1 Introduction to Psychology and Neuroscience
written by Jennifer Stamp
Chapter Outline
- The Scientific Study of Psychology and Neuroscience
- Scientific Methods, Ethics, and Discovery: Lessons from Psychedelic Research
- Contemporary Psychology and Neuroscience
- Careers in Psychology and Neuroscience
The images below show the central nervous systems of a typical spider and human (Fig IP.1). If you had to, which one would you choose for yourself? You’d probably prefer the human nervous system you already have, since you couldn’t read these words without it. But what if you needed to build a web to catch prey? A human can learn to build traps, but web-building spiders are superior, even with a tiny “brain” smaller than a grain of salt.
Figure IP.1 (a) Central nervous system of a typical spider and (b) human. The spider is magnified to show detail, while the human is shrunk to fit on the page. Image source: Spider CNS from Nieder (2021)
Although a spider’s nervous system makes up a large proportion of its body size, most is devoted to sensory input (touch and vision) and motor output (movement), essential for building webs and catching prey (Nieder, 2021). The human nervous system also has sensory inputs and motor outputs, but most of our brain is devoted to information processing, the mental work involved in interpreting information, making decisions, and guiding behaviour. The distinct organization of neuronal connections results in different abilities across species, but the building blocks of the nervous system, called neurons, are very similar between humans, spiders, rats, mice, cats, squid, and fruit flies (Rivera-Rivera et al., 2025). For this reason, non-human animals are often used to ask questions about the brain and behaviour of humans, usually studied by people in the fields of psychology and neuroscience.
Understanding how nervous systems are organized, and how that organization gives rise to different abilities, is one of the central goals of psychology and neuroscience. In this textbook, we will explore how the brain and nervous system interact with our experiences to shape perception, thinking, learning, emotion, personality, social behaviour, and mental health.
