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What is the cause of differences that are too small to see?

What is the cause of differences that are too small to see?



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Consider two identical pieces of paper.

Scenario 1: On both something is drawn in black ink. If the difference between the areas covered in black ink is sufficiently small, I cannot see the difference between the two drawings.

Scenario 2: Now imagine that the same parts are covered with ink, but their color differs. Again, if the difference is sufficiently small, I cannot see the difference.

Firstly: what causes this? I am aware of the terminology of just-noticeable differences/limina, but do not understand precisely what causes them. Is there some discretization of continuous signals going on that causes 'nearby signals' to be treated the same way?

Secondly: one person may have better vision than another, but are there physical constraints that are the same for any two persons and that imply that if the difference in scenario 1 or 2 is sufficiently small, no two persons will be able to see a difference?

Addenda: I phrased the question informally by not defining what a 'small difference' is, trusting/hoping that this does not lead to confusion. If desired, such statements can be made precise by adopting appropriate distance functions. In scenario 1, one way to measure distance between two areas covered in ink could be to use the Hausdorff distance; likewise, one way to measure the distance between colors in the second scenario could depend on the difference in responsiveness of the three types of cone cells.


The spatial resolving capacity of the visual system is called visual acuity, namely the ability of the eye to see fine detail. There are various ways to measure and specify visual acuity, depending on the type of acuity task used.

Visual acuity is limited by

  • diffraction,
  • aberrations and
  • photoreceptor density in the eye.

The photoreceptor density allows a resolution that by far exceeds the limitations imposed by the other two.

Diffraction of light is an important factor limiting acuity. This is caused by optical limitations of the eye, mainly the light scattering by the cornea and other structures (Fig. 1). Raleigh's criterion is used to calculate the resolution of the eye for stimuli that are degraded by the optics of the eye: two points or lines are just resolved if the peak of the point spread function lies on the first trough of the other point spread function (Fig. 2).

Aberrations also are an important source of image degradation on the retina. These include the well known spherical aberrations that lead to near- and far sightedness, as the retinal image becomes out of focus. These can be corrected well with glasses and lenses (Berrio et al., 2010).

Other sources that affect acuity are:

  • The size of the pupil; Large pupils reduce diffraction, but aggravate aberrations of the eye. A small pupil reduces optical aberrations, but resolution will be diffraction limited. Therefore, a mid-size pupil of about 3 - 5 mm is optimal as a compromise between diffraction and aberration limitarions
  • Illumination: photopic vision allows the cones to operate and that yields higher acuities than rod-mediated vision (Kallioniatis & Luu (2012).
  • For the same reasons the area of the retina stimulated affects acuity - the cones are clustered in the center of the retina, called the fovea. Foveal acuity is much higher than peripheral vision (Kallioniatis & Luu (2012).
  • Time of exposure of the target causes adaptation. If the cones are adapted to the timulus, they may become less responsive and acuity drops (Kallioniatis & Luu (2012)
  • Eye movements degrade visual acuity as a stable retinal image is needed (Kallioniatis & Luu (2012).

References
- Kallioniatis & Luu, Visual Acuity. In: The Organization of the Retina and Visual System, 2012
- Berrio et al., JOV (2010); 10(14)


Fig. 1. Resolution limit eye. source: Kallioniatis & Luu (2012).


Fig. 2. Reigheigh criterion. source: Kallioniatis & Luu (2012)


Obsessive-Compulsive Disorder (OCD)

OCD can cause intense feelings of stress or shame, but many types of treatment can help.

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Obsessive-compulsive disorder (OCD) is a condition that many have heard of but few understand.

According to data from the National Institute of Mental Health, OCD isn’t uncommon: 2.3% of U.S. adults will develop it at some point. Children can also develop OCD.

The media often represents those with OCD as overly organized people who can’t stop washing their hands. While this might be partly accurate for some people with OCD, it’s far from the complete picture.

People with OCD tend to have distressing thoughts that won’t go away. They might act on their compulsions for temporary relief, even when they don’t really want to.

OCD can feel like a roadblock, and asking for help can be difficult. But therapy, medication, and self-care techniques can help you manage OCD and relieve unwanted symptoms.

There are two main parts of OCD:

  • Obsessions: unwanted, intrusive, and persistent thoughts
  • Compulsions: urges to do certain rituals or actions

Both obsessions and compulsions can cause distress and make day-to-day living harder.

There’s a difference between the occasional intrusive thought or good-luck ritual and OCD. Obsessions aren’t the same as having any unwanted thoughts. With OCD, these thoughts are distressing and persistent.

The rituals of people with OCD could look like being careful or superstitious. Many of us double-check locks before going out to feel safe or knock on wood for good luck. But if you live with OCD, you might feel as if you have to carry out a compulsion, even when you don’t want to.

Symptoms of OCD fall into the categories of obsessions and compulsions. They can show up in a variety of ways from person to person.

These symptoms can get in the way of daily life, especially because they can take up time.

For example, someone with a ritual of knocking on their door three times before leaving might do it even when it’s impractical — like if they’re late for work or in an emergency.

Obsessions

Obsessions are often compared to intrusive thoughts, but they’re also different from day-to-day anxieties.

If you have OCD, you might often try to suppress these thoughts or relieve the anxiety they cause with a different thought or a compulsion.

These obsessions, or thoughts, could include:

  • images of hurting others
  • thoughts you consider immoral, bad, or shameful
  • urges to do something you don’t want to do

It’s common to have one specific thought (or type of thought) that comes to you over and over again. But the thought can also change over time.

Compulsions

Compulsions are repetitive behaviors you might feel a strong need to do to soothe anxiety related to an obsession.

Some examples of compulsions include:

  • repeating words or phrases mentally
  • hand-washing
  • repeating an action
  • checking locks, windows, or other objects

These compulsions might not seem directly connected to the obsession. For example, somebody might have intrusive thoughts about hurting someone, feel upset by these thoughts, and then feel a compulsion to shake their hands to relieve that distress.

Living with OCD is a different experience for each person. Because these thoughts and compulsions can feel overwhelming, they can have a huge impact on your day-to-day life.

