Perceiving social salience: a research domain linking normal and pathological hallucination

Ralph Hoffman MDDepartment of Psychiatry

Yale University School of Med28 May 2014

ralph.hoffman@yale.edu

AVHs in Sz achieve high “social salience”

• Acoustic “voiceprint” connotes specific speakers;

• particular sounding voices have distinctive characteristics – “their own personality…”

• attributed to specific persons/agents, angels, God, the dead, or the devil, often given names;

• typically patient has conversations with voices…

Normal AHs prompted by ↑ social salience

• Erroneously hearing one’s name in public (57% college students; Posey and Losch 1983);

• vibration and pager tone hallucinations – 80-90% of medical interns, not correlated with anxiety or depression (Lin et al. 2013).

• Bereavement hallucinations, typically AVHs; fills in for lost loved one

Social withdrawal precedes and is possible risk factor for AVHs

• 87% of first-episode patients w/SZ reported prior social withdrawal vs 3% for non-psychotic patients (Tan 2001);

• 71% of SZ pts with AVHs report significant drop-off in social involvement 1-6 month before first onset• Move to new city, new school, solo travel in Europe or across

the US, peace corp duty, dissertation takes over…

• Phantom limb following amputation• Charles Bonnet Syndrome

Sensory deafferentation: hallucinations due to

network reorganization filling in for absent percepts

What about “social deafferentation?”

• Brain is dedicated to social meaning;• high levels of plasticity in “social brain”

regions• What happens when brain deprived of

social experience??• Could AVHs with high social salience

“fill in” for absent social connection

Suggestive evidence

• Baseline active social avoidance (ASA) during the prodrome correlated with hallucinations (PRIME study, unpublished)

• at baseline, correlation = 0.18;• at 1 year, correlation = 0.54.• Prisoners in solitary confinement:

36% had auditory/verbal hallucinations (Grassian Am J Psychiatry 1983); mean age 28, 11 days to 10 months SC

• What other factors besides social disconnection might come into play???

Greater dendritic length in amygdala neurons in socially isolated rats (Wang et al. 2011)

New-born hippocampal neurons after knockdown of DISC-1 gene expressionDuan et al. Cell, 2007

oncoretrovirus-mediated RNA interference