Katherine finds processing the whole image simultaneously challenging (simultanagnosia), the more cluttered the environment, the harder this becomes, because there is more visual information to process.
The effects of clutter on vision when she is wide awake and in an uncluttered situation needs to be compared with the effects when tired and in a cluttered situation, and how this impacts upon Katherine's ability to identify people should be considered.
Other factors making processing the visual scene more challenging for Katherine are that she is both exhausted - at the end of the day "she's shut down" and also excited. We know that Katherine is happiest on a horse, without the challenges of having "her two feet on the ground". This suggests that it is possible that Katherine has either visual inattention or neglect in her lower visual field.
One way to check if Katherine has a lower visual field impairment is to ask her to hold onto a chair for stability, then elevate her straight right leg in front of her, whilst looking straight ahead, and note the point her toe becomes visible. If she has to lean back a bit and has to lift her leg up to twice the height you do, to do the same thing, then it's likely she has this difficulty.
It is quite possible that Katherine is running to her mother using purely memory (using visualisation) from an activity repeated in the same way over and over again - every day Katherine ran out to meet her mother who stood in the same place. It is possible that Katherine wasn't 'looking' at all.
This issue of 'not looking' concerns what is called 'frontal attention', from our frontal lobes - the conscious decision making centre of our brains. So Katherine 'not looking' is not in itself a visual impairment, we all of us when lost in our own thoughts can miss other events. This is what the problem is when listening to a good radio play in the car and taking the wrong route without realising!
We asked Mary, who has simultanagnosia, what she thought:
"I think in a situation like this, she is probably having to work so hard to even walk through the crowd of people safely, which is on top of the exhaustion she is already feeling at the end of the day. So she is not even looking for her Mum, just going to where she normally is. There would be a lot of noise at the end of the day as well, so she wouldn't be able to process the noise and visual information around her, hence why she missed her Mum when she ran past her. She is not paying attention to anything around her, other than trying to run safely to where she wants to go. She is also probably feeling very stressed and anxious and so when her Mum is not where she was meant to be, she may panic and be unable to see anything as it is impossible for me at least to scan around when in a heightened emotional state. This could lead to anxiety about meeting her Mum after school in the future and negative behaviours, to try and avoid that situation happening again."
It is likely that Katherine's possible simultanagnostic vision, made more challenging by multiple factors listed above, was responsible for her not recognising the woman she approached as someone other than her mother. It is interesting that Katherine also didn't recognise her Teaching Assistant out of the context of the school and classroom. This indicates that Katherine relies heavily on other 'clues' to help her recognise people.
Think about Katherine's right filing cabinet where she stores the memories of the people she knows to recognise them. Katherine clearly knows the people, but to recognise them she often needs more information than what their faces look like.
Faces are filed in the brain according to where they are normally seen, so for all of us faces seen out of geographical context may not be recognised
So we think we may understand why Katherine did not recognise that she had accidentally approached the wrong person, however there are further reasons in Level 3 that may also factor, and so we carry the combined knowledge from Level 1 and Level 2 further along the pathway of thinking.
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