Assessment of cool self-regulation (executive functions)

Find below a description of various tasks of cool executive functions that are in the public domain. Testing with the proposed tasks is not costly. It involves printing out the task on cards or having a normal computer or tablet with an Office package to show stimuli on PowerPoint. Users will also need a pen and a stopwatch at hand. If you use the task on cards, bind them by spiraling the top of the sheet (card) to avoid increasing difficulty for left-handed testees. This project follows the open science movement that encourages research to be freely disseminated and reproducible worldwide. We deliberately avoided tasks that require complex equipment and software and reaction time measures for each stimuli. These are not necessary because simple tasks such as the ones proposed here are highly sensitive to executive changes. Additionally, we believe that any person, irrespective of their financial conditions, should be able to employ this type of cognitive testing. Following the philosophy that cognitive testing should be free of charge, the illustrative images in each tasks were taken from the internet, with rights for reuse with modification and or were extracted from databases and publications that have no copyright charges. At least one of each type of executive function tasks can be used in those who have difficulty discriminating colors (i.e., have achromatopsia or dyschromatopsia).

RATIONALE FOR SELECTING COOL EXECUTIVE FUNCTION TESTS

The tasks were selected from publications on executive functioning that involved confirmatory factor analyses to study the fractionation of these cognitive functions into various domains: shifting, updating and inhibition of prepotent responses (for an overview, see Friedman & Miyake, 2017). We present two tasks that tap each of these three executive abilities, both of which displays good factor loading in their domains (except Happy Sad Stroop[1]).Those who are interested in obtaining better measures of executive functioning may choose to obtain/extract a latent variable from each pair of tasks that measure the same domain[2].

Tasks were devised so as to avoid ceiling and floor effects, having been tested in pilot studies in children as young as 7 and elderly people with low schooling and young highly schooled adults. However, normative data are still not available as this is an ongoing project. Therefore, the tasks described here are useful mainly for research purposed and must include control groups with similar characteristics to those of the population under investigation.  These tasks are not yet appropriate for diagnosis of cognitive pathologies.  In the test battery below, oral responses are required. The reason for this was that we aimed at obtaining measures of executive functions that would be little contaminated by individual differences in factors such as psychomotor speed, coordination, dexterity and laterality, which vary among sexes, change over development and can be affected by schooling (e.g., Ruff & Parker, 1993; Sullivan et al., 2016), possibly independently from executive functioning.

We only included self-paced tasks and used the time to complete each block as a measure of performance, together with errors. Hence, testees pass from page to page themselves by swiping the screen, pressing the spacebar, clicking the mouse or changing pages in the case of versions printed on cards. In the lower right corner of each test page there is a picture that indicates that testees must pass to the next page to continue the task. The experimenters take note of the answers on answers sheets that are also provided and must use a stopwatch to mark the time testees take to complete each block of each task.

Any differences in motor responses needed for oral responses and/or for changing pages are controlled internally in most tasks (except for the updating ones). They include blocks of trials in which testees use various cognitive abilities but little in the way of specific executive functioning and one block that involves the same abilities but have an added executive requirement. Cost measures are calculated, that is, how much extra time is needed to do the task in the blocks that included the executive abilities of interest compared to the blocks without the executive requirement (or increases in errors).

We tried to maintain instructions in the same font (Calibri) and in sizes which are easy to read. We use this font which is non serifed because it look cleaner and is more legible onscreen and because it is the default font in many versions of the Power Point Office package (see Vandendorpe, 2006). Instructions were kept at a minimum not to overburden testees from the cognitive point of view. Examples and practice stimuli are also provided. However, these were kept at a minimum because too much practice can lead people to use strategies in performing the task and therefore rely less and less on executive functions as the task progresses (e.g., see Spreen and Strauss, 1998).

When possible, we adapted task to have black, white and gray stimuli to allow use in color-blind testees (Birch, 2012; Kohl et al., 2002; Zeki, 1990). The background was kept white when possible, to make tasks cheaper to print on cards. Stimuli used were selected so as to represent objects that are easily recognized and named by young children so as to make sure that all types of testees would know them. We avoided using letter, substituting them for numbers, which are easier for testees with low or inadequate schooling (Izard et al., 2009; Rasmussen & Bisanz, 2011).

At least one task of each type of executive function does not involve written words and can be conducted in illiterate individuals as long as the instructions are read to them. General instructions before beginning the test battery must explain to testees that they are expected to make many mistakes and that even very clever, highly young schooled adults do so. Therefore, making mistakes and forgetting during the tasks does not mean that test takers have cognitive problems. They must be told that the objective is to determine how mistakes change as people get older. Therefore, testees must be encouraged to do the best they can and not be upset if mistakes are made.