Obsessions and compulsions might affect your:

  • relationships
  • self-confidence
  • social life
  • school
  • work
  • ordinary tasks
  • mood
  • daily routine

For example, someone with an obsession-related thought during an exam might feel the need to act on a compulsion right there. If the compulsion is walking a certain number of steps or speaking out loud, they might walk out of the exam or feel anxious for the rest of it.

Some people with OCD isolate themselves because they’re afraid others will notice their compulsions. For example, someone might avoid going to social events because they’re afraid of acting on a compulsion.

The thoughts that come with OCD might also feel too shameful or scary to talk about. This shame, coupled with mental health stigma, can make OCD feel more isolating.


Psychological Effects Of The Color Gray

Many people think of gray as a "safe" color, but that is not true at all!

With gray, it's possible to create either fantastically gorgeous or truly awful interiors.

Let's start with the good stuff.

Used well, the color gray can lend interiors an elegant formality that is subtle without being overly conservative.

It is the color if you want to create an air of calm, understated confidence. For gray to have this psychological impact, it's best combined with whites and other neutrals.

But you needn't stop there. Gray can be a wonderful background color for other, more intense colors. If you get the right shade of gray (more about that below!) and stir it into a more adventurous room color scheme, it will make the other colors 'sing'.

Apart from its psychological effects, gray also has a practical property that makes it very useful for manipulating paint colors: If you are decorating with ready-mixed paints, stir a bit of gray paint into them and it will take the synthetic edge off.

Gray can bring any color to life.

This page is about the effects of grey color .

. for more info about color psychology, please go to the general psychology of color article.

On the other hand, the color gray often contains other colors. You can get the whole gamut from yellowish to orangey-brownish to purplish, bluish and greenish grays, and their psychological effects can be quite different, particularly when you use them over large areas. Check out these grey/neutral color schemes to see what I mean!

For example, a yellowish, 'murky'-looking version of gray can look quite depressing, especially if you paint more than one wall with it and combine it with brown hues in a room.

But a really neutral hue of gray (that is, a gray that has no color in it apart from 'clean' white and black) will tend to look clean and crisp in most color combinations.

(Click here for some more information about creating Neutral Color Palettes).

So the first essential thing to get right is to pick a hue of gray that works with the other colors.  How do you do that?

By experimenting.  it's the only way you can really tell if a shade of gray - or any other color for that matter - will work for a room.

You need to see it in that room, next to the other colors and in the correct light. (This will also tell you whether you're getting the desired psychological effects of a color!)

The danger with gray is that if you have this color on too many surfaces, with no other color (or a clean white) to brighten it up, the color gray will be overpowering and you'll end up in a dull, moody environment.

But throw in some whites, or more intense colors, and the color gray will become a chic, sophisticated canvas for your life.

To check out the psychological effects of other colors, take your pick from the following links:


Cultural Differences

Our cultures very much shape how we go about our business.

Culture informs our expectations, our behaviours, our motivations and our perceptions of others.

When we are working with people from the same, or similar, culture, it’s these shared rules that help give us structure and agreement in how to go about doing things, whether that’s how we communicate, run meetings or negotiate.

However, when we have to work with someone from a different culture, the rules may no longer be the same.

Bringing different expectations, understandings, motivations, etc. to the meeting or negotiation table may therefore cause problems, and it does.

The Challenges of Cultural Difference in International Business

By way of exploring these differences, we are briefly going to look at 3 ways in which culture can cause challenges.

  1. Personal Challenges – the emotional challenges faced by individuals.
  2. Cognitive Challenges – the mental challenges faced by people.
  3. Pragmatic challenges - the practical challenges faced by business.

Let’s explore these in more detail below.

1. Personal Challenges

When working in a multicultural environment or with another culture, the personal challenges can be many.

When we come across cultural differences, and are unable to recognise and deal with them, our responses are emotional. This can have a detrimental impact on many factors including sense of well-being and confidence.

Anxiety and stress are common reactions for people new to working in a foreign culture. When people find themselves confronted with difference, they feel challenged and therefore build mental walls to help them cope. These walls, more often than not, do more harm than good.

For example, decision making may be impaired or people may withdraw from others, creating even more distance between themselves and a solution.

Symptoms may also be physical, with people experiencing headaches, migraines, exhaustion and burnout.

The ‘Culture Shock’ experienced by many expatriates who move abroad is a very good example of how cultural differences affect professionals on a personal level. Not being able to manage cultural differences is a common reason cited for failed international business assignments.

The Business Culture Complexity Index™ ranks the top 50 economies of the world according to the potential complexity or ease of their business cultures.

Which country do you think is the most complex?

2. Cognitive Challenges

Working with people from different cultures can present considerable cognitive challenges.

Cognitive challenges relate to how we think, process information and essentially how we view the world.

When we come up against a foreign culture, this can cause us real problems, especially if we fail to recognise differences and adapt.

Two simple examples of this are the concepts of time and relationships.

Some cultures place a high value on time, others don’t. If you come from a culture in which ‘time is money’ and you find yourself working with a culture in which it isn’t, your cultural norms can result in you making bad decisions.

Time conscious professionals can see lateness in other cultures as unprofessional or even disrespectful. They don’t appreciate that in the culture they are working with punctuality is a much more nuanced concept.

In reverse, those cultures that are a lot more flexible with their approach to time can see the time conscious professionals as rigid and materialistic, which ties in with the value given to relationships.

In some cultures, it's relationships before business whereas in others, business first. Usually those cultures that are time conscious are less relationship orientated.

Now, what happens when you have a professional from a very task orientated culture visit a client or colleague from a very relationship focused culture?

Yes, they can see each other’s priorities incorrectly, i.e. the relationship-driven culture sees the task-driven culture as impersonal, unfriendly and disinterested, whereas the task-driven culture is seen as not taking business serious enough, spending too much time on small talk and breaching the line between personal and professional matters.

The results is a sort of cognitive dissonance – both sides are looking at one another through their own Cultural Lens which means they are interpreting behaviours incorrectly and attributing erroneous meaning to them.

This can happen at many levels, whether we are talking about a general approach to business or in the more specific areas such as how we communicate, manage hierarchy and conduct negotiations.

