1 / 10

Three Steps in the Sensation and Perception of a Stimulus

Learn about reception, transduction, & coding in sensory systems, including touch & transduction process. Understand how stimuli are coded into action potentials based on intensity, type, & location.

hardingc
Download Presentation

Three Steps in the Sensation and Perception of a Stimulus

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Three Steps in the Sensation and Perception of a Stimulus • All Sensory Systems • Follow the Same Plan • Reception • Transduction • Coding

  2. A Sensory System… • Requires different receptors to discriminate among • different forms of energy. • Should discriminate among different intensities of stimulation. • Should respond reliably. • Should respond rapidly. • Should suppress extraneous information.

  3. A Variety of Sensory Receptors

  4. Touch - Skin Receptorsconvert energy into a change in electrical potential • Free Nerve Ending • Pain • Heat/Cold • Merkel’s Discs • Touch • Ruffini’s Endings • Stretch

  5. Transduction 1. Stimulation causes deformation of the Pacinian corpuscle 2. Deformation opens pours in membrane allowing Na+ in 3. Na+ depolarizes the cell in the form of a generator potential

  6. Generator Potential • Similar to an EPSP. • Amplitude is directly proportional to the stimulus strength.

  7. Coding A set of rules for translating information from one source to another. Sensory information: is coded into action potentials via stimulus… Intensity Type Location Identity undergoes adaptation and suppression is summed across cognitive levels

  8. Stimulus Intensity Coding Nerve cells can fire at different thresholds for stimulus intensity Each alone can only fire 150 action potentials per second Combined they can fire as many as 450 action potentials per second

  9. Stimulus Type Coding Labeled Lines Each receptor has a distinct pathway to the brain Different types of stimuli can be organized in specific areas of the brain

  10. StimulusLocation Coding Somatosensory Cortex Homunculus

More Related