Jump to content
Sign in to follow this  

Measuring reaction-time: How to know if results are accurate?

Recommended Posts


I'm working on an AutoIt program that will be used in a psychological study to measure a person's reaction time.  I have a draft of the program completed, and it seems to work.  In other words, the reaction-time data is plausible.

The program displays a random digit between 2 and 8 inclusive (this is called the "target digit").  The user has to hit the corresponding key as quickly as possible.  The program measures the amount of time it takes the user to hit the key.  There are multiple trials per session, and an average reaction-time is calculated at the end of the session.

Here are the two critical AutoIt functions that perform the actual timing. (In the first function, I edited-out some lines of code that display the target digit in a GUI):

Func _PresentProblemAndGetResponse($sProblem, $sAnswer, $hGui)Local $iReactionTime
Local $iCorrect
Local $sLocalTime
Local $avResults[4]
[Edited-out the code that displays the target key in a GUI]
$hBegin = TimerInit() ; Start the stopwatch running
$iCorrect = _GetKeyPress($sAnswer) ; The parameter here is the correct answer (i.e., the solution to the problem). A returned value of 0 means user pressed wrong key; 1 means correct key.
$iDiff = Round(TimerDiff($hBegin)) ; Stop the stopwatch and get elapsed time in milliseconds
$iReactionTime = $iDiff ; This is the user's reaction time in milliseconds
$sLocalTime = _GetTime() ; This is the user's current local time
GUICtrlDelete($hLabelMessage) ; Erase the problem from the GUI
$avResults[0] = $sProblem ; Assign the relevant data to a vector
$avResults[1] = $iReactionTime
$avResults[2] = $iCorrect
$avResults[3] = $sLocalTime
Return ($avResults)
EndFunc   ;==>_PresentProblemAndGetResponse

Func _GetKeyPress($iRightAnswer)
Local $iRightAnswerCode = 30 + $iRightAnswer ; Convert the answer into the ASCII code that's required by the _IsPressed function
Local $iWrongAnswers[10] = [30, 31, 32, 33, 34, 35, 36, 37, 38, 39] ; Initialize array of wrong answer digits
$iWrongAnswers[$iRightAnswer] = '20' ; Replace the right answer with the code for the space character
While 1
For $x = 0 To 9
If _IsPressed($iRightAnswerCode) Then Return (1)
If _IsPressed($iWrongAnswers[$x]) Then Return (0)
EndFunc   ;==>_GetKeyPress


So, I have two questions.  The second question is much harder, I think.

First of fall, does my approach seem like a reasonable way to measure the time between displaying a target number and registering a user's keypress?  If not, what's a better approach?

Second, how can I verify that the results are accurate?  I've run the program over a hundred times (using myself as the subject), and the results are about what I would expect.  Actually, my main interest lies in measuring small changes that take place over the course of many sessions performed over weeks or months.  The absolute precision isn't terribly important, but consistency is very important.  In other words, if the results are high by 5%, that's not too much of a problem, as long as they are consistently high by 5%.

Thanks for considering my questions.


Share this post

Link to post
Share on other sites

Hi Alex, this could be a way to get the response time of a digit from the screen.


Global $Correct = False, $Counter = 1, $Max = 10, $Random, $Last, $Total

$hMain = GUICreate("Reaction Time Measure")
$hDigit = GUICtrlCreateLabel('',100,0,200,50,0x01)
$hResponseTime = GUICtrlCreateEdit('The test will display ' & $Max & ' digits, one digit each time. You have to press the button of the digit you see it.',0,200,400,150,0x0800)
GUICtrlSetFont($hDigit,30,900,1,'Arial Black')
$hButton = GUICtrlCreateButton("Start test",125,360,150,35)

While True
    Switch GUIGetMsg()
        Case -3 ;GUI_EVENT_CLOSE
        Case $hButton   ; Test will start

Func Test()
            $Random = Random(1,9,1)
        Until $Random <> $Last
        $Timer = TimerInit()
        Until $Correct
        $Diff = TimerDiff($Timer)
        $Correct = False
        $Counter += 1
        $Total += $Diff
        $Last = $Random
        GUICtrlSetData($hResponseTime,Round($Diff,3) & @CRLF,1)
    Until $Counter = $Max
    GUICtrlSetData($hResponseTime,"Average response time: " & Round($Total/$Max,3),1)

Func Correct()
    If @HotKeyPressed = $Random Then $Correct = True

Usually, native functions are faster then UDFs, so I like more this way. But if you still want to use _IsPressed be sure you open user32.dll and use the handle as second parameter of the function otherwise the dll will be opened every time you call the function. This may lead to different response time and for a test like yours this may be relevant.