For this reason, in the instructions we used sentences such as “when you forget…”. We used “when” and not “if” to make it clear that we expect mistakes and that they are part of the tasks. We also used the word “activity” in the instructions and not the word “test”, to try to remove the idea that testees are being tested. Testees must also be allowed to rest between blocks and tasks because they are quite hard to do, irrespective of testees’ schooling and intelligence quotient.For researchers: please take note: a) if you wish to compare people’s performance in two different times you can construct other version of each task by alternating the order of the trials in each block of the task. – do not compare performance in one of the two tasks proposed for one executive domains with the other task at another testing time because performance will vary according to the task, even though both measure the same construct; b) if various tasks are used in different people, consider varying the order between participants to avoid effects of fatigue.

References

Birch, J. (2012). Worldwide prevalence of red-green color deficiency. JOSA A, 29(3), 313-320.

Friedman, N. P., & Miyake, A. (2017). Unity and diversity of executive functions: Individual differences as a window on cognitive structure. Cortex, 86, 186-204.Izard, V., Sann, C., Spelke, E. S., & Streri, A. (2009). Newborn infants perceive abstract numbers. Proceedings of the National Academy of Sciences, 106(25), 10382-10385.

Kohl, S., Baumann, B., Rosenberg, T., Kellner, U., Lorenz, B., Vadala, M., … & Wissinger, B. (2002). Mutations in the cone photoreceptor G-protein α-subunit gene GNAT2 in patients with achromatopsia. The American Journal of Human Genetics, 71(2), 422-425.

Rasmussen, C., & Bisanz, J. (2011). The relation between mathematics and working memory in young children with fetal alcohol spectrum disorders. The Journal of Special Education, 45(3), 184-191.

Ruff, R. M., & Parker, S. B. (1993). Gender-and age-specific changes in motor speed and eye-hand coordination in adults: normative values for the Finger Tapping and Grooved Pegboard Tests. Perceptual and motor skills, 76(3_suppl), 1219-1230.

Sullivan, E. V., Brumback, T., Tapert, S. F., Fama, R., Prouty, D., Brown, S. A., … & De Bellis, M. D. (2016). Cognitive, emotion control, and motor performance of adolescents in the NCANDA study: Contributions from alcohol consumption, age, sex, ethnicity, and family history of addiction. Neuropsychology, 30(4), 449.

Vandendorpe, C. (2008). Reading on screen: The new media sphere. A Companion to Digital Literary Studies, 203-15.Zeki, S. (1990). A century of cerebral achromatopsia. Brain, 113(6), 1721-1777.

SWITCHING TASKS

Category Switch

Category Switch [based on Friedman & Miyake (2004), who adapted the task of Mayr & Kliegl (2000); see also Friedman et al. (2006, 2008)]: This is a task that assesses executive shifting that was altered in some respects as described below. Firstly, instead of using words to be categorized, we used pictures that represent common objects as this allows testing people who have difficulty reading. For the task, 16 black and white pictures that represent concrete nouns were used. These pictures were obtained from the work of Cycowicz et al. (1997) and represent object names adapted from the words used by Mayr and Kliegl (2000). They were standardized for use in Brazil (see Pompéia et al., 2001) regarding naming consistency and represent objects that are presented in reading material of children (Pinheiro, 1995, 1996). Only pictures that were easily recognizable by Brazilian children were use (Pompeia et al., 2001). Four of the images refer to large inanimate objects (bed, refrigerator, house and car); four to small inanimate objects (key, ring, fork, and whistle); four to large living things (elephant, horse, giraffe and lion); and four to small living objects (butterfly, ladybug, ant and frog). Thus, each picture can be classified in terms of two independent semantic dimensions: size and living/nonliving entities. These pictures are presented individually onscreen (sizes ranging from 7 to 9 cm in height and 4 to 8 cm in width) on a white background. The task involves three blocks. In block 1, participants are asked to classify pictures into living (“live”) or non-living (“dead”) entities. Oral responses are asked for. Participants pass from page to page themselves by swiping the screen, pressing the spacebar, clicking the mouse or changing pages in the case of versions printed on cards. The experimenters take note of the answers on answers sheets and times the time participants take to complete each block. In block 2, pictures must be classified into representing an entity that is big or small, having as a reference of size a soccer ball. In block 3 participants must switch categories, that is, categorize the first picture as “live of dead”, the second as “big or small”, the third as “live or dead” and so forth[3].                All blocks are preceded by a practice trial that included four pictures that were not used in the test blocks:  gorilla, spider, cloths peg and train. In blocks 1 and 2, 20 pictures are shown. In block 3, 40 pictures are presented. Scores are the time taken to complete block 3 minus the sum of the time taken to complete the first two blocks (switching cost). The same is done for mistakes. Switching errors are also computed.  All sequences of pictures were randomized (www.randomizer.org/), except that consecutive repetitions of pictures were prevented. All slides are numbered in the lower right corner, with Calibri font, size 12, to help the experimenter keep track.  

References

Friedman, N. P., Miyake, A., Young, S. E., DeFries, J. C., Corley, R. P., & Hewitt, J. K. (2008). Individual differences in executive functions are almost entirely genetic in origin. Journal of Experimental Psychology: General, 137(2), 201.

