Perception of Colour
20 important questions on Perception of Colour
Why is colour helpful in the way we see objects?
- info about state of the objects (e.g. the ripeness of a fruit)
What can be some consequences of colour loss?
- loss of color in dreams & imagery i.e. no recollection of colour (this doesn't effect all patients)
- choosing clothes to wear - may be relient on others
- can lead to depression as you always see everything on grey-scale and you are relient on others
What are 2 tests that can identify deficits in colour perception?
2. Colour matching and odd one out detection (Heywood et al., 1987)
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
For my 1st exam I got a C. Then, I started looking for ways to learn better and I came across Study Smart. Since then I have scored a A+, A, A- and another A. I highly recommend it to everyone who wants to hear it. I am so happy with it!!
I was struggling to finish all my first-year subjects for 3 years. Then I discovered Study Smart, which helped me to finish all of them within 3 months.
Because of StudySmart, things are going well in many ways. Before, I always had study stress and no time for anything. Now I feel calm and confident (because of the program). I used to score a B, now I usually score an A or A+.
Hey Chris, I really want to thank you very much for developing the platform, I usually got around C for my exams, now I scored an A+, an A and a A- !!
Since using Study Smart, my average has increased significantly. I even completed a statistics course with a A+ while I'm bad at statistics. I took on extra courses this year, because of Study Smart. Thanks so much!
Ever since I started studying with StudySmart I passed all my exams !!! No more re-sits!! At first, I was happy with a pass and now I only get good grades. Many thanks!
I aced all the courses I studied with Study Smart. For law, I first scored a D, and now an A! I’m 100% sure that I’ll pass all the courses I study with Study Smart.
I always thought I studied well. My grades were fine. I could never have imagined that applying these study skills would have such a huge and direct impact on my grades, my speed and the pleasure I have in learning.
For the first time, I finally feel totally confident about the way I learn. I have the perfect overview and make great progress in terms of speed and the grades I get. Thanks, Chris!
I immediately started to enjoy learning again, and my grades soared. All of a sudden, everything went better. I highly recommend Study Smart to all students..
Being able to create my materials online made the process of studying so much smoother and quicker. I no longer have to spend a huge amount of my time on creating my summaries.
At first, my notes were a mess. Now I use Study Smart to take my notes in a perfectly structured way. It helps me to save a lot of time and do other things I enjoy.
Students that study with Study Smart get better grades. The system applies all the learning methods in such a way that both well-performing students and students who struggle perform much better.
Hi Chris, I would like to thank you very much. Last year I scored C on a course, and this year I got an A+ thanks to your method! Thank you very much!
The largest effect is that my child is more enthusiastic about school! Every parent wants their children to be happy at school, Study Smart made it happen.
In high school, I failed several exams, and that has really changed now. I actually needed this tool very much back then. Since I started studying with StudySmart, I haven't had any D's. My average score is now an A and those are results I would have never had in the past
With my old method, I passed only 3 out of 8 courses. Since I started taking my notes digitally in Study Smart, I have passed all my courses on the first try. For me, StudySmart takes away the stress of wondering if I will pass or not.
Thanks to StudySmart, I passed all my exams, and with better grades than before! On top of that, I have mastered a very good study method now, which I am confident will help me earn my degree.
What are 3 preserved functions of cerebral achromatopsia?
2. Luminance discrimination (i.e. the brightness)
3. Colour cognition (e.g. verbal association, colour of known pictures/objects)
What patient demonstrates that not all individuals with cerebral achromatopsia have impaired colour imagery?
- lesion involving the left temporo-occipital sulcus and right middle occipital gyrus
---> developed cerebral achromatopsia = poor performance on Farnsworth-Munsell, colour matching and colour naming tasks
---> Intact visual imagery for colours ( i.e. she can still remember & imagine colour). She has good:
= Colour verbal memory
= Colour-object fluency
= Colour name fluency
= Mental hue comparison
(Bartolomeo et al., 1997)
Who is the patient with the mental imagery defect?
- left occipital and medial temporal infarct
= Right hemianopia (half loss of vision)
Tests
Naming visually presented colours - good performance
Colour naming of objects from memory - poor performance
Recognising if a picture of an object was coloured appropriately - good performance
Recalling appropriate colour of objects - okay performance (13/20)
Fareh et al., 1988
What did Crognale et al., 2013 demonstrate?
Patient:
- 46 year old female
- Bilateral damage to the ventral occipitotemporal cortex
- Cerebral achromatopsia
EEG showed normal chromatic visual evoked potential (Normal Chromatic VEP) demonstrated in patient with achromatopsia
= this EEG response in V1 suggests that the impairment seen in achromatopsia is not in the earlier parts of the visual pathway
= the cones are still intact i.e. light is still being taken in
What does bilateral damage to V4 lead to?
- this is rare
What does unilateral damage to V4 cause?
e.g. damage to right side of the brain means loss of colour in left side of visual field and vice versa
Who converged evidence for the involvement of the V4 complex in cortical colour perception?
Recorded the response of single neurons in monkey V4 to simple coloured visual stimulation
Limitations of study:
- isn't testing human colour perception
Benefits of study:
- exp. knows which neuron they are testing (good control)
- good spatial resolution
What did Heywood et al., (1992) find? What was a development of this initial finding?
Development - Heywood et al. (1995); Cowey et al. (2001):
Lesions that were ventral and anterior to V4 in macaque monkeys did result in impaired colour perception
What did Zeki identify in 1991?
Results: activation in the lingual & fusiform gyri (area V4) = colour centre
What is a limitation of Zeki's colour centre experiment?
Who performed an fMRI during Farnsworth-Munsell 100 hue task? What did they find?
Stimulus conditions:
- Order by colour
- Order by luminance
- Passive viewing of colour
Results: Ventral occipitotemporal activity in colour situations vs. luminance
i.e. when trying to order colour and luminance, there is more activity in anterior V4
What does cerebral achromatopsia tell us? (2 points)
- colour perception is in V4
What is meant by colour blindness?
- Inherited gene abnormality resulting in reduced retinal photoreceptor system (dichromatopsia)
- 3 types of photopigments: sensitive to long-, medium- and short-wavelength light. People who are dichromats only have 2 photopigments (i.e. missing a photo pigment)
- Red-Green colour-blindness = missing photopigment sensitive to either medium or long wavelength light
(more common in males than females)
(p. 201 neuropsychology textbook)
What are the effects of peripheral achromatopsia?
- Colour blindness (achromatopsia)
- Day blindness (light intolerance) - rods are very sensitive to bright light
- Reduced visual acuity
- Nystagmus (rapid involuntary movement of the eyes)
What are the similarities and differences between peripheral achromatopsia and cerebral achromatopsia?
- Perceptual experience of colour (or lack of it)
- Consequential behavioural impairments (some)
Differences:
- Age of onset
- Visual acuity
- Day blindness
- Emotional response
- Peripheral achromatopisa = problems before V4, with cones etc.
What is colour anomia?
- a linguistic problem = patients can't relate the red colour to the word "red"
What are 2 things that people with colour anomia can do and 2 things they cannot do?
- Farnsworth-Munsell test
- Colour matching
Cannot do
- Identify a colour
- Say which colour is red etc
---> they are okay with tasks that are purely perceptual
Try our study magic for free
a PDF, study it super fast
- No sign up, email or credit card needed!
- AI makes unlimited flashcards
- Get unlimited quizzes and tests
- Ask AI anything
- No sign up, email or credit card needed!
- Have and keep perfect overview
- Make flashcards, notes and mind maps
- Review, test and score!
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
