Main Study: What Aspects of Cognition are Affected by Smartphones?
The goals for the main study were to: (1) investigate how smartphones affect different aspects of cognition and (2) explore interactions between individual differences and these effects.
Participants were randomly assigned to their condition (i.e., design was decided using the pilot study) and then randomly completed all 12 CBS tasks. Therefore, participants placed their smartphones in one of three locations: (1) on the participant’s desk, (2) in their pocket/bag, or (3) outside the testing room. All participants were instructed to keep their phones on “silent” (i.e., to prevent any notifications) and those in the “on desk” location condition kept their devices facing down.
As in the pilot, participants completed three questionnaires to determine how individual differences may be moderating the smartphone effects: (1) the Smartphone Attachment and Dependency Questionnaire, (2) the MPIQ, and (3) the NMP-Q. Finally, to check that the main study’s participants are similar to the pilot study, all participants will complete the same Smartphone Use Questionnaire from the pilot. Our predictions for this study were mainly exploratory: we investigated which aspects of cognition were affected by smartphones and, therefore, we did not have explicit predictions for each aspect of cognition. We think that using the CBS tasks will help to answer this question because they cover a variety of measures of cognition. The only specific predictions we have are with respect to the attentionally-demanding tasks (e.g. Double Trouble), where we predict lower performance with smartphone presence (e.g., Stothart et al., 2015).
Cambridge Brain Science (CBS) Tasks
The CBS trials consisted of 12 cognitive tasks: Double Trouble Task, Odd One Out Task, Digit Span Task, Feature Match Task, Polygons Task, Paired Associates Task, Monkey Ladder Task, Grammatical Reasoning Task, Rotations Task, Spatial Span Task, Token Search Task, and the Spatial Planning Task. These 12 tasks measure four fundamental cognitive areas, which are described as follows by Hampshire et al. (2012): memory, reasoning, verbal ability, and concentration. The following task descriptions are from the CBS Website (www.cambridgebrainsciences.com). (click to see details)
Memory
Visuospatial Working Memory Task (Monkey Ladder) - A variant on a task from the non-human primate literature (Inoue & Matsuzawa, 2007). Sets of numbered squares are displayed on the screen at random locations. After a variable interval of time, the numbers disappear leaving just the blank squares and participants must respond by clicking the squares in ascending numerical sequence. Difficulty is increased or decreased by one numbered box depending on whether the participant got the previous trial correct. After three errors, the task will end.
Spatial Short-Term Memory (Spatial Span Task) - A variant on the CorsiBlock Tapping Task (Corsi, 1972), used for measuring spatial short-term memory capacity. 16 squares are displayed in a 4 x 4 grid. A sub-set of the squares will flash in a random sequence at a rate of 1 flash every 900 ms. Subsequently, participants must repeat the sequence by clicking on the squares in the same order in which they flashed. Difficulty is increased or decreased by one box depending on whether the participant got the previous trial correct. After three errors, the task will end.
Working Memory (Token Search) - Based on a test that is used to measure strategy during search behaviours (Collins et al., 1998). Boxes are displayed in random locations. Participants must find a hidden “token” by clicking on the boxes one at a time. When the token is found, it is hidden within another box. The token will not appear within the same box twice, thus, participants must search the boxes until the token has been found once in each box. If they search the same empty box twice, or search a box in which the token has previously been found, this is an error and the trial ends. Difficulty is increased or decreased by one box depending on whether the participant got the previous trial correct. After three errors, the task will end. Outcome measure is the maximum level completed (e.g. the problem with the most tokens that the user successfully completed).
Episodic Memory (Paired Associates Task) - A variant on a paradigm that is commonly used to assess memory impairments in aging clinical populations (Gould et al., 2005). Boxes are displayed at random locations on the screen. The boxes are opened one after another to reveal an enclosed object. Subsequently, the objects are displayed in random order in the centre of the screen and participants must determine which box contains the object that is presented. Difficulty is increased or decreased by one box depending on whether the participant got the previous trial correct. After three errors, the task will end.