Koch, I. (2003). The role of external cues for endogenous advance reconfiguration in task switching. Psychonomic bulletin & review, 10(2), 488-492.

Mayr, U., & Kliegl, R. (2000). Task-set switching and long-term memory retrieval.

Miyake, A., Emerson, M. J., Padilla, F., & Ahn, J. C. (2004). Inner speech as a retrieval aid for task goals: The effects of cue type and articulatory suppression in the random task cuing paradigm. Acta psychologica, 115(2-3), 123-142.

Pinheiro, A. M. V. (1995). Reading and spelling development in Brazilian Portuguese. Reading and Writing, 7(1), 111-138.

Pinheiro, A. (1996). Contagem de frequência de ocorrência e análise psicolinguística de palavras expostas a crianças na faixe pré-escolar e séries iniciais do 1 o grau. São Paulo: Associação Brasileira de Dislexia.

Pompéia, S., Miranda, M. C., & Bueno, O. F. A. (2001). A set of 400 pictures standardised for Portuguese: norms for name agreement, familiarity and visual complexity for children and adults. Arquivos de Neuro-psiquiatria, 59(2B), 330-337.

 

COLOR SHAPE

Color-Shape task [based on the article by Miyake et al. (2004) and Friedman et al. (2008)]: This task assesses executive shifting and was altered from the original version[4]. The task was built on slides with a white background. Target stimuli are squares 3 cm in height and width and circles 3 cm in diameter presented individually, either in black or gray, centered on the screen so that there is around 10 cm from the bottom and top, and 8 cm from the sides. Above each stimulus there is a clue: a monocromatic rainbow to indicate that participants should classify the target according to its color, or an abstract shapes indicating that the target must be classified according to its shape. Clues are 1.0 cm in height and 1.5 cm in width and placed 1.0 centimeter just above the target stimuli.

The task consists of three blocks, all preceded by 4 practice trials. In block 1, participants are asked to name the shapes they see, all of which have the clue (abstract shape), above the stimuli. In block 2 they must name the color of the shapes, all of the stimuli having a rainbow shaped clue above them. In block 3 (shifting block) they are asked to classifying the stimuli (shape or color) according to the clue placed above the stimuli.

Blocks 1 and 2 contained 20 target stimuli each, while block 3 included 40 stimuli. Participants are instructed to respond by classifying the stimulus on screen out loud and passing as quickly as possible to the next page. Oral responses are asked for. Participants pass from page to page themselves by swiping the screen, pressing the spacebar, clicking the mouse or changing pages in the case of versions printed on cards. In the lower right corner of the slides there is a picture that indicates that participants must pass to the next page to continue the task. The experimenters take note of the answers on answers sheets and times the time participants take to complete each block of each task. The slides are numbered to help researchers keep track.All sequences of stimuli and cues were randomized (www.randomizer.org), except that more than two consecutive classifications of the same stimulus/classification were avoided. Scores (switching costs) are the time participants take to complete block 3 minus the sum of the time taken to complete blocks 1 and 2. The same is computed for errors.

Instructions:

– Block 1: “You will see shapes one at a time. For each shape say out loud if it is a circle or square, as fast as you can, then pass to the next page to see other shapes. This symbol (abstract form) will remind you to say the shape (circle or square). Pass to the next page to practice./ Well done! Any questions? Remember to do the activity (circle / square) as fast as you can, avoiding mistakes. When you are ready to begin, pass on to the next page./ Well done! Do you want to rest before the next block? To continue pass on to the next page. “.

– Block 2: Now, say aloud whether the shapes are black or gray, as fast as you can, them pass to the next page to see other shapes. This symbol (monocromatic rainbow) will remind you to say the color (black or gray). Pass on to the next page to practice./ Well done! Any questions?/ Pass on to the next page to continue. Remember to do the activity (dead / alive) as fast as you can, answering out loud and avoiding mistakes. When you are ready to begin, pass on to the next page. / Well done. Do you want to rest before continuing? When you are ready, pass on to the next page.

– Block 3: “This is the last block of this activity! This time you must switch: when “abstract form” appears on top of the shape, say if the shape is a circle or square; when “rainbow” appears, say if it is gray or black. When you make mistakes, it does not matter. Just correct yourself and keep going. Pass on to the next page to practice./ Well done! Any questions? Remember that you should do the activity as fast as you can, avoiding mistakes. When you are ready to begin, pass on to the next page./ Well done! This activity has finished.

 References

Birch, J. (2012). Worldwide prevalence of red-green color deficiency. JOSA A, 29(3), 313-320.

Friedman, N. P., Miyake, A., Young, S. E., DeFries, J. C., Corley, R. P., & Hewitt, J. K. (2008). Individual differences in executive functions are almost entirely genetic in origin. Journal of Experimental Psychology: General, 137(2), 201.

Mayr, U., & Kliegl, R. (2000). Task-set switching and long-term memory retrieval.

Miyake, A., Emerson, M. J., Padilla, F., & Ahn, J. C. (2004). Inner speech as a retrieval aid for task goals: The effects of cue type and articulatory suppression in the random task cuing paradigm. Acta psychologica, 115(2-3), 123-142.

