Cingulate cortex · Grey Matter

The cingulate cortex is the band of cortex that wraps around the corpus callosum on the inner face of each hemisphere, connecting what the brain feels and wants with what it attends to and does.

Cingulate cortex. The cingulate cortex is the band of cortex that wraps around the corpus callosum on the inner face of each hemisphere, connecting what the brain feels and wants with what it attends to and does.

Its two halves do different jobs. The anterior cingulate cortex (ACC, roughly Brodmann areas 24, 32 and 25) receives from the amygdala, the insula and the prefrontal cortex: it registers pain and its unpleasantness, notices when an action conflicts with a goal or goes wrong, and raises the effort and control the next action gets. The posterior cingulate cortex, with the retrosplenial cortex behind it, is a hub of the default mode network, active in remembering, imagining and orienting oneself in space, and connected to the hippocampus.

Anterior damage takes away the drive to act. Bilateral anterior cingulate lesions cause apathy and, at the extreme, akinetic mutism, in which an alert patient neither moves nor speaks spontaneously although nothing is paralysed.

Posterior and retrosplenial damage affects memory and orientation more than attention. Retrosplenial lesions can cause amnesia and a loss of the sense of direction in familiar places.

The ACC appears in the example circuits of frustration, solving a maths problem and holding back an outburst, always in the role of noticing that something needs more control.

Questions: What happens to a person when the anterior cingulate cortex is damaged on both sides? The anterior cingulate cortex, with the medial prefrontal cortex around it, supplies the drive to act: it signals that something matters enough to spend effort on. When it is destroyed on both sides, usually by a stroke of both anterior cerebral arteries or a tumour, patients become apathetic, and in severe cases develop akinetic mutism: awake, following people with their eyes, not paralysed, yet neither moving nor speaking unless strongly prompted. Smaller lesions, including those made surgically for chronic pain, reduce the unpleasantness of pain and the reaction to errors more than the ability to act. What happens in the brain when frustration builds over a task that keeps failing? Each failure is an error between what was expected and what happened, and the anterior cingulate cortex responds to such errors and to the conflict of trying again. As the failures accumulate the amygdala and the hypothalamus add arousal (a faster heart, tension), and the ventromedial prefrontal cortex, which weighs whether continuing is worth it, registers the reward as being withheld. Frustration is the felt state of that combination, and it can either push effort up or tip into giving up or lashing out, depending on how prefrontal control holds. How does a racing heart become the feeling of being anxious? Signals from the heart, lungs and gut travel through the brainstem and thalamus to the back of the insula, which maps the body's inner state the way the somatosensory cortex maps the skin. The anterior insula re-represents that map together with context and emotion, and Craig proposed that this is where a bodily state becomes a felt state. Together with the anterior cingulate cortex it forms the salience network, which flags the change as something that needs attention and recruits the control needed to respond.