Zombie Fud

Hack 77. See a Person in Moving Lights (2)

As with the common fate demos [Hack #76] of how we group objects by their behavior over time, you can remove the effect by pausing the movies. This information only makes sense when it is moving (shame we can’t have animations in the book, really), which is why Figure 8-4 (a frame of the first movie) looks more like a random star constellation than a human figure.

The vivid impression of a walking human shows that we are able to integrate the correlations of the light points and match them to some kind of template we have developed for moving humans. It is orientation-specific, by the way. Watch the video upside down (it’s easier if you have a laptop), and you won’t see anything resembling human motion at all.

And we don’t perceive just abstract form from the moving lights. The demo at http://www.bml.psy.ruhr-uni-bochum.de/Demos/BMLwalker.html, shown in Figure 8-5, allows you to vary the gender, direction, weight, mood, and energy levels of the walker using the sliders on the left.

You can tell if the moving lights are from a heavyset man who’s happy or if they are from a medium-build woman who is slightly afraid. All just from way the lights move.

Taken from : Mind Hacks

Hack 77. See a Person in Moving Lights

Lights on the joints of a walking person are enough to give a vivid impression of the person, carrying information on mood, gender, and other detailsbut only while the person keeps moving.

Visual perception has special routines for grouping things that move along together into single objects [Hack #76] . That’s why we see cars as cars and not a collection of wheels, glass, and side-view mirrors just happening to travel along in the same direction. That’s all well and good, but humans live not just in a world of objects like trees and cars, but a world full of people. Given how social we are, and how tricky other people can be, it’s not surprising we also have specialized routines for grouping things that move like people together into single objects too. Looking at only a constellation of moving points of light attached to knees, elbows, and other parts of the body, we a get vivid perception of a person, a perception that doesn’t exist at all when the points of light are still.

8.4.1. In Action
Open up your browser and point it at http://www.lifesci.sussex.ac.uk/home/George_Mather/Motion/BM.HTML1 or http://www.at-bristol.org.uk/Optical/DancingLights_main.htm (both are QuickTime movies). What do you see?

Both are just points of light moving in two dimensions. Yet the first is clearly a person walking, and the second obviously two people dancing, fighting, and otherwise performing.

Taken from : Mind Hacks

8.3.2. How It Works

The gestalt grouping inferences are so preconscious and automatic that it’s hard to imagine perceiving a world that the brain hasn’t organized into objects. There’s something very clever going on here; we are taking in very little information (only how the pattern changes over time), yet, in combination with an assumption that accidental correlations of visual patterns are unlikely, we construct a compelling perception of an object. In these demos, you just can’t ignore the object. You are utterly unable to make yourself see a moving collection of dots instead of the shape in motion because the construction of the object is happening before the level of consciousness.

Common fate can lead to some sophisticated inferences. “Kinetic Depth” (http://www.biols.susx.ac.uk/home/George_Mather/Motion/KDE.HTML; a QuickTime video), just from a collection of moving lights, allows you to see an object with three-dimensional depth moving in a particular way. In this case, the pattern of dots causes you to see a sphere rotating on its axis.

What’s really cute about this video is that there’s an ambiguity in the visual informationyou can see the sphere rotating in one of two ways. Your visual system makes a choice for you, and you see some of the dots moving behind some of the others, which move in the opposite direction. The set you see as “in front” determines the direction in which you see the sphere rotating. If you watch for a while, your perception will switch and you’ll see it reverse. You don’t need to make any effort to for this to happen; it occurs naturally, probably due to some kind of adaptation process. Since you see the sphere rotating in one particular direction, the neurons that represent that perception will be active. Over time, they actively tune down their response, and the neurons that code for the other apparent rotation can now dominate. This kind of gain control [Hack #26] plays a similar role in motion aftereffects [Hack #25], in which neurons that are active for particular directions of movement down-regulate after being consistently stimulated and neurons active for the opposing direction take over and dominate our perception when the consistent moving stimulus is removed.

Taken from : Mind Hacks

8.3.1. In Action

“IllusionMotion CaptureGrouping” (http://psy.ucsd.edu/chip/illu_mot_capt_grpng.html; a Real video requiring Real Player) demonstrates just how completely your perception of a single item is altered by global context and common fate. Watch the video for at least 30 seconds. At first you see just a dot blinking on and off next to a square. But then other dots are added in the surrounding area, and as the first dot blinks off, they all shift right. Now your unavoidable impression is of the first dot moving behind the square. The appearance of the other dots, and their behavior, gives your visual system correlations that are just too strong to ignore. The single dot is still blinking on and offyou just can’t see it like that any more.