 
 

UPDATING TASKS

Number Memory [adapted from the Letter memory task; Miyake et al. (2000) and Friedman et al. (2006, 2008)]: This tasks measures executive updating. The original task used letters as stimuli. To avoid difficulty in dealing with this type of stimuli for those who had inadequate schooling we chose instead to use numbers from 1 to 9 as stimuli, considering that numbers are learned earlier and do not depend on schooling to the same extent (Izard et al., 2009, Rasmussen & Bisants, 2010, Mix, 2013).The task is to recall the last three numbers presented in sequences with a different number of stimuli (5, 7 and 9 number long list following the model of Friedman et al., 2006, 2008). Numbers were presented sequentially in Calibri font, black color, size 56, on white background, in the center of the screen, one at a time (Friedman, 2006 and 2008, St Clair-Thompson and Gathercole, 2006) in randomized order (www.randomizer.org/) except that no sequential repetitions of the same numbers in each sequence ocurred. The sequence of the list lengths was also randomized. To ensure that participants continuously update the numbers in their working memory, they are asked to speak the numbers aloud as they are presented, updating them to the last three (Miyake et al., 2000, Friedman et al., 2008). For example, if the sequence of numbers is: “8-9-2-5-4”, they should say “8 … 89 …. 892 …. 925 …. 254”. The last slide shows three question marks in place of the last three numbers to remember. The first practice trial included sequential number (12345…). Three other practice trials follow, with numbers in mixed order: one sequences of each size with 5, 7 and 9 numbers. Then there are nine test trials with three sequences of each size (Friedman et al., 2006, 2008). The participants are instructed to say the numbers aloud as they update the content of their working memory (Miyake et al., 2000, Friedman et al., 2008) respecting serial position and to say the word “blank” or something similar if they do not remember a certain number. In order to have a more reliable updating measure, the fixed time of presentation was removed, as suggested in the work of McMillan et al. (2007). Therefore, tasks are self-paced. Oral responses are required. Participants pass from page to page themselves by swiping the screen, pressing the spacebar, clicking the mouse or changing pages in the case of versions printed on cards. In the lower right corner of the slides there is a picture that indicates that participants must pass to the next page to continue the task. The experimenters take note of the answers on answers sheets and times the time participants take to complete each block of each task. All slides are numbered in the lower right corner, with Calibri font, size 12, to help experimenters keep track.The score is the total number of numbers recalled in the right serial position for each list length and also in alternative positions (see Friedman et al., 2008). Another score is the total number of numbers remembered in the correct and other orders in all trials (Friedman et al., 2006, 2008; St Clair-Thompson & Gathercole, 2006; McMillan et al., 2007). Sum of time to do trials of each length and the total time to do all trials are also be computed.

 

Instructions:

References

Friedman, N. P., Miyake, A., Corley, R. P., Young, S. E., DeFries, J. C., & Hewitt, J. K. (2006). Not all executive functions are related to intelligence. Psychological science, 17(2), 172-179.

Friedman, N. P., Miyake, A., Young, S. E., DeFries, J. C., Corley, R. P., & Hewitt, J. K. (2008). Individual differences in executive functions are almost entirely genetic in origin. Journal of Experimental Psychology: General, 137(2), 201.

Izard, V., Sann, C., Spelke, E. S., & Streri, A. (2009). Newborn infants perceive abstract numbers. Proceedings of the National Academy of Sciences, 106(25), 10382-10385.

McMillan, K. M., Laird, A. R., Witt, S. T., & Meyerand, M. E. (2007). Self-paced working memory: validation of verbal variations of the n-back paradigm. Brain research, 1139, 133-142.

Miyake, A., Friedman, N. P., Emerson, M. J., Witzki, A. H., Howerter, A., & Wager, T. D. (2000). The unity and diversity of executive functions and their contributions to complex “frontal lobe” tasks: A latent variable analysis. Cognitive psychology, 41(1), 49-100.

Mix, K. S. (2013). Habilidades iniciais em operações com números: a transição dos primeiros meses de vida até a primeira infância. In: Encliclopédia sobre o desenvolvimento na primeira infância. Michigan State University, Tradução para o Português, 2013. http://www.enciclopedia-crianca.com/

St Clair-Thompson, H. L., & Gathercole, S. E. (2006). Executive functions and achievements in school: Shifting, updating, inhibition, and working memory. Quarterly journal of experimental psychology, 59(4), 745-759.

Rasmussen, C., & Bisanz, J. (2011). The relation between mathematics and working memory in young children with fetal alcohol spectrum disorders. The Journal of Special Education, 45(3), 184-191.

