5. Kafli Flashcards
How many senses do we have?
Five
How does sensation occur?
The sense organs translate environmental stimuli into nerve impulses and then send them to the brain
What is it called when a person interprets what their senses are telling them?
Perception
The process whereby the characteristics of a stimulus are converted into nerve impulses is called?
Sensory transduction
The scientific field that studies the relationship between the physical characteristics of a stimulus and sensory capabilities is called?
Psychophysics
The stimulus detection process by which our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brain is called?
Sensation
Sensory transduction is the process whereby the characteristics of a stimulus are?
Converted into nerve impulses
Psychophysics studies the relationship between the physical characteristics of a stimulus and..?
Sensory capabilities
The concern with absolute limits of sensitivity and the difference between stimuli is best associated with the study of..?
Psychophysics
The lowest intensity at which a stimulus can be detected 50% of the time is called?
Absolute threshold
How does sensation occur?
The sense organs translate environmental stimuli into nerve impulses and then send them to the brain
The higher the absolute threshold is, the ___is the observer.
Less sensitive
What are the examples of measuring absolute thresholds?
- From which amount onwards can participants taste sugar in 1l bottle of water
- From which distance can participants hear a tick of a watch under quiet conditions
- From which distance can participants see a candle flame on a clear, dark night
What are the two kinds of sensitivity that the field of psychophysics is concerned with?
The absolute limits of sensitivity and differences between stimuli
Signal detection theory states that the idea of decision criterion is more reasonable than the idea of a fixed absolute threshold for detecting a stimulus. Why is that?
- There is no single point on the intensity scale that separates non-detection from detection
- An individuals sensitivity fluctuates
- There is a range of intensities over which the uncertainty about the presence of a stimulus varies
The active process of organising stimulus input and giving it meaning is called?
Perception
Signal detection theory is..?
Concerned with the factors that influence sensory judgements
Signal-detection research tells us how well participants can discriminate trials from which a stimulus was presented from trials in which it was not. The resulting discriminability index is called?
d’ (‘d prime’)
The smallest difference between two stimuli that people can perceive 50% of the time is called?
The just noticeable difference
The law that states that the difference threshold or just noticeable difference, is directly proportional to the magnitude of the stimulus with which the comparison is being made is called?
Weber’s law
Signal detection theory states that the idea of a decision criterion is more reasonable than the idea of a fixed absolute threshold for detecting a stimulus. Why is that?
- There is a range of intensities over which the uncertainty about the presence of a stimulus varies
- An individual sensitivity fluctuates
- There is no single point on the intensity scale that separates non-detection from detection
Fechner extended Weber’s original work by showing that there is a logarithmic relationship between stimulus intensity and the intensity of the sensation. This means that, the higher up the scale of intensity we go..?
The more stimulus needs to increase in order for the sensation to increase
The aptitude with which we make discriminations across any given class of stimulus range can be expressed as?
Weber’s fraction
Paul jumps in to go swimming. At first the water is cold and he starts shivering. Over time he yells to his friend to come on in the water feels great. This is an example of..?
Sensory adaptation
Sensory adaptation refers to the fact that we become less and less sensitive to an unchanging stimulus. Following this logic, how come stationary objects do not fade away when we stare at them?
We continuously make tiny, involuntary eye movements, which keep retinal images changing
Light adaptation makes it so that we adapt to an increased level of background light, so that it is possible to distinguish objects from the background, despite both the object and the background..?
Having very similar levels of light
Stimuli in the environment that are unchanging tend to..?
Diminish perceptual sensitivity to them
Thanks to sensory adaptation, stimuli are processed by our brain in a very efficient and economic way. Sensory adaptation ensures that..?
- Sensory systems particularly respond to changes in stimulation
- Adaptation occurs in response to unchanging/constant stimulation
What are the two steps of sensory transduction?
- Impulses are converted to the appropriate brain areas
- The energy of physical stimulations is converted into nerve impulses
Dark adaptation makes it so that we adapt to a lower level of light, and____our sensitivity to objects that are specified by smaller levels of light
Increases
What is the normal stimulus for vision?
Electromagnetic energy
The adjustable opening behind the cornea, that can dilate (get wider) or constrict, and influences the amount of light that enters the eye is called the..?
Pupil
Photoreceptors in the retina synapse with..?
Bipolar cells
How are light waves measured?
In nanometers
Which part of the eye is an elastic structure that becomes thinner in order to focus on distant objects and thicker to focus on closer objects?
Lens
If a person’s lens is not thick enough and the image is focused on a point behind the retina, the person most likely suffers from..?
Hyperopia
The part of the eye that contains rods and cones is called the?
Retina
The part of the eye that is multi-layered, light-sensitive tissue located at the rear of the fluid-filled eyeball is called the?
Retina