Examples of Cultural Differences in International Business

If you would like to further your reading on cultural differences in international business, then these are all excellent additional resources:

  1. Cultural Differences in Mergers & Acquisitions
  2. Cultural Differences in International Retail
  3. 3 Real-life Examples of Cultural Misunderstandings in Business
  4. Free Self-Study Guide to Cultural Differences
  5. Cross Cultural Marketing Blunders
  6. How Lack of Cultural Awareness Can Cost A Business Big

3. Practical Challenges

Doing business with people from different cultures can also affect the more practical aspects of work.

Whether we realise it or not, we have all been conditioned by our cultures to approach work and the practicalities of business in specific ways.

All of us have specific ideas as to what is the good or bad way to conduct a job interview, give a presentation or handle a customer complaint.

Many of these do not necessarily translate into other cultures, which can cause challenges.

For example, the simple act of eye contact can cause several practical challenges. What happens when you have a culture that sees eye contact as a sign of confidence and engagement interact with one that sees eye contact as rude? If the two parties are unaware of this there can be several consequences such as a lack of trust, poor communication, a failed job interview of a confusing meeting.

Management is another good example of where we see differing cultural expectations cause challenges in the workplace. What happens when you have a manager who is used to a more hands-off leadership style, whereby they leave their team to their job, come into a country where the management style is much more authoritative and directive? They can come across as weak and unqualified. And if it is was the other way around, the manager would be seen as a control freak who doesn’t trust their team to do anything.

The result can be a very messy. In Iraq a few years ago a foreign expat manager actually managed to cause a riot and get himself beaten up due to not understanding local ways.

Cultural Differences in Business

So, as we can see culture can affect international business in many ways.

In essence, when you have two or more differing views, opinions, assumptions or presumptions come together, the result can be negative due to a lack of understanding between the two.

The more aware you are of your own culture and the affect it has on you, the more aware you will become of how culture affects others and what you can do about it.

Take a Course on Cultural Awareness

If you would like to learn more about cultural differences and how they affect business, then our eLearning course is perfect!

We cover everything from understanding culture to cultural differences in business, including a look at differences in approach to time, communication and teamwork.

Feel free to watch the video sample below or go to the course page to learn more.


How much is too much evolution?

A common mantra among YECs is to say they believe in evolution, but only limited, "horizontal" evolution "within kinds" and not "vertical" large-scale evolution between or above "kinds." But the problem with such statements is that they are entirely subjective. I have yet to see a YEC provide a clear answer on this. What exactly constitutes a "kind"? How much evolution is too much? Where exactly do YECs draw the line between acceptable and unacceptable evolution and on what rigorous, scientific basis do they do so? YECs will often cite the polar extremes but fail to rigorously define where exactly the dividing line is between possible and impossible evolution. Instead, from what I can tell, YECs base their beliefs on subjective feelings of what seems or "feels" like too much evolution.

For example, these two skulls have similarities but also distinct differences. Are the differences too much for YECs to acknowledge that they are related? Comparative anatomy and genetics both support the conclusion that these two are in fact closely related, but YECs will still reject the evidence if they subjectively feel like the differences are too great.

Similarly, comparative anatomy (including sophisticated computer measurements and analysis) and genetics supports the conclusion that all these skulls are related.

YECs often dismiss such things out of hand (despite the evidence) saying that such changes in morphology are too great, but they have no objective basis for doing so and instead dismiss arbitrarily and based on subjective "gut" feelings of what seems like too much change.

So how much is too much? Are the skulls above, for example, too different in their range of size and morphologies to be related through common ancestry?

Looking at two things that show similarities only show similarities, they don't show why they are similar only that they are. Jumping to conclusions about historical causes just because of looks isn't a strong argument, it isn't even an argument really. We can see similar things today with common species that have similar traits yet are vastly different.

Looking at two things that show similarities only show similarities, they don't show why they are similar only that they are. Jumping to conclusions about historical causes just because of looks isn't a strong argument, it isn't even an argument really. We can see similar things today with common species that have similar traits yet are vastly different.

No one "jumps to conclusions. just because of looks." You are trivializing sophisticated analysis. Detailed quantitative comparisons are fundamental to many scientific disciplines. For example, we use comparative genetics to determine relationships all the time. You have no problem with this and even accept the findings of science that two individuals are related if the anatomical or genetic differences aren't "too much" in your subjective opinion, but if you feel like the differences are "too much" then you dismiss it like you've done here. In other words, you *don't* reject the use of anatomical and genetic similarities to deduce relationships just so long as the differences aren't "too much," but if the differences are subjectively "too great" in your opinion, then suddenly the same method based on degree of similarity suddenly becomes invalid. But on what basis do you make this determination? How much is too much? Where is the dividing line between possible and impossible evolution and how do you know?

Plus, as I said with the skull examples, it's not simply anatomical similarities but also genetic similarities that support the conclusion of common ancestry.

These skulls have similar morphologies and are also genetically similar (except for one chromosome which is markedly different). Using the same accepted methods we use in forensic analysis of bones and DNA, we come to the conclusion that these two individuals are related and had a common ancestor:

Anatomical and genetic evidence likewise supports the conclusion that all these skulls below are related and they all had a common ancestor:

See, what you are doing is accepting the use of anatomic and genetic similarities to determine relationships in one case, while rejecting it in another based only on your subjective feelings of what "seems" like "too much" evolution or too great a difference in morphology.

One thing to think about is how closely related species can be. A horse is closely related to a donkey. So closely related that they can inter breed and make mules.

One thing to think about is how closely related species can be. A horse is closely related to a donkey. So closely related that they can inter breed and make mules.

Right and there are noticeable differences in their skeletons particularly in size, but without knowing they are skeletons of donkeys and horses and mules YECs could reject them and say they are not related if the skeletal differences are "too much" in their subjective opinion, which again raises the question I pose to YECs: How much is too much evolution? Where do YECs draw the line between possible and impossible evolution and on what basis do they do so?

If you quantify change in any way and a change of magnitude X is considered possible, just choose N bigger than Y/X and you know how a change of magnitude Y can be achieved.

One thing to think about is how closely related species can be. A horse is closely related to a donkey. So closely related that they can inter breed and make mules.

Right and there are noticeable differences in their skeletons particularly in size, but without knowing they are skeletons of donkeys and horses and mules YECs could reject them and say they are not related if the skeletal differences are "too much" in their subjective opinion, which again raises the question I pose to YECs: How much is too much evolution? Where do YECs draw the line between possible and impossible evolution and on what basis do they do so?

