Sensory systems Flashcards
Neurons and nerve impulses are essentially the same in each sensory system, yet
We subjectively experience them as different
Each sensory system has multiple representations and each representation mediates….
a different aspect of the sense
RECEPTORS are
specialized parts of cells that transduce or concert sensory energy into neural energy - the type of energy the receptor responds to is different for each sense modality
Receptors and neurons in sensory cortex have…
receptive fields; i.e., they respond only to a stimulation in a certain area/ range:
- Each sensory system requires 3-4 neurons to get information from the receptor to the cortex.
- Number of cells decrease in the first 2-3 synapses and then increase at the cortical level. This means there is not a direct point-to-point transmission from receptor to cortex.
- At these synapses:
a. motor responses can be produced
b. the signal can be modified – e.g. cortical regulation can inhibit or amplify the signal
c. can interact with other systems
Characteristics of stimulus can be coded by an
increase or decrease in firing rate of neuron, the magnitude of change, the particular type of neuron that fires and the pattern of neurons that fire
(Book says) Perception of distinct sensory modalities may be due to…
Cortical specificity, learning or receptor/ neuron affinity for specific types of stimulation
- study done since this book published disconnected visual input from occipital lobe and connected it to primary auditory cortex in temporal lobe and it responded to visual input
Sensory input goes to several different pathways other than the one that processes the sensation. These other pathways regulate the…
…sensory system’s orientation, focus, and contribute to biological rhythms.
Within the cortically mediated sensory system, there are…
Multiple representations of the receptive field. Each rep. processes a different aspect of the sensation
