PSY101

Explore the accompanying experiments, videos, simulations and animations on MyPsychLab.
This chapter includes activities on:

• Normal vision, nearsightedness, farsightedness
• Perceiving sound
• The olfactory system
• Manipulating your sense of smell
• Check your understanding and prepare for your exams using the multiple choice, short answer and essay practice tests also available

The chef who couldn't smell - book extract
Molly Birnbaum

• One afternoon at my father's house, my stepmother Cyndi baked my favourite dessert: apple crisp. When she took it out of the oven, everyone exclaimed, 'That smell! It's delicious!'
  I sniffed. Nothing. She held the fresh-baked apples, ripe with sugar and spice, close to my face. I inhaled. The air felt different, thick and humid. But there was no scent. 'I can't smell a thing.'
  When I took a bite, I could feel the softness of the fruit and the crunch of the top. But the flavour? It tasted of nothing but a dull sweet, a muted sugar.
  'I can't taste,' I said.

Source: The Guardian, 15 July 2011.

What you should be able to do after reading chapter 5

• Describe the difference between sensation and perception
• Describe the processes involved in sensation, such as transduction and sensory coding.
• Describe each of the sense organs and how they function
• Think of reasons why such senses have evolved

Questions to think about

• How many senses do we have?
• Are some senses more important to us than others?
• Which sense do we use least (or think we do) and why?
• Do the different senses function along similar lines, using similar mechanisms?
• Is the importance of a sense reflected in the amount of brain capacity needed to support it?
• Why are some animals more reliant on some senses than others?
• Are there stimuli that we sense, even though we are not consciously aware of sensing them?
• How can we tell the difference between the sight (and sound) of a bird and a plane, or between the smell of chocolate and gas?

Sensation and behaviour

Our senses are the means by which we experience the world; everything we…