Cognitive Psychology - IBP Year 1 - Workgroup notes

Workgroup 1

• Experiment 1: Signal detection (decide whether a suspect is in the line-up)

- Data:

                             Yes                            No

Signal present        Hits                            Misses

Signal absent         False alarms               Correct rejection     

- The things that prevent us from detecting a signal is referred to as noise.

- Sensitivity = the ability to distinguish a signal from noise.

- Criterion= our tendency to detect a signal, regardless of whether it is really there or not.

- Intern response > criterium: ‘yes’        Hits and false alarms

Intern response < criterium: ‘no’            Correct rejections and misses

- Decisions whether a signal is present depend on the strength of the signal itself and on the characteristics of the person doing the detecting.

• Experiment 2: Mental rotation 3D (mentally rotate 3D-objects to decide whether they are similar)

- When our mental representation of an object is bigger at a certain point of time, it is easier to answer questions about details of this object.

- There is a strong relation between the degree of mental rotation that is necessary and the time it takes to make a judgement about an object’s similarity to another.

• Experiment 5: Attentional blink

- During attentional blink experiments, participants usually don’t have any trouble reporting the first target. However, whether participants perceive the second target as well, depends on the time interval between the first and the second target. An explanation to this is that the working memory opens and closes when encoding information, which takes time.

• Experiment 6: Simon effect

- The Simon effect is aboutirrelevant location information and it’s relation to reaction time and accuracy. The experiment asks the subjects to press C whenever they see an orange block appearing and M whenever they see a blue block. 

- The reaction time is apparently faster when the location of the stimulus corresponds with the location of the reaction; Simon’s hypothesis. 

- An alternative hypothesis is the direct neural link hypothesis: Stimuli appearing in the right visual field will go to the left hemisphere that is operating the left hand to press the button. 

- We tested the Simon effect by testing whether having your hands crossed makes a difference.

- We found that the main effect of arm position was significant; the main effect of congruence was also significant, yet the interaction between arm position and congruence was not significant. So; the effect of congruence is not different for straight arms compared with crossed arms, meaning the direct neural link hypothesis is rejected in this experiment.

• Experiment 7: Stroop effect

- We have trouble to name the ink colour of the word when the word states another colour.

- We were instructed to do this experiment at home, because we ran out of time.

Workgroup 3

• Experiment 3: Balance Scale Task

- This experiment included a reasoning task. We were asked to divide a number of weights among the containers on both sides of a balance scale. Then we had to predict what would happen on the scale; to which side it would lean.

- To which side the balance scale leans, depends on the number of weights on each side and the distance between the weights from the middle of the scale. There are four possible rules people tend to use during the balance scale task. 

• Experiment 4: Short-term memory (The research report is about this experiment.)

- The theory is that our phonological loop has a capacity of seven plus or minus two. During this experiment, we are going to test this rule.

- In this experiment, we test the following hypotheses: Short words are easier to remember than long words. And secondly, words with letters with different sounds are easier to remember words with letters with similar sounds.

- The guidelines for the research report can be found on Blackboard. Notice that the template is out-dated and we can use pages 3-6 for the body part of the report (introduction, methods, results and discussion) instead of only pages 2 and 3. Page 1 must contain the title (see the template), page 2 the abstract of a maximum of 100 words and page 7 contains the references.

Workgroup 4

Experiment 8: Lexical Decision Task

- People use the context in which an object is located in order to identify the object.

- Top-down processes also influence word recognition. We for example do not recognize PWEOR as a word (power) whereas we are able to read: I CULOD UDRESNANTD (I could understand).

- Semantic primingtasks make us of our ability to recognize the word ‘dog’ faster when the word ‘cat’ is primed, than the word ‘apple’; because the latter isn’t a word that belongs to the same category.

- During the lexical decision task we were instructed to identify words as being a normal English word or a nonsense word as fast as we could. We tested whether we were quicker to recognize English words of which the word category was primed in our memory by another word.

• Experiment 9: Sentence Verification

- Knowledge is stored in the form of semantic networks. The idea is that the greater the semantic distancebetween two representations in our memory, the longer it takes us to reach the one from the other.

- Networks are arranged according to the hierarchical structure: If an item is found under one concept, which is itself nested within another, the original item belongs to both higher-level concepts.

- Within networks, the principle of inheritance applies: Features are only stored once and as high as possible in the hierarchy.