sexual affiliation as a model to study the neural networks involved in motivated social interactions

Pr. Harold Mouras

(harold.mouras@u-picardie.fr)

Professor in Neuroscience

School of Psychology – Amiens University, France

WAS 2015 Meeting – Singapore, July 25th

2015

•   unify  different  observa2on’s  levels:  psychological,  neural…  

•   different  studies  presented  by  “sphere”:  central;  peripheral  

Affective neurosciences of social links

 Since  two  decades,  modern  neuroimaging  techniques  allowed  to  observe  neural  processes  involved  in  percep2ve,  cogni2ve  or  motor  paradigms  

 Two  exponen2ally  developing  fields      

Affec2ve  neurosciences  (Panksepp,  2003)  

Social  neurosciences  (Insel  et  Fernald,  

2004)  

Within  psychology  and  neuroscience,  correspondences  have  been  shown  between  cogni2ve  and  neural  systems  involved  in:    

•   ac2on’s  produc2on    •   ac2on’s  percep2on  by  an  observer  

•   mirror  neurons:  originally  a  “motor”  concep2on  

•   to  feel  an  emo2on  during  the  observa2on  of  another  person  involves  a  physiological  synchrony  between  the  protagonists  (Levenson  &  Ruef,  1992)  

•   rela2onships  between  individuals  obey  to  a  mo2va2onal  component  of  inter-­‐aQrac2on  (posi2ve  or  nega2ve)  

•   this  concep2on  has  spread  to  the  emo2ons  and  mo2va2on  

•  BeQer  understanding  of  emo2onal  processes  (neural  and  psychological)  in  contexts  integra2ng  a  rela2onal  dimension  (and  concepts  such  as  the  self,  the  other  and  their  representa2ons)  

Sexual  mo2va2on  and  affilia2on:  a  specific  and  precise  working  model  and  func2onal  context  to  explore  the  neural  and  psychological  underpinnings  of  mo2vated  social  rela2onships  

•  Explore  through  two  outstanding  results  the  recent  advances  in  neural  and  bodily  processes  involved  in  sexual  behavior  

•  General  contribu2on  for  social  neurosciences  

Neural correlates

•  In  ethology:  sexual  behavior  is  a  well-­‐recognized  goal-­‐directed  behavior  

•  The  involvement  of  the  brain  is  quite  obvious  (neuropharmacology  etc…)  

•  Its  explora2on  by  func2onal  neuroimaging  remains  recent  (2000)  

•  Several  theories  of  emo2on  consider  as  central  bodily  reac2ons  for  the  emo2on  itself  (Damasio  for  example)  

•  Few  simultaneously  measured  penile  and  neural  responses  

•   Arnow  et  al.  (2002):    • first  simultaneous  fMRI  (brain)/  penile  plethymosgraphy  (erec2on)  study  

• No  brain  areas  found  by  classical  subtrac2ve  analyses  vs  an  insular/claustrum  network  correlated  with  penile  response  

Early  responses  Inverted  paQerns  

Low  levels  Volumetric  measure  ++  

Late  levels  Volumetric  =  Circum.  

•  MR-­‐compa2ble  volumetric  penile  plethysmograph:  study  the  correla2on  between  the  cerebral  and  erec2le  responses  

•  Explore  the  temporal  rela2on  between  them  

Mouras  et  al.  (2008).  NeuroImage  

Highest:  when  cerebral  responses  preceded  by  20  seconds  the  erec2le  response  

•  Mirror  neurons  seem  also  involved  in   the   physiological   component  coding,  which  seems  an2cipatory  

•  The   physiological   synchrony  between   protagonists   seems  central  

Motor correlates

•   Numerous  studies  on  the  link  between  motor  and  affec2ve  behavioral  components  

•   Automa2c  responses  driven  by  emo2onal  s2muli:  role  in  specie's  survival  -­‐>  behavioral  adapta2on  regarding  the  func2onal  context  

Bidimensional  concept  of  emo2ons  and  mo2va2ons  (IAPS;  Lang  et  al.,  2008):  approach-­‐avoidance  type  behavior  

Unpleasant  Fear  Mu2la2on  

Pleasant  Family  Ero2c  

•   use  of  sport  sciences  techniques  to  measure  body’s  center  of  pressure’s  displacement  varia2ons  (Gurfinkel  1973;  Winter  et  al.,  1990)  

•  Emo2on  conceptualized  as  an  ac2on’s  tendency  

•  Numerous  studies  reported  an  influence  of  emo2on  on  all  steps  of  motor  processes  (Bradley,  1992;  Hälbig,  2011)  

•  Ac2on’s  tendency  is  central  in  sexual  mo2va2on  which  is  induced  by  an  appropriate  target  

•  Example:  Bindra  defines  the  Central  Mo2ve  State  as  an  hypothe2cal  group  of  neural  processes  promo2ng  goal-­‐directed  ac2ons  for  specific  s2muli  

•  Frijda:  mo2va2on  will  induce  an  ac2ons’  sequence  •  Both  et  al.,  2004:  Interest  and  tendinous  reflexes  increases  linearly  with  arousal  of  sexual  videos  as  compared  to  neutral  ones  

•  S2ns  et  al.,  2007:  Gait’s  ini2a2on  faster  in  response  to  smiling  than  angry  face  

•  Naugle  et  al.,  2010:  difference  of  walking  speed  only  from  the  second  step  for  sexual  s2muli  as  compared  to  unpleasant  ones  

•  Gélat  et  al.,  2011:  in  incongruent  task  (move  towards  an  unpleasant  s2m.)  -­‐>  interference  with  cogni2ve  resources  creates  an  early  freezing  