“A Time Gestalt Principle Example: Common Fate” (http://tepserver.ucsd.edu/~jlevin/gp/time-example-common-fate; a Java applet),1 shown in Figure 8-3, is an interactive demonstration of how your visual system deduces the shape of objects from movement, without any color or shading clues to help out.

You see a shape with a static-like texture moving across a similarly randomized background. Click anywhere in the image to start and stop the demo. Frozen, there is no pattern to see; you see just a random mess. This is the real force of common fate. The correlations exist only across time, in movementit’s only when the demo is moving that you can see an object among the noise.

Taken from : Mind Hacks

Gestalt principles exist in visual

Gestalt principles exist in visual processing not because they are always right, but because on average, they are useful. They’re good rules of thumb for making sense of the world. It’s not that similar things can’t be separate; it’s more that most of the time they aren’t. Although random coincidences can happen, they are vastly outnumbered by meaningful coincidences.

The world isn’t a mess of disconnected parts, and it’s useful to see the connectionsif you’re hunting an animal, it makes sense to see it as a single gestalt rather than a paw here and a tail there.

8.2.3. End Notes
The gestalt grouping principles are interesting, but are they really useful? Good print or web page design involves easy comprehension, and knowing how the principles can conflict or mislead in your layout helps along the way. James Levin has applied the gestalt grouping principles to web design (http://tepserver.ucsd.edu:16080/~jlevin/gp).

Illustration inspired by Fred Attneave’s demonstrations as used in “How the Mind Works” by Steven Pinker.

8.2.4. See Also
Max Wertheimer was the first to identify the principles in his 1923 paper “Laws of Organization in Perceptual Forms” (http://psy.ed.asu.edu/~classics/Wertheimer/Forms/forms.htm).

As well as the basic grouping principles, which work looking at static objects, others deduce grouping from behavior over time [Hack #76] .

Taken from : Mind Hacks

Proximity

Proximity
We preconsciously group items that are close together, so in the picture you see columns rather than rows or a grid. This principle is the cause of the triangles in the original diagram coming together into two sets and the reason the lone triangle didn’t feel part of either of them.

Similarity
We prefer to group together objects of the same kind. In the example, you see alternating rows of circles and squares rather than columns of mixed shapes.

Closure
There’s a tendency to complete patterns. There’s no triangle in the example pattern, but we see one because the arrangement of the three Pac Man shapes would be completed if one were there.

Continuation
Just as we like to see completed patterns, we like seeing shapes that continue along the same path, smoothly. We see two lines crossing in the example, rather than two arrowheads touching at their points or four lines meeting together.

Hack 75. Grasp the Gestalt

We group our visual perceptions together according to the gestalt grouping principles. Knowing these can help your visual information design to sit well with people’s expectations.

It’s a given that we see the world not as isolated parts, but as groups and single objects. Instead of seeing fingers and a palm, we see a hand. We see a wall as a unit rather than seeing the individual bricks. We naturally group things together, trying to make a coherent picture out of all the individual parts. A few fundamental grouping principles can be used to do most of the work, and knowing them will help you design well-organized, visual information yourself.

8.2.1. In Action
Automatic grouping is such second nature that we really notice only its absence. When the arrangement of parts doesn’t sit well with the grouping principles the brain uses, cracks can be seen. Figure 8-1 shows some of these organizational rules coming into play.1

Figure 8-1. Two groups of triangles that point different ways and a middle triangle that can appear to point either way, depending on which group you see it being part of 2

You don’t see 17 triangles. Instead, you see two groups of eight and one triangle in the middle. Your similarity drive has formed the arrangement into rows and columns of the shapes and put them into two groups: one group points to the bottom left, the other points off to the right.

Each group belongs together partly because the triangles are arranged into a pattern (two long rows pointing in a direction) and partly because of proximity (shapes that are closer together are more likely to form a group). The triangle in the middle is a long way from both groups and doesn’t fall into the same pattern as either. It’s left alone by the brain’s grouping principles.

You can, however, voluntarily group the lone triangle. By mentally putting it with the left-hand set, it appears to point down and left along with the other triangles. You can make it point right by choosing to see it with the other set.

8.2.2. How It Works
The rules by which the brain groups similar objects together are called gestalt grouping principles in psychology. Although there’s no direct German-to-English translation, “gestalt” means (roughly) “whole.” When we understand objects and the relationships between them in a single, coherent pattern rather than as disconnected items, we understand the group as a gestalt. We have a gestalt comprehension of each of the sets of triangles in Figure 8-1, for instance.

