Exam 9: Multi-Group Design: Im Feeling Hot, but Is the Earth Hot, Too

Use the following to answer questions Scenario II Scenario II is based on fabricated data inspired by the following study: Black, J. E., Isaacs, K. R., Anderson, B. J., Alcantara, A. A. & Greenough, W. T. (1990). Learning causes synaptogenesis, whereas motor activity causes angiogenesis, in cerebellar cortex of adult rats. Proceedings of the National Academy of Science, 87, 5568-5572. Experience and Brain Plasticity Study The purpose of this study was to examine how various types of motor experiences affect neuronal and vascular changes in the brain. To that end, rats were randomly assigned to one of four behavioral conditions. Rats in the inactive control (IC) condition were raised in standard rat cages with minimal access to physical activity. Rats in the voluntary exercise (VX) condition were raised in standard cages with free access to physical activity via an attached wheel. Rats in the forced exercise (FX) condition also participated in exercise, but were forced to do so on a motorized treadmill. Lastly, rats in the acrobatic condition (AC) engaged in physical activity that included learning a skill. Specifically, the AC rats were trained to traverse a series of tightropes that were progressively more difficult. After 30 days in their respective treatments all of the rats were sacrificed and their brains removed. The researchers examined the brains for synapse density and vascular density. ANOVA revealed animals in the AC condition had a significantly greater synapse density than the other treatment conditions. The results also revealed that the VX rats had a significantly greater blood vessel density compared with the IC rats, but not with the FX and AC rats. These results indicate different behavioral experiences have different effects on the brain's morphology. -(Scenario II) Which of the following was a dependent variable in Scenario II?

Juan is interested in his peers' responses in reaction to spiders. He designs an experimental paradigm where he has fake spiders and real spiders and then monitors his peers' fear responses. Based on Juan's design which variable is the independent variable (IV)?

Use the following to answer questions Scenario III Scenario III is based on fabricated data inspired by the following study: Duran, J., Morton, G. & Sikorski, A.M. Poster No. 31. Elucidating the relative concentration of physical activity to memory consolidation and memory retrieval. Faculty for Undergraduate Neuroscience Meeting. San Diego, CA: FUN 2010 Exercise and Memory Study These researchers examined whether acute physical activity could improve the memory retention of recently studied items, and whether memory was differentially affected by the timing of exercise intervention. After studying a list of 40 English-Swahili word pairs, healthy adult human volunteers were randomly assigned to one of three treatment conditions. Participants in the consolidation treatment (CONS) exercised for 20 minutes immediately after studying the word pairs and then worked on a jigsaw puzzle for 20 minutes. Participants in the retrieval condition (RET) worked on a jigsaw puzzle for 20 minutes immediately after studying the word pairs and then exercised for 20 minutes. Participants in the control condition (CONT) worked on a jigsaw puzzle for 40 minutes after studying the word pairs. . In all conditions, participants were tested 40 minutes following the initial study phase. the test phase consisted of presenting the participants with Swahili words and asking them to speak its English translation. Memory was operationally defined by the total number of correctly recalled Swahili words. The results revealed that participants who had exercised immediately after studying the Swahili-English word pairs recalled significantly more words than those in the RET or CONT conditions. These results suggest that acute exercise immediately following learning modulates memory consolidation. -(Scenario III) After their primary analysis, the researchers who conducted the study described in Scenario III counted the number of participants in each treatment condition who recalled 10 or more words. Which statistical test is appropriate to determine whether the number of people who recalled more than 10 words varied across treatment conditions?

To determine if food allergies influences participants' taste pallet, researchers conducted a chi-square test of independence between conditions . Based on this information what was the degrees of freedom in this study?

What is the benefit of having more than two groups or levels of an independent variable?

_____ provides insight into the reliability of a particular measure for a given sample.

To determine if food allergies influences participants' taste pallet, researchers conducted a chi-square test of independence between conditions . Based on this information what was the number of participants in this study?

Dr. Trudeau is in the process of a developing a(n) _____ to help standardize participants' experiences and assist researchers in systematically providing instructions to participants.

Placebo groups are often used in multigroup designs because:

Nita signed up for a medication trial at the local hospital. She was informed that she would be in the group taking a new diet pill and other groups would be taking a new energy pill. Nita began to notice that her clothes felt different, even though the scale showed no difference in her weight. She continued to feel like she was losing weight. At the end of the 6-week trial she was informed by researchers that she in fact was taking a water pill that would have no effect on weight loss. Nita was in the:

Dr. Schubert noted the following results: F(2, 94) = .72, p = .02, eta² = .30. Which of the following numbers represents between-subjects degrees of freedom in this results write-up?

A general rule is that you should have approximately _____participants per condition to yield adequate power to make predictions based on results.

Carmina was developing a study for her introduction to research course and wanted to use a multigroup design. Based on her research question she needs to include a group in which participants believe they are getting some treatment, but in fact are not receiving any treatment. Carmina is considering using a:

Dr. Lumen's recent findings support the notion that his null hypothesis is false. This would suggest that Dr. Lumen's study:

Dr. Schubert noted the following results: F(2, 94) = .72, p = .02, eta² = .30. Which of the following numbers represents the F score in this results write-up?

Dr. Vela is studying comorbid substance use disorders and anxiety disorders among African Americans, Caucasians, Hispanic Americans, and Native Americans between 15 years and 65 years of age. Dr. Vela is using a:

Dr. Schubert noted the following results: F(2, 94) = .72, p = .02, eta² = .30. Which of the following numbers represents within-subjects degrees of freedom in this results write-up?

_____ are statistical tests that allow researchers to test comparisons between groups that are predicted ahead of time.