Lexical Decision Task

Technical Manual

Last Modified: January 01, 2023 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements a simple Lexical Decision Task to investigate semantic memory and lexical access. The implemented procedure is based on:

Lepore & Brown (2002), The Role of Awareness: Divergent Automatic Stereotype Activation and Implicit Judgment Correction, Social Cognition, 20 (4), pp 321-351.

This script uses placeholders for actual stimuli.

Duration

3 minutes

Description

Participants are asked to categorize words into words and nonwords by pressing the E-key (non words) or I-key (words) as fast as possible when a word/nonword stimulus appears on screen.

Procedure

3 types of words (category words, neutral words, nonwords) tested within participants in a mixed design

1 Practice Block: 6 trials (3 neutral words, 3 nonwords; order randomly selected)
1 Test Block: 52 trials (13 category words, 13 neutral words, 26 non words; order and stimuli randomly selected)

Trial Sequence:
• (for 700ms) -> stimulus (250ms) -> blank screen until response (latency measured from onset of stimulus)
(Durations can be edited under section Editable Parameters)

Stimuli

are spaceholders - actual stimuli can be easily inserted under section Editable Stimuli

Instructions

can be edited under section Editable Instructions

Summary Data

File Name: lexicaldecisiontask_summary*.iqdat

Data Fields

NameDescription
inquisit.version Inquisit version number
computer.platform Device platform: win | mac |ios | android
startDate Date the session was run
startTime Time the session was run
subjectId Participant ID
groupId Group number
sessionId Session number
elapsedTime Session duration in ms
completed 0 = Test was not completed
1 = Test was completed
propCorrect Overall proportion correct across all testtrials
meanRT Overall mean latency of correct responses across all correct testtrials
std Overall standard deviation of correct latencies
medianRT Overall median latency of correct responses across all correct testtrials
propCorrectCatW Proportion correct of responses to category words
meanRTCatW Mean latency of correct responses to category words
stdCatW Standard deviation of correct responses to category words
medianRTCatW Median latency of correct responses to category words
propCorrectNeutralW Proportion correct of responses to neutral words
meanRTNeutralW Mean latency of correct responses to neutral words
stdNeutralW Standard deviation of correct responses to neutral words
medianRTNeutralW Median latency of correct responses to neutral words
propCorrectNonW Proportion correct of responses to non words
meanRTNonW Mean latency of correct responses to non words
stdNonW Standard deviation of correct responses to non words
medianRTNonW Median latency of correct responses to non words

Raw Data

File Name: lexicaldecisiontask_raw*.iqdat

Data Fields

NameDescription
build Inquisit version number
computer.platform Device platform: win | mac |ios | android
date Date the session was run
time Time the session was run
subject, group, With the current subject/groupnumber
session Session number
blockCode Name of the current block
blockNum Number of the current block
trialCode Name of the current trial
trialNum Number of the current trial
condition "Category Word", "Neutral Word", "Non Word"
presentedStim The currently presented word or non-word
response The participant's response (scancode of response button)
18 = E (non word)
23 = I (word)
57 = spacebar
correct The correctness of the response (1 = correct; 0 = incorrect)
latency The response latency (in ms); latency measured from onset of stimulus

Parameters

The procedure can be adjusted by setting the following parameters.

NameDescriptionDefault
fixationDuration The duration (in ms) of the fixation stimulus presented at the start of each trial 700ms
stimDuration The duration (in ms) of the presented word/nonword in ms 250ms
stimSize The proportional height (to active canvas) of the stimuli 5%