Four of the most commonly quoted grouping principles are proximity, similarity, closure, and continuation. An example of each is shown in Figure 8-2.

Figure 8-2. The four most quoted gestalt grouping principles

Proximity

We preconsciously group items that are close together, so in the picture you see columns rather than rows or a grid. This principle is the cause of the triangles in the original diagram coming together into two sets and the reason the lone triangle didn’t feel part of either of them.

Similarity

We prefer to group together objects of the same kind. In the example, you see alternating rows of circles and squares rather than columns of mixed shapes.

Closure

There’s a tendency to complete patterns. There’s no triangle in the example pattern, but we see one because the arrangement of the three Pac Man shapes would be completed if one were there.

Continuation

Just as we like to see completed patterns, we like seeing shapes that continue along the same path, smoothly. We see two lines crossing in the example, rather than two arrowheads touching at their points or four lines meeting together.

When none of these principles apply, it’s still possible to mentally group items together. When you put the middle triangle in Figure 8-1 with one group or the other, it picks up the orientation of the group as a whole. It’s a voluntary grouping that modifies how you see.

Taken from : Mind Hacks

Hack 75. Grasp the Gestalt

We group our visual perceptions together according to the gestalt grouping principles. Knowing these can help your visual information design to sit well with people’s expectations.

It’s a given that we see the world not as isolated parts, but as groups and single objects. Instead of seeing fingers and a palm, we see a hand. We see a wall as a unit rather than seeing the individual bricks. We naturally group things together, trying to make a coherent picture out of all the individual parts. A few fundamental grouping principles can be used to do most of the work, and knowing them will help you design well-organized, visual information yourself.

8.2.1. In Action
Automatic grouping is such second nature that we really notice only its absence. When the arrangement of parts doesn’t sit well with the grouping principles the brain uses, cracks can be seen. Figure 8-1 shows some of these organizational rules coming into play.1

You don’t see 17 triangles. Instead, you see two groups of eight and one triangle in the middle. Your similarity drive has formed the arrangement into rows and columns of the shapes and put them into two groups: one group points to the bottom left, the other points off to the right.

Taken from : Mind Hacks

Chapter 8. Togetherness

8.1. Hacks 75-80
What makes “this” a word, rather than being simply the adjacently written letters t, h, i, s? Or, to ask a similar question, why should we see a single dog running across a field rather than a collection of legs, ears, hair, and a wet nose flying over the grass? And why, when the dog knocks us over, do we know to blame the dog?

To put these questions another way: how do we group sensations into whole objects, and how do we decide that a certain set of perceptions constitutes cause and effect?

It’s not a terribly easy problem to solve. The nature of causality isn’t transmitted in an easy-to-sense form like color is in light. Rather than sense it directly, we have to gues. We have built-in heuristics to do just that, and these heuristics are based on various forms of togetherness. The word “this” hangs together well because the letters are in a straight line, for example, and they’re closer to one another than the letters in the surrounding words. Those are both principles by which the brain performs grouping. To take the second question, we see the parts of the dog as a single animal because they move together. That’s another heuristic.

This recognition acuity lets us see human forms from the tiniest of clues, but it alsoas we’ll see in [Hack #77] is not perfect and can be duped. We’ll see how we can perceive animacythe aliveness shown by living creatureswhere none exists and how we can ignore the cause in cause and effect. Sometimes that’s the best way to find out what our assumptions really are, to see when they don’t quite match what’s happening in the real world.

Taken from : Mind Hacks

7.6.3. In Real Life

There’s a way to hack this habit bias, and it’s well-known to advertisers. If people generally stick with what they know, the most important thing you can do is get them to start off with your product in the first place (hence the value of kids as a target market). But you can make use of the bias: people choose based on what they did before, so it is more effective to advertise to influence what they choose rather than how they feel about that choice. Even if there’s no good reason for someone using your product in the first place, the fact that they did once has established a strong bias for them doing so again. A computer user may prefer one browser, but if another one comes bundled with her new operating system, we can bet that’s what she’ll end up relying on. You may have no rational reason for choosing Brand A over Brand B when you buy jam, but if the manufacturers of Brand B can get you to try it (maybe by giving you a free sample or a special offer), they’ve overcome the major barrier that would have stopped you from buying it next time.

Status quo bias works for beliefs as well as behaviors. In many situations we are drawn to confirm what we already know, rather than test it in a way that might expose it to be false [Hack #72] .

It’s an experience I’ve had a lot when debugging code. I do lots of things that prove to me that it must be the bug I first think it is, but when I fix that bug, my code still doesn’t work.
It’s not just me, right?
T.S.

Taken from : Mind Hacks