There are different ways to influence the human body and brain. Some work from the inside of it and they require nanobots or implants. Others can be done externally and without the use of electrodes/nanobots. The methods below do not require nanobots:

Directed Energy is a form of focused electromagnetic radiation. It uses different frequencies and its effects vary from nausea and overheating to internal organ failure, heart attacks and death. It can also be used to submit audio into the skull of a person. 

Transcranial Magnetic Stimulism is the changing of the state of neurons in the brain by sending an electric current through a magnetized part of it. 

Optogenetics does mainly the same but uses a form of light.

Nervus Vagus Stimulism is overtaking the main nerve responsible for processes such as breathing, heart rate, digestion and others. It connects the head to the rest of the body and can be stimulated internally but also from the outside.

Directed Energy

Directed Energy Weapons use electromagnetic radiation in different forms and frequencies. High frequency microwaves and lasers can destroy objects like buildings, while electromagnetic radiation with much wider wavelengths such as Extremely or Very Low Frequency and radio MilliMeter Waves cause physical harm to bodies. DEW have been in development since at least the '70s. Their biological effects are well known and have been field operational since at least 1976. The US government uses DE in its Active Denial System, a crowd dispersal method by means of targeting people with a beam of radiation of 5G (95 GHz) or more. DEW are supposed to be nonlethal but they can be deadly. 

Directed Energy in the form of ELF, VLF and MMW has biological consequences if used on people with effects ranging from nausea, overheating, muscle spasms, organ failure, miscarriages and heart attacks to death. The US army lists these effects in documents as far back as 1976 when they were already ready to be used in the field, meaning that the necessary equipment for it could be transported in trucks.

The WHO describes how ELF in higher doses than those found in nature affects muscles and nerves. Scientific studies show that ELF affects physiology in the form of hormonal and other changes as well as behavioral consequences.

The US Congress lists Directed Energy, specifically ELF, VLF and ULF as weapons systems. It describes it as, amongst other things, a mood management tool for its population. The United Nations have a document filed under the heading "torture" that has all patented Directed Energy Weapons that can be used against civilians, together with their required frequencies and effects. 

Transcranial Magnetic Stimulism

Transcranial Magnetic Stimulation uses an electric current through a magnetic field which can change the state of the neurons in the brain. If you do this over the motor cortex it can cause twitches of the hand or face, over the visual cortex it can cause flashes of light  and over dorsolateral prefrontal cortex it can change how you judge things or choose. This is a noninvasive technique that does not require electrodes. It has been around since at least 1934, see the article "Remote control of the electrical stimulation of the nervous system".

Deep Brain Stimulation does need the use of electrodes but as it can now be used by means of focused ultrasound only as well it deserves a mention. DBS has an affect on behavior and can be used to induce feelings and emotions. Jose Delgado used a precursor of it called ESB, Electrical Stimulation of the Brain, in the '50s and was able to change people's moods and motor functions through the use of radiofrequency waves. In an experiment he stopped a charging bull with the press of a button. Later there was no need for surgery anymore as it all can be done by electromagnetic radiation alone.

Optogenetics

Optogenetics is a technique using light to manipulate the state of neurons. It can be used to alter behavior amongst other things. 

Nervus Vagus Stimulism