Psychology

• ISI(interstimulus interval) is the temporal interval between the offset of one stimulus to the onset of another. This timer began either after a decision was made or the total time ran out.

• Response time is simply the time in which a user would make a response (tap or swipe)

  • Mechanically on mobile platforms we were limited to tapping and swiping for quick and intuitive responses (Noting that elderly groups typically chose to swipe while younger groups tapped)

• Total time was the amount of a time a user had to make a response following the onset of a signal

  • This was adaptive and would decrease or increase based on success or failure, respectively, in order to adjust difficulty.

• Time between the onset of the stop signal was also adaptive based on response time in order to prevent the user from responding before the stop signal appeared. This would closely match the typical response time in order to increase difficulty over time combined with the adaptive Total Time.

The most basic forms of the 3 tasks are as follows:

1. Go/No-Go Task: One of two signals is displayed (Go: green circle or No-Go: red circle). If the Go signal is displayed, then an action is taken. If the No-Go signal is displayed, then no action is taken.

2. Stop Signal Task: Similar to the Go/No-Go task with an exception. A stop signal* will occasionally appear after a Go signal, which means the usual action taken must NOT be taken. *For assessments an image of a U.S. street stop sign was used

3. Rule Switch: A rule is displayed (sort by color or shape) and the user must categorize the signal that appears. I presented the user with 1 of 4 possible combinations: blue/red circle or blue/red square. After the signal is sorted or timed out there is a possibility of the current rule switching to the other rule.

The Game Narrative

​Farm themed* game for kids: Animals were to help farmer get his crops grown and harvested.

*Farm theme was voted upon by the team

The first iteration of the game was comprised of the 3 inhibition tasks each in the form of a game related to the theme. As a filler before any artist was brought in I used various shapes and colors (similar to the basic assessment version) to represent the animals. The backgrounds I doodled from Paint.

​ - RT (response time), Sound signal, and Stop signal timers were displayed for our knowledge and use.

Go/No-Go

The idea for the Go/No-Go task was to have animals help you plant crops by bringing in seeds (animal with seeds = go signal) with the occasional mistake of them bringing in something else (animal with farm tool, trash, or seeds of the wrong crop = no-go signal). 

“Animals” would pop out of the borough holding an item and begin moving towards the gate. The amount of time it takes for the animals to get to the gate is the total time and during this time the user must make the choice to open the gate and allow the “animal” in or leave it closed and let the “animal” run off after rejection.

Mechanically the user could either swipe the gate open or tap to open. This action was restricted to only function when the signal first appears and begins its movement towards the gate. Once a decision has been made or the signal reaches the gate the functionality ceases until the next signal appears.

Possible Advancements in Game Difficulty for Go/No-Go

1. Total time to respond would adjust slightly based on performance with each phase to allow for training

2. Items the animals are carrying would represent the keys (Go/No-Go signals) and to start with a lower difficulty the correct and incorrect keys would be obvious (seeds vs trash) with specific animals carrying specific items.

3. Mixing of the different forms of difficult adjustments would allow for a wider range of possible increments

   • To add difficulty animals would no longer be linked to specific items

   • Items would begin to vary more with similarly colored items, but still obviously shaped differently to allow for a more natural increment of difficult

   • Higher difficulty would be seeds of a different crop

Stop Signal

For the Stop Signal task a sorting game was to be created.

Animals again popping out of boroughs but this time holding items to be sorted (tools or harvested crops) to help with the farming. The stop signal would likely be tools breaking or the animal taking a bite of the harvested crop and therefore the items would no longer need to be sorted.

Mechanically the user would either swipe or tap to indicate the direction of sorting.

Possible Advancements in Game Difficulty for Stop Signal

1. Total time to respond would adjust slightly based on performance with each phase to allow for training (Easiest form of adjustments to difficulty)

2. Delayed sound or visual cue for the stop signal

3. Use only a sound or visual cue for the stop signal

4. Mix in with Rule-Switch and have the signs flip around to show new rules for sorting

Rule Switch

The Rule Switch task included another sorting game. 

An farm related task had not been agreed upon for this game so I programmed the basic form of the psychological task into the game (sorting by shape or color). This included an audio cue to indicate the rule switch as well as the visual text. The audio was either a sound bite of myself saying “shape” or “color” or a generic blip.

Possible Advancements in Game Difficulty for Rule Switch

1. Total time to respond would adjust slightly based on performance with each phase to allow for training (Again)

2. Adding another layer to the rule switching: color, shape, design

3. Force a specific mechanic (i.e. tap or swipe) when playing and include a key-switch whereby the user is forced to switch their action. 

Tap -> Swipe or Swipe -> Tap

1. Combination with the stop signal task

*1 and 2 are the most promising as they keep the task exclusive

*Because this work was done for a research lab the repository showcasing my programming abilities is unfortunately private and property of UC Riverside