CHAPTER 4 The basics of sensation and perception

CHAPTER 4 The basics of sensation and perception by Shirmeen Ijaz

SENSATION • Sensations can be defined as the stimulation of sense organs. It is a process of bringing information from the world into the body and to the brain.

Five senses • Eyes • Ears • Nose • Skin • Tongue

PERCEPTION • Perception is a process that takes place in our brain, it involves understanding. • Sensation and Perception work together - one isn't much good without the other.

THE PERCEPTUAL PROCESS The process of perception consist of six steps. Environmental stimulus Action Transduction Processing Recognition Perception

THE PERCEPTUAL PROCESS • Environmental stimulus The environmental stimulus is everything in our environment that has the potential to be perceived, e. g, light or sound. • Transduction converts energy in the environment into electrical energy. Combining the environmental stimulus with transduction generates a sensation.

• Processing • The electrical signals then undergo neural processing. The path followed by a particular signal depends on what type of signal it is (i. e. an auditory signal or a visual signal). Through the series of interconnect neurons located throughout the body, electrical signals are propagated from the receptors cells to the brain.

• Perception In the next step of the perception process, we actually perceive the stimulus object in the environment. It is at this point that we become consciously aware of the stimulus. (Figure out the sensation) • Recognition Perception doesn't just involve becoming consciously aware of the stimuli. It is also necessary for our brain to categorize and interpret what it is we are sensing. Our ability to interpret and give meaning to the object is known as recognition.

• Action (action or doing something because of a stimulus) The final step of the perceptual process involves some sort of action in response to the environmental stimulus. This could involve a variety of actions, such as turning your head for a closer look or turning away to look at something else. The action phase of perceptual development involves some type of motor action that occurs in response to the perceived and recognized stimulus.

THE PERCEPTUAL PROCESS Environmental stimulus duck floating in the nearby pond. (image on the retina) Action Transduction as turning your head for a closer look or turning away to look at something else. image on the retina is then transformed into electrical signals Processing Recognition processed through the neurons in the visual network. you realize that there is a duck floating on the water. Perception become aware of that there is something out on the pond

NEURON • The basic purpose of a neuron is to receive incoming information and, based upon that information, send a signal to other neurons, brain and parts of body.

FUNCTIONAL CLASSIFICATION OF A NEURON The basic purpose of a neuron is to receive incoming information and, based upon that information, send a signal to other neurons, muscles, or glands. There are 3 types of neurons. Sensory 1. Sensory neurons. From senses to CNS receptor 2. Motor neurons. From CNS to other parts of the body Sensory neuron 3. Interneuron. Provide connection between sensory and motor neurons. Located entirely within the spinal cord or CNSInterneuron Motor neuron Relationship Among Different Types of Neurons Muscle or Gland

FOUR LOBES OF THE CEREBRAL CORTEX Pressure, touch, and pain. Visual processing Auditory, taste & smell processing Movement, decision-making, problem solving, and planning.

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