If you think they all come from a common ancestor you can arrive at that conclusion readily and if you think a common ancestor for all life is bogus, not so much.

You still haven't answered the fundamental question: How much is too much evolution? Where *specifically* do you draw the line and on what basis?

I can see small changes within each lifeform, but not major overhauls.

Can you delineate more specifically where the dividing line is? Genesis "kind" does not seem to equate with what biologists define as a "species." Does a Genesis "kind" equate with genus or some other taxonomic category (or somewhere in between?

How can you deem something impossible if you don't know what is necessary to get from A to B?

Take the two sets of skulls below. The first two skulls are related and share a common ancestor. All the skulls in the second picture are also all related to each other and have a common ancestor.

In both cases, the skulls show large differences in morphology, and I know the underlying genetics in both cases. In fact, only a few small changes in DNA are needed to create these large changes in skull size, shape and form. Now if you come along and look at these cases and subjectively it feels or seems like too much change in morphology to suit your taste, then you will tell me it's impossible. But how can you do so if you don't know how much change in DNA is needed and by what mechanism? Doesn't that just amount to guessing on your part?

A common mantra among YECs is to say they believe in evolution, but only limited, "horizontal" evolution "within kinds" and not "vertical" large-scale evolution between or above "kinds." But the problem with such statements is that they are entirely subjective. I have yet to see a YEC provide a clear answer on this. What exactly constitutes a "kind"? How much evolution is too much? Where exactly do YECs draw the line between acceptable and unacceptable evolution and on what rigorous, scientific basis do they do so? YECs will often cite the polar extremes but fail to rigorously define where exactly the dividing line is between possible and impossible evolution. Instead, from what I can tell, YECs base their beliefs on subjective feelings of what seems or "feels" like too much evolution.

For example, these two skulls have similarities but also distinct differences. Are the differences too much for YECs to acknowledge that they are related? Comparative anatomy and genetics both support the conclusion that these two are in fact closely related, but YECs will still reject the evidence if they subjectively feel like the differences are too great.

Similarly, comparative anatomy (including sophisticated computer measurements and analysis) and genetics supports the conclusion that all these skulls are related.

YECs often dismiss such things out of hand (despite the evidence) saying that such changes in morphology are too great, but they have no objective basis for doing so and instead dismiss arbitrarily and based on subjective "gut" feelings of what seems like too much change.

So how much is too much? Are the skulls above, for example, too different in their range of size and morphologies to be related through common ancestry?

Depending on how fast the changes in evolution occur, if very slow it would not be in the fossil record I'm be looking for similarities, but in living creatures. There should be strings of very similar life that show the changes that have been occurring over time, instead we see distinct living creatures.

Continuous gradational changes in morphology is the exception rather than the rule not just in the fossil record but in living populations too due to functional and developmental constraints. Most major discontinuities are.due to small scale changes and tinkering in regulatory genes, gene expression and developmental timing.

If evolution were true, if everything changes slowly, even form. We do not see that in life.

It's a misconception that evolution only occurs slowly via gradual, incremental steps as explained above in post #13

Really, it happens in giant leaps of massive change all at once?

It's a misconception that evolution only occurs slowly via gradual, incremental steps as explained above in post #13

But isn't it the case that evolution takes many generations to manifest itself in the creation of new species and forms? That being the case, we need to study lifeforms with rapid reproductive cycles in order to see evolution taking place and that generally means microbial life.

At least no examples of higher-order lifeforms come to mind that can reproduce on a scale of days. Some rodent species can produce two litters per year but even then would evolved traits be easily identifiable?

If evolution were true, if everything changes slowly, even form. We do not see that in life.

But you need to study lifeforms with rapid reproductive cycles and that usually means microbial ones, which are invisible to us. Most of the living things you see in your environment have evolved but often over many generations, involving periods of at least thousands of years or longer.

Really, it happens in giant leaps of massive change all at once?

It depends on what you mean by 'giant leaps of massive change'. In fact, that is the problem addressed in this thread: YECs rarely define the line between acceptable and unacceptable evolution that represents too great of a change. The divding line is fuzzy and given no formal, rigorous treatment by YECs, who speak subjectively on the subject.

So I don't know what you mean by 'giant leaps of massive change', and you have yet to clearly, and rigorously locate the divding line between evolutionary change you consider acceptable and unacceptable, so I can only speak in similar generalities.

In general, changes in morphology that you would probably consider 'major' are usually not the result of evolving entire suites of brand new genes, but instead are usually the result of small scale genetic tinkering with what's already available.

Take the vertebrate tetrapod limb, for example. The various different types and skeletal arrangements (which represent 'major' changes in morphology) can be produced by mere changes in the kinetics (i.e., the rates) of developmental pathways.

Similarly, all the different, various types of eyes in the animal kingdom and the major differences between them result from tinkering with a single regulatory gene.

It's a misconception that evolution only occurs slowly via gradual, incremental steps as explained above in post #13

But isn't it the case that evolution takes many generations to manifest itself in the creation of new species and forms? That being the case, we need to study lifeforms with rapid reproductive cycles in order to see evolution taking place and that generally means microbial life.

At least no examples of higher-order lifeforms come to mind that can reproduce on a scale of days. Some rodent species can produce two litters per year but even then would evolved traits be easily identifiable?

Generation time (GT) certainly has an important effect on evolution. GT is strongly correlated with rates of molecular evolution. The higher the GT, generally the higher rate of molecular evolution that is observed.

However, that doesn't necessarily mean that it takes many generations for evolution to 'manifest' itself. First, there are many, many different species that look very similar morphologically. There are thousands of different species of frogs, for example, that all look like. well, frogs. So it is a common misconception that speciation is always associated with large changes in morphology. It usually is not. Speciation simply requires reproductive isolation/barriers. Speciation also does not require numerous generations, and can happen instantaneously.

So the question of evolution manifesting different 'forms' is somewhat different from speciation which may or may not be accompanied by significant changes in form. But many generations are not necessarily required for noticeable changes in form to occur either. Significant changes in form can also occur 'instantaneously'.

