Final answer:
The example of Lena becoming hungry at the smell of food is rooted in perception, which is a combination of sensory input and psychological processes that initiate hunger. This shows how the senses of taste and smell work in concert to affect behavior and how classical conditioning, along with homeostasis and allostasis, influence our perception of hunger.
Step-by-step explanation:
The scenario described, where Lena becomes hungry because the smell of a coworker's lunch reminds her it is lunchtime, is an example of perception. This is directly connected to the biological response wherein our senses interact with our psychological processes to create a reaction, in this case, hunger.
Such a response happens because our brains sort out messages from our senses and digestive system to indicate it's time to eat. These messages can be triggered by seeing, smelling, or even thinking about food because of the close relationship between olfaction (the sense of smell) and gustation (the sense of taste), which together contribute to the flavor of food and our desire to eat.
This kind of psychological reaction can be traced back to classical conditioning, as seen in Dr. Pavlov's experiment, where a neutral stimulus (like the sound of a bell) after being repeatedly associated with a non-neutral stimulus (food that causes salivation) eventually leads to a conditioned response (salivation at the sound of the bell). The interaction between homeostasis, the body's natural state of balance, and allostasis, which involves behavioral and physiological adjustments, plays a crucial role in our perception of hunger and satiety.