When individuals with schizophrenia experience auditory hallucinations, brain imaging studies have shown that certain areas of the brain associated with processing sound can be activated. These brain regions include the auditory cortex, which is responsible for receiving and processing auditory information from the environment. So, in a sense, the brain is perceiving the hallucinated sounds in a way similar to how it processes real external sounds.
However, the key distinction with auditory hallucinations is that these sounds are not externally generated. Instead, they are perceived as coming from within the person's mind rather than from the external world. This leads to the second aspect of your question - the inner voice and the lack of control.
Auditory hallucinations are often described as hearing voices, but it's important to note that these voices are not under the person's voluntary control. They are perceived as separate entities, and the individual experiencing them may feel powerless to stop or control the content, intensity, or frequency of these hallucinated voices. In some cases, these voices can be distressing or disruptive, leading to significant impairment in daily functioning.
The exact cause of auditory hallucinations in schizophrenia is not fully understood, but it is believed to be related to abnormalities in brain circuits and neurotransmitter systems. It involves a complex interplay of factors, including genetics, environmental influences, and alterations in brain chemistry.
It's worth noting that while auditory hallucinations are most commonly associated with schizophrenia, they can also occur in other conditions and disorders, such as bipolar disorder, major depressive disorder, and certain neurological conditions.
In summary, auditory hallucinations in schizophrenia involve activation of brain regions associated with processing sound, but the experience is more akin to an inner voice that the individual cannot control. It's a manifestation of the complex disturbances in brain function seen in schizophrenia.