BIO-4015B Summative Practical Group B

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BIO-4015B Summative Practical Group B. Student number: (Spring 2021) .............................. -------------------------------------------------------------------------------------------------------------- INTRODUCTION -------------------------------------------------------------------------------------------------------------Theoretical preparations before starting to work on the given tasks ? Revise the lectures on ‘VISION’ and ‘NERVE SIGNALLING’ ? Study the lecture on ‘HEARING’ (Self study) as well as the corresponding parts of textbooks on physiology ? Attend the introduction lecture ? Students are allocated to two groups: A and B ? Read and follow the instructions on Blackboard and within the form Practical preparation for using the ‘Practical Workbook’ ? GoTo Blackboard: Course BIO-4015B ? Summative Assessment ? Coursework 2020-21_Reaction Time Practical ”BIO-4015B_Practical_2021_Workbook_Group A” “BIO-4015B_Practical_2021_Workbook_Group B” ? Download the workbook (Word format) and use this form for generating your report o Fill in the student number on page 1 o Use a standard font for filling text boxes (‘e.g. Arial/11-12 pt) o Use the preset boxes for adding: Results/Calculations Figures Discussion/Write-up In case of “mishaps” just download the empty file again ? Calculations can be done by any adequate/available method (Excel, SPSS, Prism/Graphpad) ? Submission of the finished report should be done as ONE single document o Follow the instructions for the submission by Blackboard o Use the following name: ‘Studentnumber_BIO-4015B_Practical_Group A (or B)’ 1 Studentnumber: .................................. -------------------------------------------------------------------------------------------------------------- Practical on Reaction Times -------------------------------------------------------------------------------------------------------------A. General comments on ‘Reaction Times’ and the idea of the practical Reaction time defines the time span between a signal and an output reaction. In the practical we/You measure reaction times upon different stimuli and different output reactions. • Reaction times will be measured/calculated for two different types of signals: o Visual/Ocular signals or o Acoustic signals • Induced reactions will be either o pressing a button with your thumb or o catching a ruler with your fingers • Reaction times are measured for both hands (left and right) and experimental data are given in the form. Left/right hand preference: The preferred dominant hand is self-certified by the test persons and indicated in the workbook Statistical analyses: • The Null hypothesis states for these experiments: “There is no difference between reaction times of both hands” • In order to test this hypothesis, the results of the measurements should be analysed by using statistical methods (t-test) to calculate the probability of the “Nullhypothesis”. B. Reaction times upon an acoustic stimulus (Sound detection; Hearing) Data collection (Demonstration in Introduction sessions): • For measuring acoustic reaction times, a computer-based system is used: ‘BioPAC’. • The proband is using headphones and ‘click’ sounds are heard in different “click” sound patterns, either random (0.1-10 seconds) or constant (3 seconds). • Upon hearing the clicks the proband has to press a button with his thumb. In separate experiments either the left or the right thumb is used • The reaction times are collected by the BIOPAC program and given as ‘seconds’. • Data were collected and are prefilled in the tables (see below) • Four series of experiments are done by each test-person: (A) Click sounds at random time intervals and 10 reaction times with the left hand are collected (B) Click sounds at random time intervals and 10 reaction times with the right hand are collected (C) Click sounds at constant time intervals and 10 reaction times with the left hand are collected (D) Click sounds at constant time intervals and 10 reaction times with the right hand are collected 2 Studentnumber: .................................. C. Reaction times upon a ‘visual stimulus’ (Ocular test; Vision) Data collection (Done before): • For measuring visual reaction times, a simple ‘Ruler-catching test’ was performed • The principal experiments was described in the introduction sessions (see there) • The ruler was dropped after random periods of time (“that’s the fun bit ....”) and the test person catches the ruler as fast as possible after its release • The distance ‘D’ is then measured at a constant position resembling the top of the hand (measurement: ‘cm’). The reaction time has to be calculated from the distance of the ruler travelled. • This experiment is repeated 10 times with the left and 10 times with right hand • The readings for the distance ‘D’ (in cm) were noted and filled in the tables given. Calculation of reaction time: • The measurements are taken as the ‘distance’ the ruler migrated • Therefore, reaction times can be calculated by using the following formula: T: time D: distance the ruler travelled g: Standard gravitational acceleration (g = 9.8 