 

2-BACK

Spatial two-back task [adapted from Friedman et al. (2008) and Vuontela et al. (2003)]: This task measure executive updating. On each slide there are 10 outlines (in black) of squares measuring 1.6×1.6 cm on a white background. On each slide, one of these squares becomes totally black, giving the impression that it lit up (target squares). The participant must observe the position of these black squares and say orally if the position of the black square they see onscreen is in the same or a different place than the black square that lit up two slides back. In the original task the rate of presentation is fixed. However, in the present work, the task is self-paced, as suggested in the work of McMillan et al. (2007; see also Lawlor-Savage and Goghari, 2016). The order of position of target squares randomized (www.randomizer.org/ ) with the exception that the square seen onscreen does not correspond to that seen 3- or 1-back (Friedman et al., 2008) and does not light up in in two subsequent screens.The task is composed of 3 practice blocks with twelve trials, each of which contain three “same” answers. The test trials contain four blocks with 24 screens each, each of which contain six “same” answers. At the beginning of each test trial, in the upper left corner, the first two slides are numbered to indicate to the participant that no answer is not required. For each screen after the second one an answer “same” of “different” is required. Similar answers are acceptable, expressing the same meaning. If the participant does not remember the can say “blank”. Oral responses are asked for. Participants pass from page to page themselves by swiping the screen, pressing the spacebar, clicking the mouse or changing pages in the case of versions printed on cards. In the lower right corner of the slides there is a picture that indicates that participants must pass to the next page to continue the task. The experimenters take note of the answers on answers sheets and times the time participants take to complete each block of each task. All slides are numbered in the lower right corner with a Calibri font, size 12, so the experiment can keep track.

The score is the mean time taken to complete the test trials and the mean number of correct “same” and “different” answers (Friedman et al., 2008; Vuontela et al., 2003). Omissions (“blank” answers) are counted as errors (Friedman et al., 2008, Ecker, 2014).  

References

Friedman, N. P., Miyake, A., Young, S. E., DeFries, J. C., Corley, R. P., & Hewitt, J. K. (2008). Individual differences in executive functions are almost entirely genetic in origin. Journal of Experimental Psychology: General, 137(2), 201.

Lawlor-Savage, L., & Goghari, V. M. (2016). Dual N-back working memory training in healthy adults: A randomized comparison to processing speed training. PloS one, 11(4), e0151817.

McMillan, K. M., Laird, A. R., Witt, S. T., & Meyerand, M. E. (2007). Self-paced working memory: validation of verbal variations of the n-back paradigm. Brain research, 1139, 133-142.

Vuontela, V., Steenari, M. R., Carlson, S., Koivisto, J., Fjällberg, M., & Aronen, E. T. (2003). Audiospatial and visuospatial working memory in 6–13 year old school children. Learning & Memory, 10(1), 74-81.

 

INHIBITION TASKS

HAPPY SAD TASK STROOP

Happy Sad Stroop [adapted from the work of Lagatutta et al. (2011), Kramer et al., 2015)]: This task measures executive inhibition. The stimuli were obtained from the NIMSTIM database (Totenham et al., 2009) and were chosen based on a pilot study with 78 young volunteers, who verified the consistency of responses in relation to the images of different emotions. We selected the images of actors whose sad and happy faced were rated as such by over 90% of the volunteers, one male and one female, as in the work of Lagatutta et al.  (2011). The chosen photographs were from models 7 (female  07F_HA_C, 07F_SA_C, 36M) and 34 (male 34M _HA_C and 34M_SA_C). The task includes three blocks, the first being a “warm-up” block (not included in the original test), akin to the first phase of the traditional Stroop task, in which only colors are shown. This task included emojis (3.4 cm in diameter) in the public domain with happy and sad expressions (10 each), displayed on a white background, distributed in 4 rows with five emojis each, half of which are happy and the other half, sad. They were distributed in such a way that there is a top and bottom margin 4.7 cm. There was no right and left margin. The task itself involves two blocks with photos (4 x 3.67 cm) arranged in a 5 x 4 matrix totaling 20 stimuli. These included the images of happy and sad faces of both actors presented 5 times each, ordered randomly. There is a 4.5 cm margin at the top and the bottom, but no left and right margins. The first test block is the congruent block. Participants are asked to name the expressions on the photos, from left to right, as quickly as possible. For the next, incongruent block, they have to do the opposite: say “sad” for happy faces and “happy” for sad faces. The order of stimuli in all blocks were randomly positioned (www.randomizer.org/) except that the same expression was not presented more than twice in a row. Oral responses are required. Time taken to complete each block and number of mistakes are computed. The score is the inhibition cost, that is, the extra time taken to complete the incongruent trial minus the congruent trial. The same is done for errors. Self-corrected errors are not counted as such because participants’ scores are already penalized by the increased time taken in doing so (Lagattuta et al., 2011).

Instructions:

– Warm-up trial: You will see pictures. Please tell me whether each picture is “happy “or” sad”, from left to right, as fast as you can.  When you are ready to begin, pass on to the next page. – the experimenter must time the time it takes for the participant to complete the task, say “well done” at the end, and swipe to pass on to the next page to continue -.

