EPA lecture one – perception
Week 1
29/01/20
Perception
Perception – the organisation, identification, and interpretation of sensation in order to form
a mental representation
Sensation – the stimulation of a sense organ (e.g., the eye)
In the 1800s the first perception study was conducted; Helmholtz was interested in the
relationships between measurable physical stimuli and human perception. Gestalt
psychologists use the idea that “the whole is more than the sum of its parts”. Gestalt
psychologists established a set of perceptual principles that are still used by designers
today, for example, the FedEx logo has a hidden arrow. Richard Gregory (1970) suggested
that perception is a constructive process.
• Top-down processes help us interpret information from the senses
• Bottom-up processes information from that senses
This can explain a lot of the Gestalt principles, we do not see the world as it is, but we
construct our perception of the world.
Perceptions of the word are different due to our individuals’ sense which input the
information differently to someone else. We can measure how humans respond to different
stimuli to learn about perception. Perception is subjective, for example, how we perceive
depth. How we perceive depth can be influences by imagine cues to infer the depth.
The human eye
The process of information through the eyeball
• Waves of light enter the eye thorough the cornea – the outer surface of the eyeball.
• The light passes through the pupil- the small black hole in the centre of your eye
• The lens focuses the light onto the retina.
• The centre of focus is a spot on the back of the eye called the fovea.
• The back of the eye contains light sensitive cells that turn the light energy into
chemical energy – a nerve impulse.
• This impulse is carried along the optic nerve to the brain.
The retina: light sensitive cells
The retina contains cells that have chemicals that react to light waves and generate a nerve
signal. These cells are sensitive to electromagnetic waves that fall within ‘visual light’.
Wavelengths of the light waves determines the colour that will be perceived by the human
eyes. There are two types of sensitive cells, the cones, and the rods.
• Cones - detect colour under normal daylight conditions and allow us to see in fine
colour. The retina contains 6 million cone cells, mostly located in the fovea.
, • Rods – become active under low light and useful for night vision but do not carry
information about colour. About 120 million robs on your retina – distributed
everywhere expect the fovea. Its more sensitive to light at 498nm.
The optic nerve
You have “blind spot” on the retina because there are no rod or cone cells on the optic
nerve. The cone cells are sensitive to light. The fovea has a high concentration of light
sensitive cells, so this is where visual acuity is the best.
The visual processing the brain
From the eye – the visual information travels from the optic nerve towards the back of the
brain. The occipital lobe is associated with visual processing.
Area V1
• Damage to area V1 causes blindness (early doctors studied bullet wounds and stoke
damage)
• Cells in V1 are sensitive to a specific area of the visual field
• 50% of V1 is devoted to the central 2% of the visual field – the fovea
• V1 neurones are selective for several attributes, including orientation. Damage to
area V1 causes blindness (early doctors studied bullet wounds and stoke damage)
• Cells in V1 are sensitive to a specific area of the visual field – topographic map
• 50% of V1 is devoted to the central 2% of the visual field – the fovea
• V1 neurones are selective for several attributes, including orientation.
• Hubel & Wiesel implanted electrodes into cells in V1 to record the activity of
neurones.
The pathways
After the early visual processing, there are two pathways that process different aspects of
visual information.
• The dorsal pathway, the where
• The ventral pathway, what
Face perception
The ventral system recognises “what” we see. One area is specialised for the perception of
objects. Another region in the ventral stream is specialised for faces. Damage to this area
causes prosopagnosia, the ability to perceive faces.
Cells for specific people
Hubel and Wiesel placed microelectrodes into areas V1, they found cells that were selective
to lines at certain angles in a certain area of the visual field. It became possible to record
from single cells in humans too. This enables us to learn about that response profiles of
individuals neurones along the ventral stream.
, EPA lecture two – attention
Week 2
06/02/20
Attention
Attention is the subject that people understand but can find it difficult to define. Attention can
be defined as the selective aspect of perception and response; it was noted that attention is
what comes between perception and our response which can be represented by our
behaviour whether that be conscious or subconscious (Anne Triesman, 1969). We cannot
react to everything; attention is the link between perception and experience. However,
Robert Steinberg (2003) argued that “attention acts as a means of focusing limited mental
resources on the information and cognitive processes that are most salient at a given
moment”.
Psychological research on attention diagram
1950s - 60s
How to “filter out” irrelevant information – filter models
1970s - 90s
Controlled versus automatic attentional processing
2000s
Focus on cognitive control in attention
Bottleneck model
early models of attention attempted to explain how we can focus on some information and
ignore other information; this allows the mind to make a cognitive filter which allows some
information to pass and while other information is removed.
In 1958 Broadbent developed information bottleneck, Broadbent had noticed that radar
operators in the war were able to focus on a single pilot’s voice and ignore other voices.
From this he devised an investigation on the effects of noise and performance in applied
situation, for example, squadron planes and the control centres. From this he published an
important book called perception and communication. Broadbent believed that we had a
limited capacity to process information, this can be further supported by Miller’s 7+ or -2
items theory. Broadbent’s model was very important because it allowed us to think about
attention in similar ways to computer processing information. For example, the input goes to
the filter which goes to the perception which goes to output. This idea that the mind can be
understood like a computer processing system is the central ideal of cognitive psychology.