m/sec2) ---------------------------------------------------------------------------------------------------------------- Statistical analyses ---------------------------------------------------------------------------------------------------------------Use a statistical test (t-test) to analyse the data and test the Null hypothesis • Use a statistical test for the comparison of data and testing of the null-hypothesis. A t-test is usually adequate. Reasons/Limitations of using this test should be discussed in Part 1e (see below) • Any program for statistical calculations could be used: Excel, SPSS, Prism/Graphpad.) • Compare the following test results by statistical methods as indicated also in the data tables (see below) Auditory tests o Reaction times of left and right hands in auditory test at random signals o Reaction times of left and right hands in auditory test at constant signals o Compare results of random vs. constant sound patterns from the same hands Ocular/Visual tests o Reaction times of left and right hands in visual test (Random ruler test) • Fill in your results in the corresponding tables of the form • In any case use adequate numbers of decimals 3 Studentnumber: .................................. Part 1: Data analysis I Calculations and statistical analyses of given data sets Data Group B • • • • • • Testperson: Self-declaration: “Betty B.” The person stated to be RIGHT-handed The following data are collected from a real person and should be analysed. The distance of the ruler travelled until caught is given and the reaction time has to be calculated by using the formula given below. Calculations/Results should be filled in the provided tables Calculate Mean, Stdev and SEM (Standard error of mean) The significance of the difference should be tested by “2-sample, 2-tailed t-tests” For convenience, use the tables for including calculations and results 1a. Data: Left hand Trial number 1 2 3 4 5 6 7 8 9 10 OCULAR/Visual Test Distance traveled by ruler Reaction time (T) Right hand (D, in cm) (T, in sec) Trial number 15.4 16.3 11.9 14.2 51.2 15.6 13.8 15.9 17.3 14.9 Mean STDEV SEM t test (Auditory test) of reaction times (Left vs Right hand) 1 2 3 4 5 6 7 8 9 10 Distance traveled by ruler Reaction time (T) (D, in cm) (T, in sec) 10.4 9.9 11.9 14.4 14.1 8.9 10.4 12.2 13.1 10.1 Mean STDEV SEM p-value = Comments/Problems: (1) Reaction times have to be calculated from the readings of the distance the ruler travelled until ruler was caught. The calculation of the reaction time is described in the ‘Introduction’ above (2) Readings in the ocular test are only accurate to about 1-3 mm. Use that information for deciding on the number of decimals. (3) Some measurements were missed during auditory testing (indicated by “missed”) 4 Studentnumber: .................................. 1b. Data: Auditory test: RANDOM time intervals Left hand Trial Reaction number time (sec) 0.157 1 0.172 2 0.183 3 0.205 4 0.167 5 0.191 6 0.201 7 0.159 8 0.213 9 0.144 10 Mean STDEV SEM t test (Auditory test) (Left vs Right hand) 1c. Data: Trial number 1 2 3 4 5 6 7 8 9 10 Mean STDEV SEM Missed reaction > Right hand Trial Reaction number time (sec) 0.198 1 0.211 2 0.192 3 0.225 4 0.197 5 0.207 6 7 (missed) 0.223 8 0.19 9 0.172 10 Mean STDEV SEM p-value = Auditory test: CONSTANT time intervals Left hand Reaction time (sec) Trial number 1 2 3 4 5 6 7 8 9 10 Mean STDEV SEM 0.139 0.172 0.213 0.166 0.168 0.189 0.229 0.165 0.188 0.219 t test (Auditory test) (Left vs Right hand) Right hand Reaction time (sec) 0.155 0.199 0.124 0.153 0.151 0.163 0.141 0.122 0.197 0.133 p-value = 5 Studentnumber: .................................. 1d. Test: • • • Auditory test: Comparison of Reaction times ‘Constant’ versus ‘Random’ signal patterns Use the data/results given which have been calculated above Compare the reactions of the same hands at different sound patterns Results from Part 1a-1c should be copied in the corresponding boxes and the results of t-tests should be filled in the labelled boxes Random sound pattern Random sound pattern Left hand Reaction time (sec) Trial number Mean SEM Mean SEM Constant sound pattern Constant sound pattern Left hand Reaction time (sec) Trial number Mean SEM Mean SEM LEFT HAND t test (Auditory test) (Random vs Constant) p-value Right hand Reaction time (sec) Right hand Reaction time (sec) RIGHT HAND t test (Auditory test) (Random vs Constant) = p-value Did You make any adjustments/corrections or changes to individual datasets? (- if applicable) 6 Studentnumber: .................................. e. Statistics: Rationale of using t-tests for statistical testing Briefly explain the rationale and limitations of using a t-test to compare the given data sets. (max. 100 words) 7 Studentnumber: .................................. Part 2: • • Data Analysis II Graphical representation of data Use the data/calculations of Part 1 to generate adequate graphs illustrating the presence/lack of differences and describe the major aspects in legends. The figures should summarise the key differences of the results on reaction times. It is up to you to choose the type of graph, which best suits the data. In addition, the figure should be clear and professionally presented (suitable for publication in a scientific • journal) as well