– Incongruent trial:  Now you will see the same pictures as before, but you must do the opposite. When you see the picture of a sad face, say “happy” and when you see a picture with a happy face, say “sad”, as fast as you can, from left to right. When you are ready to begin, pass on to the next page. – the experimenter must time the time it takes for the participant to complete the task, say “well done” at the end, indicating that the task has finished -.

References

Lagattuta, K. H., Sayfan, L., & Monsour, M. (2011). A new measure for assessing executive function across a wide age range: Children and adults find happy‐sad more difficult than day‐night. Developmental Science, 14(3), 481-489.

Kramer, H. J., Lagattuta, K. H., & Sayfan, L. (2015). Why is happy–sad more difficult? Focal emotional information impairs inhibitory control in children and adults. Emotion, 15(1), 61.

Tottenham, N., Tanaka, J. W., Leon, A. C., McCarry, T., Nurse, M., Hare, T. A., … & Nelson, C. (2009). The NimStim set of facial expressions: judgments from untrained research participants. Psychiatry research, 168(3), 242-249.

 

 STROOP COLOR-NAMING TASK (Victory version)

Stroop Color-Naming task [based on the Stroop Victoria version (Strauss, Sherman, & Spreen, 2006), adapted for local use by Duncan (2006); see also “Neuropsychology SA” http://www.neuropsychologysa.co.za/article/victoria-stroop-test-in-public-domain /]: This task measures executive inhibition (Cothran et al., 2008; Diamond, 2013; Miyake et al., 2000). The Victoria version was selected because it is shorter than the original version and better assessed inhibition because it avoids learning effects (Spreen & Strauss, 1998). Furthermore, it includes a condition in which naming the colors of neutral words is required, which helps determine color naming without exposure to the interference condition (i.e., naming colors of the ink in which words that are color names are printed in; see below), allowing the correction of response speed (see Troyer & Straus, 2006).The instrument consists of three blocks. The first block allows the determination of responders’ ability to distinguish the colors and also helps “warm up”, or orally produce the names of the colors used in the other blocks. It consists of a slide with a white background with 24 colored rectangles, measuring 1 centimeter in height and 3 centimeters in width each, distributed in six lines with four rectangles in each row. The space between the lines is 1 cm and the space between the stimuli is 2 cm. There is a top and bottom margin of 6.4 cm. The colors of the stimuli are brown, pink, green and blue according to the work of (Duncan, 2006). Here, the following colors in HSL (hue, saturation and luminosity) values from Power Point were used: brown (hue: 17; saturation: 255; luminosity: 64), pink (hue: 241; saturation: 255; luminosity: 179), green (hue: 104; saturation: 255; luminosity: 88), and blue (hue: 139; saturation: 255; luminosity: 120). These colors appear only once in each row. Participants are asked to name the rectangle colors from left to right, as fast as possible. The next is the congruent trial, which contains 24 stimuli following the same patterns of the warm-up trial, but in which the rectangles are replaced by two-syllable words that are not color names. The neutral words used in Portuguese were the same as those used in Duncan’s work (2006): “cada, nunca, hoje, tudo” (they mean: each, never, today and everything). The words were typed in Calibri font 32 points, in lowercase letter printed in the same colors as the rectangles. These words in different colors are distributed so that they appear only once in each row and follow the same color order used in the rectangles of the first slide.

Participants are instructed to name out loud the colors in which the words are typed (and not read the words), as fast as they can. In the incongruent block the stimuli, disposition and color inks are equivalent to those in the congruent 24, except that the words are names of colors (brown, pink, green, blue, in Portuguese: “marrom, rosa, verde, azul”) printed in incongruent colors (e.g., the word “green” is printed in the color blue). Again, participants are asked to name the ink color out loud (and not read the words), as fast as possible. Oral responses are required. Time taken to complete each block and number of mistakes are computed. The scores is the inhibition cost, that is, the extra time taken to complete the incongruent trial minus the congruent trial. The same is done for errors. Self-corrected errors are not counted as such because participants’ scores are already penalized by the increased time taken in doing so (Lagattuta et al., 2011).

Instructions:

Cothran, D. L., & Larsen, R. (2008). Comparison of inhibition in two timed reaction tasks: The color and emotion Stroop tasks. The Journal of psychology, 142(4), 373-385.

 

Diamond, A. (2013). Executive functions. Annual review of psychology, 64, 135-168.

Duncan, M. T. (2006). Obtenção de dados normativos para desempenho no teste de Stroop num grupo de estudantes do ensino fundamental em Niterói. Jornal Brasileiro de Psiquiatria.

Miyake, A., Friedman, N. P., Emerson, M. J., Witzki, A. H., Howerter, A., & Wager, T. D. (2000). The unity and diversity of executive functions and their contributions to complex “frontal lobe” tasks: A latent variable analysis. Cognitive psychology, 41(1), 49-100.

Spreen, O., & Strauss, E. (1998). A compendium of neuropsychological tests: Administration, norms, and commentary. Oxford University Press.

Strauss, E., Sherman, E. M., & Spreen, O. (2006). A compendium of neuropsychological tests: Administration, norms, and commentary. American Chemical Society.