Critical analysis of early filter model
Week 1
29/01/20
Perception
Perception – the organisation, identification, and interpretation of sensation in order to form
a mental representation
Sensation – the stimulation of a sense organ (e.g., the eye)
In the 1800s the first perception study was conducted; Helmholtz was interested in the
relationships between measurable physical stimuli and human perception. Gestalt
psychologists use the idea that “the whole is more than the sum of its parts”. Gestalt
psychologists established a set of perceptual principles that are still used by designers
today, for example, the FedEx logo has a hidden arrow. Richard Gregory (1970) suggested
that perception is a constructive process.
• Top-down processes help us interpret information from the senses
• Bottom-up processes information from that senses
This can explain a lot of the Gestalt principles, we do not see the world as it is, but we
construct our perception of the world.
Perceptions of the word are different due to our individuals’ sense which input the
information differently to someone else. We can measure how humans respond to different
stimuli to learn about perception. Perception is subjective, for example, how we perceive
depth. How we perceive depth can be influences by imagine cues to infer the depth.
The human eye
The process of information through the eyeball
• Waves of light enter the eye thorough the cornea – the outer surface of the eyeball.
• The light passes through the pupil- the small black hole in the centre of your eye
• The lens focuses the light onto the retina.
• The centre of focus is a spot on the back of the eye called the fovea.
• The back of the eye contains light sensitive cells that turn the light energy into
chemical energy – a nerve impulse.
• This impulse is carried along the optic nerve to the brain.
The retina: light sensitive cells
The retina contains cells that have chemicals that react to light waves and generate a nerve
signal. These cells are sensitive to electromagnetic waves that fall within ‘visual light’.
Wavelengths of the light waves determines the colour that will be perceived by the human
eyes. There are two types of sensitive cells, the cones, and the rods.
• Cones - detect colour under normal daylight conditions and allow us to see in fine
colour. The retina contains 6 million cone cells, mostly located in the fovea.
, • Rods – become active under low light and useful for night vision but do not carry
information about colour. About 120 million robs on your retina – distributed
everywhere expect the fovea. Its more sensitive to light at 498nm.
The optic nerve
You have “blind spot” on the retina because there are no rod or cone cells on the optic
nerve. The cone cells are sensitive to light. The fovea has a high concentration of light
sensitive cells, so this is where visual acuity is the best.
The visual processing the brain
From the eye – the visual information travels from the optic nerve towards the back of the
brain. The occipital lobe is associated with visual processing.
Area V1
• Damage to area V1 causes blindness (early doctors studied bullet wounds and stoke
damage)
• Cells in V1 are sensitive to a specific area of the visual field
• 50% of V1 is devoted to the central 2% of the visual field – the fovea
• V1 neurones are selective for several attributes, including orientation. Damage to
area V1 causes blindness (early doctors studied bullet wounds and stoke damage)
• Cells in V1 are sensitive to a specific area of the visual field – topographic map
• 50% of V1 is devoted to the central 2% of the visual field – the fovea
• V1 neurones are selective for several attributes, including orientation.
• Hubel & Wiesel implanted electrodes into cells in V1 to record the activity of
neurones.
The pathways
After the early visual processing, there are two pathways that process different aspects of
visual information.
• The dorsal pathway, the where
• The ventral pathway, what
Face perception
The ventral system recognises “what” we see. One area is specialised for the perception of
objects. Another region in the ventral stream is specialised for faces. Damage to this area
causes prosopagnosia, the ability to perceive faces.
Cells for specific people
Hubel and Wiesel placed microelectrodes into areas V1, they found cells that were selective
to lines at certain angles in a certain area of the visual field. It became possible to record
from single cells in humans too. This enables us to learn about that response profiles of
individuals neurones along the ventral stream.
, EPA lecture two – attention
Week 2
06/02/20
Attention
Attention is the subject that people understand but can find it difficult to define. Attention can
be defined as the selective aspect of perception and response; it was noted that attention is
what comes between perception and our response which can be represented by our
behaviour whether that be conscious or subconscious (Anne Triesman, 1969). We cannot
react to everything; attention is the link between perception and experience. However,
Robert Steinberg (2003) argued that “attention acts as a means of focusing limited mental
resources on the information and cognitive processes that are most salient at a given
moment”.
Psychological research on attention diagram
1950s - 60s
How to “filter out” irrelevant information – filter models
1970s - 90s
Controlled versus automatic attentional processing
2000s
Focus on cognitive control in attention
Bottleneck model
early models of attention attempted to explain how we can focus on some information and
ignore other information; this allows the mind to make a cognitive filter which allows some
information to pass and while other information is removed.
In 1958 Broadbent developed information bottleneck, Broadbent had noticed that radar
operators in the war were able to focus on a single pilot’s voice and ignore other voices.
From this he devised an investigation on the effects of noise and performance in applied
situation, for example, squadron planes and the control centres. From this he published an
important book called perception and communication. Broadbent believed that we had a
limited capacity to process information, this can be further supported by Miller’s 7+ or -2
items theory. Broadbent’s model was very important because it allowed us to think about
attention in similar ways to computer processing information. For example, the input goes to
the filter which goes to the perception which goes to output. This idea that the mind can be
understood like a computer processing system is the central ideal of cognitive psychology.
Critical analysis of early filter model
