Final answer:
The 'smaller vibrations that remain in the brain after the sensations stop and lead to simple ideas' refer to the concept of after-sensations in psychology.
Step-by-step explanation:
The question you've asked pertains to the concept in psychology known as after-sensations or mental traces of vibrations. Although 'vibrations' is not a term typically used in contemporary psychology, it can metaphorically describe the residual activity in the brain that happens after the initial sensory input has ceased.
These after-sensations or echoes lead to what are sometimes referred to as simple ideas or impressions, which can be thought of as the basic components of more complex thoughts.
The mind-body interaction is a complex topic that intermingles with philosophy, and the idea that non-physical entities such as the mind can influence the physical brain is at the core of the dualist perspective.
However, in terms of modern neuroscience, the brain itself, including structures like the pineal gland, is entirely physical, and all mental processes are understood to arise from physical interactions within the brain's complex network of neurons.
Concepts such as synaptic plasticity are used to explain how the brain integrates new information and is capable of learning and memory, as suggested by the research of Nabavi and co-workers (Nature, 511, 2014).
This process is deeply connected with the human nervous system's ability to handle streams of sensory information, process it through the influence of emotions and memories, and result in the thoughts and behaviors that guide our interactions with the world.