3. Neural Processing

Description

Psychology (Intro to Sensation & Perception) Flashcards on 3. Neural Processing, created by Reeth G on 16/05/2024.
Reeth G
Flashcards by Reeth G, updated 6 months ago
Reeth G
Created by Reeth G 6 months ago
0
0

Resource summary

Question Answer
Roughly how many ganglion cells do we have in proportion to photoreceptors? (ratio) G:PR = 1:126
what is the function of ganglion cells? to condense raw information from photoreceptors & select the most important info from the retinal image
how do ganglion cells carry out this function? (in terms of detecting stimulus) they identify changes in patterns on light -- but simply between light and dark, NOT illumination level nor orientation of light
what objective measure/experiment has helped us learn all this about retinal ganglion cells? single cell recording
what approach is this from physiological approach
who was the first test experiment for this process SCR? a cat unethical to do it on humans
explain the process of single cell recording an electrode is inserted into the axon of a singular individual neuron & its activity - nerve impulses/action potentials - are recorded
what units does it record voltage
if a neuron is active - does it increase in voltage or frequency? only frequency, voltage remains the same.
how is the single cell recording experiment initially started off? where no stimulus is presented and only darkness is visible
what has been found to be recorded with this? there were occasional nerve impulses fired off by ganglion cells & was not completely inactive
what is this known as? the baseline activity of a ganglion cell
what are other words to describe baseline activity? the activity of a ganglion cell when at rest
what is the point of the single cell recording experiments? to find a stimulus that presents a change in baseline activity of ganglion cell - whether its an increase or decrease
what stimulus is used for retinal ganglion cells' being recorded? light
What is the receptive field? the mapped out area on a retina where, when stimulated by light, elicits a change in the firing rate of nerve impulses of the ganglion cell
how many regions does it have? what are they? two regions: excitatory & inhibitory
what happens if a brighter spot of light is shone on the excitatory region? increased, higher frequency in action potentials fired
what about in the inhibitory regions? a further decreased rate of frequency of nerve impulses
what is the effect of shining light on inhibitory regions on the baseline activity of ganglion cells? a suppression of nerve impulses -- there is a decrease in firing rate, lower than the baseline activity rate
why are ganglion cells only influenced by a certain area on the retina? due to neural convergence
why does this convergence create two types of response regions due to lateral inhibition
what is lateral inhibition where inhibition is transmitted laterally across the retina by horizontal and amacrine cells
what is the term used to describe the organisation of receptive field regions for the retinal ganglion cells centre-surround antagonism
what are the 2 types of this organisation? on centre, off surround (+, -) off centre, on surround (-, +)
why do we have such an organisation? makes it ideal for detecting spots of light, edges & boundaries between areas of light & dark
what does it not detect, however? orientation of light illumination level of light
why is it important for ganglion cells to recognise this change in pattern of light & dark? carry the most !! visual info
Each photoreceptor is... part of more than one ganglion cells' receptive field
resulting in an overlap of... receptive fields with neighbouring ganglion cells
what does this mean overall? (a statement) receptive fields of all ganglion cells together cover the whole visual field
Show full summary Hide full summary

Similar

History of Psychology
mia.rigby
Biological Psychology - Stress
Gurdev Manchanda
Bowlby's Theory of Attachment
Jessica Phillips
Psychology subject map
Jake Pickup
Psychology A1
Ellie Hughes
Memory Key words
Sammy :P
Psychology | Unit 4 | Addiction - Explanations
showmestarlight
The Biological Approach to Psychology
Gabby Wood
Chapter 5: Short-term and Working Memory
krupa8711
Cognitive Psychology - Capacity and encoding
T W
Nervous Systems and the Brain - Lecture 1
Georgina Burchell