My example is raw but can be improved to work as you like. Hope this was helpful in any way.

When the words fail... music speaks

Share this post

Link to post
Share on other sites

Hello AndreiK,

Thank you for the detailed answer.  I will try your suggestions this weekend.  For now, I'll mark the question as answered, although I think I'll eventually post again about my second question (regarding precision / accuracy in the results).

Thanks again.

-- Alex Chernavsky

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Similar Content

    • ufukreis1212
      By ufukreis1212
      Hello, I am new members. Help me please. I want vbs convert to au3 .
      This vbs code : 
      'deneme Set SystemSet = GetObject("winmgmts:").InstancesOf ("Win32_OperatingSystem") strOSArch = GetObject("winmgmts:root\cimv2:Win32_OperatingSystem=@").OSArchitecture Set objNetwork = CreateObject("Wscript.Network") Set wshShell = CreateObject( "WScript.Shell" ) strComputerName = wshShell.ExpandEnvironmentStrings( "%COMPUTERNAME%" ) Set oShell = WScript.CreateObject("WScript.Shell") proc_arch = oShell.ExpandEnvironmentStrings("%PROCESSOR_ARCHITECTURE%") Set oEnv = oShell.Environment("SYSTEM") strComputer = "." Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\CIMV2") Set colMB = objWMIService.ExecQuery("Select * from Win32_BaseBoard") Set colCSes = objWMIService.ExecQuery("SELECT * FROM Win32_ComputerSystem") Set colProcessors = objWMIService.ExecQuery("Select * from Win32_Processor") Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\CIMV2") Set colItemsx = objWMIService.ExecQuery( _ "SELECT * FROM Win32_VideoController",,48) '------------------------------------------------------------------- Set obj = GetObject("winmgmts:").InstancesOf("Win32_PhysicalMemory") i = 1 For Each obj2 In obj memTmp1 = obj2.capacity / 1024 / 1024 TotalRam = TotalRam + memTmp1 i = i +1 Next '-------------------------------------------------------------------- Dim objWMIService : Set objWMIService = GetObject("winmgmts:\\.\root\cimv2") Set colItems = objWMIService.ExecQuery("Select Architecture from Win32_Processor") For Each objItem in colItems if objItem.Architecture = 0 then strArchitecture = "x86" end if if objItem.Architecture = 9 then strArchitecture = "x64" end if next '-------------------------------------------------------------------- strComputer = "." ' Local computer strMemory = "" i = 1 set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2") set colItems = objWMIService.ExecQuery("Select * from Win32_PhysicalMemory") For Each objItem In colItems if strMemory <> "" then strMemory = strMemory & vbcrlf strMemory = strMemory & "Bank" & i & " : " & (objItem.Capacity /1024 /1024) & " Mb" i = i + 1 Next installedModules = i - 1 Set colItems = objWMIService.ExecQuery("Select * from Win32_PhysicalMemoryArray") For Each objItem in colItems totalSlots = objItem.MemoryDevices Next '---------------------------------------------------------------------- Set objWMISvc = GetObject( "winmgmts:\\.\root\cimv2" ) Set colItems = objWMISvc.ExecQuery( "Select * from Win32_ComputerSystem" ) For Each objItem in colItems strComputerDomain = objItem.Domain Next for each System in SystemSet For Each objItem in colItemsx For Each objProcessor in colProcessors For Each bbType In colMB MbVendor = bbType.Manufacturer MbModel = bbType.Product MsgBox "İşletim Sistemi : " & System.Caption & vbNewLine & _ "İşletim Sistemi Versionu : " & + System.Version & vbNewLine & _ "Windows Mimari Yapısı: " & strOSArch & vbNewLine & _ "Kullanıcı isminiz: " & objNetwork.UserName & vbNewLine & _ "Bilgisayar ismi: " & strComputerName & vbNewLine & _ "Çalışma Grubu: " & strComputerDomain & vbNewLine & _ "--------------------------------------" & vbNewLine & _ "Anakart: " & MbVendor & " " & "[" & MbModel & "]" & vbNewLine & _ "--------------------------------------" & vbNewLine & _ "Grafik Kartı: " & objItem.Caption & vbNewLine & _ "Driver Version: " & objItem.DriverVersion & vbNewLine & _ "--------------------------------------" & vbNewLine & _ "İşlemci Üreticisi: " & objProcessor.Manufacturer & vbNewLine & _ "İşlemci İsmi: " & objProcessor.Name & vbNewLine & _ "CPU Mimarisi: " & strArchitecture & vbNewLine & _ "İşlemci Çekirdek sayısı: " & oEnv("NUMBER_OF_PROCESSORS") & vbNewLine & _ "--------------------------------------" & vbNewLine & _ "Toplam RAM: " & TotalRam & " MB" & vbNewLine & _ "Toplam Slot: " & totalSlots & vbNewLine & _ "Boş Slot: " & (totalSlots - installedModules) & vbNewLine & _ "Ramlerin bulunduğu slotlar:" & vbcrlf & strMemory,0,"deneme" Next Next Next Next please help me , thanks.
    • JuanFelipe
      By JuanFelipe
