ItʼS Not What You Perceive ItʼS The Way That You Perceive It: Reflections On The Relationship Between Perceptual Appearance And Perceptual Aesthetics
Creators: name: Simmons, David R.
Publisher: name: Zenodo
Year: 2012

description: For  some  time  we  have  been  interested  in  the  measurement  of visual  appearance  in  medical  applications.  My  previous presentations at CIE Expert Symposia have focused on the measurement  and  characterisation  of dental  fluorosis  (i.e.  white mottling on the teeth caused by the ingestion of too much fluoride in childhood)  and  post-surgical  facial  scarring  ([1],  [2]).  In this presentation,  however,  I  wish  to  broaden  the  focus  to  include other work from my laboratory on emotional aspects of colour processing  and perceptual  processing  in autism. The issue I wish to   address   is   the   importance   of   verbal   descriptions   of   our perceptions  in understanding  how to solve a variety of puzzles in perception,  and  how  we  might  take  this  idea  further  in  future research.
Beginning  with  the work  on fluorosis,  the specific  remit  was  to solve a practical  problem:  to what extent  are teenagers  bothered by having dental fluorosis? Previous research in public health dentistry had suggested that the white mottling on the teeth which can result from mild fluorosis was actually desirable to some teenagers   because   it  made  their  teeth  look  whiter  and  more "sparkly". We addressed this question by producing digital simulations  of different  levels  of fluorosis  and embedding  these simulations   into  a  web-site.   The  key  question   we  asked  our (teenage)  participants  was: Is this appearance  acceptable  or not? Unsurprisingly,  ratings of acceptability  decreased  with increasing fluorosis  level,  although  this  dependence  went  away  at  longer viewing distances (corresponding  approximately  to conversational distance). However, there was a strong baseline lack of tolerance for  seeing  anybody's  teeth  close-up  which  was  problematic  for our measurements.
With the work on post-surgical  facial scarring again the remit was a practical one: to quantify  the difference  in colour between  scar and  surrounding  skin.  Here  again,  we  ran  into  difficult  issues having collected the data. Scars are by no means homogeneously or consistently coloured and differ from surrounding skin in much more  than  just  their  colour.     Another   issue  was  that  whilst individuals  have no problem  identifying  the presence  and extent of  a  scar  it  is  much  harder  to  do  that  in  a  meaningful   way objectively.  We  were  forced,  therefore,  into  combining  colour with texture measurement  in order to attempt  to characterise  the scars  automatically  and  also  using  panels  of  observers  to  draw around  the  scars  on  a  touch  screen  to  give  us  some  idea  of "ground truth" for our measurements. This work illustrates the usefulness  of consensus  coding in visual appearance  research.  In essence, the relevant adjective to describe our stimuli was "scarriness",  which  refers  to that combination  of texture,  colour and 3D shape that we call scarring. However, in additional experiments  we  also  asked  participants  to  describe  the  scars  in their own words. Whilst many colour, texture and 3D shape







descriptors  were  used,  other  words  like  "delicate"  and  "tender" refer to more  empathic  possibilities,  closer  to the CIE's  idea of "total" visual appearance ([3]).
This leads us onto aesthetic aspects of visual perception.  There is a growing  body  of  literature  on  the  aesthetic  aspects  of  colour perception   (see,  [4]),  which  is  beginning  to  be  extended  into visual appearance  qualities such as texture (e.g. [5]). Participants have   no   difficulty   in   specifying   not  only   what   their   "most preferred" colour is, but also which they find most pleasant, unpleasant, lively or calming. There is also a surprising consensus on which  colours  make us feel happy and sad.   This fascinating area of research  is also beginning  to look carefully  at individual differences, especially those between males and females, different cultures  and  different  age  groups.  These  groups  can  differ  not only in what their responses  are, but also in how much  they are influenced by suggestion and prior exposure.
Individuals on the autism spectrum have unusually strong sensory preferences  ([6]). Indeed we have found that not only individuals with diagnoses of autism spectrum disorder (ASD) but also those with   higher   levels   of   autistic   personality   traits   demonstrate marked differences in their responses to environmental sensory stimulation  than those with few such traits. These difficulties  can make some types of sensory stimulation intolerable. Whilst the list of  stressors  includes  obvious  things  like  flickering  lights,  fire alarms and chemical smells, these can also be such apparently innocuous   things   as  brightly   coloured   objects,   brushing   past somebody in a supermarket and the smells of everyday foods.
This survey of research  might suggest that the idea of predicting perceptual  responses is a hopeless task, complicated  as it appears to be by the presence of these large individual differences. I would like to argue that a combination of careful characterisation  of participant groups, using demographic data and personality questionnaires,  and  careful  attention  to the words  people  use to describe  their  sensory  experiences,  at least  in the first  instance, will  lead  to  a greater  ability  to move  forward  in  this  field  and thereby establish at least what the "average human" response will be in representative situations. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down.
description: {"references": ["[1]   SIMMONS, D.R. et al. Visual Appearance: Applications in public health dentistry and maxillo-facial surgery. CIE x032:2007, 114-122.\n[2]  SIMMONS, D.R., TAWDE, S. &amp; AYOUB, A.F. What is a facial scar? Proceedings of The 2nd CIE Expert Symposium on Apperance: When Appearance meets lighting \u2026 Gent, Belgium, 8-10 September, 2010.\n[3]   CIE 175:2006 A framework for the measurement of visual appearance.\n[4]   SIMMONS, D.R. Colour and Emotion. In: New Directions in Colour Studies Eds. Biggam, C.P., Hough, C.A., Kay, C.J. &amp; Simmons, D.R. Amsterdam, The Netherlands: John Benjamins, 2011.\n[5]   SIMMONS, D.R. &amp; RUSSELL, C. Visual texture affects the perceived unpleasantness of colours. Perception, 2008, 37 (supplement), 146\n[6]   SIMMONS, D.R. et al. Vision in autism spectrum disorders.\nVision Research, 2009, 2705-2739."]}