The proposed experiment would involve participants randomly assigned to a control group or a group consuming caffeine. The task required of each group would be a standardized cognitive test that measures reaction time, focus, and accuracy. Participants would also be asked to rate their alertness before and after completing the task. The results of the experiment would then be compared to measure the effect of caffeine on cognitive performance.
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Design an experiment to investigate the effects of caffeine on cognitive performance.

### Response:
The proposed experiment would involve participants randomly assigned to a control group or a group consuming caffeine. The task required of each group would be a standardized cognitive test that measures reaction time, focus, and accuracy. Participants would also be asked to rate their alertness before and after completing the task. The results of the experiment would then be compared to measure the effect of caffeine on cognitive performance.
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**Experiment Title:** Investigating the Effects of Caffeine on Cognitive Performance

**Objective:**

To determine whether caffeine has a positive or negative impact on cognitive performance, specifically attention, memory, and reaction time, in a controlled laboratory setting.

**Hypothesis:**

Based on existing research, we hypothesize that moderate levels of caffeine consumption will improve cognitive performance, particularly attention and memory, while excessive caffeine consumption will have a negative impact on cognitive performance.

**Materials:**

* 100 healthy adults (ages 18-30)
* Randomized order of caffeine and placebo groups
* Standardized cognitive tasks (attention, memory, reaction time)
* Caffeine tablets or energy drinks
* Placebo tablets or sugar water
* Measuring equipment ( stopwatch, computer software)

**Experimental Design:**

This is a between-subjects, repeated-measures design.

1. **Preparation Phase:** Participants will be randomly assigned to either a caffeine group or a placebo group.
2. **Caffeine and Placebo Administration:** Participants in the caffeine group will receive a standardized dose of 200mg of caffeine (1-2 cups of brewed coffee) 30 minutes before cognitive task administration, while participants in the placebo group will receive a placebo (sugar water).
3. **Cognitive Tasks:** Participants will complete a series of standardized cognitive tasks, including:
	* Attention task: Identifying and counting blocks in a visual array.
	* Memory task: Completing a memory game (e.g., memory matrix).
	* Reaction time task: Reacting to visual stimuli.
4. **Data Collection:** Participants will complete each cognitive task twice, with a 30-minute break between tasks. The data will be collected using standardized equipment.
5. **Post-Experiment:**

* **Post-Experiment Questionnaire:** Participants will complete a standardized questionnaire to assess their self-reported experience of caffeine and cognitive performance.
* **Physiological Measurements:** Participants will undergo physiological measurements (e.g., heart rate, blood pressure) at baseline and post-experiment to assess any potential effects of caffeine on cardiovascular and respiratory systems.

**Experimental Timeline:**

* **Preparation Phase:** 1 week
* **Data Collection:** 2 days
* **Post-Experiment:** 1 day

**Sample Size:**

To ensure adequate power, we will recruit 100 participants. The sample size will be increased to 200 participants if the results show a significant effect of caffeine on cognitive performance.

**Inclusion Criteria:**

* Healthy adults (ages 18-30)
* No known medical conditions that may affect cognitive performance
* No history of anxiety, depression, or other neurological disorders
* Ability to complete cognitive tasks and administer the questionnaire

**Exclusion Criteria:**

* Pregnant or breastfeeding women
* Participants with a history of caffeine sensitivity or addiction
* Participants with a history of neurological disorders (e.g., Parkinson's disease, multiple sclerosis)

By following this experimental design, we aim to provide a robust investigation of the effects of caffeine on cognitive performance, shedding light on the potential benefits and limitations of this widely consumed stimulant.