One of the complicating factors in all this is the discovery that molecular evolution and morphological evolution occur at different rates and are not as directly correlated with each other as we would intuitively expect. This, in fact, is why we can study the evolution of specific genes and proteins independently of morphological evolution. Genetic changes often occur with little to no noticeable effect on morphology. But the general truth still holds that 'major' changes in morphology are usually not correlated with the evolution of entire new suites of genes, but genetic tinkering with what already exists.

I should also add that evolutionary studies are not restricted to studying natural populations evolving over many generations. Rather, today actual evolutionary history is 'read'/inferred directly from genomes.


What is the cause of differences that are too small to see? - Psychology

The sense of taste affords an animal the ability to evaluate what it eats and drinks. At the most basic level, this evaluation is to promote ingestion of nutritious substances and prevent consumption of potential poisons or toxins. There is no doubt that animals, including humans, develop taste preferences. That is, they will choose certain types of food in preference to others. Interestingly, taste preference often changes in conjunction with body needs. Similarly, animals often develop food aversions, particularly if they become ill soon after eating a certain food, even though that food was not the cause of the illness - surely you have experienced this yourself. Food preferences and aversions involve the sense of taste, but these phenomena are almost certainly mediated through the central nervous system.

Taste Receptor Cells, Taste Buds and Taste Nerves

The sense of taste is mediated by taste receptor cells which are bundled in clusters called taste buds. Taste receptor cells sample oral concentrations of a large number of small molecules and report a sensation of taste to centers in the brainstem.

In most animals, including humans, taste buds are most prevalent on small pegs of epithelium on the tongue called papillae. The taste buds themselves are too small to see without a microscope, but papillae are readily observed by close inspection of the tongue's surface. To make them even easier to see, put a couple of drops of blue food coloring on the tongue of a loved one, and you'll see a bunch of little pale bumps - mostly fungiform papillae - stand out on a blue background.

Taste buds are composed of groups of between 50 and 150 columnar taste receptor cells bundled together like a cluster of bananas. The taste receptor cells within a bud are arranged such that their tips form a small taste pore, and through this pore extend microvilli from the taste cells. The microvilli of the taste cells bear taste receptors.

Interwoven among the taste cells in a taste bud is a network of dendrites of sensory nerves called " taste nerves ". When taste cells are stimulated by binding of chemicals to their receptors, they depolarize and this depolarization is transmitted to the taste nerve fibers resulting in an action potential that is ultimately transmitted to the brain. One interesting aspect of this nerve transmission is that it rapidly adapts - after the initial stimulus, a strong discharge is seen in the taste nerve fibers but within a few seconds, that response diminishes to a steady-state level of much lower amplitude.

Once taste signals are transmitted to the brain, several efferent neural pathways are activated that are important to digestive function. For example, tasting food is followed rapidly by increased salivation and by low level secretory activity in the stomach.

Among humans, there is substantial difference in taste sensitivity. Roughly one in four people is a "supertaster" that is several times more sensitive to bitter and other tastes than those that taste poorly. Such differences are heritable and reflect differences in the number of fungiform papillae and hence taste buds on the tongue.

In addition to signal transduction by taste receptor cells, it is also clear that the sense of smell profoundly affects the sensation of taste. Think about how tastes are blunted and sometimes different when your sense of smell is disrupted due to a cold.

Taste Sensations

The sense of taste is equivalent to excitation of taste receptors, and receptors for a large number of specific chemicals have been identified that contribute to the reception of taste. Despite this complexity, five types of tastes are commonly recognized by humans:

  • Sweet - usually indicates energy rich nutrients
  • Umami - the taste of amino acids (e.g. meat broth or aged cheese)
  • Salty - allows modulating diet for electrolyte balance
  • Sour - typically the taste of acids
  • Bitter - allows sensing of diverse natural toxins

None of these tastes are elicited by a single chemical. Also, there are thresholds for detection of taste that differ among chemicals that taste the same. For example, sucrose, 1-propyl-2 amino-4-nitrobenzene and lactose all taste sweet to humans, but the sweet taste is elicited by these chemicals at concentrations of roughly 10 mM, 2 uM and 30 mM respectively - a range of potency of roughly 15,000-fold. Substances sensed as bitter typically have very low thresholds.

Examples of some human thresholds
Taste Substance Threshold for tasting
Salty NaCl 0.01 M
Sour HCl 0.0009 M
Sweet Sucrose 0.01 M
Bitter Quinine 0.000008 M
Umami Glutamate 0.0007 M

It should be noted that these tastes are based on human sensations and some comparative physiologists caution that each animal probably lives in its own "taste world". For animals, it may be more appropriate to discuss tastes as being pleasant, unpleasant or indifferent. Additionally, there are some clear differences among animals in what they can taste. Cats, for example, do not respond to sweets due to a deletion in the gene that encodes one of the sweet receptors.

Perception of taste also appears to be influenced by thermal stimulation of the tongue. In some people, warming the front of the tongue produces a clear sweet sensation, while cooling leads to a salty or sour sensation.

Taste Receptors

A very large number of molecules elicit taste sensations through a rather small number of taste receptors. Furthermore, it appears that individual taste receptor cells bear receptors for one type of taste. In other words, within a taste bud, some taste receptor cells sense sweet, while others have receptors for bitter, sour, salty and umami tastes. Much of this understanding of taste receptors has derived from behavioral studies with mice engineered to lack one or more taste receptors.

The pleasant tastes (sweet and umami) are mediated by a family of three T1R receptors that assemble in pairs. Diverse molecules that lead to a sensation of sweet bind to a receptor formed from T1R2 and T1R3 subunits. Cats have a deletion in the gene for T1R2, explaining their non-responsiveness to sweet tastes. Also, mice engineered to express the human T1R2 protein have a human-like response to different sweet tastes. The receptor formed as a complex of T1R1 and T1R3 binds L-glutamate and L-amino acids, resulting the umami taste.

The bitter taste results from binding of diverse molecules to a family of about 30 T2R receptors. Sour tasting itself involves activation of a type of TRP (transient receptor potential) channel. Surprisingly, the molecular mechanisms of salt taste reception are poorly characterized relative to the other tastes.

Control of Food Intake

Salivary Glands and Saliva


Are Your Differences TOO Different or Just Right?

