PSY 111 1st Edition Lecture 16 Sensation and Perception o Oliver Sacks video Talks about Charles Bonnet Syndrome the hallucinations produced in this syndrome as you loose visions the visual part of your brain visual cortex occipital lobe become hyperactive Charles Bonnet syndrome include geometric hallucination primary visual cortex which is located in the cerebral cortex specifically in the occipital lobe which s more towards the back of the head and elaborate facial hallucinations temporal lobe which is on the sides of your brain Use fMRI to find the part of brain that it activated when patients have hallucinations Temporal lobe epilepsy You wouldn t have Charles bonnet syndrome if you were born blind you would have to become blind Bottom up process sense organ gather data and send it to the brain Top down process brain makes sense of info that comes into the brain When you have Charles bonnet syndrome which type of processing is messed up top down not bottom up because its not your sensory organs that are messed up it is your brain being hyperactive How are these hallucinations different from psychotic hallucinations Psychotic hallucinations are directed to the person and interact with the person and people with psychotic hallucinations are not aware they are hallucinating Why do people get car sick air sick and sea sick Because your brain is dependent on being able to see and with this comes with a fluid in your ear that help your brain to be able to see where you are on a place car or boat this fluid moves rapidly and it throws off your brain s ability to see o Outline Sensation Sense organs Sensory info Thresholds Vision Hearing Kinesthetic and vestibular sense Sensory adaptation o Perception Theories of perception signal detection and gestalt Perception Sensation and perception o Intimately related o Plays complementary roles with each other o Have slightly different roles in our interpretation of the word Sensation 5 sense organs sight hearing taste sweet sour bitter salty and umami touch smell Refers of to the process of sensing our environment by gathering information this info is sent to our brain for interpretation through the frequency of firing the more you experience the sense the more your brain lights up and vice versa All of this is done through our sensory organs Absolute threshold our ability to distinguish a particular stimuli is dependent on the stimulus being present at that particular stimuli it marks the difference between not being able to perceive a stimulus and being just barely able to perceive it Why do our senses get worse over time because of the break down of the cell cycle Difference threshold measures the smallest increase or decrease in a physical stimulus that is noticed also know as the just noticeable difference it is dependent on the initial intensity of stimulus weber s law it is also dependent on context learning culture and life experiences Sensory Receptors highly specialized cells in the body detect and respond to one type of sensory stimuli Transduction process through which the sensory receptors convert the sensory stimulation into neural impulses electrochemical language of the brain Ex if its pain you are going to be releasing more endorphins Sensory adaptation process by which the sensory receptors grow and accustomed to constant unchanging levels of stimuli sights sound or smells so that we notices the less and less or even not at all The sensory systems Vision uses light visible light spectrum goes form infrared to ultraviolet and we only see white light shortest light waves appear violet longest light waves appear red Make sure you know the human and its parts and draw it out iris lense pupil ciliary muscle the fovea blind spot optic nerve retina rods and Cones Light comes in through your pupil and the lenses contracts or relaxes and the light hits the retina in the back The lenses decides the lenses