Lecture 34. Sensation and Perception Flashcards
What does sensory input inform an animal about ?
The environment and therefore drives bahvior
What is sensory filtering regarded as ?
Critical to recognition of the sign stimulus
What does a sign stimulus trigger ?
A fixed action pattern
What is the model systems approach ?
- Simpler nervous system
2. Ecological specialisms
What do invertebrates and vertebrates nervous systems share ?
Properties at a molecular and cellular level eg. neurotransmitters
What are the morphological differences in a vertebrate and an invertebrate ?
- Vertebrate - Spinal cord and brain
2. Invertebrate - Segmental nervous system
What is an identified neuron ?
A neuron that is recognisable as it occurs in the same location, morphology, chemistry and has the same function in every member of a species
What is the connectome ?
A map of the neural connectivity’s to understand brain function
How many neurons does the C. elegans have ?
302 neurons
How many neurons in the human brain ?
10 ^12
How many neurons in the mouse brain ?
70, 000, 00
How many neurons in the fly brain ?
100,000
What did Wilder Penfield study ?
The sensory and motor homunculus
What does the size of cortical representation reflect ?
Sensory input from different parts of the brain
What is cortical representation not ?
It is not static but modifiable through changing input and learning
What animal did Merzenich experiment on ?
Monkey
What did Merzenich experiments show ?
- Progressive change in cortical representation after transection of the median nerve
- Synaptic plasticity is thought to underlie cortical plasticity
What is sensory cancellation ?
How a self generated sensory input is ignored
What is one form of sensory input that is often irrelevant ?
Any input that we are causing by our own actions
What is an example of sensory cancellation
- Why cant humans tickle themselves
What is corollary discharge ?
Any excitation pattern that results in a movement that will cause a displacement of the visual image on the retina may have a corollary discharge into the visual centers to compensate for the retinal displacement
What does the weakly electric fish generate ?
Electrical signals to probe the environment
What can the fish return signal in the brain do ?
The electrolocation commands can be gated, amplified or predicted
How do visual cues convey information ?
Rapidly
What are visual receptors dependent on ?
Light
What are displayed during foraging and social scenarios ?
Specific pigmentation patterns
How can animals create visual signals ?
By small subcutaneous photophores in the muscle tissue
What type of behavior can sensory input drive ?
Collective behavior
What is gregarization ?
Locusts altering behavior from solitary to swarming
What are polyphenic animals ?
Animals that can exhibit different characteristics under different circumstances
What is correlated with the degree of behavioral gregarization ?
Serotonin in the thoracic CNS