      Hello friends, I have a query, it happens that I have a matrix nxn, the first column of this contains each cell a number with 21 digits, when I pass this matrix to Excel I obviously write that number as 1,10016E + 20, I solved it by adding a * at the end of each cell, but I want it to be written as a text so that I do not have to remove that *, I searched in Google but could not find an effective solution, thanks in advance. 
    • Puls3
      By Puls3
      Hi, This is my first post on the AutoIt Forums, I most of the time was able to get help from this community by merely searching though google and have been able to solve hundreds of problems this way, though in this case I was incapable of finding a solution to my problem. I am quite confident that it is a user error (And my fault) but I haven't been able to determine what I did wrong, any and all help would be greatly appreciated! I have uploaded my whole script pardon passwords to provide as much information as possible.
      I declared a global array at the top of the script and am having issues when I try to set it's value, and I fail to understand why.
      Error Message:
      "D:\Projects\AutoIt\Arena\Base.au3" (270) : ==> Subscript used on non-accessible variable.:
      $ExpMax[$i] = IniRead($TempSavePath, "Combatant" & $i, "ExpMax", $ExpMax[0])
      $ExpMax^ ERROR
      ConsoleWrite Log:
      Checking launch parameters.
      No launch parameters.
      Initiating load.
      Checking for save file.
      Save file not found.
      Load canceled.
      Loading or creating Combatant 1
    • RamDemon
      By RamDemon
      Did anyone tried to  use Redis  with AutoIT as store DB ?
       Redis <-- more about it
    • nooneclose
      By nooneclose
      Hey. I'm working on a new project and was wondering if there is a better way to "update" my Column E array. 
      Here is my code: 
      Local $nI  = 0                                                            ;Creates a name index of 0: nI = Name index Local $nII = 1                                                            ;Creates a name index of 1 for second loop: nII = Name Index 2 For    $iN = 0 To $IndexRows Step 1                                       ;Checks the roster for any names that appear twice      For $iN2 = 0 To $IndexRows Step 1          if $d_Names[$nI] == $d_Names[$nII] And $d_Names[$nII] <> "" Then              Local $timeSheetName = _ArraySearch($e_Names, $d_Names[$nI], 0, 0, 0, 0, 1)              ;MsgBox($MB_SYSTEMMODAL, "Found it", $d_Names[$nI] & " In column E on Row " & $timeSheetName)              Local $eI  = $timeSheetName + 1              ;ConsoleWrite($timeSheetName & @CRLF)              ;ConsoleWrite($eI & @CRLF)              ;ConsoleWrite(@CRLF)              _Excel_RangeInsert($OpenWorkbook.ActiveSheet, "E" & $eI & ":F" & $eI, $xlShiftDown)                                                                          ;Inserts a empty cell in columns E and F.              _Excel_RangeWrite($OpenWorkbook, $OpenWorkbook.ActiveSheet, $d_Names[$nII], "E" & $eI)                                                                         ;Fills the empty cell in columns E with the doubled name              $aArray_Index = 2                                           ;Array element counter              For $Index = 2 To $IndexRows Step 1                        ;Loops through every row in the Excel file unto no rows are found or a null row is found                  $Array_Value_E = _Excel_RangeRead($OpenWorkbook, Default, "E"&$Index)                  $e_names[$aArray_Index] = $Array_Value_E                ;While the code loops every value in column E is stored in the E array (updating the array)                  $aArray_Index += 1              Next              ExitLoop          EndIf      Next      $nI  += 1      $nII += 1 Next Basically, It checks a roster for people whose name appears twice then inserts a new "row" for that person because they work in two different departments.
      I have to find that name however in Column E if two appear in column D. My code works but I think it is not as efficient as it could be. 
      Any ideas on how to improve the "update" for my array?
      (once it finds the double names in Column D it then searches for that name by going name by name in the Column E array and once it finds it inserts a new row. However, the E array doesn't have that new row stored in it so I have to "update" the array to properly find the next name)
      Any and all tips would be greatly appreciated. 
      NOTE: Just assume I'm opening the excel file properly please do not add that code in, it only complicates your answer.