| Define sensory perception | Sensory perception is our conscious interpretation of the external world as created by the brain from the pattern of nerve impulses delivered to it by sensory receptors. |
| Describe the attributes of a sensory stimulus | Modality: The form of energy transformed into sensation (the type of stimulus). Intensity: The strength of the stimulus, at or above a threshold level. Duration: The length of time that the stimulus persists. Location: The position of stimulus input. |
| Describe the different sensory receptors and sensory modalities | Mechanoreceptors – touch, pressure, vibration, stretch, hearing Thermoreceptors – temperature change Photoreceptors – light Chemoreceptors – taste, smell, oxygen and carbon dioxide Osmoreceptors – osmotic pressure of body fluids Nociceptors – pain (fast pricking pain, slow burning pain and heat/cold) |
| Explain modality in regards to sensory information and coding of sensory stimuli | Receptors respond to specific types of stimuli "Labelled line” - receptors of a certain modality transmit their information to specific subsets of neurons on the way to the cortex Some pathways are non-specific (polymodal) due to convergence of inputs from receptors of different modalities. |
| Explain intensity in regards to sensory information and coding of sensory stimuli | Frequency-coding of action potentials Recruitment of additional sensory units by larger stimuli Higher concentrations of neurotransmitter in the synaptic cleft produce larger receptor potentials in the second order neuron |
| Explain location in regards to sensory information and coding of sensory stimuli | Receptive fields Discrimination of stimuli by size, number and overlap of receptive fields “Map strategy” organization of sensory pathways |
| What is the role of the nerves in processing of visuals, auditory OR tactile information? | Nerves are bundled tracts of axons, which carry signals from receptive fields throughout the body to spinal cord or brainstem. |
| What is the role of the dermatomes in processing of visuals, auditory OR tactile information? | Dermatomes are areas of the skin that are supplied by a single spinal nerve, they help relay sensory, motor and autonomic information between the rest of the body and the CNS. |
| What is the role of the retina in processing of visuals, auditory OR tactile information? | The retina is a layer of nervous tissue that covers the back two-third of the eyeball stimulating light so that the sensation of vision can be initiated. |
| What is the role of the cochlea in processing of visuals, auditory OR tactile information? | The external and middle portions of the ear transmit sound waves to the fluid-filled inner ear, amplifying sound energy in the process. Mechanoreceptors in cochlea convert sound waves into action potentials, making hearing possible. |
| Define 'sensory homunculus" | The sensory homunculus is the sensory fields of the body that are mapped in the parietal cortex in a pattern. Body parts of sensory homunculus are proportional to the amount of cerebral cortex devoted to a given body region and to how richly that region is innervated. |
| Define 'retinotopic map' | The retinotopic map is the visual field of the retina is mapped in the occipital cortex. |
| Define 'tonotopic map' | The tonotopic map is the way the auditory cortex is organized, which includes properties such as: Frequency of tones Frequency ratios between harmonics and the pitch of complex sounds Speed and direction of frequency sweeps Sound intensity and location of sound in space |