Troyer, A. K., Leach, L., & Strauss, E. (2006). Aging and response inhibition: Normative data for the Victoria Stroop Test. Aging, Neuropsychology, and Cognition, 13(1), 20-35.

 

MONOCHROMATIC STROOP

The literature reports that 6 to 8% of the population has difficulty in discriminating colors, that is, they present some form of dyschromatopsia (Gordon, 1998) or achromatopsia, which can be acquired or congenital (Barboni et al., 2009; Picchinin et al., 2007). There are many types of dyschromatopsia and achromatopsia, but all, in principle, allow the differentiation of black, gray and white. We therefore constructed a Stroop task that uses these colors. It is exactly the same as the traditional Victoria version of the Stroop task (Spreen and Strauss, 1998), except that only three colors/words are used.The instrument consists of three blocks. The first block allows the determination of responders’ ability to distinguish the colors and also helps “warm up”, or orally produce the names of the colors used in the other blocks. It consists of a slide with a light gray background (HSL, or hue, saturation and luminosity values from Power Point; hue: 170; saturation: 0; luminosity: 217) and 24 colored rectangles, measuring 1 centimeter in height and 3 centimeters in width each, distributed in six lines with four rectangles in each row. The space between the lines is 1 cm and the space between the stimuli is 2 cm. There is a top and bottom margin of 6.4 cm. The colors of the stimuli are white (hue: 170; saturation: 0; luminosity: 255), gray (hue: 170; saturation: 0; luminosity: 127) and black (hue: 170; saturation: 0; luminosity: 0). The order of the colors was randomly determined for the warm-up block, with only one repetition of colors per row (www.random.org) and kept the same in the other blocks. Participants are asked to name the rectangle colors from left to right, as fast as possible. The next is the congruent trial, which contains 24 stimuli following the same patterns of the warm-up trial, but in which the rectangles are replaced by two-syllable words that are not color names. The neutral words used in Portuguese were the same as those used in Duncan’s work (2006; excluding the word “hoje”): “cada, nunca, tudo” (they mean: each, never, everything). The words were typed in Calibri font, 32 points, in lowercase letter, in the same colors as the rectangles. Participants are instructed to name out loud the colors in which the words are typed (and not read the words), as fast as they can. In the incongruent block the stimuli, disposition and color inks are equivalent to those in the congruent 24, except that the words are names of colors (white, gray, black; in Portuguese: “branco, preto, cinza”) printed in incongruent colors (e.g., the word “white” is printed in the color black). Again, participants are asked to name the ink color out loud (and not read the words), as fast as possible. Oral responses are required. Time taken to complete each block and number of mistakes are computed. The scores is the inhibition cost, that is, the extra time taken to complete the incongruent trial minus the congruent trial. The same is done for errors. Self-corrected errors are not counted as such because participants’ scores are already penalized by the increased time taken in doing so (Lagattuta et al., 2011).

Instructions:

-Warm up trial: You will see colors. Please tell me the colors that will appear, from left to right, as fast as you can. When you are ready to begin, pass on to the next page. – the experimenter must time the time it takes for the participant to complete the task, say “well done” at the end, and swipe to pass on to the next page to continue -.

-Congruent trial: Now you will see words. Please say out loud the colors in which the words are written, as fast as you can. For example: “show example”. When you are ready to begin, pass on to the next page.  – the experimenter must time the time it takes for the participant to complete the task, say “well done” at the end, and swipe to pass on to the next page

-Incongruent trial:  Now you must do the same thing, but the words will change. For example: “show example”. When you are ready to begin, pass on to the next page.   – the experimenter must time the time it takes for the participant to complete the task, say “well done” at the end, and indicate that the task has finished -.

References

Barboni, M. T. S., Feitosa-Santana, C., Zachi, E. C., Lago, M., Teixeira, R. A. A., Taub, A., … & Ventura, D. F. (2009). Preliminary findings on the effects of occupational exposure to mercury vapor below safety levels on visual and neuropsychological functions. Journal of occupational and environmental medicine, 51(12), 1403-1412.

Birch, J. (2012). Worldwide prevalence of red-green color deficiency. JOSA A, 29(3), 313-320.

Fisher, L. M., Freed, D. M., & Corkin, S. (1990). Stroop Color-Word Test performance in patients with Alzheimer’s disease. Journal of Clinical and Experimental Neuropsychology, 12(5), 745-758.

Kohl, S., Baumann, B., Rosenberg, T., Kellner, U., Lorenz, B., Vadala, M., … & Wissinger, B. (2002). Mutations in the cone photoreceptor G-protein α-subunit gene GNAT2 in patients with achromatopsia. The American Journal of Human Genetics, 71(2), 422-425.

Strauss, E., Sherman, E. M., & Spreen, O. (1991). A compendium of neuropsychological tests: Administration, norms, and commentary. American Chemical Society.

Zeki, S. (1990). A century of cerebral achromatopsia. Brain, 113(6), 1721-1777.

