1.1 Introduction

Sensation describes how our senses work from a biological perspective, whereas perception describes how our brain interprets the neural signals it receives about the world outside us. Sensation and Perception has been a core course for Psychology majors for many years. It provides students with a more in-depth understanding of how the nervous system works to interpret information in our environments. Sensory experiences are foundational to many psychological phenomena. What we see, hear, smell, taste, and feel determines what we pay attention to, the kinds of memories we form, our emotional responses, and our decisions and actions. Understanding how sensation and perception work can give us insights into what causes vision and hearing problems and how we might help to correct them. It helps people to design effective signs for buildings, roads,  and advertisements. It helps us to understand why we are better at recognizing faces of people of the same race(s) that we hang out with. It helps to explain how our early experiences shape our preferences for specific foods and smells and why some of us are picky eaters while others will eat anything at all. These are just a few topics that we will cover in this book.

I also want to acknowledge that the field of Sensation and Perception (like many subfields of psychology) have been heavily influenced by studies conducted by WEIRD researchers with WEIRD participants. The word WEIRD stands for White people from Educated, Industrialized, Rich, Democracies. As you will see in this book – our experiences very much shape how our brains interpret the sensory signals it receives, but cultural differences in perception is a relatively new (and understudied) field. Where possible, I have introduced cross-cultural studies in the field, but acknowledge that this book still represents mostly western ways of thinking.