A Picture is Worth a thousand…Parts?

It is presumed that adults can not recognize a face in parts as easily as the complete facial structure.  It is presumed to be as such because adults recognize the features of an individual’s face more easily than the context of the facial patterns in isolation (762).

This gestalt-like facial processing theoretically begins in infancy and has a developmental milestone that is disrupted if something delays or obliterates this phenomenon.  On television shows and in magazines I recall partial viewings of celebrities’ faces and I almost never got it right.  Such is the finding of Young et al in 1987 study in which adults found it difficult to recognize the top half of a celebrities’ face when it was aligned  with bottom half of a different face (762).

  Some theorists believe there is an intimate ability to recognize faces.  However, this research study invalidates that theory.  A controlled experiment was done with patients that were born with or suffered from visual impairments at infancy.

These participants were all less than seven months when visual acuity was affected.  Vision was later corrected and the experiment for holistic facial identification had commenced (765).

To test for the gestalt-like effect, participants were asked to move a joystick forward if the top halves were the same and back if the top halves were different.  Composites were created by splitting face images horizontally across the middle of the nose, and then recombining the faces using the top and bottom halves of different individuals.  In the aligned position, the top and bottom were properly aligned.

In the misaligned condition the top half was shifted horizontally to the left (764).  The results were astounding.  The group that had visual imperfections at infancy actually performed better than their control counterparts on same trials when faces were aligned (766).

This group was also more accurate on different trials than on same trials and did not vary with alignment (766).  This supports the theory that this ability is not innate.  Holistic face processing or a composite face effect was not a sustained ability of those with visual impairments at a critical time period.  Such patients fail to integrate facial features into a Gestalt (767).

This experiment shows that early visual input is very critical for the normal development of facial processing.  It also raises the question of whether early vision is necessary to preserve the neural substrate that would allow training to induce the later development of holistic processing of non-face objects (767),  I find it rather interesting and this bizarre phenomenon begs the question of when the critical time period begins and ends.

The article states that by age six, adult-like processing takes place.  It does not state if visual perception is disrupted after age six, if this ability for gestalt-like processing is still apparent.  Thus this experiment does not prove that infancy is the critical time period or developmental milestone for this ability.

To be sufficient, it would have to include a group of participants that had visual impairments later in life and the length of the impairment would have to be similar.  What about visual impairments for one and two year olds? This only mentions infancy from 3 to 6 months.

This experiment is partial, at best.  I would also like to know how the control group compares to those who have visual impairments that have not been corrected.  Are such people able to recognize faces aligned and misaligned with similar circumstances? These are critical points to validate and substantiate the findings of this experiment.