It is believed that the hyperdirect pathway may be involved in stop signalling.

The hyperdirect pathway is a significant neural circuit in the basal ganglia that facilitates rapid responses to environmental cues. This pathway connects the cortex directly to the subthalamic nucleus (STN), which then connects to the globus pallidus internus (GPi) and substantia nigra pars reticulata (SNr).

1. Stop Signaling: The hyperdirect pathway is crucial for stop signaling because it allows for a fast inhibitory response to stimuli that require immediate attention. When an individual needs to stop a movement or an action, the hyperdirect pathway can quickly transmit signals from the cortex to the STN, prompting the output structures of the basal ganglia (GPi and SNr) to inhibit unwanted motor actions.

2. Timing and Speed: The anatomical connections in the hyperdirect pathway facilitate a quicker response compared to other pathways, such as the indirect pathway, which involves multiple relay stations and therefore a longer processing time. This rapid response is essential in situations requiring immediate reaction, such as sudden changes in the environment.

3. Clinical Relevance: Disruption of the hyperdirect pathway can be observed in various movement disorders, such as Parkinson's disease, where the ability to initiate or stop movements is impaired. Understanding the role of this pathway in stop signaling could lead to better therapeutic strategies for those affected by such conditions.

In summary, the hyperdirect pathway plays a critical role in the ability to process stop signals efficiently, allowing organisms to quickly adapt their behavior in response to changing stimuli.