&ldquoAre we just too different?&rdquo This is a question many couples ask themselves as the initial high of romantic love wanes. Take Dorothy and Leah (fictional composites of couples I&rsquove seen in my private practice). They&rsquove been together for a year, living together for two months. Recently, Dorothy has started thinking she&rsquos made a big mistake. Although she&rsquos never felt more &ldquoat home&rdquo with someone, she and Leah are very different.

Dorothy enjoys outdoor sports like kayaking and biking whereas Leah likes indoor sports like cheering her favorite teams on a flat screen TV. Dorothy looks forward to gourmet meals whereas Leah prefers food that materializes from a box, bag or can. Dorothy gets excited by art museums and exotic travel whereas Leah swoons over YouTube videos and exotic travel down the imported food aisle of the local grocery store. In addition to these overt differences, these two women have widely diverging &mdash even opposing &mdash needs for touch, closeness, and emotional expression.

Wondering if differences are too divergent can eat away at a couple&rsquos faith in their connection, stalling their ability to make a decision about whether to move forward or call it quits. As a couple steps out of their comfort zone into greater interdependence and commitment, fears of enmeshment or abandonment arise. The uncertainty and vulnerability that accompanies taking the next step in a relationship, such as moving in, getting engaged, getting married, or researching baby names &mdash not necessarily in that order &ndashcan cause couples to seek answers, guarantees, clues to the future, and proof that their relationship either will &mdash or won&rsquot &mdash work.

There&rsquos no hard and fast way to assess whether differences are too different or workable. What matters more than actual differences is a couple&rsquos capacity to honor one another as they are while being open to each other&rsquos influence. Often, this balance between acceptance and a willingness to change takes time to achieve, but even a willingness to learn to honor each other&rsquos differences can help a relationship grow resilient and flexible. A more predictive question than &ldquoAre we just too different?&rdquo might be &ldquoCan we tolerate each other&rsquos differences while remaining curious about them?&rdquo

Over time, true, deep curiosity allows partners to learn more, understand more, and organically shift their perspectives. In a balanced relationship where power is shared and respect is mutual, heartfelt curiosity can help both members of a couple grow up into being more inclusive in their views, attitudes and behaviors. The Dorothys of the world learn to honor couch sitting and dinners from boxes and the Leahs of the world learn to appreciate gourmet food and art. More importantly, the Dorothys and Leahs of the world learn to stretch their comfort zones to understand, value and wholeheartedly attempt to meet their partners emotional needs.

Often, it&rsquos the lack of true connection with a partner that can make differences between you and her (or him) feel like &ldquodeal breakers&rdquo. One way to build a stronger foundation is by learning to communicate with your partner in a way that allows both of you to express yourself without feeling judged. This can lead both of you to change and adapt your attitudes, relational approaches and behaviors willingly rather than out of a sense of obligation.

There are many books on simple communication strategies for couples and even just one of two sessions with a coach or therapist who specializes in effective communication can help you learn some basic (though not necessarily easy) practices such as reflective listening, using vulnerable vs. defensive language, and containment. Setting a timer, designating who is going to listen and who is going to talk for a few minutes, then switching roles, can help both partners express concerns less defensively. Try to just listen when you&rsquore the listener so your partner feels safe speaking. Say &ldquothank you for sharing&rdquo after your partner has finished. Share what touched you about what they revealed to reinforce the message that you care. Small adjustments to the way you speak, listen and respond can set the stage for deeper sharing and more honesty.

You&rsquore bound to feel &ldquotoo different&rdquo at some point in your relationship. It takes patience, curiosity and open communication to assess whether your differences are too different &mdash or just right.


Positive Psychology and the Chinese Mindset

Yee-Ming Tan, MAPP, provides executive coaching services and leadership development training to senior executives. Recent clients include: Cathay Pacific, Goldman Sachs, and Microsoft. Yee-Ming also publishes a series of tools, RippleCards, for people who choose to cultivate greater well-being in their lives.

In my workshops, I find that Chinese executives are receptive to positive interventions but something about Chinese culture gets in the way of their pursuit of happiness, and until these concerns are addressed, their pursuit of happiness will be a futile endeavor. Two weeks ago, I facilitated a resilience workshop for a group of middle managers from the logistics industry in Beijing, and last week, a stress management workshop for executives in Shanghai. I thought I’d share some insights from these two workshops, and in general about the psychological well-being of Chinese professionals.

Geert Hofstede in his work “Culture’s Consequences,” probed deeply into the differences between individualist cultures and collectivist cultures. An individualist culture encourages individual preferences and dynamics in a society, setting the individual ego up against others, while a collectivist culture, of which Chinese culture is one, stresses the collective interest and downplays personal preferences and interests. According to Chinese culture, the relationship between the individual and the collective is intimately linked with social norms, which are tied to value systems shared by the majority. The following concepts may help you understand the causes of stress and adversity from the perspective of Chinese people.

Guanxi literally means “relationships.” It is the network of relationships among various parties that cooperate together and support one another. It can be seen as who you know and what they perceive to be their obligation to you.

Reciprocity 互惠

This concept can be defined as individuals and groups exchanging favors. People will ask for favors from those with whom they have guanxi. The recipient of a favor or gift will feel obliged to return the favor. It sometimes causes unnecessary stress and strain on a relationship because we do things out of “have to” rather than “choose to” or “love to” motivation. Every time I share something with my neighbor, some fruit or homemade cakes, my neighbor will reciprocate the next day with something of equivalent perceived value. My generosity actually put them on the spot, scrambling to find something to reciprocate!

Sense of social image in front of another person is perceived as critical for many in China. Losing face, saving face and giving face is very important. A person can lose face as a result of failure or not achieving goals, losing his or her temper, confronting an individual or putting people on the spot or acting in an arrogant manner or failing to show appropriate respect.

People will go to great length to remain polite and courteous in order to maintain surface harmony, even when it is false harmony. Disagreement is not expressed in fear of disrupting surface harmony so intermediaries are often used to deliver bad or unpleasant news. Confrontations are to be avoided. Disagreeing or asserting oneself, especially in front of someone perceived to be higher in the hierarchy of relationship, is seen as being rude and disrespectful.

Status consciousness 等级观念

Chinese people are very status conscious. Hierarchical structures of the society and business organizations are based on a strict observation of rank where the individual is subordinate to the organization, to the elders, to the majority, and so on.

