Table 1.
Neuroimaging paradigms used to investigate prospective memory and their characteristics in terms of ongoing task, focal and non-focal PM cues and examining overall, sustained, or transient activations.
| Paper | Ongoing task | PM task (S/D) | PM task type | % Trials on which PM targets appear | Neural activation examined |
||
|---|---|---|---|---|---|---|---|
| Overall Only | Sustained | Transient | |||||
| Okuda et al. (1998) | Repeat sets of 5 words aloud | Tap for words encoded prior to scanning (S) | Focal | 5% | X | ||
| Okuda et al. (2007) | Serial addition of digits | Squeeze hands when seven appeared (S) | Focal | 12.5% | X | ||
| Kalpouzos et al. (2010) | Virtual reality navigation of five routes | Perform list of errands (D) | Focal | N/A; 22 total | X | X | |
| Benoit et al. (2011) | Two similar tasks: (1) navigate edges of shapes, at corners, decide a L or R turn; (2) classify capital letters for straight or curved lines | Respond when at certain corners of shapes; respond for certain letters (S) | Focal | 11% | X | ||
| Gilbert (2011) | Two-back task with words or pictures | When pic or word had colored border, encode as PM cue and key-press when see it later (S) | Focal | 3% | X | X | |
| Gilbert et al. (2012) | Same as Gilbert (2011) | Same as Gilbert (2011) | Focal | Same as Gilbert (2011) | X | X | |
| McDaniel et al. (2013) | Semantic classification task, 525 trials | F: respond to a certain word; NF: respond to a certain syllable (S) | Focal, Non-focal | 4% | X | X | |
| Burgess et al. (2001) | Four similar tasks, e.g., press key in direction of larger of two numbers | Respond if both even numbers (S) | Non-focal | 20% | X | ||
| Burgess et al. (2003) | Three tasks from Burgess et al. (2001) | Same as Burgess et al. (2001) | Non-focal | Same as Burgess et al. (2001) | X | ||
| den Ouden et al. (2005) | Answer questions pertaining to intentions and consequences, e.g., “you are at the cinema and have trouble seeing the screen. Do you move to another seat? Likely or unlikely?” | Respond if background is red, of five total colors (S) | Non-focal | 23% | X | ||
| Simons et al. (2006) | Two tasks: (1) Indicate the longer of a pair of a lowercase and uppercase word (2) Indicate direction of a shape relative to a triangle in a grid |
Cue ID: (1) Respond to semantically associated pairs (2) Respond if shapes were a chess knight’s move away from one another (S); Intention retrieval: (1) When words are both lowercase, decide if syllables of two words are greater or less than four; (2) When shapes are the same color, decide if sides of the non-triangle are greater or less than five (S) |
Non-focal | NA; 32 total | X | ||
| Gilbert et al. (2009) | Two similar tasks: (1) Indicate direction of capital of two letters; (2) indicate direction of two dots (versus 1) | (1) Respond if same letter (2) Respond if dots form a line (S) | Non-focal | 12.5% | X | X | |
| Reynolds et al. (2009) | One-back task, respond if same or different from previous trial | Special key-press for target color of stimuli (S) | Non-focal | 11% | X | X | |
| Hashimoto et al. (2011) | Two-back task, respond if same or different from two back | Food category words (S) | Non-focal | 6% | X | ||
| Rea et al. (2011) | Decide same/diff gender of face pairs | Respond to specific face pair (S) | Non-focal | 3% | X | ||
| Rusted et al. (2011) | Sort playing cards by suit | Respond to seven card (S) | Non-focal | 8% | X | ||
| Beck et al. (2014) | Move joystick in the direction of a colored arrow presented on the screen in relation to a fixation cross | Key-press instead if arrow is red (S) | Non-focal | 17% | X | X | |
The studies are ordered by the type of PM cue and publication year. In the PM task, D refers to having different PM intention throughout the PM task [e.g., Kalpouzos et al. (2010), participants had a list of various errands to complete]; S refers to having the same PM intention throughout [e.g., Hashimoto et al. (2011), participants were asked to respond to every food category word].