SN (salience network): the network focused on here
DMN (default mode network) –self-referential; it is activated during social reasoning, such as when we think about our own and/or others’ minds. signals from AI influence DMN;
CEN (central executive network) – key nodes in PPC (posterior parietal cortex); maintenance and manipulation of information and decision-making ;
OTHER NETWORKS:
Cinguloopercular network -set-maintenance activities
Ventral attention network –right lateralized ; overlaps with SN
Task Positive Network (TPN): activated by mechanical, causal, logical, or mathematical reasoning—e.g., when watching videos about physics
SALIENCE NETWORK (SN)
etymology: Salient: from leaping in Latin, used for a military bulge
Salience: being noticeable, standing out. Salient entities attract attention, are meaningful or behaviorally relevant. (Salience detection was most studied in visual search.)
SALIENCE INCLUDES:
- low-level sensory features (e.g., stimulus color or intensity)
- high-level cognitive and affective processes (e.g., emotional salience or personal relevance).
The SN PLAYS A CENTRAL ROLE IN COGNITIVE CONTROL (Sarah Peters, Downar)
- integrating sensory input to guide attention,
- attend to motivationally salient stimuli
- recruit appropriate functional brain-behavior networks to modulate behavior.
ABNORMAL STRUCTURE AND FUNCTION ARE ESPECIALLY SIGNIFICANT IN THE TWO MAJOR CORTICAL NODES OF THE SN:
—dorsal anterior cingulate cortex (dACC)
—anterior insula (AI)
ASSOCIATED SUBCORTICAL STRUCTURES IN THE SN INCLUDE:
- dorsal striatum
- mediodorsal thalamus
- dopaminergic brainstem nuclei
The five SN structures above comprise a discrete regulatory loop circuit—the SN’s cortico-striato-thalamo-cortical loop, which seems central to mechanisms of cognitive control. SN dysfunction impairs self-regulation of cognition, behavior and emotion. All psychiatric disorders include loss of cognitive control, particularly in have distortions of perception.
[The only patient who never responds to TMS is someone with MDD who has no cognitive distortions. They do not have low self-esteem, or excessive guilt. They do not blame themselves They do not view others or the world negatively. They know they have an illness, and regret they do not function and that others have to help them.]
Abnormalities in SN occur in MDD, SUD, anxiety disorders, OCD, schizophrenia, and ED’s (eating disorders).
There is a common substrate across all diagnoses: loss of gray matter in the dACC (dorsal anterior cingulate cortex) and bilateral AI (anterior insula). The loci of gray matter loss corresponded closely with the core cortical nodes of the SN. The resultant impairment of cognitive control is a transdiagnostic feature across many psychiatric illnesses (McTeague et al., 2016) and a target for brain stimulation (Downar et al.,2016).
- rTMS normalizes abnormalities in the SN loop. This may be why TMS occasionally puts multiple chronic disorders into complete remission in a single person—an outcome one could not imagine with psychopharmacology alone.
Addendums, with some additional details
- I have 3 examples of patients with multiple psychiatric diagnoses who became completely normal with TMS. One would scarcely imagine this outcome.
- TMS treatment of bipolar depression and how to do it safely—which we have done with well over 50 patients.
- Y.I.:Our OCD results with TMS using Brainsway h7 helmet:
Five out of 20 [25%] of our patients had a greater than 50% decline in the YBOCS . The average decline was 69%. The average number of treatments was 34.
Six out of 20 [30%] had 25-50% decline in YBOCS—average of 36, average treatments 55.
So 55% of 20 patients had a >25% decline in YBOCS, with an average 51% decline in YBOCS and an average of 45 TMS treatments
“Facts do not cease to exist because they are ignored.” — Aldous Huxley
- TMS: extremely effective for depression, many brain disorders
- Climate change–and the Republican party in US.
- Vitamin D is a steroid hormone (calciferol) that we are are all very depleted in, because of little exposure to UVB light. It is important for bones, cancers, immunity, autoimmune disorders, et al.
- Low dose lithium prevents Alzheimer’s
