HOLIDAY REVISION – Cognition (week 8 and 9) Name:_______________________________

Cognition Sensation and perception

o Sensory organs and their stimuli o Perception – illusions and distortions of visual perception.

Sensation and perception (distortions of visual perception and illusions)

Use the glossary to define the following terms:Sensation

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Perception

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Monocular depth perception – Pictorial cues.

1. Linear Perspective __________________________________________________________________________________

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2. Relative Size__________________________________________________________________________________

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3. Overlap

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EXTRA:Perception has been explained in 2 main ways. Summarise the key aspects of each theory. Bottom-up theories Top-down theories

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A visual illusion is a consistent perceptual error in interpreting real external stimulus. This is different to hallucinations where people perceive objects/events that have no external reality.

When we experience a visual illusion, the stimulus provides us with cues that mislead our perception. As a result, a mismatch between our perception and the reality of the actual stimulus occurs. Although perception of common stimuli is often described as unique, this is not the case with a visual illusion. With visual illusions, all individuals tend to be misled by the stimulus in the same way. In a visual illusion, motion, length, position, curvature and direction of the stimulus is consistently misjudged.

Define visual illusion.

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The Müller-Lyer Illusion

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The activity requires the use of an apparatus that allows students to estimate the length of one line against the length of the other. What makes this tricky is that one line has “arrow-heads” while the other has V-shapes emitting from its ends. These differing line ends, for reasons that have been debated for decades, seem to trick the perceiver into perceiving one line is longer than it actually is and/or the other as shorter. This is what the lines look like:

Which line looks longer to you?

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One explanation of this illusion is that it is based on our experience with the angular lines created by the

inside and outside corners of buildings. These angular lines suggest either a further away line or a closer one; if we interpret a line of the same length on the back of our retina as being further away, we shall naturally perceive it as longer. Think about this while looking at the pictures below.

The lines in the first photo are similar to the line with the arrowheads. Since we perceive this building corner as pointing towards us, we interpret the vertical line as shorter than that of such a corner that is receding into the distance.

On the other hand, if the corner we are viewing is pointing away from us, as in the second photo, the lines created by the angles of the corner are like the V-shaped line. We interpret this line as being further away and therefore longer, according to this theory of why the illusion occurs.

http://psychologyrats.edublogs.org/about/visual-perception/the-muller-lyer-illusion/

In your own words, explain why this illusion occurs.

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Poggendorff Illusion (pg. 421-422 SOS book)

What happens in this illusion?

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How is this illusion explained?

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Perceptual anomalies.

Definition Causes.

Motion after effect.

Change blindness.

Synaesthesia.

Cognition5

Consciousness waking consciousness

o selective attentiono divided attentiono habituationo dishabituation

altered state of consciousness o sleepo daydreamingo meditationo hypnosis

physiological responses indicating different states of consciousnesso electrical activity of the braino heart rateo body temperatureo galvanic skin response

Read pages 416-421 of your SOS textbook to answer the following questions.

Define Consciousness

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Using page 98 (SOS), create an illustration of the different states of consciousness.

Waking consciousness refers to: _______________________________________________________

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Altered states of consciousness refers to ________________________________________________

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Using the information above, label your diagram to assist you to remember which state of

consciousness is waking and which is altered.6

How can a person know that they have experienced a change in their level of consciousness?

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How is waking consciousness different to altered states of consciousness? (416 SOS)

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Using your SOS text and the PDF document, complete the following:

Waking consciousness (98 and 417-418 SOS)

Features:

Selective attention Divided attention

Habituation Dishabituation

Altered states of consciousness (416, 99-101 SOS)

Features:7

NaturalSleep

Daydreaming

InducedMeditation

Hypnosis

Physiological responses indicating different states of consciousness (419-421 and 101-103 SOS)(measuring states of consciousness)

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Can consciousness be measured directly? Why/Why not? ___________________________________

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Brain waves

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Draw different brain wave patterns for the following states of consciousness

Alert/working I-----------------------------------------------------------------------I

Relaxed/reflecting I-----------------------------------------------------------------------I

Drowsy/ideating I-----------------------------------------------------------------------I

Sleep/dreaming I-----------------------------------------------------------------------I

Deep, dreamless sleep I-----------------------------------------------------------------------I

Describe how the brainwaves differ when a person is alert to when they are in a state of dreamless

sleep. (Use the words amplitude and frequency).

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Heart rate

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Body temperature

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Galvanic skin response (Electric conductivity of the skin – used in lie detector tests)

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