Culture in Action

Here are a few typical stressful events that emerge from these cultural qualities:

  • You are going to Paris on a business trip, and a business associate wants you to help her buy three Hermes handbags. You have a tight schedule and don’t want to spend your spare moments running around Paris looking for these bags. You feel you can’t say no because it would upset your business associate and this might affect the working relationship in the future. However, you feel bad because you really don’t want to do it, and you resent the fact that the business associate put you in this situation.
  • Your peer in the U.S. headquarters asks you for some product information that is not a priority of the operation in China. You are already overloaded with your work and do not have any spare resources to meet this request. You tell your counterpart, “I will try,” when you know there is not a chance you can deliver because you don’t like to turn down a request. You are also stressed out because you are put in the position of having to say no, repeatedly. You wonder why your counterpart makes things difficult for you. He should be more considerate.

Given this cultural context, it is no wonder that there isn’t a word for assertiveness in the Chinese language. It is often translated as decisive, over-confident, aggressive, and it is viewed as a socially undesirable trait. In the Chinese mindset, it never occurs to people that they are equal partners in such interaction, that one can make a request and the other can turn it down politely or at least express his difficulties so both parties can jointly figure out a solution. Expressing oneself authentically is especially hard for fear of upsetting the surface harmony and damaging the relationship.

Breaking Through Cultural Mindset Barriers

I discovered an effective approach to break through these cultural mindset barriers. While it is important to understand the cultural context, it is not so useful to focus on challenging these ingrained beliefs. Instead, I introduce concepts from psychology like locus of control, self-efficacy, and assertiveness as a starting point to explore mindset barriers and then introduce the ABCDE resilience building technique as described in The Resilience Factor

Individuals with an internal locus of control attribute the cause or control of events to something inside of themselves (they are the captains of their ships) while individuals with an external locus of control believe that they are not in control of their environment and the outcomes are instead controlled by luck, destiny, or the power of others. Just knowing this concept alone helps the executives to feel more empowered. They also begin to realize that they tend to operate from an external locus of control in events they found stressful, and if they shift the control inward to take charge, they start to see options and solutions to their difficult situations.

This approach seems to work well. It does not directly challenge the deeply ingrained beliefs about the uniqueness of Chinese culture. Instead it helps them integrate the tools from modern psychology. These executives welcome the opportunity to empower (another concept difficult to translate into Chinese) themselves and be better equipped psychologically to deal with the stresses in their lives.

Culture may be a collective programming of the mind, but I hold the view that human nature is infinitely malleable and that human beings can choose the ways of life they prefer. Here in China, many people do operate according to their cultural conditioning, but the majority of people I encounter in China do want to be happier. They welcome the know-how from positive psychology to help them become more resilient.

References:
Davis, J. S. (2009). Frames of Meaning for Life. A summary of the presentation by Professor Yong-Lin Moon at the IPPA World Congress about cultural differences in perspective.

Trompenaars, F. (1996). Resolving international conflict: Culture and business strategy. Business Strategy Review, 7, 51-68.

Whetten, D. & Cameron, K. (2007). Developing Management Skills (7th ed, pp. 54-55, 82-84, 105). Upper Saddle River, NJ: Pearson / Prentice-Hall.

This book contains a locus of control instrument. It also discusses cultural differences in locus of control, as well as the pros and cons of both internal and external loci of control in business settings.

Images
The image of the Third Thinking Workshop in China is used with permission from Yee-Ming Tan, who took it during one of her workshops.
The Hexie or Harmony calligraphy was done by Mr. Wang Man Li.


Treatments

In the earliest stages of behavior modification therapy, pedophiles may be narrowly viewed as being attracted to inappropriate persons. Such aversive stimuli as electric shocks have been administered to persons undergoing therapy for pedophilia. This approach has not been very successful.

In 2002, the most common form of treatment for pedophilia is psychotherapy , often of many years' duration. It does not have a high rate of success in inducing pedophiles to change their behavior.

Pedophilia may also be treated with medications. The three classes of medications most often used to treat pedophilia (and other paraphilias) are: female hormones, particularly medroxyprogesterone acetate, or MPA luteinizing hormone-releasing hormone (LHRH) agonists, which include such drugs as triptorelin (Trelstar), leuprolide acetate, and goserelin acetate and anti-androgens, which block the uptake and metabolism of testosterone as well as reducing blood levels of this hormone. Most clinical studies of these drugs have been done in Germany, where the legal system has allowed their use in treating repeat sexual offenders since the 1970s. The anti-androgens in particular have been shown to be effective in reducing the rate of recidivism.

Surgical castration is sometimes offered as a treatment to pedophiles who are repeat offenders or who have pleaded guilty to violent rape.

Increasingly, pedophiles are being prosecuted under criminal statutes and being sentenced to prison terms. Imprisonment removes them from society for a period of time but does not usually remove their pedophilic tendencies. In 2002, many states have begun to publish the names of persons being released from prison after serving time for pedophilia. Legal challenges to this practice are pending in various jurisdictions.


Thinking

Two themes have been most prominent in the gestalt treatment of thinking: one concerns the occurrence of understanding or insight the other, the occurrence of processes of discovery. Of these, understanding is the more general phenomenon it occurs often in the absence of the discovery of solutions and provides a basis for them. To understand is to have an awareness of a required relation between immediately given facts. When such understanding is present the relation is experienced as “following from” the given facts—that is, the nexus between them is itself understandable. Given two premises and a conclusion the latter either develops out of the former or contradicts it. Such relations, which have the character of “if A, then B and only B,” contrast most strongly with the association between heterogeneous facts the terms and their relation form a unit all parts of which are dependent upon one another. An understandable relation between two terms is not a third term added to them given any two of the parts the third is demanded. The relation in question is thus a dependent part-property of a whole. The first point of the gestalt account of thinking is that understanding or insight in the sense here described per vades human experience and that no thinking is possible in its absence. Understandable relations have the character of requiredness, or “oughtness.” This is the outstanding trait of facts of aesthetics and ethics as well as of logic in each of these realms requiredness is relationally determined, being a property of an interdependent situation. Thus, the concept of value becomes related to that of organization. One observes an important aspect of requiredness when a situation is incomplete in such cases the gap has particular properties that produce tendencies toward completion in accordance with the character of what is given. Gestalt theorists have sought to explore the conditions of requiredness out of a concern for establishing whether there are ethical invariants these invariants would provide an alternative to a relativistic foundation for ethics.