 

 

 

WORKING MEMORY CAPACITY

RUNNING MEMORY SPAN

Running memory span [adapted from Cowan et al. (2005); Broadman & Engle, 2010]: This task measures working memory capacity and is not self-paced (see Bunting et al., 2006). Participant are shown lists of consecutive single digit numbers, one at a time, at a fast speed (300ms/digit). When the list ends, participants must try to remember as many numbers as possible from the end of the list, in the same order as they appeared. They are also allowed to skip a number if they indicate that that was done. For example, if the last numbers were “1,2,3,4,5”, they can say “2, I don’t remember (or blank) 4, 5”. The numbers are displayed in the center of the screen in black Calibri font, size 18 on a white background (Broadway & Engle, 2010). The digits 1 to 9 are present in random order (www.randomizer.org/) except that the same number is not presented twice or more time in a row. These lists of digits have varying lengths, ranging from 11 to 20 numbers (Cowan et al., 2005). There are two practice blocks, each with ten lists of different lengths (11-20 numbers each list) presented in random order. There are two test blocks with twenty lists each with 11 to 20 numbers. The order of the list lengths is also randomized. The score is the mean numbers of numbers recalled in the correct serial positions (Cowan et al., 2005; Broadway & Engle, 2010). The rationale underlying this task is that as it does not allow strategies to be used because of the fast presentation rate, numbers that are retrieved from memory are those that are “fit” in testees working memory (see Bunding et al., 2006).

Instructions:

You will see numbers displayed very quickly. When “?” appears, say out loud the largest number of numbers that you can remember that were at the end of the list, in the SAME order in which they appeared; if the numbers were …8-7-6-2-4 and then “?” appears, you can say “6-2-4” , or “6, I don’t remember, 4”. Or “2-4”, or even just “4”. Pass on to the next page to practice. / Well done. Any questions? When you are ready to begin, pass on to the next page. / Well done! This activity has finished.

References

Broadway, J. M., & Engle, R. W. (2010). Validating running memory span: Measurement of working memory capacity and links with fluid intelligence. Behavior Research Methods, 42(2), 563-570.

Bunting, M., Cowan, N., & Scott Saults, J. (2006). How does running memory span work?. Quarterly Journal of Experimental Psychology, 59 (10), 1691-1700.

Cowan, N., Elliott, E. M., Saults, J. S., Morey, C. C., Mattox, S., Hismjatullina, A., & Conway, A. R. (2005). On the capacity of attention: Its estimation and its role in working memory and cognitive aptitudes. Cognitive psychology, 51 (1), 42-100.

Endnotes:

[1] In the publications that involve fractionating executive functions, inhibition has been usually assessed with tasks that involve registering timing of response to stimuli individually, which goes agains the present proposal because this involves having equipment and software that are costly. The Happy Sad Stroop is a paper and pencil task that has been shown to measure inhibition and was therefore proposed as an alternative to the Stroop task that was also repeatedly used in the executive fractionation literature.

[2] A latent variable does not correspond directly to participants’ performance. Rather, it is inferred from mathematical models which extract the common elements of performance in different tasks. If there is theoretical evidence that two tasks measure a similar construct, a latent variable obtained from these tasks will indicate what they have in common, while eliminating other abilities that may also contribute to performance in each task but that are not executive functioning per se. For example, two tasks may involve executive shifting but one may rely on motor responses while the other on perceptual speed. A latent variable extracted from these tests should reflect the shifting component they have in common, removing other cognitive abilities needed to perform the task.

[3] Unlike the original study, which presented cues to guide categorization of stimuli, here testees must keep this order in mind, as there are no external clues. This was only done in the other shifting task used (Color Shape) because the presence of external cues or internal cues (based on memory of previous categorization and future intentions) can lead to slightly different effects (see Koch, 2003). Thus, we believed having two shifting tasks that differed in this respect would strengthen our shifting latent variable.

[4] In the original version, the stimuli consisted of green or red colored rectangle centered onscreen within which there was either a circle or triangle (target shapes). Just above the target stimuli there appeared either the letter C or S indicating what the participant should answer: C referred to classifying the “color” of the rectangle and S to classifying the shape included in the rectangle. During the preparation of the task and after conducting pilot studies, the following adaptations were made: the external rectangle was not used as a stimulus to prevent the volunteer from confusing its shape with that of the stimuli themselves. Therefore, only the shapes that were inserted inside the rectangle were kept. We used circles and squares (instead of triangles), because the word triangle is longer to pronounce in Portuguese and because some children had difficulty naming it in pilot studies. The colors used in the original work, green and red, were also replaced for black and gray to avoid having to exclude participants with any difficulty in color discrimination (e.g. Piccinin et al., 2007; Birch, 2012). The letters C and S used as clues in the original work were replaced with symbols to avoid possible difficulties in low or badly schooled individuals. Thus the letter “C” used as a clue for the “Color” response was replaced by a monochromatic rainbow symbol, and the letter “S” used as a clue for the “Shape” response was replaced for an abstract black and white shape.