every corner. However, if had been built with true right angles, it would have looked as it does in figure (b). c. To compensate for this illusion, the Parthenon was designed to have a slight upward curvature as shown in (c). (Source: Coren & Ward, 1989, p.5.) Is the man aiming for the elephant or the antelope? FOUR PERFECTLY ROUND CIRCLES rotating clockwise or counter- clockwise ?