Perception 3,3

Question 1

One purpose of perception is to inform us about what is out there in the environment?

What is the perception foundations?

Answer 1

Of information from the environment

For visual perception this information is light

Question 2

Diagram of information

explain

Answer 2

Information from the light entering the eye and the electrical signals to the brain is crucial for perceiving any object in the environment

because without it, the object will not be represented in the nervous system

The sequence of events from eye to brain is called bottom up processing

starts at the “bottom” or beginning of the system, when environmental energy stimulates the receptors.

Question 3

What is bottom up processing?

Answer 3

Processing that starts with information received by the receptors. This type of processing is also called data-based processing.

Question 4

What else needs to be involved other than the information from light entering eye?

Answer 4

• perception needs more information than what is provided by activation of the receptors and bottom-up processing.
• Perception also involves factors such as a person’s knowledge of the environment, the expectations people bring to the perceptual situation, and their attention to specific stimuli. This additional information is the basis of top-down processing—processing that originates in the brain, at the “top” of the perceptual system (see Figure 3.10).

Question 5

What is top down processing?

Answer 5

Processing that involves a person’s knowledge or expectations. This type of processing has also been called knowledge-based processing.

Question 6

Diagram of top donw and bottom up processing?

Answer 6

Question 7

Figure 3.11

example of top-down processing involved in perceiving objects

Answer 7

• An example of how top-down processing is involved in perceiving objects is illustrated in Figure 3.11. Depending on whether you interpret the central stimulus as a part of a row or a column, you will either perceive it as the letter S (as part of a row of letters) or as the number 5 (as part of a column of numbers).

Question 8

Infleunce of context has been demonstrated in study by oliva and torrabla 2007

multiple personalities of a blob

Answer 8

• Participants in their study were asked to identify a blurred object in a scene (the “blob”).
• Results showed that even though the “blobs” in all the pictures were identical, they were perceived as different objects (for example, a shoe on a person bending down, or a car or person on the street) depending on its orientation and the context within which they were seen.

Question 9

How does top down processing influence speech perception?

Watching Spanish TV channel

Answer 9

• If you don’t speak Spanish you won’t understand anything the people are saying. In fact, the dialogue will sound like an unbroken string of sound, except occasionally when a familiar word like gracias or casa pops out.
• Your perception will reflect the fact that the sound signal for speech is generally continuous, and when there are breaks in the sound, they do not necessarily occur between words. You can see this in Figure 3.13 by comparing the place where each word in the sentence begins with the pattern of the sound signal.

Question 10

What about when sometime understands Spanish watching this?

vs english

Answer 10

perceives this unbroken string of sound as individual, meaningful words in a conversation. Because of their knowledge of the language, they are able to tell when one word ends and the next one begins, a phenomenon called speech segmentation.

listener familiar only with English and another listener familiar with Spanish can receive identical sound stimuli but experience different perceptions means that each listener’s experience with language (or lack of it!) is influencing his or her perception. The continuous sound signal enters the ears and triggers signals that are sent toward the speech areas of the brain (bottom-up processing); if a listener understands the language, that knowledge (top-down processing) creates the perception of individual words.

Question 11

What is speech segmentation?

Answer 11

The process of perceiving individual words within the continuous flow of the speech signal.

Question 12

Perception of pain is an example of how top down processing influences

Answer 12

perception

Question 13

What model sued in 1950s and 1960s to explain pain?

Answer 13

Direct pathway model

Question 14

How did direct pathway model worked?

Answer 14

pain occurs when receptors in the skin called nociceptors are stimulated and send their signals in a direct pathway from the skin to the brain (Melzack & Wall, 1965). This is a bottom-up process because it depends on stimulation of the receptors

Question 15

What is definition of direct pathway model?

Answer 15

Model of pain perception that proposes that pain signals are sent directly from receptors to the brain.

Question 16

What happened in 1960s that differ from direct pathway model?

Answer 16

researchers began noting situations in which the level and even the presence of pain was affected by factors in addition to stimulation of the skin.

e.g

• athlete who finishes his race despite a broken toe, which he only feels and becomes aware of after the final sprint.
• Or, think about patients who chronically suffer from intense pain despite not having any clear physical damage to their bodies.
• Finally, and perhaps you have experienced this yourself, think about the moments that you started to feel pain only after you saw (and paid attention to) the bleeding wound at the side of your leg.

Question 17

Modern researchers shown that pain can be influenced by?

Answer 17

what a person expects, how the person directs his or her attention, and whether distracting stimuli are present (Wiech, Ploner, & Tracey, 2008).

Question 18

Hospital study surigcal piatents were told what to expect and instructed to relax to alleviate the pain

what is shown?