as contain all essential labels. You can use excel, SPSS or any other useful program to prepare your graph. Figure 2a: Visual reaction times of left and right hand Copy figures in this box 8 Studentnumber: .................................. Legend Figure 2a: • • • • A figure legend has to be included The legend should start with a short, but clear title and then summarise the experimental set-up and explain what the figure shows. The legend should enable the reader to understand the figure, without reference to any other information. Maximum words for the legend: 120 words maximum (max 120 words) 9 Studentnumber: .................................. Figure 2b: Reaction times of left and right hand upon different sound patterns (Constant and Random patterns) Copy figure/s in this box 10 Studentnumber: .................................. Legend Figure 2b: • • • • A figure legend has to be included The legend should start with a short, but clear title and then summarise the experimental set-up and explain what the figure shows. The legend should enable the reader to understand the figure, without reference to any other information. Maximum words for the legend: 120 words maximum (max 120 words) 11 Studentnumber: .................................. Part 3: Summary of experiments and results Discussion of experiments Introduction: • • Briefly outline the general idea of the experiments Define the questions asked and the basic hypotheses tested (max. 100 words) Materials and Methods • • Briefly describe the methods used but mention any essential technical aspects. The informations should be sufficient to repeat the experiment. Briefly also define the general strategy of statistical analysis. 12 Studentnumber: .................................. (max. 200 words) Results • • • Briefly summarise the (numerical) results of experiments Correlate the data with the results of the statistical data Which major conclusions may be drawn from the statistical analyses on the (max. 150 words) 13 Studentnumber: .................................. Discussion Use the knowledge you gained from the lectures on ‘Nerve signalling’, ‘Vision’ and the study of the material on ‘Hearing’ to discuss the following questions (A-D) in the context of relevant physiological facts. • • • • The descriptions should be accurate and precise Clear descriptions are more important than extensive essays Focus on the questions and logic argumentation You may consult textbooks (Follow the UEA guidelines for Plagiarism) 14 Studentnumber: .................................. Discussion/Question A: Auditory tests and L/R preference o Based on the statistical results derived from your data, is there a correlation between the reaction times measured in the auditory tests (Biopac) and the assumption of the proband’s preferred hand? o Do You see a similar preference in all tests done? o Which conclusions would you like to draw about the indicated ‘L/R preference’ and the results from the given data? (max. 200 words) 15 Studentnumber: .................................. Discussion/Question B: Auditory tests and sound patterns o Compare the auditory reaction times (Hearing) of the same hand upon different sound patterns (random versus constant intervals). o Are there significant differences? o How would You explain any differences – if seen? (max. 200 words) 16 Studentnumber: .................................. Discussion/Question C: Visual tests and L/R preference o Is there a correlation between the reaction times measured in the visual tests (“Ruler test”) and the given assumption of a ‘preferred’ hand? o Are these results comparable with the results from the auditory tests? o If there are differences, how would You explain this? (max. 200 words) 17 Studentnumber: .................................. Discussion/Question D: Reaction times in visual and acoustic tests o Compare the results from the visual and the auditory tests. As the tests are very different, no statistical analysis can be performed, and a comparison should only be done by comparing the numbers for the reaction times of the same hands. o Are there differences indicated between the reaction times? o Would You like to draw a conclusion from that comparison? o Are there potential physiological reasons for the differences/effects? (max. 200 words) 18 Studentnumber: .................................. ------------------------------------------------------------------------------------------------ MARKING -----------------------------------------------------------------------------------------------Part Tasks Max. marks 6 Part 1 1a. Data Correct calculations: Visual reaction times 1b. Data 6 Max. 30 1e. Statistic Correct calculations Acoustic reaction times (Random) Correct calculations Acoustic reaction times (Constant) Correct calculations Acoustic reaction times Comparison Patterns Rationale of statistical method Part 2 Fig. 2a Graph of visual reaction times 8 Figure legend 5 Graphs of acoustic reaction times 12 Figure legends 5 Introduction 2 Materials and Methods 3 Brief description of numerical results 3 Discussion A 8 Discussion B 8 Discussion C 8 Discussion D 8 1c. Data 1d. Test Fig. 2b Max. 30 Part 3 Max. 40 Write-up TOTAL MARKS POSSIBLE Marks given 6 8 4 (100) 19