Sensation and Perception Flashcards
An intruder is hiding in Hannah’s wardrobe and confronts her when she comes home from work. Which nervous system is the most likely to be activated?
Her sympathetic nervous system.
What is the Corpus callosum
A part of the brain which is a band of neural fibres linking the right and left hemispheres
Neurogenesis in the adult human brain is known to:
contribute to brain plasticity.
When compared to communication of the nervous system communication of the endocrine system
is slow and global.
Out of every 100 photons entering the eye, roughly __________ are detected by photoreceptors
10
In psychophysics, Weber’s Law states that:
the just noticeable difference increases as the background stimulus intensity increases
psychophysics is the …
scientific study of the relationship between physical characteristics of stimuli and sensory capabilities
The Theory of indirect perception asserts that…
perceptual experience is NEITHER of the world NOR just what is sensed
The parasympathetic nervous system is…
a network of nerves that relaxes your body after periods of stress or danger. It also helps run life-sustaining processes, like digestion, during times when you feel safe and relaxed
What is the sympathetic nervous system
a network of nerves that helps your body activate its “fight-or-flight” response. This system’s activity increases when you’re stressed, in danger or physically active.
What is the somatic nervous system
is the part of the peripheral nervous system associated with the voluntary control of body movements via skeletal muscles
What is the peripheral nervous system.
our peripheral nervous system (PNS) is that part of your nervous system that lies outside your brain and spinal cord. It plays key role in both sending information from different areas of your body back to your brain, as well as carrying out commands from your brain to various parts of your body.
What is brain plasticity
Neural plasticity, also known as neuroplasticity or brain plasticity, can be defined as the ability of the nervous system to change its activity in response to intrinsic or extrinsic stimuli by reorganizing its structure, functions, or connections.
what is the just noticeable difference
also known as the difference threshold, is the minimum level of stimulation that a person can detect 50% of the time
Overall, the Gestalt laws show us that:
the visual system makes various assumptions about the world
These principles aim to show how complex scenes can be reduced to more simple shapes. They also aim to explain how the eyes perceive the shapes as a single, united form rather than the separate simpler elements involved.
Signal detection theory is
a method of differentiating a person’s ability to discriminate the presence and absence of a stimulus (or different stimulus intensities) from the criterion the person uses to make responses to those stimuli.
What is Direct Perception or Naive Realism
1.Observers directly perceive the world
2.perceptions should be directly determined by the stimulus
3.perceptions should be unambiguous, i.e. the sensorymeasurements should be sufficient to result in an accuratepercept
What are the main Problems with Direct Perception or Naive Realism
- Illusions - bi-stable illusions show a changing perceptual experience despite an unchanging stimulus.
- Perceptual ambiguity -The sensory measurements you make are not always sufficient to decide on one unique correct percept
3.The problem of identity - Do the things we perceive possess identifiable, mind independent characteristics?
4) The problem of skepticism How can we know that what we perceive exists at all?
“Because our senses cannot put us in contact with external objects directly, we cannot have certainty of whether what we perceive actually exists in the external world.”
Is a counter to which theory of perception?
Direct Perception or Naive Realism
Describe Indirect perception
Perceptions are of our internal mental model(representation) of the world, not of the world itself.You do not experience the world (direct perception).You experience a model of the world (indirect perception).
What can solve the illusion and ambiguity issues of direct Perception. Our internal representation (or explanation or story) of the world can vary even if the external world does not.
The Theory of Indirect perception
Perception is described as an inverse problem
provide a description of an inverse problem
Inverse problem: the process of calculating from a set of observations the causal factors that produced them.We start with the effects and must then estimate the causes, as opposed to starting with the causes and then calculating the effects (forward problem)
How does the brain attempt to solve the inverse problem of perception?
The brain interprets sensory data But it makes assumptions gestalt perception assumptions (or regularities) and uses previous experience objects and scenes
What approach is described below
Perception is ‘different than the sum of its parts’.
We receive and process sensory input(bottom-up).
But more is added to the perceptual experience, and this comes from within our minds/brains (top-down).
The Gestalt approach
Cloud shapes are an example of which Gestalt Law
Gestalt law: Emergence
Innate disposition to perceive patterns in stimuli based on top-down principles.
What are the Gestalt laws: Principles of grouping
Closure
Similarity
Symmetry
Proximity
Continuity
Common fate
Changing stimulus which provide the same perceptual categorization
such as a face seen from multiple angles or light environments
is an example of what
Gestalt law: Perceptual constancies/invariance
The below is a description of what?
A mental representation or image containing the critical and distinctive features of a person, object or other perceptual phenomenon. Mental templates which allow us to parse and classify sensory input. This may explain perceptual constancies. This is an unconscious process, we only experience the end result: ‘qualia’
Perceptual schema
The below is a description of what?
What you eventually perceive depends on your readiness to interpret stimuli in a particular way. This is heavily influenced by context, experience, personality, mood, culture, age,arousal and many other factors….
Perceptual set
what is Molyneux’s Problem
Assume a blind man can tell the difference between a cube and a sphere by the way they feel when he touches them.
If the man was then given the ability to see could he tell which was the sphere and which was the cube simply by looking at them.
What does the Absence of hue-sensitive photo-pigment in certain cone photo-receptors lead to
Colour-deficient vision such as :
‘Dichromats’ are colour-blind to only one of the colour systems
‘Monochromats’ are entirely colour-blind, being sensitive to only the black-white system.
Who Said “Perception is externally guidedhallucination.”
Roger N. Shepard