Answer 18

• the patients requested fewer painkillers following surgery and were sent home 2.7 days earlier than patients who were not provided with this information. Studies have also shown that a significant proportion of patients with pathological pain get real relief from taking a placebo, a pill that they believe contains painkillers but that, in fact, contains no active ingredients (Finniss & Benedetti, 2005; Weisenberg, 1977, 1999). In another study, it was found that the activity of serious gaming (active distraction) could reduce pain behaviour and subjective distress in children undergoing wound care (Nilsson, Enskär, Hallquist, & Kokinsky, 2013).

Question 19

What is a placebo?

Answer 19

A pill or procedure that patients believe delivers active ingredients (usually pain killers), but which contains no active ingredient.

Question 20

Most theories try to explain the pain-reducing effects of placebos highlight the role of expectation.

e.g

Answer 20

• it is possible that when people expect less pain (due to placebos), their attention is refocused on other things than the pain, which, in turn, may cause people to experience less pain.

Question 21

Considering how a placebo works and diverting their attention to other things other than pain

how do expectations operate?

Answer 21

• Operate as a form of cognitive control by influencing and redirecting attention

Question 22

What is cognitive or attention control an example of?

Answer 22

an executive process which involves the prefrontal lobe (note that the term “control” does not necessarily mean that one is conscious of it).

Question 23

Another way without saying expectations without the mediating role of executive attention.

e.g

Answer 23

expectations created by the placebo may stimulate the release of endogenous opioids (a pain reducing neurotransmitter) (Wager, Scott, & Zubieta, 2007).

Question 24

What did Buhle and colleagues 2012 aimed to find out these two possible mechanisms would most unrlie the placebo effect

How did they do this?

Answer 24

• They used a type of reasoning that is often applied in cognitive psychology research, drawing on the fact that we have only a limited set of resources that we often have to share and divide over different tasks or functions.

Question 25

What two things Buhle reasoned?

Answer 25

1. if the analgesic effect of placebo-induced expectations depends on executive attention processes in the prefrontal lobe (explanation 1), then keeping these executive processes busy with another task would lead to a smaller placebo effect.
2. if the placebo effect does not draw on the same limited resources of the prefrontal lobe (explanation 2), then such additional task would not interfere with the (direct) effect of expectation, and may even cause an extra analgesic effect.

Question 26

What does analgesic mean?

Answer 26

Drug to relieve pain

Question 27

How did Buhle set up their experiment?

Answer 27

he task they chose to keep the executive processes busy was a working memory task, requiring participants to judge whether a presented letter was the same or different from the letter presented three trials before (3-back test, see Figure 3.14).

Question 28

What does this figure show on Buhle’s procedure?

Answer 28

• All participants in control session and placebo session on two separate days
• Each session , moderate thermal pain was applied in two blocks and two blocks without WM task
• After each block and after the heat stimulus had returned to baseline
• Aparticipant had than rated their pain that experienced

Question 29

What does this figure show from Buhle’s procedure?

Answer 29

• both the placebo treatment and the WM task produced clear analgesic effects and that these effects were almost perfectly additive
• placebo analgesia did not affect performance on the working memory task.
• analgesic effects of placebos and distraction work via different and separate mechanisms.

Question 30

What did Buhle concluded?

Answer 30

• expectations created by a placebo do not work via the executive attention system in the prefrontal lobe but instead are more likely to directly influence pain perception (thus support for explanation two). The practical implication of these findings is clear, namely that reduction of pain feelings can be achieved best by placebo treatment AND distraction of the person in pain.

Question 31

Important of Chapter 3 examples

Answer 31

• context affects our perception of the blob; how knowledge of speech affects our ability to create words from a continuous speech stream; and how expectation and attention can influence a person’s experience of pain—illustrate that perception is created not only by signals from the environment (bottom-up processing) but also by what the individual brings to it (top-down processing).

Question 32

Humans are better at identifying ambiguous stimuli such as blurred photos because humans

Answer 32

can resolve ambiguities by top-down processing.

The human advantage over computers in identifying ambiguous, degraded, or blurred stimuli is due, in part, to the additional top-down knowledge available to humans.

Question 33

Sofia is fluent in English and German and when she listens to a speaker using either of those two languages, she is able to identify distinct words. However, she has only recently begun learning Hebrew and when she listens to a speaker, she finds it difficult to identify any words, even simple words she recognizes in isolation. Sofia is best described as experiencing issues with

Answer 33

speech segmentation.

When someone has experience with a language, he or she is able to tell when one word ends and the next one begins, a phenomenon called speech segmentation. Without that knowledge and experience, the words seem to blend together.

Question 34

Lucas is helping a friend move and slams his hand between the door frame and a large couch. He continues his labours without seeming to notice it until someone points out that his hand is dripping blood on the newly-cleaned carpet. Suddenly his hand hurts quite a bit. This is most accurately described as reflecting the effects of _____ on pain perception.

Answer 34

Attention

Attention can have an effect on the perception of pain and when a person’s attention is directed away from a painful injury, pain may be lessened.