Reasoning
Mental Rotation (Rotations) - Often used for measuring the ability to manipulate objects spatially in mind (Silverman et al., 2000). Two grids of coloured squared are displayed to either side of the screen with one of the grids rotated by a multiple of 90 degrees. When rotated, the grids are either identical or differ by the position of just one square. Participants must indicate whether or not the grids are identical. Participants have 90 seconds to solve as many problems as possible. Primary outcome measure is overall score - the sum of the difficulties of all successfully answered problems, minus the sum of the difficulties of all incorrectly answered problems.
Visuospatial Processing (Polygons) - Based on the Interlocking Pentagons Task, which is often used in the assessment of age- related disorders (Folstein et al., 1975). A pair of overlapping polygons is displayed on one side of the screen. Participants must indicate whether a polygon displayed on the other side of the screen is identical to one of the interlocking polygons. Difficulty is increased by making the differences between the polygons more subtle or decreased by making the differences between the polygons more pronounced. Participants have 90 seconds to solve as many problems as possible. Primary outcome measure is overall score - the sum of the difficulties of all successfully answered problems, minus the sum of the difficulties of all incorrectly answered problems.
Deductive Reasoning (Odd One Out) - Based on a sub-set of problems from the Cattell Culture Fair Intelligence Test (Cattell, 1949). Nine patterns will appear on the screen. The features that make up the patterns are colour, shape, and number and are related to each other according to a set of rules. Participants must deduce the rules that relate the object features and select the pattern that do not correspond to those rules. Difficulty is increased or decreased depending on whether the participant got the previous trial correct. Participants have 3 minutes to solve as many problems as possible. Primary outcome measure is the number of correctly answered problems, minus the number of incorrectly answered problems.
Planning (Spatial Planning) - A direct descendant of the “Tower of London” task, Spatial Planning is a classic neuropsychological test of planning (Shallice, 1982). When the test begins, numbered beads are positioned on a tree-shaped frame. Participants must reposition the beads so they are configured in ascending numerical order, in as few moves as possible. Problems become progressively harder, and participants have three minutes to solve as many as possible. The primary outcome measure is the overall score, calculated by subtracting the number of moves made from twice the minimum number of moves required.
Verbal Ability
Verbal Reasoning (Grammatical Reasoning) - Based on Alan Baddeley’s three minute grammatical reasoning test (Baddeley, 1968). Short sentences describing the relationship of two shapes along with an image of the shapes are displayed on the screen. Participants must indicate whether the sentence correctly describes the pair of objects displayed on the screen. Participants have 90 seconds to solve as many problems as possible. Primary outcome measure is the number of problems solved correctly, minus the number of problems answered incorrectly.
Verbal Short-Term Memory (Digit Span) - A variant on the verbal working memory component of the WAIS-R intelligent test (Weschler, 1981). A sequence of numbers will appear on the screen one after another. Once the sequence is complete, participants must repeat the sequence. Difficulty is increased or decreased by one number depending on whether the participant got the previous trial correct. After three errors, the task ends. Primary outcome measure is the maximum level (i.e. the problem with the highest number of digits) that the player successfully completed.
Concentration
Attention (Feature Match) - Based on the classical feature search tasks that have been used to measure attentional processing (Treisman & Gelade, 1980). Two grids are displayed on the screen, each containing an array of abstract shapes. In half of the trials the grids differ by just one shape. Participants must indicate whether or not the grid’s contents are identical. Difficulty is increased or decreased by one shape depending on whether the participant got the previous trial correct. Participants have 90 seconds to solve as many problems as possible. Primary outcome measure is overall score - the sum of the difficulties of all successfully answered problems, minus the sum of the difficulties of all incorrectly answered problems.
Response Inhibition (Double Trouble, Colour-Word Remapping Task) - A variant on the Stroop test (Stroop, 1935). Three coloured words are displayed on the screen: one at the top and two at the bottom. Participants must indicate which of two coloured words at the bottom of the screen correctly describes the colour that the word at the top of the screen is written in. The colour word mappings may be congruent, incongruent, or doubly incongruent, depending on whether or not the colour of the top word matches the colour that it is written in. Participants have 90 seconds to solve as many problems as possible.
A total of ### undergraduate students participated in this study.