•  Posturography:  not  much  used  in  mo2va2onal  condi2ons  

•  Emo2ons  could  influence  decision  through  pavlovian’s  system  ac2on:  Ly  et  al.  (2014):  •  Angry  faces  slow  down  approach  behavior  

•  Individual  differences  in  emo2onal  bias  predicted  those  in  body  freezing  

•  Freezing  has  been  observed  in  anxious  situa2ons  

•  some2mes  in  front  of  disgus2ng  s2muli  (S2ns  et    al.)  along  with  HR  decelera2on  

•  No  varia2on  of  the  COP  has  been  previously  reported  in  front  of  sexually  explicit  s2muli  (Hillman  et  al.,  2004;  S2ns  et  al.,  2007)  

•  33  healthy  males  included  in  a  block-­‐design  paradigm  •  Three  videos  defining  three  experimental  condi2ons:  humoir  (H);  neutral  (N);  sexually  explicit  (S)  •  Experimental  run:  white  screen  (20s)  ;  9  experimental  blocks  (50s);  white  screen  (20s)  

• Motor  correlates:  BIOPAC  system  interfaced  with  a  SATEL  force  plasorm  •  Analyses:  calcula2on  of  postural  indexes  such  as  body's  Center  Of  Pressure  (COP)  AN  and  ML  direc2ons;  area  under  the  curve;  sway  magnitude;  SD  of  the  displacement  

dimension of the stimuli and not by their valence [43]. Sexual stimuli are the most arousing sti-muli of the category of positive emotional and motivational stimuli. Our results can be inter-preted in the light of a recent review of the literature focusing on the concept of freezing asfreezing is usually considered to be thisa threat-related defense strategy [44]. At first sight, ourbehavioral responses appear to be incongruous in response to motivating stimuli. Haagenarset al. [44] reported immobility as the main characteristic of other types of response, such as ori-enting or tonic immobility, behavioral inhibition and reported that immobility may be difficultto differentiate from freezing. According to these authors, freezing may have been inconsistent-ly reported as orienting, avoidance, vigilance, attentive immobility and anxiety. The results ofthe present study would therefore be consistent with the development of a freezing-like strategy

Fig 1. Mean ± SD for postural indices as a function of the stimulus (A) Amplitude of the sway of the COP in the mediolateral direction (Amp [COP]-ML) (B)Amplitude of the sway of the COP in the anteroposterior direction (Amp [COP]-AP) (C) Standard displacement of the COP in the mediolateral direction (SD[COP]-ML) (D) Standard displacement of the COP in the anteroposterior direction (SD [COP]-AP) (E) Area encompassed by displacements of the COP(COP-Area) Significant differences are indicated as follows: * p < 0.05, ** p<0.01 when comparing stimulus.

doi:10.1371/journal.pone.0127097.g001

Freezing and Sexual Behavior

PLOS ONE | DOI:10.1371/journal.pone.0127097 May 20, 2015 6 / 10

S  condi2on  as  compared  to  the  N  –condi2on:    •  Significant  effect  on  SD  COP-­‐AP  and  SD  COP-­‐ML  indexes  

•  Significant  effect  on  Amp-­‐COP  ML  index:  lower  displacement  amplitude  in  the  ML  direc2on  

•  Differen2al  modula2on  in  sexual  condi2on  of  motor  correlates  as  compared  to  others  physiological  measures  •  Results  not  in  accordance  with  the  primary  hypothesis  of  an  approach-­‐type  behavior  in  response  to  sexual  s2muli  •  Support  the  idea  of  an  early  freezing  in  response  to  sexual  s2muli  

• Horslen  et  al.,  2011:    freezing  modula2on  by  the  arousal  dimension  of  the  s2muli  

• Haagenars  et  al.,  2014:  freezing  could  be  the  primary  component  of  behavioral  responses  such  as  tonic  immobility  and/or  behavioral  inhibi2on  

•  Early  freezing  (1  to  2  s)  responses  in  response  to  unpleasant  films  (record  temporal  courses  ++)  •  Early  freezing  response:  necessary  for  dissimula2on  and  ac2on’s  prepara2on  (Mc  Naughton  et  al.,  2004)  •  Paradoxical  aspect  of  sexual  response:  postural  responses  tend  to  demonstrate  early  anxious  aspects  of  the  sexual  response  

In  accordance  with  previous  studies  repor2ng  ac2on’s  prepara2on    •  through  freezing  (Griebel  et  al.,  1996;  Kalin  et  al.,  1997)  •  Involving  supplementary  cogni2ve  resources  recruitment  (slower  rea2on  2mes  in  experimental  tasks;  Mokros  A  et  al.,  2010;  Sanwla  et  al.,  2009  etc…)  

Fachinew  et  al.,  2006  «  their  baby  and  family  pictures  may  have  elicited  a  predisposi2on  to  social  bonding  and  that  the  pre-­‐ac2va2on  of  muscles  involved  in  the  antero-­‐posterior  displacement  could  reflect  prepara2on  for  processes  like  aQachement  and  reduc2on  of  social  distance  »  

•  Sexual  mo2va2on:  an  excellent  func2onal  context  to  study  the  neural,  motor  and  physiological  correlates  of  mo2vates  social  rela2onships  • Our  studies  demonstrates  the  complexity  (par2cularly  temporal)  of  the  motor  and  neural  correlates  

http://www.socioaffectiveneuroscipsychol.net/ Special issues on the question of sexuality

Thank  you  for  our  a.en0on  !