Connections between concrete empirical events are not, however, understandable in the same way as logical connections. That heavy bodies fall when dropped cannot be automatically deduced the underlying functional connections are hidden, and conclusions concerning them must be based on induction. Accordingly, the prevailing tendency of psychology since David Hume has been to stress the role of purely factual regularities in our knowledge of causal action. Gestalt psychology proposes that empirical events too are often related in ways that are structurally simple and that these relations facilitate the learning of the causal interplay. Duncker (1935) has pointed out that there are farreaching correspondences between the phenomenal properties of causes and of their effects. They are often coincident in space and time and thus stand out against a background of more indifferent events. A sound is heard where an object is seen to strike a sheet of paper acquires a crease where it is folded fire burns shortly after a match is applied to an object. There are also pronounced similarities of content and form between cause and effect. The shape of a footprint corresponds to that of a shoe a hot object transmits heat to its surroundings a wet object moistens things in contact with it. Further, variations of cause often produce parallel variations of effect. The accelerated rhythm of the motions of knocking parallels the changing rhythm of the sounds produced the stronger the push one applies to an object, the faster and farther it moves. These relations make possible a systematic ordering of empirical facts, although the relations are not fully intelligible.

Gestalt psychology treats productive thinking as the development of new structures or organizations. The discovery of a solution begins with a situation and a goal that cannot be directly reached what requires explanation is how the gap is bridged. The principal point of the gestalt account is that the operations of thinking do not occur piecemeal but are effects of organization and reorganization. First, thinking is a directed process based on an initial view of a coherent but incomplete situation. The direction arises from the problem itself—more accurately, from the gap between the view of the given conditions and the goal. The urge to over come the difficulty creates the tensions and vectors that lead to a re-examination of the materials and of the problem. This formulation asserts a distinction between an aggregate of independent facts and a structure there can scarcely be productive thinking when the possibility of grasping a principle is excluded. Further, under the stress of the initially incomplete view the material is reorganized parts and relations previously unnoted or in the back ground emerge, often abruptly, analogously to the reversal of perceptual forms, and parts previously separated become united. These changes in the meaning of parts, including changes of relation and direction, produce the transition to a new view that has greater coherence. From the outset the steps are guided by the main lines of the problem and are taken with reference to each other. The operations of centering and recentering, of separating fundamental from peripheral features, spring from the whole character of the situation or from a structural view of the gap and its stresses. These formulations account for the fact that the organization of the problem situation often changes before the more detailed steps can be elaborated.

The preceding account represents only some first steps toward a theory discovery. There is at this time no satisfactory explanation of the occurrence of sudden reorganization that favors the emergence of a solution. Reference to understanding or insight does not constitute an explanation, since these are descriptive terms that do not clarify the underlying operations.

The treatment of thinking in gestalt psychology was formulated in explicit opposition to the associationism of the early decades of the twentieth century, which excluded reference to understandable relations and, indeed, to relations generally. Associationism postulated that connections between psychological events are neutral and devoid of meaning—that is, given events A and B, nothing in the character of A points to B rather than to any other event. Associationism also excluded reference to operations of organization and reorganization. Accordingly, it described the emergence of changed views and of new solutions in terms of the reshuffling of associative chains, the components of which remain constant. This approach defined knowledge as a repertoire or inventory of specific data and of connections between them. From the standpoint of gestalt theory the striking powers of thinking seem to disappear under the associationistic treatment. Thinking involves functions different from association, although it draws some of its materials from associations. No purely contingent associations, however strong, can provide understanding.

Another point at issue is the role of past experience in the process of solution. Associative accounts treat thinking mainly as a product of past experience. Gestalt theory does not question the contribution of past experience but asserts that thinking involves more than recall. Since innumerable associations lead out from a given problem situation, a solution cannot arise on the basis of associative reproduction alone. Some selection must take place. Further, it is questionable whether the products of past experience enter into thinking in unaltered form they may have to be reorganized in order to meet the demands of the problem. Nor may one neglect the fact that recalled material is itself often the product of understanding that has occurred in the past reference to past experience does not exclude understanding. Finally, the solution of a problem may not even require recall of added facts this is the case when the appropriate facts are given as part of the problem. Conversely, one may fail to solve a problem under these conditions.

In recent decades a revised associationism has attempted to encompass the organized character of thinking operations within the framework of a stimulus-response analysis. Realizing the inadequacy of the earlier one-stage associative paradigm, it has postulated the presence of intervening mediational processes, which would bridge the gap between apparently noncontiguous events (e.g., Osgood 1953). The inferred mediating events in question are assigned the same properties as overt stimulus-response connections. Their function is to introduce further associative links between overtly observable connections and, thus, to provide a replacement for cognitive operations. This elaboration admits no organizing principle other than that of association it continues to adhere to a linear model of thinking operations, treating them as chains of stimulus-response connections. It is too early to evaluate this effort at this time it is not clear how it can accommodate the presence of rules or principles, the seeing of given materials in a new way, or the achieving of a view in terms of which one can understand a mass of detail.

The psychology of thinking touches upon questions of education, of teaching and learning, since there is no sharp separation between discovering a solution and understanding it when it is explained. This aspect has been treated most extensively by Wertheimer in Productive Thinking (1945). In this connection he has contrasted learning by drill and by understanding. A pupil may memorize the steps of a solution and reproduce them without error, but if he has failed to understand, he will become helpless or make senseless errors when the details of the problem are changed. If he has understood the relation of the steps to the goal, he will be able to adapt the solution to a new set of conditions that retains the essential structural relations. Indeed the ability to produce the necessary transpositions constitutes an operational test of understanding (see, e.g., Katona 1940). In teaching and learning, as in the discovery of a solution, to leave out the relation of a given fact to the whole is to take away the essentials of thinking. Educational practices that stress piecemeal preoccupation with details, exactness of repetition, and instantaneous response tend to be inimical to thinking. [SeeLearning Problem solving Thinking.]


Watch the video: Μαθησιακές Ευκολίες - Αυτισμός: Ποια είναι η αιτία εκδήλωσής του;. Ειδικός Παιδαγωγός (August 2022).